1
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Csordas M, Starko S, Neufeld CJ, Thompson SA, Baum JK. Multiscale stability of an intertidal kelp (Postelsia palmaeformis) near its northern range edge through a period of prolonged heatwaves. Ann Bot 2024; 133:61-72. [PMID: 37878014 PMCID: PMC10921842 DOI: 10.1093/aob/mcad148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 10/06/2023] [Indexed: 10/26/2023]
Abstract
BACKGROUND AND AIMS Climate change, including gradual changes and extreme weather events, is driving widespread species losses and range shifts. These climatic changes are felt acutely in intertidal ecosystems, where many organisms live close to their thermal limits and experience the extremes of both marine and terrestrial environments. A recent series of multiyear heatwaves in the northeast Pacific Ocean might have impacted species even towards their cooler, northern range edges. Among them, the high intertidal kelp Postelsia palmaeformis has traits that could make it particularly vulnerable to climate change, but it is critically understudied. METHODS In 2021 and 2022, we replicated in situ and aerial P. palmaeformis surveys that were conducted originally in 2006 and 2007, in order to assess the state of northern populations following recent heatwaves. Changes in P. palmaeformis distribution, extent, density and morphometrics were assessed between these two time points over three spatial scales, ranging from 250 m grid cells across the entire 167 km study region, to within grid cells and the individual patch. KEY RESULTS We found evidence consistent with population stability at all three scales: P. palmaeformis remained present in all 250 m grid cells in the study region where it was previously found, and neither the extent within cells nor the patch density changed significantly between time points. However, there was evidence of slight distributional expansion, increased blade lengths and a shift to earlier reproductive timing. CONCLUSIONS We suggest that apparent long-term stability of P. palmaeformis might be attributable to thermal buffering near its northern range edge and from the wave-exposed coastlines it inhabits, which may have decreased the impacts of heatwaves. Our results highlight the importance of multiscale assessments when examining changes within species and populations, in addition to the importance of dispersal capability and local conditions in regulating the responses of species to climate change.
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Affiliation(s)
- Matthew Csordas
- Department of Biology, University of Victoria, Victoria, BC, V8W 2Y2, Canada
| | - Samuel Starko
- Department of Biology, University of Victoria, Victoria, BC, V8W 2Y2, Canada
- UWA Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, WA 6009, Australia
| | - Christopher J Neufeld
- Department of Biology, University of Victoria, Victoria, BC, V8W 2Y2, Canada
- The Kelp Rescue Initiative, Bamfield Marine Sciences Centre, Bamfield, BC, V0R 1B0, Canada
- Department of Biology, University of British Columbia Okanogan, Kelowna, BC, V1V 1V7, Canada
| | | | - Julia K Baum
- Department of Biology, University of Victoria, Victoria, BC, V8W 2Y2, Canada
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Salland N, Wilding C, Jensen A, Smale DA. Spatiotemporal variability in population demography and morphology of the habitat-forming macroalga Saccorhiza polyschides in the Western English Channel. Ann Bot 2024; 133:117-130. [PMID: 37962600 PMCID: PMC10921834 DOI: 10.1093/aob/mcad181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 11/13/2023] [Indexed: 11/15/2023]
Abstract
BACKGROUND AND AIMS Large brown macroalgae serve as foundation organisms along temperate and polar coastlines, providing a range of ecosystem services. Saccorhiza polyschides is a warm-temperate kelp-like species found in the northeast Atlantic, which is suggested to have proliferated in recent decades across the southern UK, possibly in response to increasing temperatures, physical disturbance and reduced competition. However, little is known about S. polyschides with regard to ecological functioning and population dynamics across its geographical range. Here we examined the population demography of S. polyschides populations in southwest UK, located within the species' range centre, to address a regional knowledge gap and to provide a baseline against which to detect future changes. METHODS Intertidal surveys were conducted during spring low tides at three sites along a gradient of wave exposure in Plymouth Sound (Western English Channel) over a period of 15 months. Density, cover, age, biomass and morphology of S. polyschides were quantified. Additionally, less frequent sampling of shallow subtidal reefs was conducted to compare intertidal and subtidal populations. KEY RESULTS We recorded pronounced seasonality, with fairly consistent demographic patterns across sites and depths. By late summer, S. polyschides was a dominant habitat-former on both intertidal and subtidal reefs, with maximum standing stock exceeding 13 000 g wet weight m-2. CONCLUSIONS Saccorhiza polyschides is a conspicuous and abundant member of rocky reef assemblages in the region, providing complex and abundant biogenic habitat for associated organisms and high rates of primary productivity. However, its short-lived pseudo-annual life strategy is in stark contrast to dominant long-lived perennial laminarian kelps. As such, any replacement or reconfiguration of habitat-forming macroalgae due to ocean warming will probably have implications for local biodiversity and community composition. More broadly, our study demonstrates the importance of high-resolution cross-habitat surveys to generate robust baselines of kelp population demography, against which the ecological impacts of climate change and other stressors can be reliably detected.
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Affiliation(s)
- Nora Salland
- The Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK
- School of Ocean and Earth Science, University of Southampton, European Way, Southampton SO14 3ZH, UK
| | - Catherine Wilding
- The Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK
| | - Antony Jensen
- School of Ocean and Earth Science, University of Southampton, European Way, Southampton SO14 3ZH, UK
| | - Dan A Smale
- The Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK
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3
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Castro LC, Vergés A, Straub SC, Campbell AH, Coleman MA, Wernberg T, Steinberg P, Thomas T, Dworjanyn S, Cetina-Heredia P, Roughan M, Marzinelli EM. Effect of marine heatwaves and warming on kelp microbiota influence trophic interactions. Mol Ecol 2024; 33:e17267. [PMID: 38230446 DOI: 10.1111/mec.17267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 10/18/2023] [Accepted: 12/13/2023] [Indexed: 01/18/2024]
Abstract
The range-expansion of tropical herbivores due to ocean warming can profoundly alter temperate reef communities by overgrazing the seaweed forests that underpin them. Such ecological interactions may be mediated by changes to seaweed-associated microbiota in response to warming, but empirical evidence demonstrating this is rare. We experimentally simulated ocean warming and marine heatwaves (MHWs) to quantify effects on two dominant temperate seaweed species and their microbiota, as well as grazing by a tropical herbivore. The kelp Ecklonia radiata's microbiota in sustained warming and MHW treatments was enriched with microorganisms associated with seaweed disease and tissue degradation. In contrast, the fucoid Sargassum linearifolium's microbiota was unaffected by temperature. Consumption by the tropical sea-urchin Tripneustes gratilla was greater on Ecklonia where the microbiota had been altered by higher temperatures, while Sargassum's consumption was unaffected. Elemental traits (carbon, nitrogen), chemical defences (phenolics) and tissue bleaching of both seaweeds were generally unaffected by temperature. Effects of warming and MHWs on seaweed holobionts (host plus its microbiota) are likely species-specific. The effect of increased temperature on Ecklonia's microbiota and subsequent increased consumption suggest that changes to kelp microbiota may underpin kelp-herbivore interactions, providing novel insights into potential mechanisms driving change in species' interactions in warming oceans.
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Affiliation(s)
- Louise C Castro
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, New South Wales, Australia
- Evolution and Ecology Research Centre, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
- Coastal and Regional Oceanography Lab, School of Mathematics and Statistics, The University of New South Wales, Sydney, New South Wales, Australia
| | - Adriana Vergés
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, New South Wales, Australia
- Evolution and Ecology Research Centre, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
- Sydney Institute of Marine Science, Mosman, New South Wales, Australia
| | - Sandra C Straub
- UWA Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, Western Australia, Australia
| | | | - Melinda A Coleman
- Department of Primary Industries, Coffs Harbour, New South Wales, Australia
| | - Thomas Wernberg
- UWA Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, Western Australia, Australia
| | - Peter Steinberg
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, New South Wales, Australia
- Sydney Institute of Marine Science, Mosman, New South Wales, Australia
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore City, Singapore
| | - Torsten Thomas
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, The University of New South Wales, Sydney, New South Wales, Australia
| | - Symon Dworjanyn
- National Marine Science Centre & Centre for Coastal Biogeochemistry Research, School of Environment, Science and Engineering, Southern Cross University, Coffs Harbour, New South Wales, Australia
| | - Paulina Cetina-Heredia
- Coastal and Regional Oceanography Lab, School of Mathematics and Statistics, The University of New South Wales, Sydney, New South Wales, Australia
| | - Moninya Roughan
- Coastal and Regional Oceanography Lab, School of Mathematics and Statistics, The University of New South Wales, Sydney, New South Wales, Australia
| | - Ezequiel M Marzinelli
- Sydney Institute of Marine Science, Mosman, New South Wales, Australia
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore City, Singapore
- The University of Sydney, Faculty of Science, School of Life and Environmental Sciences, Sydney, New South Wales, Australia
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4
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DiFiore BP, Stier AC. Variation in body size drives spatial and temporal variation in lobster-urchin interaction strength. J Anim Ecol 2023; 92:1075-1088. [PMID: 37038648 DOI: 10.1111/1365-2656.13918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 03/06/2023] [Indexed: 03/20/2023]
Abstract
How strongly predators and prey interact is both notoriously context dependent and difficult to measure. Yet across taxa, interaction strength is strongly related to predator size, prey size and prey density, suggesting that general cross-taxonomic relationships could be used to predict how strongly individual species interact. Here, we ask how accurately do general size-scaling relationships predict variation in interaction strength between specific species that vary in size and density across space and time? To address this question, we quantified the size and density dependence of the functional response of the California spiny lobster Panulirus interruptus, foraging on a key ecosystem engineer, the purple sea urchin Strongylocentrotus purpuratus, in experimental mesocosms. Based on these results, we then estimated variation in lobster-urchin interaction strength across five sites and 9 years of observational data. Finally, we compared our experimental estimates to predictions based on general size-scaling relationships from the literature. Our results reveal that predator and prey body size has the greatest effect on interaction strength when prey abundance is high. Due to consistently high urchin densities in the field, our simulations suggest that body size-relative to density-accounted for up to 87% of the spatio-temporal variation in interaction strength. However, general size-scaling relationships failed to predict the magnitude of interactions between lobster and urchin; even the best prediction from the literature was, on average, an order of magnitude (+18.7×) different than our experimental predictions. Harvest and climate change are driving reductions in the average body size of many marine species. Anticipating how reductions in body size will alter species interactions is critical to managing marine systems in an ecosystem context. Our results highlight the extent to which differences in size-frequency distributions can drive dramatic variation in the strength of interactions across narrow spatial and temporal scales. Furthermore, our work suggests that species-specific estimates for the scaling of interaction strength with body size, rather than general size-scaling relationships, are necessary to quantitatively predict how reductions in body size will alter interaction strengths.
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Affiliation(s)
- Bartholomew P DiFiore
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, California, 93106, USA
| | - Adrian C Stier
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, California, 93106, USA
- Marine Science Institute, University of California Santa Barbara, Santa Barbara, California, 93116, USA
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5
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Bell TW, Cavanaugh KC, Saccomanno VR, Cavanaugh KC, Houskeeper HF, Eddy N, Schuetzenmeister F, Rindlaub N, Gleason M. Kelpwatch: A new visualization and analysis tool to explore kelp canopy dynamics reveals variable response to and recovery from marine heatwaves. PLoS One 2023; 18:e0271477. [PMID: 36952444 PMCID: PMC10035835 DOI: 10.1371/journal.pone.0271477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 03/03/2023] [Indexed: 03/25/2023] Open
Abstract
Giant kelp and bull kelp forests are increasingly at risk from marine heatwave events, herbivore outbreaks, and the loss or alterations in the behavior of key herbivore predators. The dynamic floating canopy of these kelps is well-suited to study via satellite imagery, which provides high temporal and spatial resolution data of floating kelp canopy across the western United States and Mexico. However, the size and complexity of the satellite image dataset has made ecological analysis difficult for scientists and managers. To increase accessibility of this rich dataset, we created Kelpwatch, a web-based visualization and analysis tool. This tool allows researchers and managers to quantify kelp forest change in response to disturbances, assess historical trends, and allow for effective and actionable kelp forest management. Here, we demonstrate how Kelpwatch can be used to analyze long-term trends in kelp canopy across regions, quantify spatial variability in the response to and recovery from the 2014 to 2016 marine heatwave events, and provide a local analysis of kelp canopy status around the Monterey Peninsula, California. We found that 18.6% of regional sites displayed a significant trend in kelp canopy area over the past 38 years and that there was a latitudinal response to heatwave events for each kelp species. The recovery from heatwave events was more variable across space, with some local areas like Bahía Tortugas in Baja California Sur showing high recovery while kelp canopies around the Monterey Peninsula continued a slow decline and patchy recovery compared to the rest of the Central California region. Kelpwatch provides near real time spatial data and analysis support and makes complex earth observation data actionable for scientists and managers, which can help identify areas for research, monitoring, and management efforts.
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Affiliation(s)
- Tom W. Bell
- Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
| | - Kyle C. Cavanaugh
- Department of Geography, University of California Los Angeles, Los Angeles, California, United States of America
| | | | - Katherine C. Cavanaugh
- Department of Geography, University of California Los Angeles, Los Angeles, California, United States of America
| | - Henry F. Houskeeper
- Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
- Department of Geography, University of California Los Angeles, Los Angeles, California, United States of America
| | - Norah Eddy
- The Nature Conservancy, Sacramento, California, United States of America
| | | | - Nathaniel Rindlaub
- The Nature Conservancy, Sacramento, California, United States of America
| | - Mary Gleason
- The Nature Conservancy, Sacramento, California, United States of America
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6
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Pessarrodona A, Grimaldi CM. On the ecology of Cystophora spp. forests. J Phycol 2022; 58:760-772. [PMID: 36054376 PMCID: PMC10092567 DOI: 10.1111/jpy.13285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 07/17/2022] [Indexed: 06/15/2023]
Abstract
Cystophora is the second largest genus of fucoids worldwide and, like many other forest-forming macroalgae, is increasingly threatened by a range of anthropogenic impacts including ocean warming. Yet, limited ecological information is available from the warm portion of their range (SW Western Australia), where severe range contractions are predicted to occur. Here, we provide the first insights on the abundance, diversity, productivity, and stand structure of Cystophora forests in this region. Forests were ubiquitous over more than 800 km of coastline and dominated sheltered and moderately-exposed reefs. Stand biomass and productivity were similar or greater than that of kelp forests in the temperate reef communities examined, suggesting that Cystophora spp. play a similarly important ecological role. The stand structure of Cystophora forests was, however, different than those of kelp forests, with most stands featuring an abundant bank of sub-canopy juveniles and only a few plants forming the canopy layer. Stand productivity followed an opposite seasonal pattern than that of kelps, with maximal growth in late autumn through early winter and net biomass loss in summer. Annually, stands contributed between 2.2 and 5.7 kg · m-2 (fresh biomass) to reef productivity depending on the dominant stand species. We propose that Cystophora forests play an important and unique role in supporting subtidal temperate diversity and productivity throughout temperate Australia, and urge a better understanding of their ecology and responses to anthropogenic threats.
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Affiliation(s)
- Albert Pessarrodona
- UWA Oceans Institute and School of Biological SciencesUniversity of Western AustraliaCrawleyWestern Australia6009Australia
| | - Camille M. Grimaldi
- UWA Oceans Institute and Oceans Graduate SchoolUniversity of Western AustraliaCrawleyWestern Australia6009Australia
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7
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Starko S, Neufeld CJ, Gendall L, Timmer B, Campbell L, Yakimishyn J, Druehl L, Baum JK. Microclimate predicts kelp forest extinction in the face of direct and indirect marine heatwave effects. Ecol Appl 2022; 32:e2673. [PMID: 35584048 DOI: 10.1002/eap.2673] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/22/2022] [Accepted: 03/29/2022] [Indexed: 06/15/2023]
Abstract
Marine heatwaves threaten the persistence of kelp forests globally. However, the observed responses of kelp forests to these events have been highly variable on local scales. Here, we synthesize distribution data from an environmentally diverse region to examine spatial patterns of canopy kelp persistence through an unprecedented marine heatwave. We show that, although often overlooked, temperature variation occurring at fine spatial scales (i.e., a few kilometers or less) can be a critical driver of kelp forest persistence during these events. Specifically, though kelp forests nearly all persisted toward the cool outer coast, inshore areas were >3°C warmer at the surface and experienced extensive kelp loss. Although temperatures remained cool at depths below the thermocline, kelp persistence in these thermal refugia was strongly constrained by biotic interactions, specifically urchin populations that increased during the heatwave and drove transitions to urchin barrens in deeper rocky habitat. Urchins were, however, largely absent from mixed sand and cobble benthos, leading to an unexpected association between bottom substrate and kelp forest persistence at inshore sites with warm surface waters. Our findings demonstrate both that warm microclimates increase the risk of habitat loss during marine heatwaves and that biotic interactions modified by these events will modulate the capacity of cool microclimates to serve as thermal refugia.
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Affiliation(s)
- Samuel Starko
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
| | - Christopher J Neufeld
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
- Department of Biology, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Lianna Gendall
- Department of Geography, University of Victoria, Victoria, British Columbia, Canada
| | - Brian Timmer
- Department of Geography, University of Victoria, Victoria, British Columbia, Canada
| | - Lily Campbell
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
| | - Jennifer Yakimishyn
- Pacific Rim National Park Reserve of Canada, Ucluelet, British Columbia, Canada
| | - Louis Druehl
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
- Canadian Kelp Resources, Bamfield, British Columbia, Canada
| | - Julia K Baum
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
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8
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Eger AM, Marzinelli EM, Christie H, Fagerli CW, Fujita D, Gonzalez AP, Hong SW, Kim JH, Lee LC, McHugh TA, Nishihara GN, Tatsumi M, Steinberg PD, Vergés A. Global kelp forest restoration: past lessons, present status, and future directions. Biol Rev Camb Philos Soc 2022; 97:1449-1475. [PMID: 35255531 PMCID: PMC9543053 DOI: 10.1111/brv.12850] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 02/22/2022] [Accepted: 02/23/2022] [Indexed: 01/08/2023]
Abstract
Kelp forest ecosystems and their associated ecosystem services are declining around the world. In response, marine managers are working to restore and counteract these declines. Kelp restoration first started in the 1700s in Japan and since then has spread across the globe. Restoration efforts, however, have been largely disconnected, with varying methodologies trialled by different actors in different countries. Moreover, a small subset of these efforts are 'afforestation', which focuses on creating new kelp habitat, as opposed to restoring kelp where it previously existed. To distil lessons learned over the last 300 years of kelp restoration, we review the history of kelp restoration (including afforestation) around the world and synthesise the results of 259 documented restoration attempts spanning from 1957 to 2020, across 16 countries, five languages, and multiple user groups. Our results show that kelp restoration projects have increased in frequency, have employed 10 different methodologies and targeted 17 different kelp genera. Of these projects, the majority have been led by academics (62%), have been conducted at sizes of less than 1 ha (80%) and took place over time spans of less than 2 years. We show that projects are most successful when they are located near existing kelp forests. Further, disturbance events such as sea-urchin grazing are identified as regular causes of project failure. Costs for restoration are historically high, averaging hundreds of thousands of dollars per hectare, therefore we explore avenues to reduce these costs and suggest financial and legal pathways for scaling up future restoration efforts. One key suggestion is the creation of a living database which serves as a platform for recording restoration projects, showcasing and/or re-analysing existing data, and providing updated information. Our work establishes the groundwork to provide adaptive and relevant recommendations on best practices for kelp restoration projects today and into the future.
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Affiliation(s)
- Aaron M. Eger
- Centre for Marine Science and Innovation & Ecology and Evolution Research Centre, School of Biological, Earth and Environmental SciencesThe University of New South WalesSydneyNSW2052
| | - Ezequiel M. Marzinelli
- The University of Sydney, School of Life and Environmental SciencesSydneyNSW2006Australia
- Sydney Institute of Marine Science19 Chowder Bay RdMosmanNSW2088Australia
- Singapore Centre for Environmental Life Sciences EngineeringNanyang Technological UniversitySingapore637551Singapore
| | - Hartvig Christie
- Norwegian Institute for Water ResearchØkernveien 94Oslo0579Norway
| | | | - Daisuke Fujita
- University of Tokyo Marine Science and Technology, School of Marine Bioresources, Applied PhycologyKonan, Minato‐kuTokyo108‐8477Japan
| | - Alejandra P. Gonzalez
- Departamento de Ciencias Ecológicas, Facultad de CienciasUniversidad de ChileLas Palmeras 3425, ÑuñoaSantiagoChile
| | - Seok Woo Hong
- Department of Biological SciencesSungkyunkwan UniversitySuwon2066South Korea
| | - Jeong Ha Kim
- Department of Biological SciencesSungkyunkwan UniversitySuwon2066South Korea
| | - Lynn C. Lee
- Gwaii Haanas National Park Reserve, National Marine Conservation Area Reserve, and Haida Heritage Site60 Second Beach Road, SkidegateHaida GwaiiBCV0T 1S1Canada
- Canada & School of Environmental Sciences, University of Victoria3800 Finnerty RoadVictoriaBCV8P 5C2Canada
| | - Tristin Anoush McHugh
- Reef Check Foundation, Long Marine Laboratory115 McAllister RoadSanta CruzCA95060U.S.A.
- Present address:
The Nature Conservancy830 S StreetSacramentoCA95811U.S.A.
| | - Gregory N. Nishihara
- Organization for Marine Science and TechnologyInstitute for East China Sea Research, Nagasaki University1551‐7 Taira‐machiNagasaki City851‐2213Japan
| | - Masayuki Tatsumi
- Institute for Marine and Antarctic Studies, University of TasmaniaHobartTAS7004Australia
| | - Peter D. Steinberg
- Centre for Marine Science and Innovation & Ecology and Evolution Research Centre, School of Biological, Earth and Environmental SciencesThe University of New South WalesSydneyNSW2052
- Sydney Institute of Marine Science19 Chowder Bay RdMosmanNSW2088Australia
| | - Adriana Vergés
- Centre for Marine Science and Innovation & Ecology and Evolution Research Centre, School of Biological, Earth and Environmental SciencesThe University of New South WalesSydneyNSW2052
- Sydney Institute of Marine Science19 Chowder Bay RdMosmanNSW2088Australia
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Fraser CI, Dutoit L, Morrison AK, Pardo LM, Smith SDA, Pearman WS, Parvizi E, Waters J, Macaya EC. Southern Hemisphere coasts are biologically connected by frequent, long-distance rafting events. Curr Biol 2022; 32:3154-3160.e3. [PMID: 35679870 DOI: 10.1016/j.cub.2022.05.035] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 02/20/2022] [Accepted: 05/12/2022] [Indexed: 12/20/2022]
Abstract
Globally, species distributions are shifting in response to environmental change,1 and those that cannot disperse risk extinction.2 Many taxa, including marine species, are showing poleward range shifts as the climate warms.3 In the Southern Hemisphere, however, circumpolar oceanic fronts can present barriers to dispersal.4 Although passive, southward movement of species across this barrier has been considered unlikely,5,6 the recent discovery of buoyant kelp rafts on beaches in Antarctica7,8 demonstrates that such journeys are possible. Rafting is a key process by which diverse taxa-including terrestrial, e.g., Lindo,9 Godinot,10 and Censky et al.,11 and marine, e.g., Carlton et al.12 and Gillespie et al.13 species-can cross oceans.14 Kelp rafts can carry passengers7,15-17 and thus can act as vectors for long-distance dispersal of coastal organisms. The small numbers of kelp rafts previously found in Antarctica7,8 do not, however, shed much light on the frequency of such dispersal events.18 We use a combination of high-resolution phylogenomic analyses (>220,000 SNPs) and oceanographic modeling to show that long-distance biological dispersal events in Southern Ocean are not rare. We document tens of kelp (Durvillaea antarctica) rafting events of thousands of kilometers each, over several decades (1950-2019), with many kelp rafts apparently still reproductively viable. Modeling of dispersal trajectories from genomically inferred source locations shows that distant landmasses are well connected, for example South Georgia and New Zealand, and the Kerguelen Islands and Tasmania. Our findings illustrate the power of genomic approaches to track, and modeling to show frequencies of, long-distance dispersal events.
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Affiliation(s)
- Ceridwen I Fraser
- Department of Marine Science, University of Otago, Dunedin, New Zealand.
| | - Ludovic Dutoit
- Department of Marine Science, University of Otago, Dunedin, New Zealand; Department of Zoology, University of Otago, Dunedin, New Zealand.
| | - Adele K Morrison
- Research School of Earth Sciences and Australian Centre for Excellence in Antarctic Science, Australian National University, Canberra, ACT, Australia
| | - Luis Miguel Pardo
- Instituto de Ciencias Marinas y Limnológicas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Centro FONDAP de Investigación en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Valdivia, Chile
| | - Stephen D A Smith
- National Marine Science Centre, Southern Cross University, Coffs Harbour, NSW, Australia
| | - William S Pearman
- Department of Marine Science, University of Otago, Dunedin, New Zealand
| | - Elahe Parvizi
- Department of Zoology, University of Otago, Dunedin, New Zealand
| | - Jonathan Waters
- Department of Zoology, University of Otago, Dunedin, New Zealand
| | - Erasmo C Macaya
- Centro FONDAP de Investigación en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Valdivia, Chile; Departamento de Oceanografía, Universidad de Concepción, Concepción, Chile.
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10
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Straub SC, Wernberg T, Marzinelli EM, Vergés A, Kelaher BP, Coleman MA. Persistence of seaweed forests in the anthropocene will depend on warming and marine heatwave profiles. J Phycol 2022; 58:22-35. [PMID: 34800039 DOI: 10.1111/jpy.13222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/02/2021] [Accepted: 11/10/2021] [Indexed: 06/13/2023]
Abstract
Marine heatwaves (MHWs), discrete periods of extreme warm water temperatures superimposed onto persistent ocean warming, have increased in frequency and significantly disrupted marine ecosystems. While field observations on the ecological consequences of MHWs are growing, a mechanistic understanding of their direct effects is rare. We conducted an outdoor tank experiment testing how different thermal stressor profiles impacted the ecophysiological performance of three dominant forest-forming seaweeds. Four thermal scenarios were tested: contemporary summer temperature (22°C), low persistent warming (24°C), a discrete MHW (22-27°C), and temperature variability followed by a MHW (22-24°C, 22-27°C). The physiological performance of seaweeds was strongly related to thermal profile and varied among species, with the highest temperature not always having the strongest effect. MHWs were highly detrimental for the fucoid Phyllospora comosa, whereas the laminarian kelp Ecklonia radiata showed sensitivity to extended thermal stress and demonstrated a cumulative temperature threshold. The fucoid Sargassum linearifolium showed resilience, albeit with signs of decline with bleached and degraded fronds, under all conditions, with stronger decline under stable control and warming conditions. The varying responses of these three co-occurring forest-forming seaweeds under different temperature scenarios suggests that the impact of ocean warming on near shore ecosystems may be complex and will depend on the specific thermal profile of rising water temperatures relative to the vulnerability of different species.
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Affiliation(s)
- Sandra C Straub
- UWA Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, Australia
| | - Thomas Wernberg
- UWA Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, Australia
- Institute of Marine Research, Flødevigen Research Station, His, Norway
| | - Ezequiel M Marzinelli
- School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore
- Sydney Institute of Marine Science, Mosman, Australia
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia
| | - Adriana Vergés
- Sydney Institute of Marine Science, Mosman, Australia
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia
| | - Brendan P Kelaher
- National Marine Science Centre, Southern Cross University, Coffs Harbour, Australia
| | - Melinda A Coleman
- UWA Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, Australia
- National Marine Science Centre, Southern Cross University, Coffs Harbour, Australia
- Department of Primary Industries, NSW Fisheries, Coffs Harbour, Australia
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11
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Abstract
Ocean acidification is one the biggest threats to marine ecosystems worldwide, but its ecosystem wide responses are still poorly understood. This study integrates field and experimental data into a mass balance food web model of a temperate coastal ecosystem to determine the impacts of specific OA forcing mechanisms as well as how they interact with one another. Specifically, we forced a food web model of a kelp forest ecosystem near its southern distribution limit in the California large marine ecosystem to a 0.5 pH drop over the course of 50 years. This study utilizes a modeling approach to determine the impacts of specific OA forcing mechanisms as well as how they interact. Isolating OA impacts on growth (Production), mortality (Other Mortality), and predation interactions (Vulnerability) or combining all three mechanisms together leads to a variety of ecosystem responses, with some taxa increasing in abundance and other decreasing. Results suggest that carbonate mineralizing groups such as coralline algae, abalone, snails, and lobsters display the largest decreases in biomass while macroalgae, urchins, and some larger fish species display the largest increases. Low trophic level groups such as giant kelp and brown algae increase in biomass by 16% and 71%, respectively. Due to the diverse way in which OA stress manifests at both individual and population levels, ecosystem-level effects can vary and display nonlinear patterns. Combined OA forcing leads to initial increases in ecosystem and commercial biomasses followed by a decrease in commercial biomass below initial values over time, while ecosystem biomass remains high. Both biodiversity and average trophic level decrease over time. These projections indicate that the kelp forest community would maintain high productivity with a 0.5 drop in pH, but with a substantially different community structure characterized by lower biodiversity and relatively greater dominance by lower trophic level organisms.
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Affiliation(s)
- Adam J. Schlenger
- Institute of the Environment and Sustainability, University of California Los Angeles, Los Angeles, California, United States of America
| | - Rodrigo Beas-Luna
- Facultad de Ciencias Marinas, Universidad Autónoma de Baja California, Ensenada B.C. Mexico
| | - Richard F. Ambrose
- Institute of the Environment and Sustainability, University of California Los Angeles, Los Angeles, California, United States of America
- Department of Environmental Health Sciences, University of California, Los Angeles, Los Angeles, California, United States of America
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12
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Abstract
Vergés and Campbell introduce the kelp forest ecosystem.
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Affiliation(s)
- Adriana Vergés
- Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, UNSW Sydney, NSW 2052, Australia; Sydney Institute of Marine Science, Mosman, NSW 2088, Australia.
| | - Alexandra H Campbell
- USC Seaweed Research Group, University of the Sunshine Coast, Sunshine Coast, QLD 4556, Australia
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13
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Carnell PE, Keough MJ. More severe disturbance regimes drive the shift of a kelp forest to a sea urchin barren in south-eastern Australia. Sci Rep 2020; 10:11272. [PMID: 32647344 PMCID: PMC7347924 DOI: 10.1038/s41598-020-67962-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 06/15/2020] [Indexed: 11/16/2022] Open
Abstract
Climate change is influencing the frequency and severity of extreme events. This means that systems are experiencing novel or altered disturbance regimes, making it difficult to predict and manage for this impact on ecosystems. While there is established theory regarding how the frequency of disturbance influences ecosystems, how this interacts with severity of disturbance is difficult to tease apart, as these two are inherently linked. Here we investigated a subtidal kelp (Ecklonia radiata) dominated community in southern Australia to assess how different disturbance regimes might drive changes to a different ecosystem state: sea urchin barrens. Specifically, we compared how the frequency of disturbance (single or triple disturbance events over a three month period) influenced recruitment and community dynamics, when the net severity of disturbance was the same (single disturbance compared to triple disturbances each one-third as severe). We crossed this design with two different net severities of disturbance (50% or 100%, kelp canopy removal). The frequency of disturbance effect depended on the severity of disturbance. When 50% of the canopy was removed, the highest kelp recruitment and recovery of the benthic community occurred with the triple disturbance events. When disturbance was a single event or the most severe (100% removal), kelp recruitment was low and the kelp canopy failed to recover over 18 months. The latter case led to shifts in the community composition from a kelp bed to a sea-urchin barren. This suggests that if ecosystems experience novel or more severe disturbance scenarios, this can lead to a decline in ecosystem condition or collapse.
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Affiliation(s)
- Paul E. Carnell
- School of BioSciences, The University of Melbourne, Parkville, VIC 3010 Australia
- Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Geelong, VIC 3216 Australia
| | - Michael J. Keough
- School of BioSciences, The University of Melbourne, Parkville, VIC 3010 Australia
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14
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Takagi S, Sato Y, Kokubun A, Inomata E, Agatsuma Y. Odor-active compounds from the gonads of Mesocentrotus nudus sea urchins fed Saccharina japonica kelp. PLoS One 2020; 15:e0231673. [PMID: 32298339 PMCID: PMC7161986 DOI: 10.1371/journal.pone.0231673] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 03/28/2020] [Indexed: 11/18/2022] Open
Abstract
Gonad size, color, texture and taste of Mesocentrotus nudus sea urchins collected from a barren can be improved by a short-term cage culture while being fed fresh Saccharina japonica kelp during May-July. We investigated the effect of S. japonica feeding during May-July on the improvement of gonad flavor in M. nudus collected from a barren. After feeding, we analyzed the odor-active volatile organic compounds (VOCs) from the gonads using gas chromatography-mass spectrometry and GC-sniffing analyses and compared to those from the gonads of wild sea urchins from an Eisenia kelp bed (fishing ground) and a barren. A total of 48 VOCs were detected from the gonads of cultured and wild sea urchins. Of them, a larger number of odor-active compounds were detected in the gonads of cultured sea urchins (25) than in those from the Eisenia bed (14) and the barren (6). Dimethyl sulfide from the gonads of sea urchins from the barren was described as having a strong, putrid odor. Sea urchin-like aromas were attributed to 2-butanol, 2-ethylhexanol, benzaldehyde and ethylbenzene from the gonads of cultured sea urchin and those of the Eisenia bed. Kelp feeding decreased the putrid odor from dimethyl sulfide, and enhanced pleasant, sweet aromas.
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Affiliation(s)
- Satomi Takagi
- Laboratory of Marine Plant Ecology, Graduate School of Agricultural Science, Tohoku University, Aza-Aoba, Aramaki, Aoba, Sendai, Miyagi, Japan
| | - Yoichi Sato
- Riken Food Co., Ltd., Miyauchi, Tagajyo, Miyagi, Japan
- Nishina Center for Accelerator-Based Science, RIKEN, Hirosawa, Wako, Saitama, Japan
| | - Atsuko Kokubun
- Food Analysis Laboratory, Quality Assurance Division, RIKEN VITAMIN Co., Ltd., Aoyagi, Soka, Saitama, Japan
| | - Eri Inomata
- Laboratory of Marine Plant Ecology, Graduate School of Agricultural Science, Tohoku University, Aza-Aoba, Aramaki, Aoba, Sendai, Miyagi, Japan
| | - Yukio Agatsuma
- Laboratory of Marine Plant Ecology, Graduate School of Agricultural Science, Tohoku University, Aza-Aoba, Aramaki, Aoba, Sendai, Miyagi, Japan
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15
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Ng CA, Micheli F. Short-term effects of hypoxia are more important than effects of ocean acidification on grazing interactions with juvenile giant kelp (Macrocystis pyrifera). Sci Rep 2020; 10:5403. [PMID: 32214142 PMCID: PMC7096494 DOI: 10.1038/s41598-020-62294-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 02/07/2020] [Indexed: 11/09/2022] Open
Abstract
Species interactions are crucial for the persistence of ecosystems. Within vegetated habitats, early life stages of plants and algae must survive factors such as grazing to recover from disturbances. However, grazing impacts on early stages, especially under the context of a rapidly changing climate, are largely unknown. Here we examine interaction strengths between juvenile giant kelp (Macrocystis pyrifera) and four common grazers under hypoxia and ocean acidification using short-term laboratory experiments and field data of grazer abundances to estimate population-level grazing impacts. We found that grazing is a significant source of mortality for juvenile kelp and, using field abundances, estimate grazers can remove on average 15.4% and a maximum of 73.9% of juveniles per m2 per day. Short-term exposure to low oxygen, not acidification, weakened interaction strengths across the four species and decreased estimated population-level impacts of grazing threefold, from 15.4% to 4.0% of juvenile kelp removed, on average, per m2 per day. This study highlights potentially high juvenile kelp mortality from grazing. We also show that the effects of hypoxia are stronger than the effects of acidification in weakening these grazing interactions over short timescales, with possible future consequences for the persistence of giant kelp and energy flow through these highly productive food webs.
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Affiliation(s)
- Crystal A Ng
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA.
- Schmid College of Science and Technology, Chapman University, Orange, CA, USA.
| | - Fiorenza Micheli
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
- Stanford Center for Ocean Solutions, Pacific Grove, CA, USA
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16
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Abstract
Climate change is altering the intensity and variability of environmental stress that organisms and ecosystems experience, but effects of changing stress regimes are not well understood. We examined impacts of constant and variable sublethal hypoxia exposures on multiple biological processes in the sea urchin Strongylocentrotus purpuratus, a key grazer in California Current kelp forests, which experience high variability in physical conditions. We quantified metabolic rates, grazing, growth, calcification, spine regeneration, and gonad production under constant, 3-hour variable, and 6-hour variable exposures to sublethal hypoxia, and compared responses for each hypoxia regime to normoxic conditions. Sea urchins in constant hypoxia maintained baseline metabolic rates, but had lower grazing, gonad development, and calcification rates than those in ambient conditions. The sublethal impacts of variable hypoxia differed among biological processes. Spine regrowth was reduced under all hypoxia treatments, calcification rates under variable hypoxia were intermediate between normoxia and constant hypoxia, and gonad production correlated negatively with continuous time under hypoxia. Therefore, exposure variability can differentially modulate the impacts of sublethal hypoxia, and may impact sea urchin populations and ecosystems via reduced feeding and reproduction. Addressing realistic, multifaceted stressor exposures and multiple biological responses is crucial for understanding climate change impacts on species and ecosystems.
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Affiliation(s)
- Natalie H N Low
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, 93950, USA.
| | - Fiorenza Micheli
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, 93950, USA
- Stanford Center for Ocean Solutions, Pacific Grove, CA, 93950, USA
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17
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Avila C, Angulo-Preckler C, Martín-Martín RP, Figuerola B, Griffiths HJ, Waller CL. Invasive marine species discovered on non-native kelp rafts in the warmest Antarctic island. Sci Rep 2020; 10:1639. [PMID: 32005904 PMCID: PMC6994651 DOI: 10.1038/s41598-020-58561-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 01/17/2020] [Indexed: 11/13/2022] Open
Abstract
Antarctic shallow coastal marine communities were long thought to be isolated from their nearest neighbours by hundreds of kilometres of deep ocean and the Antarctic Circumpolar Current. The discovery of non-native kelp washed up on Antarctic beaches led us to question the permeability of these barriers to species dispersal. According to the literature, over 70 million kelp rafts are afloat in the Southern Ocean at any one time. These living, floating islands can play host to a range of passenger species from both their original coastal location and those picked in the open ocean. Driven by winds, currents and storms towards the coast of the continent, these rafts are often cited as theoretical vectors for the introduction of new species into Antarctica and the sub-Antarctic islands. We found non-native kelps, with a wide range of "hitchhiking" passenger organisms, on an Antarctic beach inside the flooded caldera of an active volcanic island. This is the first evidence of non-native species reaching the Antarctic continent alive on kelp rafts. One passenger species, the bryozoan Membranipora membranacea, is found to be an invasive and ecologically harmful species in some cold-water regions, and this is its first record from Antarctica. The caldera of Deception Island provides considerably milder conditions than the frigid surrounding waters and it could be an ideal location for newly introduced species to become established. These findings may help to explain many of the biogeographic patterns and connections we currently see in the Southern Ocean. However, with the impacts of climate change in the region we may see an increase in the range and number of organisms capable of surviving both the long journey and becoming successfully established.
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Affiliation(s)
- Conxita Avila
- Department of Evolutionary Biology, Ecology, and Environmental Sciences, University of Barcelona & Biodiversity Research Institute (IRBio), Av. Diagonal 643, 08028, Barcelona, Catalonia, Spain.
| | - Carlos Angulo-Preckler
- Department of Evolutionary Biology, Ecology, and Environmental Sciences, University of Barcelona & Biodiversity Research Institute (IRBio), Av. Diagonal 643, 08028, Barcelona, Catalonia, Spain
| | - Rafael P Martín-Martín
- Department of Biology, Healthcare and the Environment, University of Barcelona & Biodiversity Research Institute (IRBio), Av. Diagonal 643, 08028, Barcelona, Catalonia, Spain
| | - Blanca Figuerola
- Institute of Marine Sciences (ICM-CSIC), Pg. Marítim de la Barceloneta 37-49, 08003, Barcelona, Catalonia, Spain
| | - Huw James Griffiths
- British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB30ET, England
| | - Catherine Louise Waller
- University of Hull, Department of Biological and Marine Sciences, Cottingham Road, Hull, HU6 7RX, UK
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18
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Peters JC, Waters JM, Dutoit L, Fraser CI. SNP analyses reveal a diverse pool of potential colonists to earthquake-uplifted coastlines. Mol Ecol 2020; 29:149-159. [PMID: 31711270 DOI: 10.1111/mec.15303] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 10/17/2019] [Accepted: 11/04/2019] [Indexed: 11/28/2022]
Abstract
In species that form dense populations, major disturbance events are expected to increase the chance of establishment for immigrant lineages. Real-time tests of the impact of disturbance on patterns of genetic structure are, however, scarce. Central to testing these concepts is determining the pool of potential immigrants dispersing into a disturbed area. In 2016, a 7.8 magnitude earthquake occurred on the South Island of New Zealand. Affecting approximately 100 km of coastline, this quake caused extensive uplift (several metres high), extirpating many intertidal populations, including keystone intertidal kelp species. Following the uplift, we set out to determine the geographic origins of detached kelp specimens which rafted into the disturbed zone. Specifically, we used genotyping-by-sequencing (GBS) approaches to compare beach-cast southern bull-kelp (Durvillaea antarctica and Durvillaea poha) samples to established populations throughout the species' ranges, and thus infer the geographic origins of potential colonists reaching the disturbed coast. Our findings revealed an ongoing supply of diverse lineages dispersing to the newly uplifted coastline, suggesting potential for establishment of "exotic" lineages following disturbance. Furthermore, we found that some drifting individuals of each species came from far-distant regions, some >1,200 km away. These results show that diverse lineages - in many cases from very distant sources - can compete for new space in the wake of an exceptional disturbance event, illustrating the potential of long-distance dispersal as a key mechanism for reassembly of coastal ecosystems. Furthermore, our findings demonstrate that high-resolution genomic baselines can be used to robustly assign the provenance of dispersing individuals.
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Affiliation(s)
- Johnette C Peters
- Fenner School of Environment and Society, Australian National University, Canberra, ACT, Australia
| | | | - Ludovic Dutoit
- Department of Zoology, University of Otago, Dunedin, New Zealand
- Department of Marine Science, University of Otago, Dunedin, New Zealand
| | - Ceridwen I Fraser
- Fenner School of Environment and Society, Australian National University, Canberra, ACT, Australia
- Department of Marine Science, University of Otago, Dunedin, New Zealand
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19
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Li H, Monteiro C, Heinrich S, Bartsch I, Valentin K, Harms L, Glöckner G, Corre E, Bischof K. Responses of the kelp Saccharina latissima (Phaeophyceae) to the warming Arctic: from physiology to transcriptomics. Physiol Plant 2020; 168:5-26. [PMID: 31267544 DOI: 10.1111/ppl.13009] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 05/31/2019] [Accepted: 06/27/2019] [Indexed: 06/09/2023]
Abstract
The Arctic region is currently facing substantial environmental changes due to global warming. Melting glaciers cause reduced salinity environments in coastal Arctic habitats, which may be stressful for kelp beds. To investigate the responses of the kelp Saccharina latissima to the warming Arctic, we studied the transcriptomic changes of S. latissima from Kongsfjorden (Svalbard, Norway) over a 24-hour exposure to two salinities (Absolute Salinity [SA ] 20 and 30) after a 7-day pre-acclimation at three temperatures (0, 8 and 15°C). In addition, corresponding physiological data were assessed during an 11-days salinity/temperature experiment. Growth and maximal quantum yield for photosystem II fluorescence were positively affected by increased temperature during acclimation, whereas hyposalinity caused negative effects at the last day of treatment. In contrast, hyposalinity induced marked changes on the transcriptomic level. Compared to the control (8°C - SA 30), the 8°C - SA 20 exhibited the highest number of differentially expressed genes (DEGs), followed by the 0°C - SA 20. Comparisons indicate that S. latissima tends to convert its energy from primary metabolism (e.g. photosynthesis) to antioxidant activity under hyposaline stress. The increase in physiological performance at 15°C shows that S. latissima in the Arctic region can adjust and might even benefit from increased temperatures. However, in Arctic fjord environments its performance might become impaired by decreased salinity as a result of ice melting.
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Affiliation(s)
- Huiru Li
- Fisheries College, Ocean University of China, Qingdao, 266003, China
- Marine Botany, Faculty Biology/Chemistry, University of Bremen, Bremen, 28359, Germany
| | - Cátia Monteiro
- Marine Botany, Faculty Biology/Chemistry, University of Bremen, Bremen, 28359, Germany
- Station Biologique de Roscoff, plateforme ABiMS, CNRS: FR2424, Sorbonne Université (UPMC), Roscoff, 29680, France
- Sorbonne Université, CNRS, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff, Roscoff, 29680, France
| | - Sandra Heinrich
- Molecular Plant Genetics, Institute for Plant Science and Microbiology, University of Hamburg, Hamburg, 22609, Germany
| | - Inka Bartsch
- Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, 27570, Germany
| | - Klaus Valentin
- Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, 27570, Germany
| | - Lars Harms
- Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, 27570, Germany
| | - Gernot Glöckner
- Institute of Biochemistry I, Medical Faculty, University of Cologne, Cologne, 50931, Germany
| | - Erwan Corre
- Station Biologique de Roscoff, plateforme ABiMS, CNRS: FR2424, Sorbonne Université (UPMC), Roscoff, 29680, France
| | - Kai Bischof
- Marine Botany, Faculty Biology/Chemistry, University of Bremen, Bremen, 28359, Germany
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20
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Abstract
Extreme climatic events have recently impacted marine ecosystems around the world, including foundation species such as corals and kelps. Here, we describe the rapid climate-driven catastrophic shift in 2014 from a previously robust kelp forest to unproductive large scale urchin barrens in northern California. Bull kelp canopy was reduced by >90% along more than 350 km of coastline. Twenty years of kelp ecosystem surveys reveal the timing and magnitude of events, including mass mortalities of sea stars (2013-), intense ocean warming (2014-2017), and sea urchin barrens (2015-). Multiple stressors led to the unprecedented and long-lasting decline of the kelp forest. Kelp deforestation triggered mass (80%) abalone mortality (2017) resulting in the closure in 2018 of the recreational abalone fishery worth an estimated $44 M and the collapse of the north coast commercial red sea urchin fishery (2015-) worth $3 M. Key questions remain such as the relative roles of ocean warming and sea star disease in the massive purple sea urchin population increase. Science and policy will need to partner to better understand drivers, build climate-resilient fisheries and kelp forest recovery strategies in order to restore essential kelp forest ecosystem services.
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Affiliation(s)
- L Rogers-Bennett
- Coastal Marine Science Institute, Karen C. Drayer Wildlife Health Center, University of California, Davis, and California Department of Fish and Wildlife, Bodega Marine Laboratory 2099 Westside Rd., Bodega Bay, CA, 94923-0247, USA.
| | - C A Catton
- Coastal Marine Science Institute, Karen C. Drayer Wildlife Health Center, University of California, Davis, and California Department of Fish and Wildlife, Bodega Marine Laboratory 2099 Westside Rd., Bodega Bay, CA, 94923-0247, USA
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21
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Al-Janabi B, Wahl M, Karsten U, Graiff A, Kruse I. Sensitivities to global change drivers may correlate positively or negatively in a foundational marine macroalga. Sci Rep 2019; 9:14653. [PMID: 31601889 PMCID: PMC6787226 DOI: 10.1038/s41598-019-51099-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 09/25/2019] [Indexed: 02/06/2023] Open
Abstract
Ecological impact of global change is generated by multiple synchronous or asynchronous drivers which interact with each other and with intraspecific variability of sensitivities. In three near-natural experiments, we explored response correlations of full-sibling germling families of the seaweed Fucus vesiculosus towards four global change drivers: elevated CO2 (ocean acidification, OA), ocean warming (OW), combined OA and warming (OAW), nutrient enrichment and hypoxic upwelling. Among families, performance responses to OA and OW as well as to OAW and nutrient enrichment correlated positively whereas performance responses to OAW and hypoxia anti-correlated. This indicates (i) that families robust to one of the three drivers (OA, OW, nutrients) will also not suffer from the two other shifts, and vice versa and (ii) families benefitting from OAW will more easily succumb to hypoxia. Our results may imply that selection under either OA, OW or eutrophication would enhance performance under the other two drivers but simultaneously render the population more susceptible to hypoxia. We conclude that intraspecific response correlations have a high potential to boost or hinder adaptation to multifactorial global change scenarios.
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Affiliation(s)
- Balsam Al-Janabi
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Department of Marine Ecology, Duesternbrooker Weg 20, D-24105, Kiel, Germany
| | - Martin Wahl
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Department of Marine Ecology, Duesternbrooker Weg 20, D-24105, Kiel, Germany.
| | - Ulf Karsten
- University of Rostock, Institute of Biological Sciences, Applied Ecology and Phycology, Albert-Einstein-Strasse 3, D-18059, Rostock, Germany
| | - Angelika Graiff
- University of Rostock, Institute of Biological Sciences, Applied Ecology and Phycology, Albert-Einstein-Strasse 3, D-18059, Rostock, Germany
| | - Inken Kruse
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Department of Marine Ecology, Duesternbrooker Weg 20, D-24105, Kiel, Germany
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22
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Tala F, López BA, Velásquez M, Jeldres R, Macaya EC, Mansilla A, Ojeda J, Thiel M. Long-term persistence of the floating bull kelp Durvillaea antarctica from the South-East Pacific: Potential contribution to local and transoceanic connectivity. Mar Environ Res 2019; 149:67-79. [PMID: 31154063 DOI: 10.1016/j.marenvres.2019.05.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/16/2019] [Accepted: 05/18/2019] [Indexed: 05/06/2023]
Abstract
Current knowledge about the performance of floating seaweeds as dispersal vectors comes mostly from mid latitudes (30°-40°), but phylogeographic studies suggest that long-distance dispersal (LDD) is more common at high latitudes (50°-60°). To test this hypothesis, long-term field experiments with floating southern bull kelp Durvillaea antarctica were conducted along a latitudinal gradient (30°S, 37°S and 54°S) in austral winter and summer. Floating time exceeded 200d in winter at the high latitudes but in summer it dropped to 90d, being still higher than at low latitudes (<45d). Biomass variations were due to loss of buoyant fronds. Reproductive activity diminished during long floating times. Physiological changes included mainly a reduction in photosynthetic (Fv/Fm and pigments) rather than in defence variables (phlorotannins and antioxidant activity). The observed long floating persistence and long-term acclimation responses at 54°S support the hypothesis of LDD by kelp rafts at high latitudes.
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Affiliation(s)
- Fadia Tala
- Departamento de Biología Marina, Universidad Católica del Norte, Larrondo, 1281, Coquimbo, Chile; Centro de Investigación y Desarrollo Tecnológico en Algas (CIDTA), Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile.
| | - Boris A López
- Departamento de Acuicultura y Recursos Agroalimentarios, Universidad de Los Lagos, Avenida Fuchslocher, 1305, Osorno, Chile
| | - Marcel Velásquez
- Laboratorio de Macroalgas Antárticas y Subantárticas (LMAS), Universidad de Magallanes, Facultad de Ciencias, Casilla 113-D, Punta Arenas, Chile; Instituto de Ecología y Biodiversidad, IEB-Chile, Universidad de Chile, Santiago, Chile
| | - Ricardo Jeldres
- Departamento de Oceanografía, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile; Centro FONDAP de Investigaciones en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Chile
| | - Erasmo C Macaya
- Departamento de Oceanografía, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile; Centro FONDAP de Investigaciones en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Chile; Millennium Nucleus Ecology and Sustainable Management of Oceanic Island (ESMOI), Coquimbo, Chile
| | - Andrés Mansilla
- Laboratorio de Macroalgas Antárticas y Subantárticas (LMAS), Universidad de Magallanes, Facultad de Ciencias, Casilla 113-D, Punta Arenas, Chile; Instituto de Ecología y Biodiversidad, IEB-Chile, Universidad de Chile, Santiago, Chile
| | - Jaime Ojeda
- Laboratorio de Macroalgas Antárticas y Subantárticas (LMAS), Universidad de Magallanes, Facultad de Ciencias, Casilla 113-D, Punta Arenas, Chile; Instituto de Ecología y Biodiversidad, IEB-Chile, Universidad de Chile, Santiago, Chile; School of Environmental Studies, University of Victoria, Victoria, British Columbia, Canada
| | - Martin Thiel
- Departamento de Biología Marina, Universidad Católica del Norte, Larrondo, 1281, Coquimbo, Chile; Millennium Nucleus Ecology and Sustainable Management of Oceanic Island (ESMOI), Coquimbo, Chile; Centro de Estudios Avanzados en Zonas Áridas, Coquimbo, Chile
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23
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Feehan CJ, Grace SP, Narvaez CA. Ecological feedbacks stabilize a turf-dominated ecosystem at the southern extent of kelp forests in the Northwest Atlantic. Sci Rep 2019; 9:7078. [PMID: 31068664 PMCID: PMC6506546 DOI: 10.1038/s41598-019-43536-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 04/26/2019] [Indexed: 11/09/2022] Open
Abstract
Temperate marine ecosystems globally are undergoing regime shifts from dominance by habitat-forming kelps to dominance by opportunistic algal turfs. While the environmental drivers of shifts to turf are generally well-documented, the feedback mechanisms that stabilize novel turf-dominated ecosystems remain poorly resolved. Here, we document a decline of kelp Saccharina latissima between 1980 and 2018 at sites at the southernmost extent of kelp forests in the Northwest Atlantic and their replacement by algal turf. We examined the drivers of a shift to turf and feedback mechanisms that stabilize turf reefs. Kelp replacement by turf was linked to a significant multi-decadal increase in sea temperature above an upper thermal threshold for kelp survival. In the turf-dominated ecosystem, 45% of S. latissima were attached to algal turf rather than rocky substrate due to preemption of space. Turf-attached kelp required significantly (2 to 4 times) less force to detach from the substrate, with an attendant pattern of lower survival following 2 major wave events as compared to rock-attached kelp. Turf-attached kelp allocated a significantly greater percentage of their biomass to the anchoring structure (holdfast), with a consequent energetic trade-off of slower growth. The results indicate a shift in community dominance from kelp to turf driven by thermal stress and stabilized by ecological feedbacks of lower survival and slower growth of kelp recruited to turf.
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Affiliation(s)
- Colette J Feehan
- Department of Biology, Montclair State University, Montclair, NJ, 07043, USA.
| | - Sean P Grace
- Department of Biology and Werth Center for Coastal and Marine Studies, Southern Connecticut State University, New Haven, CT, 06515, USA
| | - Carla A Narvaez
- Department of Biology, Villanova University, Villanova, PA, 19085, USA
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24
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Gao X, Kim JH, Park SK, Yu OH, Kim YS, Choi HG. Diverse responses of sporophytic photochemical efficiency and gametophytic growth for two edible kelps, Saccharina japonica and Undaria pinnatifida, to ocean acidification and warming. Mar Pollut Bull 2019; 142:315-320. [PMID: 31232310 DOI: 10.1016/j.marpolbul.2019.03.063] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 03/25/2019] [Accepted: 03/30/2019] [Indexed: 06/09/2023]
Abstract
Ocean acidification and warming represent major environmental threats to kelp mariculture. In this study, sporophytic photochemical efficiency and gametophytic growth of Saccharina japonica and Undaria pinnatifida were evaluated under different pCO2 levels (360, 720, and 980 ppmv) and temperatures (5, 10, 15, and 20 °C for sporophytes; 15 and 20 °C for gametophytes). Sporophytic photochemical efficiencies of both kelps were significantly greater at 720 ppmv than at 360 and 980 ppmv. Female gametophytes of both kelps grew significantly better at 360 ppmv than at higher pCO2 levels. The growth of U. pinnatifida gametophytes was significantly greater at 20 °C than at 15 °C, while no significant difference was observed for the growth of S. japonica. These results indicate that increased pCO2 stimulated sporophytic photochemical efficiency while inhibited gametophytic growth of these kelps, which might negatively affect their seedling cultivation. U. pinnatifida exhibited higher productivity in warmer ocean than S. japonica.
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Affiliation(s)
- Xu Gao
- Faculty of Biological Science and Sea & Biotech, Wonkwang University, Iksan 54538, Republic of Korea
| | - Ju-Hyoung Kim
- Faculty of Marine Applied Biosciences, Kunsan National University, Gunsan 54150, Republic of Korea
| | - Seo Kyoung Park
- Faculty of Biological Science and Sea & Biotech, Wonkwang University, Iksan 54538, Republic of Korea
| | - Ok Hwan Yu
- Marine Ecosystem Research Center, Korea Institute of Ocean Science & Technology, Busan 49111, Republic of Korea
| | - Young Sik Kim
- Department of Marine Biotechnology, Kunsan National University, Gunsan 54150, Republic of Korea
| | - Han Gil Choi
- Faculty of Biological Science and Sea & Biotech, Wonkwang University, Iksan 54538, Republic of Korea.
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25
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Blain CO, Shears NT. Seasonal and spatial variation in photosynthetic response of the kelp Ecklonia radiata across a turbidity gradient. Photosynth Res 2019; 140:21-38. [PMID: 30877516 DOI: 10.1007/s11120-019-00636-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Accepted: 03/07/2019] [Indexed: 06/09/2023]
Abstract
Understanding the photoacclimation response of macroalgae across broad spatial and temporal scales is necessary for predicting their vulnerability to environmental changes and quantifying their contribution to coastal primary production. This study investigated how the photosynthesis-irradiance response and photosynthetic pigment content of the kelp Ecklonia radiata varies both spatially and seasonally among seven sites located across a turbidity gradient in the Hauraki Gulf, north-eastern New Zealand. Photosynthesis-irradiance curves were derived under laboratory conditions for whole adult E. radiata using photorespirometry chambers. Lab-derived photosynthesis-irradiance curves in summer were also compared with in situ measurements made on kelp at each of the seven study sites. Photosynthetic parameters and pigments showed clear seasonal patterns across all sites as demonstrated by higher photosynthetic pigment levels and photosynthetic efficiency occurring in autumn and winter, and higher maximum rates of photosynthesis and respiration occurring in summer. Lamina biomass was similar across sites, yet thalli exhibited a clear photokinetic response to increasing turbidity. At turbid sites photosynthetic pigment levels and photosynthetic efficiency was higher, and respiration and saturation and compensation irradiances lower, compared to high-light sites. The results presented here further our understanding of low-light acclimation strategies in kelp and highlight the degree of seasonality in photosynthetic parameters. Though E. radiata demonstrates a clear capacity to photoacclimate to a degrading light environment, further research is needed to investigate the extent to which the observed acclimation can offset the likely negative effects of increasing turbidity on kelp forest primary production.
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Affiliation(s)
- Caitlin O Blain
- Leigh Marine Laboratory, Institute of Marine Science, University of Auckland, Auckland, New Zealand.
| | - Nick T Shears
- Leigh Marine Laboratory, Institute of Marine Science, University of Auckland, Auckland, New Zealand
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26
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Miranda RJ, Coleman MA, Tagliafico A, Rangel MS, Mamo LT, Barros F, Kelaher BP. Invasion-mediated effects on marine trophic interactions in a changing climate: positive feedbacks favour kelp persistence. Proc Biol Sci 2019; 286:20182866. [PMID: 30900532 PMCID: PMC6452063 DOI: 10.1098/rspb.2018.2866] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 02/28/2019] [Indexed: 12/24/2022] Open
Abstract
The interactive effects of ocean warming and invasive species are complex and remain a source of uncertainty for projecting future ecological change. Climate-mediated change to trophic interactions can have pervasive ecological consequences, but the role of invasion in mediating trophic effects is largely unstudied. Using manipulative experiments in replicated outdoor mesocosms, we reveal how near-future ocean warming and macrophyte invasion scenarios interactively impact gastropod grazing intensity and preference for consumption of foundation macroalgae ( Ecklonia radiata and Sargassum vestitum). Elevated water temperature increased the consumption of both macroalgae through greater grazing intensity. Given the documented decline of kelp ( E. radiata) growth at higher water temperatures, enhanced grazing could contribute to the shift from kelp-dominated to Sargassum-dominated reefs that is occurring at the low-latitude margins of kelp distribution. However, the presence of a native invader ( Caulerpa filiformis) was related to low consumption by the herbivores on dominant kelp at warmer temperatures. Thus, antagonistic effects between climate change and a range expanding species can favour kelp persistence in a warmer future. Introduction of species should, therefore, not automatically be considered unfavourable under climate change scenarios. Climatic changes are increasing the need for effective management actions to address the interactive effects of multiple stressors and their ecological consequences, rather than single threats in isolation.
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Affiliation(s)
- Ricardo J. Miranda
- National Marine Science Centre, Southern Cross University, Coffs Harbour, New South Wales 2450, Australia
- Laboratório de Ecologia Bentônica, Programa de Pós-Graduação em Ecologia, Instituto de Biologia, Centro Interdisciplinar em Energia e Meio Ambiente, Universidade Federal da Bahia, Salvador, BA 40170-290, Brazil
| | - Melinda A. Coleman
- National Marine Science Centre, Southern Cross University, Coffs Harbour, New South Wales 2450, Australia
- Department of Primary Industries, New South Wales Fisheries, National Marine Science Centre, 2 Bay Drive, Coffs Harbour, New South Wales 2450, Australia
| | - Alejandro Tagliafico
- National Marine Science Centre, Southern Cross University, Coffs Harbour, New South Wales 2450, Australia
| | - Maria S. Rangel
- National Marine Science Centre, Southern Cross University, Coffs Harbour, New South Wales 2450, Australia
| | - Lea T. Mamo
- National Marine Science Centre, Southern Cross University, Coffs Harbour, New South Wales 2450, Australia
| | - Francisco Barros
- Laboratório de Ecologia Bentônica, Programa de Pós-Graduação em Ecologia, Instituto de Biologia, Centro Interdisciplinar em Energia e Meio Ambiente, Universidade Federal da Bahia, Salvador, BA 40170-290, Brazil
| | - Brendan P. Kelaher
- National Marine Science Centre, Southern Cross University, Coffs Harbour, New South Wales 2450, Australia
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27
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Starko S, Bailey LA, Creviston E, James KA, Warren A, Brophy MK, Danasel A, Fass MP, Townsend JA, Neufeld CJ. Environmental heterogeneity mediates scale-dependent declines in kelp diversity on intertidal rocky shores. PLoS One 2019; 14:e0213191. [PMID: 30913219 PMCID: PMC6435185 DOI: 10.1371/journal.pone.0213191] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 02/16/2019] [Indexed: 11/18/2022] Open
Abstract
Biodiversity loss is driven by interacting factors operating at different spatial scales. Yet, there remains uncertainty as to how fine-scale environmental conditions mediate biological responses to broad-scale stressors. We surveyed intertidal rocky shore kelp beds situated across a local gradient of wave action and evaluated changes in kelp diversity and abundance after more than two decades of broad scale stressors, most notably the 2013-2016 heat wave. Across all sites, species were less abundant on average in 2017 and 2018 than during 1993-1995 but changes in kelp diversity were dependent on wave exposure, with wave exposed habitats remaining stable and wave sheltered habitats experiencing near complete losses of kelp diversity. In this way, wave exposed sites have acted as refugia, maintaining regional kelp diversity despite widespread local declines. Fucoids, seagrasses and two stress-tolerant kelp species (Saccharina sessilis, Egregia menziesii) did not decline as observed in other kelps, and the invasive species Sargassum muticum increased significantly at wave sheltered sites. Long-term monitoring data from a centrally-located moderate site suggest that kelp communities were negatively impacted by the recent heatwave which may have driven observed losses throughout the region. Wave-sheltered shores, which saw the largest declines, are a very common habitat type in the Northeast Pacific and may be especially sensitive to losses in kelp diversity and abundance, with potential consequences for coastal productivity. Our findings highlight the importance of fine-scale environmental heterogeneity in mediating biological responses and demonstrate how incorporating differences between habitat patches can be essential to capturing scale-dependent biodiversity loss across the landscape.
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Affiliation(s)
- Samuel Starko
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
| | - Lauren A. Bailey
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Elandra Creviston
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
- Department of Biology, University of Victoria, Victoria, British Columbia, Canada
| | - Katelyn A. James
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
| | - Alison Warren
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
- Department of Biology, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Megan K. Brophy
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
| | - Andreea Danasel
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
| | - Megan P. Fass
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - James A. Townsend
- Bamfield Marine Sciences Centre, Bamfield, British Columbia, Canada
- Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada
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28
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Burnett NP, Koehl MAR. Mechanical properties of the wave-swept kelp Egregia menziesii change with season, growth rate and herbivore wounds. J Exp Biol 2019; 222:jeb190595. [PMID: 30679240 DOI: 10.1242/jeb.190595] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 01/17/2019] [Indexed: 11/20/2022]
Abstract
The resistance of macroalgae to damage by hydrodynamic forces depends on the mechanical properties of their tissues. Although factors such as water-flow environment, algal growth rate and damage by herbivores have been shown to influence various material properties of macroalgal tissues, the interplay of these factors as they change seasonally and affect algal mechanical performance has not been worked out. We used the perennial kelp Egregia menziesii to study how the material properties of the rachis supporting a frond changed seasonally over a 2 year period, and how those changes correlated with seasonal patterns of the environment, growth rate and herbivore load. Rachis tissue became stiffer, stronger and less extensible with age (distance from the meristem). Thus, slowly growing rachises were stiffer, stronger and tougher than rapidly growing ones. Growth rates were highest in spring and summer when upwelling and long periods of daylight occurred. Therefore, rachis tissue was most resistant to damage in the winter, when waves were large as a result of seasonal storms. Herbivory was greatest during summer, when rachis growth rates were high. Unlike other macroalgae, E. menziesii did not respond to herbivore damage by increasing rachis tissue strength, but rather by growing in width so that the cross-sectional area of the wounded rachis was increased. The relative timing of environmental factors that affect growth rates (e.g. upwelling supply of nutrients, daylight duration) and of those that can damage macroalgae (e.g. winter storms, summer herbivore outbreaks) can influence the material properties and thus the mechanical performance of macroalgae.
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Affiliation(s)
- Nicholas P Burnett
- Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, CA 95616, USA
| | - M A R Koehl
- Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
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29
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Qiu Z, Coleman MA, Provost E, Campbell AH, Kelaher BP, Dalton SJ, Thomas T, Steinberg PD, Marzinelli EM. Future climate change is predicted to affect the microbiome and condition of habitat-forming kelp. Proc Biol Sci 2019; 286:20181887. [PMID: 30963929 PMCID: PMC6408609 DOI: 10.1098/rspb.2018.1887] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 01/14/2019] [Indexed: 01/09/2023] Open
Abstract
Climate change is driving global declines of marine habitat-forming species through physiological effects and through changes to ecological interactions, with projected trajectories for ocean warming and acidification likely to exacerbate such impacts in coming decades. Interactions between habitat-formers and their microbiomes are fundamental for host functioning and resilience, but how such relationships will change in future conditions is largely unknown. We investigated independent and interactive effects of warming and acidification on a large brown seaweed, the kelp Ecklonia radiata, and its associated microbiome in experimental mesocosms. Microbial communities were affected by warming and, during the first week, by acidification. During the second week, kelp developed disease-like symptoms previously observed in the field. The tissue of some kelp blistered, bleached and eventually degraded, particularly under the acidification treatments, affecting photosynthetic efficiency. Microbial communities differed between blistered and healthy kelp for all treatments, except for those under future conditions of warming and acidification, which after two weeks resembled assemblages associated with healthy hosts. This indicates that changes in the microbiome were not easily predictable as the severity of future climate scenarios increased. Future ocean conditions can change kelp microbiomes and may lead to host disease, with potentially cascading impacts on associated ecosystems.
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Affiliation(s)
- Zhiguang Qiu
- Centre for Marine Bio-Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Melinda A. Coleman
- Department of Primary Industries, NSW Fisheries, PO Box 4321, Coffs Harbour, New South Wales 2450, Australia
| | - Euan Provost
- National Marine Science Centre, Southern Cross University, Coffs Harbour, New South Wales 2450, Australia
| | - Alexandra H. Campbell
- Centre for Marine Bio-Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
- GeneCology Research Centre, University of the Sunshine Coast, Queensland 4556, Australia
| | - Brendan P. Kelaher
- National Marine Science Centre, Southern Cross University, Coffs Harbour, New South Wales 2450, Australia
| | - Steven J. Dalton
- National Marine Science Centre, Southern Cross University, Coffs Harbour, New South Wales 2450, Australia
- School of Biological Sciences, University of Queensland, St Lucia, Queensland 4072, Australia
| | - Torsten Thomas
- Centre for Marine Bio-Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Peter D. Steinberg
- Centre for Marine Bio-Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
- Sydney Institute of Marine Science, 19 Chowder Bay Road, Mosman, New South Wales 2088, Australia
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, SBS-01N-27, Singapore 637551, Republic of Singapore
| | - Ezequiel M. Marzinelli
- Centre for Marine Bio-Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
- Sydney Institute of Marine Science, 19 Chowder Bay Road, Mosman, New South Wales 2088, Australia
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, 60 Nanyang Drive, SBS-01N-27, Singapore 637551, Republic of Singapore
- School of Life and Environmental Sciences, Coastal and Marine Ecosystems, University of Sydney, Sydney, New South Wales 2006, Australia
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30
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Layton C, Shelamoff V, Cameron MJ, Tatsumi M, Wright JT, Johnson CR. Resilience and stability of kelp forests: The importance of patch dynamics and environment-engineer feedbacks. PLoS One 2019; 14:e0210220. [PMID: 30682047 PMCID: PMC6347235 DOI: 10.1371/journal.pone.0210220] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 12/17/2018] [Indexed: 12/02/2022] Open
Abstract
Habitat forming 'ecosystem engineers' such as kelp species create complex habitats that support biodiverse and productive communities. Studies of the resilience and stability of ecosystem engineers have typically focussed on the role of external factors such as disturbance. However, their population dynamics are also likely to be influenced by internal processes, such that the environmental modifications caused by engineer species feedback to affect their own demography (e.g. recruitment, survivorship). In numerous regions globally, kelp forests are declining and experiencing reductions in patch size and kelp density. To explore how resilience and stability of kelp habitats is influenced by this habitat degradation, we created an array of patch reefs of various sizes and supporting adult Ecklonia radiata kelp transplanted at different densities. This enabled testing of how sub-canopy abiotic conditions change with reductions in patch size and adult kelp density, and how this influenced demographic processes of microscopic and macroscopic juvenile kelp. We found that ecosystem engineering by adult E. radiata modified the environment to reduce sub-canopy water flow, sedimentation, and irradiance. However, the capacity of adult kelp canopy to engineer abiotic change was dependent on patch size, and to a lesser extent, kelp density. Reductions in patch size and kelp density also impaired the recruitment, growth and survivorship of microscopic and macroscopic juvenile E. radiata, and even after the provisioning of established juveniles, demographic processes were impaired in the absence of sufficient adult kelp. These results are consistent with the hypothesis that ecosystem engineering by adult E. radiata facilitates development of juvenile conspecifics. Habitat degradation seems to impair the ability of E. radiata to engineer abiotic change, causing breakdown of positive intraspecific feedback and collapse of demographic functions, and overall, leading to reductions in ecosystem stability and resilience well before local extirpation.
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Affiliation(s)
- Cayne Layton
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Victor Shelamoff
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Matthew J. Cameron
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Masayuki Tatsumi
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Jeffrey T. Wright
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Craig R. Johnson
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
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31
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Epstein G, Smale DA. Between-habitat variability in the population dynamics of a global marine invader may drive management uncertainty. Mar Pollut Bull 2018; 137:488-500. [PMID: 30503460 DOI: 10.1016/j.marpolbul.2018.10.055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 10/17/2018] [Accepted: 10/26/2018] [Indexed: 06/09/2023]
Abstract
Understanding population dynamics of established invasive species is important for designing effective management measures and predicting factors such as invasiveness and ecological impact. The kelp Undaria pinnatifida has spread to most temperate regions of the world, however a basic understanding of population dynamics is lacking for many regions. Here, Undaria was monitored for 2 years, at 9 sites, across 3 habitats to investigate habitat-related variation in population structure, reproductive capacity and morphology. Populations on marina pontoons were distinct from those in reef habitats, with extended recruitment periods and higher abundance, biomass, maturation rates and fecundity; potentially driven by lower inter-specific and higher intra-specific competition within marinas. This suggests that artificial habitats are likely to facilitate the spread, proliferation and reproductive fitness of Undaria across its non-native range. More broadly, generalising population dynamics of invasive species across habitat types is problematic, thus adding high complexity to management options.
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Affiliation(s)
- Graham Epstein
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK; Ocean and Earth Science, University of Southampton, National Oceanography Centre Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK.
| | - Dan A Smale
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK
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32
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González CP, Edding M, Torres R, Manríquez PH. Increased temperature but not pCO 2 levels affect early developmental and reproductive traits of the economically important habitat-forming kelp Lessonia trabeculata. Mar Pollut Bull 2018; 135:694-703. [PMID: 30301088 DOI: 10.1016/j.marpolbul.2018.07.072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 07/23/2018] [Accepted: 07/26/2018] [Indexed: 06/08/2023]
Abstract
The effects of ocean warming and ocean acidification on developmental and reproductive traits of Lessonia trabeculata were evaluated. Meiospores were cultured for 35 days in an experimental mesocosm where temperature (~15 and 19 °C) and partial CO2 pressure (pCO2, ~400 and 1300 μatm) were controlled. The results indicate that germination was reduced at 19 °C, whereas the increase of pCO2 only had effects at 15 °C. Likewise, the increase in temperature significantly affected the vegetative growth of female gametophytes. Sex ratio was not affected significantly by any of the variables studied. Fertility and reproductive success decreased by about 50% at 19 °C. The pCO2 levels had no significant effects on most early developmental traits. The results suggest that ocean warming or periodic warming events (e.g. an El Niño event) might affect the recruiting capacity of this or other similar species by affecting their early developmental stages.
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Affiliation(s)
- Claudio P González
- Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Coquimbo, Chile; Laboratorio de Ecología y Conducta de la Ontogenia Temprana (LECOT), Coquimbo, Chile; Laboratorio de Botánica Marina, Departamento de Biología Marina, Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile
| | - Mario Edding
- Centro de Investigación y Desarrollo Tecnológico en Algas (CIDTA), Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile; Laboratorio de Botánica Marina, Departamento de Biología Marina, Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile
| | - Rodrigo Torres
- Centro de Investigación en Ecosistemas de la Patagonia (CIEP), Coyhaique, Chile; Centro de Investigación: Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Punta Arenas, Chile
| | - Patricio H Manríquez
- Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Coquimbo, Chile; Laboratorio de Ecología y Conducta de la Ontogenia Temprana (LECOT), Coquimbo, Chile.
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Liggan LM, Martone PT. Under pressure: biomechanical limitations of developing pneumatocysts in the bull kelp (Nereocystis luetkeana, Phaeophyceae). J Phycol 2018; 54:608-615. [PMID: 30098020 DOI: 10.1111/jpy.12776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 07/16/2018] [Indexed: 06/08/2023]
Abstract
Maintaining buoyancy with gas-filled floats (pneumatocysts) is essential for some subtidal kelps to achieve an upright stature and compete for light . However, as these kelps grow up through the water column, pneumatocysts are exposed to substantial changes in hydrostatic pressure, which could cause complications as internal gases may expand or contract, potentially causing them to rupture, flood, and lose buoyancy. In this study, we investigate how pneumatocysts of Nereocystis luetkeana resist biomechanical stress and maintain buoyancy as they develop across a hydrostatic gradient. We measured internal pressure, material properties, and pneumatocyst geometry across a range of thallus sizes and collection depths to identify strategies used to resist pressure-induced mechanical failure. Contrary to expectations, all pneumatocysts had internal pressures less than atmospheric pressure, ensuring that thalli are always exposed to a positive pressure gradient and compressional loads, indicating that they are more likely to buckle than rupture at all depths. Small pneumatocysts collected from depths between 1 and 9 m (inner radius = 0.4-1.0 cm) were demonstrated to have elevated wall stresses under high compressive loads and are at greatest risk of buckling. Although small kelps do not adjust pneumatocyst material properties or geometry to reduce wall stress as they grow, they are ~3.4 times stronger than they need to be to resist hydrostatic buckling. When tested, pneumatocysts buckled around 35 m depth, which agrees with previous measures of lower limits due to light attenuation, suggesting that hydrostatic pressure may also define the lower limit of Nereocystis in the field.
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Affiliation(s)
- Lauran M Liggan
- Department of Botany and Beaty Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada, V6T1Z4
- Bamfield Marine Sciences Centre, 100 Pachena Road, Bamfield, British Columbia, Canada, V0R1B0
| | - Patrick T Martone
- Department of Botany and Beaty Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada, V6T1Z4
- Bamfield Marine Sciences Centre, 100 Pachena Road, Bamfield, British Columbia, Canada, V0R1B0
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Yoshino H, Yamaji F, Ohsawa TA. Genetic structure and dispersal patterns in Limnoria nagatai (Limnoriidae, Isopoda) dwelling in non-buoyant kelps, Eisenia bicyclis and E. arborea, in Japan. PLoS One 2018; 13:e0198451. [PMID: 29902241 PMCID: PMC6002018 DOI: 10.1371/journal.pone.0198451] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 05/20/2018] [Indexed: 11/18/2022] Open
Abstract
The marine isopod genus Limnoria contains algae-eating species. Previous phylogeographic studies have suggested that Limnoria species feeding on buoyant kelp underwent low genetic differentiation on a large spatial scale because rafting on floating host kelps promotes high levels of gene flow. In this paper, we survey the genetic structure of Limnoria nagatai, which bores into the non-buoyant kelps Eisenia bicyclis and E. arborea. We analyze the mitochondrial DNA (cytochrome oxidase subunit I [COI] gene) and morphological traits of L. nagatai, and the host kelps E. bicyclis and E. arborea from 14 populations along the Japanese archipelago of the Pacific Ocean and the Sea of Japan. Four major lineages are recognized within L. nagatai: three lineages in the Pacific Ocean, and one lineage in the Sea of Japan which might be a cryptic species. For L. nagatai, we show high genetic differentiation between geographically separated habitats in the Pacific Ocean, while low differentiation is found among continuous host kelps habitats in the Pacific Ocean as well as the Sea of Japan. L. nagatai in E. bicyclis in the Pacific Ocean has experienced large population expansion after the Last Glacial Maximum (LGM), whereas the lineage in E. bicyclis in the Sea of Japan has not. We suggest that Limnoria feeding on non-buoyant kelps, may attain low genetic differentiation because they might be able to disperse long distance if the habitat of host kelps is continuous. The historical events affecting Limnoria after the LGM may differ between the coasts of the Pacific Ocean and the Sea of Japan.
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Affiliation(s)
- Hiroki Yoshino
- Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan
| | - Futa Yamaji
- Department of Biology, Graduate School of Science, Chiba University, Chiba, Japan
| | - Takeshi A. Ohsawa
- Department of Biology, Graduate School of Science, Chiba University, Chiba, Japan
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Waters JM, King TM, Fraser CI, Craw D. Crossing the front: contrasting storm-forced dispersal dynamics revealed by biological, geological and genetic analysis of beach-cast kelp. J R Soc Interface 2018; 15:20180046. [PMID: 29563248 PMCID: PMC5908539 DOI: 10.1098/rsif.2018.0046] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Accepted: 02/27/2018] [Indexed: 11/12/2022] Open
Abstract
The subtropical front (STF) generally represents a substantial oceanographic barrier to dispersal between cold-sub-Antarctic and warm-temperate water masses. Recent studies have suggested that storm events can drastically influence marine dispersal and patterns. Here we analyse biological and geological dispersal driven by two major, contrasting storm events in southern New Zealand, 2017. We integrate biological and physical data to show that a severe southerly system in July 2017 disrupted this barrier by promoting movement of substantial numbers of southern sub-Antarctic Durvillaea kelp rafts across the STF, to make landfall in mainland NZ. By contrast, a less intense easterly storm (Cyclone Cook, April 2017) resulted in more moderate dispersal distances, with minimal dispersal between the sub-Antarctic and mainland New Zealand. These quantitative analyses of approximately 200 freshly beach-cast kelp specimens indicate that storm intensity and wind direction can strongly influence marine dispersal and landfall outcomes.
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Affiliation(s)
- Jonathan M Waters
- Department of Zoology, University of Otago, 340 Great King St, Dunedin 9016, New Zealand
| | - Tania M King
- Department of Zoology, University of Otago, 340 Great King St, Dunedin 9016, New Zealand
| | - Ceridwen I Fraser
- Fenner School of Environment and Society, Australian National University, Building 141 Daley Road, ACT 2601, Australia
| | - Dave Craw
- Department of Geology, University of Otago, 340 Great King St, Dunedin 9016, New Zealand
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Assis J, Araújo MB, Serrão EA. Projected climate changes threaten ancient refugia of kelp forests in the North Atlantic. Glob Chang Biol 2018; 24:e55-e66. [PMID: 28710898 DOI: 10.1111/gcb.13818] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 04/22/2017] [Accepted: 06/25/2017] [Indexed: 05/22/2023]
Abstract
Intraspecific genetic variability is critical for species adaptation and evolution and yet it is generally overlooked in projections of the biological consequences of climate change. We ask whether ongoing climate changes can cause the loss of important gene pools from North Atlantic relict kelp forests that persisted over glacial-interglacial cycles. We use ecological niche modelling to predict genetic diversity hotspots for eight species of large brown algae with different thermal tolerances (Arctic to warm temperate), estimated as regions of persistence throughout the Last Glacial Maximum (20,000 YBP), the warmer Mid-Holocene (6,000 YBP), and the present. Changes in the genetic diversity within ancient refugia were projected for the future (year 2100) under two contrasting climate change scenarios (RCP2.6 and RCP8.5). Models predicted distributions that matched empirical distributions in cross-validation, and identified distinct refugia at the low latitude ranges, which largely coincide among species with similar ecological niches. Transferred models into the future projected polewards expansions and substantial range losses in lower latitudes, where richer gene pools are expected (in Nova Scotia and Iberia for cold affinity species and Gibraltar, Alboran, and Morocco for warm-temperate species). These effects were projected for both scenarios but were intensified under the extreme RCP8.5 scenario, with the complete borealization (circum-Arctic colonization) of kelp forests, the redistribution of the biogeographical transitional zones of the North Atlantic, and the erosion of global gene pools across all species. As the geographic distribution of genetic variability is unknown for most marine species, our results represent a baseline for identification of locations potentially rich in unique phylogeographic lineages that are also climatic relics in threat of disappearing.
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Affiliation(s)
- Jorge Assis
- Center of Marine Sciences, CCMAR-CIMAR, University of Algarve, Faro, Portugal
| | - Miguel B Araújo
- National Museum of Natural Sciences, CSIC, Madrid, Spain
- InBio/CIBIO, University of Évora, Largo dos Colegiais, Évora, Portugal
- Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
| | - Ester A Serrão
- Center of Marine Sciences, CCMAR-CIMAR, University of Algarve, Faro, Portugal
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Dunn RP, Baskett ML, Hovel KA. Interactive effects of predator and prey harvest on ecological resilience of rocky reefs. Ecol Appl 2017; 27:1718-1730. [PMID: 28581670 DOI: 10.1002/eap.1581] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 05/03/2017] [Accepted: 05/16/2017] [Indexed: 06/07/2023]
Abstract
A major goal of ecosystem-based fisheries management is to prevent fishery-induced shifts in community states. This requires an understanding of ecological resilience: the ability of an ecosystem to return to the same state following a perturbation, which can strongly depend on species interactions across trophic levels. We use a structured model of a temperate rocky reef to explore how multi-trophic level fisheries impact ecological resilience. Increasing fishing mortality of prey (urchins) has a minor effect on equilibrium biomass of kelp, urchins, and spiny lobster predators, but increases resilience by reducing the range of predator harvest rates at which alternative stable states are possible. Size-structured predation on urchins acts as the feedback maintaining each state. Our results demonstrate that the resilience of ecosystems strongly depends on the interactive effects of predator and prey harvest in multi-trophic level fisheries, which are common in marine ecosystems but are unaccounted for by traditional management.
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Affiliation(s)
- Robert P Dunn
- Coastal and Marine Institute & Department of Biology, San Diego State University, San Diego, California, 92182, USA
- Department of Environmental Science and Policy, University of California, Davis, Davis, California, 95616, USA
| | - Marissa L Baskett
- Department of Environmental Science and Policy, University of California, Davis, Davis, California, 95616, USA
| | - Kevin A Hovel
- Coastal and Marine Institute & Department of Biology, San Diego State University, San Diego, California, 92182, USA
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Zarco-Perello S, Wernberg T, Langlois TJ, Vanderklift MA. Tropicalization strengthens consumer pressure on habitat-forming seaweeds. Sci Rep 2017; 7:820. [PMID: 28400614 PMCID: PMC5429775 DOI: 10.1038/s41598-017-00991-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 03/17/2017] [Indexed: 11/21/2022] Open
Abstract
Ocean warming is driving species poleward, causing a 'tropicalization' of temperate ecosystems around the world. Increasing abundances of tropical herbivores on temperate reefs could accelerate declines in habitat-forming seaweeds with devastating consequences for these important marine ecosystems. Here we document an expansion of rabbitfish (Siganus fuscescens), a tropical herbivore, on temperate reefs in Western Australia following a marine heatwave and demonstrate their impact on local kelp forests (Ecklonia radiata). Before the heatwave there were no rabbitfish and low rates of kelp herbivory but after the heatwave rabbitfish were common at most reefs and consumption of kelp was high. Herbivory increased 30-fold and kelp abundance decreased by 70% at reefs where rabbitfish had established. In contrast, where rabbitfish were absent, kelp abundance and herbivory did not change. Video-analysis confirmed that rabbitfish were the main consumers of kelp, followed by silver drummers (Kyphosus sydneyanus), a temperate herbivore. These results represent a likely indirect effect of the heatwave beyond its acute impacts, and they provide evidence that range-shifting tropical herbivores can contribute to declines in habitat-forming seaweeds within a few years of their establishment.
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Affiliation(s)
- Salvador Zarco-Perello
- School of Biological Sciences and UWA Oceans Institute, The University of Western Australia, Crawley (Perth), 6009, Western Australia, Australia.
| | - Thomas Wernberg
- School of Biological Sciences and UWA Oceans Institute, The University of Western Australia, Crawley (Perth), 6009, Western Australia, Australia.
| | - Tim J Langlois
- School of Biological Sciences and UWA Oceans Institute, The University of Western Australia, Crawley (Perth), 6009, Western Australia, Australia
| | - Mathew A Vanderklift
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Oceans and Atmosphere Flagship, Indian Ocean Marine Research Centre, Crawley, Western Australia, 6009, Australia
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Assis J, Berecibar E, Claro B, Alberto F, Reed D, Raimondi P, Serrão EA. Major shifts at the range edge of marine forests: the combined effects of climate changes and limited dispersal. Sci Rep 2017; 7:44348. [PMID: 28276501 PMCID: PMC5343584 DOI: 10.1038/srep44348] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 02/08/2017] [Indexed: 11/09/2022] Open
Abstract
Global climate change is likely to constrain low latitude range edges across many taxa and habitats. Such is the case for NE Atlantic marine macroalgal forests, important ecosystems whose main structuring species is the annual kelp Saccorhiza polyschides. We coupled ecological niche modelling with simulations of potential dispersal and delayed development stages to infer the major forces shaping range edges and to predict their dynamics. Models indicated that the southern limit is set by high winter temperatures above the physiological tolerance of overwintering microscopic stages and reduced upwelling during recruitment. The best range predictions were achieved assuming low spatial dispersal (5 km) and delayed stages up to two years (temporal dispersal). Reconstructing distributions through time indicated losses of ~30% from 1986 to 2014, restricting S. polyschides to upwelling regions at the southern edge. Future predictions further restrict populations to a unique refugium in northwestern Iberia. Losses were dependent on the emissions scenario, with the most drastic one shifting ~38% of the current distribution by 2100. Such distributional changes might not be rescued by dispersal in space or time (as shown for the recent past) and are expected to drive major biodiversity loss and changes in ecosystem functioning.
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Affiliation(s)
- J. Assis
- CCMAR, Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
| | - E. Berecibar
- Estrutura de Missão para a Extensão da Plataforma Continental (EMEPC), Rua Costa Pinto 165, 2770-042, Paço de Arcos, Portugal
| | - B. Claro
- CCMAR, Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
| | - F. Alberto
- Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, USA
| | - D. Reed
- Marine Science Institute, University of California, Santa Barbara, California 93106, USA
| | - P. Raimondi
- Department of Biology, University of California, Santa Cruz, California 95064, USA
| | - E. A. Serrão
- CCMAR, Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
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Murúa P, Müller DG, Patiño DJ, Westermeier R. Giant kelp vegetative propagation: Adventitious holdfast elements rejuvenate senescent individuals of the Macrocystis pyrifera "integrifolia" ecomorph. J Phycol 2017; 53:230-234. [PMID: 27878814 DOI: 10.1111/jpy.12493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 10/27/2016] [Indexed: 06/06/2023]
Abstract
Recent findings on holdfast development in the giant kelp highlighted its key importance for Macrocystis vegetative propagation. We report here for the first time the development of adventitious holdfasts from Macrocystis stipes. Swellings emerge spontaneously from different areas of the stipes, especially in senescent or creeping individuals. After being manually fastened to solid substrata, these swellings elongated into haptera, which became strongly attached after 1 month. Within 4 months, new thalli increased in size and vitality, and developed reproductive fronds. Our results suggest the usage of these structures for auxiliary attachment techniques. These could act as a backup, when primary holdfasts are weak, and thus improve the survival rate of the giant kelp in natural beds.
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Affiliation(s)
- Pedro Murúa
- Instituto de Acuicultura, Universidad Austral de Chile, Sede Puerto Montt, PO Box 1327, Puerto Montt, Chile
- Oceanlab, University of Aberdeen, Main Street, Newburgh, AB41 6AA, UK
- The Scottish Association for Marine Science, Scottish Marine Institute, Culture Collection for Algae and Protozoa, Oban, Argyll, PA37 1QA, UK
| | - Dieter G Müller
- Fachbereich Biologie der Universität Konstanz, D-78457, Konstanz, Germany
| | - David J Patiño
- Instituto de Acuicultura, Universidad Austral de Chile, Sede Puerto Montt, PO Box 1327, Puerto Montt, Chile
| | - Renato Westermeier
- Instituto de Acuicultura, Universidad Austral de Chile, Sede Puerto Montt, PO Box 1327, Puerto Montt, Chile
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López BA, Macaya EC, Tala F, Tellier F, Thiel M. The variable routes of rafting: stranding dynamics of floating bull kelp Durvillaea antarctica (Fucales, Phaeophyceae) on beaches in the SE Pacific. J Phycol 2017; 53:70-84. [PMID: 27734500 DOI: 10.1111/jpy.12479] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 09/05/2016] [Indexed: 06/06/2023]
Abstract
Dispersal on floating seaweeds depends on availability, viability, and trajectories of the rafts. In the southern hemisphere, the bull kelp Durvillaea antarctica is one of the most common floating seaweeds, but phylogeographic studies had shown low connectivity between populations from continental Chile, which could be due to limitations in local supply and dispersal of floating kelps. To test this hypothesis, the spatiotemporal dynamics of kelp strandings were examined in four biogeographic districts along the Chilean coast (28°-42°S). We determined the biomass and demography of stranded individuals on 33 beaches for three subsequent years (2013, 2014, 2015) to examine whether rafting is restricted to certain districts and seasons (winter or summer). Stranded kelps were found on all beaches. Most kelps had only one stipe (one individual), although we also frequently found coalesced holdfasts with mature males and females, which would facilitate successful rafting dispersal, gamete release, and reproduction upon arrival. High biomasses of stranded kelps occurred in the northern-central (30°S-33°S) and southernmost districts (37°S-42°S), and lower biomasses in the northernmost (28°S-30°S) and southern-central districts (33°S-37°S). The highest percentages and sizes of epibionts (Lepas spp.), indicative of prolonged floating periods, were found on stranded kelps in the northernmost and southernmost districts. Based on these results, we conclude that rafting dispersal can vary regionally, being more common in the northernmost and southernmost districts, depending on intrinsic (seaweed biology) and extrinsic factors (shore morphology and oceanography) that affect local supply of kelps and regional hydrodynamics.
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Affiliation(s)
- Boris A López
- Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
- Departamento de Acuicultura y Recursos Agroalimentarios, Universidad de Los Lagos, Avenida Fuchslocher 1305, Osorno, Chile
| | - Erasmo C Macaya
- Laboratorio de Estudios Algales (ALGALAB), Departamento de Oceanografía, Universidad de Concepción, Casilla 160-C, Concepción, Chile
- Millennium Nucleus Ecology and Sustainable Management of Oceanic Island (ESMOI), Coquimbo, Chile
- Centro FONDAP de Investigaciones en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Valdivia, Chile
| | - Fadia Tala
- Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
- Centro de Investigación y Desarrollo Tecnológico en Algas (CIDTA), Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
| | - Florence Tellier
- Departamento de Ecología, Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Casilla 297, Concepción, Chile
- Centro de Investigación en Biodiversidad y Ambientes Sustentables (CIBAS), Universidad Católica de la Santísima Concepción, Casilla 297, Concepción, Chile
| | - Martin Thiel
- Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
- Millennium Nucleus Ecology and Sustainable Management of Oceanic Island (ESMOI), Coquimbo, Chile
- Centro de Estudios Avanzados en Zonas Áridas, CEAZA, Coquimbo, Chile
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Braje TJ, Rick TC, Szpak P, Newsome SD, McCain JM, Elliott Smith EA, Glassow M, Hamilton SL. Historical ecology and the conservation of large, hermaphroditic fishes in Pacific Coast kelp forest ecosystems. Sci Adv 2017; 3:e1601759. [PMID: 28164155 PMCID: PMC5287704 DOI: 10.1126/sciadv.1601759] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 12/18/2016] [Indexed: 06/01/2023]
Abstract
The intensive commercial exploitation of California sheephead (Semicossyphus pulcher) has become a complex, multimillion-dollar industry. The fishery is of concern because of high harvest levels and potential indirect impacts of sheephead removals on the structure and function of kelp forest ecosystems. California sheephead are protogynous hermaphrodites that, as predators of sea urchins and other invertebrates, are critical components of kelp forest ecosystems in the northeast Pacific. Overfishing can trigger trophic cascades and widespread ecological dysfunction when other urchin predators are also lost from the system. Little is known about the ecology and abundance of sheephead before commercial exploitation. Lack of a historical perspective creates a gap for evaluating fisheries management measures and marine reserves that seek to rebuild sheephead populations to historical baseline conditions. We use population abundance and size structure data from the zooarchaeological record, in concert with isotopic data, to evaluate the long-term health and viability of sheephead fisheries in southern California. Our results indicate that the importance of sheephead to the diet of native Chumash people varied spatially across the Channel Islands, reflecting modern biogeographic patterns. Comparing ancient (~10,000 calibrated years before the present to 1825 CE) and modern samples, we observed variability and significant declines in the relative abundance of sheephead, reductions in size frequency distributions, and shifts in the dietary niche between ancient and modern collections. These results highlight how size-selective fishing can alter the ecological role of key predators and how zooarchaeological data can inform fisheries management by establishing historical baselines that aid future conservation.
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Affiliation(s)
- Todd J. Braje
- Department of Anthropology, San Diego State University, San Diego, CA 92182–6040, USA
| | - Torben C. Rick
- Program in Human Ecology and Archaeobiology, Department of Anthropology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013–7012, USA
| | - Paul Szpak
- Department of Anthropology, Trent University, Peterborough, Ontario K9L 0G2, Canada
| | - Seth D. Newsome
- Department of Biology, University of New Mexico, Albuquerque, NM 87131–0001, USA
| | - Joseph M. McCain
- Department of Anthropology, San Diego State University, San Diego, CA 92182–6040, USA
| | | | - Michael Glassow
- Department of Anthropology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Scott L. Hamilton
- Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, CA 95039, USA
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Krause-Jensen D, Marbà N, Sanz-Martin M, Hendriks IE, Thyrring J, Carstensen J, Sejr MK, Duarte CM. Long photoperiods sustain high pH in Arctic kelp forests. Sci Adv 2016; 2:e1501938. [PMID: 27990490 PMCID: PMC5156516 DOI: 10.1126/sciadv.1501938] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 10/29/2016] [Indexed: 05/11/2023]
Abstract
Concern on the impacts of ocean acidification on calcifiers, such as bivalves, sea urchins, and foraminifers, has led to efforts to understand the controls on pH in their habitats, which include kelp forests and seagrass meadows. The metabolism of these habitats can lead to diel fluctuation in pH with increases during the day and declines at night, suggesting no net effect on pH at time scales longer than daily. We examined the capacity of subarctic and Arctic kelps to up-regulate pH in situ and experimentally tested the role of photoperiod in determining the capacity of Arctic macrophytes to up-regulate pH. Field observations at photoperiods of 15 and 24 hours in Greenland combined with experimental manipulations of photoperiod show that photoperiods longer than 21 hours, characteristic of Arctic summers, are conducive to sustained up-regulation of pH by kelp photosynthesis. We report a gradual increase in pH of 0.15 units and a parallel decline in pCO2 of 100 parts per million over a 10-day period in an Arctic kelp forest over midsummer, with ample scope for continued pH increase during the months of continuous daylight. Experimental increase in CO2 concentration further stimulated the capacity of macrophytes to deplete CO2 and increase pH. We conclude that long photoperiods in Arctic summers support sustained up-regulation of pH in kelp forests, with potential benefits for calcifiers, and propose that this mechanism may increase with the projected expansion of Arctic vegetation in response to warming and loss of sea ice.
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Affiliation(s)
- Dorte Krause-Jensen
- Arctic Research Centre, Aarhus University, Ny Munkegade 114, Building 1540, 8000 Århus C, Denmark
- Department of Bioscience, Aarhus University, Vejlsøvej 25, DK-8600 Silkeborg, Denmark
| | - Núria Marbà
- Department of Global Change Research, Institut Mediterrani d’Estudis Avançats (Consejo Superior de Investigaciones Científicas–Universidad de las Islas Baleares), Miquel Marquès 21, 07190 Esporles, Spain
| | - Marina Sanz-Martin
- Department of Global Change Research, Institut Mediterrani d’Estudis Avançats (Consejo Superior de Investigaciones Científicas–Universidad de las Islas Baleares), Miquel Marquès 21, 07190 Esporles, Spain
- Facultat de Geologia, Universitat de Barcelona, 08028 Barcelona, Spain
| | - Iris E. Hendriks
- Department of Global Change Research, Institut Mediterrani d’Estudis Avançats (Consejo Superior de Investigaciones Científicas–Universidad de las Islas Baleares), Miquel Marquès 21, 07190 Esporles, Spain
| | - Jakob Thyrring
- Arctic Research Centre, Aarhus University, Ny Munkegade 114, Building 1540, 8000 Århus C, Denmark
- Department of Bioscience, Aarhus University, Vejlsøvej 25, DK-8600 Silkeborg, Denmark
| | - Jacob Carstensen
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, DK-4000 Roskilde, Denmark
| | - Mikael Kristian Sejr
- Arctic Research Centre, Aarhus University, Ny Munkegade 114, Building 1540, 8000 Århus C, Denmark
- Department of Bioscience, Aarhus University, Vejlsøvej 25, DK-8600 Silkeborg, Denmark
| | - Carlos M. Duarte
- King Abdullah University of Science and Technology, Red Sea Research Center, Thuwal 23955-6900, Kingdom of Saudi Arabia
- Faculty of Biosciences, Fisheries and Economics, University of Tromsø, Tromsø, Norway
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Starko S, Martone PT. An empirical test of 'universal' biomass scaling relationships in kelps: evidence of convergence with seed plants. New Phytol 2016; 212:719-729. [PMID: 27479188 DOI: 10.1111/nph.14120] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 06/16/2016] [Indexed: 06/06/2023]
Abstract
Biomass allocation patterns have received substantial consideration, leading to the recognition of several 'universal' interspecific trends. Despite efforts to understand biomass partitioning among embryophytes, few studies have examined macroalgae that evolved independently, yet function ecologically in much the same ways as plants. Kelps allocate photosynthate among three organs (the blade(s), stipe(s) and holdfast) that are superficially convergent with organs of land plants, providing a unique opportunity to test the limits of 'universal' trends. In this study, we used an allometric approach to quantify interspecific biomass partitioning patterns in kelps and assess whether embryophyte-based predictions of biomass scaling can be applied to marine macrophytes that lack root-to-leaf hydraulic transport. Photosynthetic area and dry mass were found to scale to approximately the ¾ power and kelp biomass allocation patterns were shown to match closely to empirical measures of allometric scaling among woody plants. Larger kelp species were found to have increased relative stipe and holdfast mass than smaller species, highlighting important consequences of size for marine macroalgae. Our study provides insights into the evolution of size in the largest marine macrophytes and corroborates previous work suggesting that the morphology of divergent lineages of photoautotrophs may reflect similar selective pressures.
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Affiliation(s)
- Samuel Starko
- Department of Botany and Beaty Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada.
- Bamfield Marine Sciences Centre, 100 Pachena Rd, Bamfield, BC, V0R 1B0, Canada.
- Hakai Institute, Pruth Harbour, Calvert Island, BC, V0P 1H0, Canada.
| | - Patrick T Martone
- Department of Botany and Beaty Biodiversity Research Centre, The University of British Columbia, 6270 University Blvd, Vancouver, BC, V6T 1Z4, Canada
- Bamfield Marine Sciences Centre, 100 Pachena Rd, Bamfield, BC, V0R 1B0, Canada
- Hakai Institute, Pruth Harbour, Calvert Island, BC, V0P 1H0, Canada
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Knoblauch J, Tepler Drobnitch S, Peters WS, Knoblauch M. In situ microscopy reveals reversible cell wall swelling in kelp sieve tubes: one mechanism for turgor generation and flow control? Plant Cell Environ 2016; 39:1727-36. [PMID: 26991892 DOI: 10.1111/pce.12736] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 03/01/2016] [Accepted: 03/03/2016] [Indexed: 06/05/2023]
Abstract
Kelps, brown algae (Phaeophyceae) of the order Laminariales, possess sieve tubes for the symplasmic long-distance transport of photoassimilates that are evolutionarily unrelated but structurally similar to the tubes in the phloem of vascular plants. We visualized sieve tube structure and wound responses in fully functional, intact Bull Kelp (Nereocystis luetkeana [K. Mertens] Postels & Ruprecht 1840). In injured tubes, apparent slime plugs formed but were unlikely to cause sieve tube occlusion as they assembled at the downstream side of sieve plates. Cell walls expanded massively in the radial direction, reducing the volume of the wounded sieve elements by up to 90%. Ultrastructural examination showed that a layer of the immediate cell wall characterized by circumferential cellulose fibrils was responsible for swelling and suggested that alginates, abundant gelatinous polymers of the cell wall matrix, were involved. Wall swelling was rapid, reversible and depended on intracellular pressure, as demonstrated by pressure-injection of silicon oil. Our results revive the concept of turgor generation and buffering by swelling cell walls, which had fallen into oblivion over the last century. Because sieve tube transport is pressure-driven and controlled physically by tube diameter, a regulatory role of wall swelling in photoassimilate distribution is implied in kelps.
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Affiliation(s)
- Jan Knoblauch
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Sarah Tepler Drobnitch
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, 95060, USA
| | - Winfried S Peters
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Michael Knoblauch
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
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Wernberg T, Bennett S, Babcock RC, de Bettignies T, Cure K, Depczynski M, Dufois F, Fromont J, Fulton CJ, Hovey RK, Harvey ES, Holmes TH, Kendrick GA, Radford B, Santana-Garcon J, Saunders BJ, Smale DA, Thomsen MS, Tuckett CA, Tuya F, Vanderklift MA, Wilson S. Climate-driven regime shift of a temperate marine ecosystem. Science 2016; 353:169-72. [PMID: 27387951 DOI: 10.1126/science.aad8745] [Citation(s) in RCA: 435] [Impact Index Per Article: 54.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 05/31/2016] [Indexed: 01/10/2024]
Abstract
Ecosystem reconfigurations arising from climate-driven changes in species distributions are expected to have profound ecological, social, and economic implications. Here we reveal a rapid climate-driven regime shift of Australian temperate reef communities, which lost their defining kelp forests and became dominated by persistent seaweed turfs. After decades of ocean warming, extreme marine heat waves forced a 100-kilometer range contraction of extensive kelp forests and saw temperate species replaced by seaweeds, invertebrates, corals, and fishes characteristic of subtropical and tropical waters. This community-wide tropicalization fundamentally altered key ecological processes, suppressing the recovery of kelp forests.
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Affiliation(s)
- Thomas Wernberg
- School of Plant Biology and Oceans Institute, The University of Western Australia, 39 Fairway, Crawley, Western Australia 6009, Australia.
| | - Scott Bennett
- School of Plant Biology and Oceans Institute, The University of Western Australia, 39 Fairway, Crawley, Western Australia 6009, Australia. Department of Environment and Agriculture, School of Science, Curtin University, Bentley, Western Australia 6102, Australia. Department of Global Change Research, Institut Mediterrani d'Estudis Avançats (Universitat de les Illes Balears - Consejo Superior de Investigaciones Científicas), Esporles, Spain
| | - Russell C Babcock
- School of Plant Biology and Oceans Institute, The University of Western Australia, 39 Fairway, Crawley, Western Australia 6009, Australia. Commonwealth Scientific and Industrial Research Organisation (CSIRO) Oceans and Atmosphere, General Post Office Box 2583, Brisbane, Queensland 4001, Australia
| | - Thibaut de Bettignies
- School of Plant Biology and Oceans Institute, The University of Western Australia, 39 Fairway, Crawley, Western Australia 6009, Australia. Service du Patrimoine Naturel, Muséum National d'Histoire Naturelle, 36 Rue Geoffroy Saint-Hilaire CP41, Paris 75005, France
| | - Katherine Cure
- School of Plant Biology and Oceans Institute, The University of Western Australia, 39 Fairway, Crawley, Western Australia 6009, Australia. Australian Institute of Marine Science, 39 Fairway, Crawley, Western Australia 6009, Australia
| | - Martial Depczynski
- Australian Institute of Marine Science, 39 Fairway, Crawley, Western Australia 6009, Australia
| | - Francois Dufois
- CSIRO Oceans and Atmosphere Flagship, Private Bag 5, Wembley, Western Australia 6913, Australia
| | - Jane Fromont
- Western Australian Museum, Locked Bag 49, Welshpool DC, Western Australia 6986, Australia
| | - Christopher J Fulton
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | - Renae K Hovey
- School of Plant Biology and Oceans Institute, The University of Western Australia, 39 Fairway, Crawley, Western Australia 6009, Australia
| | - Euan S Harvey
- Department of Environment and Agriculture, School of Science, Curtin University, Bentley, Western Australia 6102, Australia
| | - Thomas H Holmes
- School of Plant Biology and Oceans Institute, The University of Western Australia, 39 Fairway, Crawley, Western Australia 6009, Australia. Marine Science Program, Science Division, Department of Parks and Wildlife, Kensington, Western Australia 6151, Australia
| | - Gary A Kendrick
- School of Plant Biology and Oceans Institute, The University of Western Australia, 39 Fairway, Crawley, Western Australia 6009, Australia
| | - Ben Radford
- Australian Institute of Marine Science, 39 Fairway, Crawley, Western Australia 6009, Australia. School of Geography and Environmental Science, The University of Western Australia, 39 Fairway, Crawley, Western Australia 6009, Australia
| | - Julia Santana-Garcon
- School of Plant Biology and Oceans Institute, The University of Western Australia, 39 Fairway, Crawley, Western Australia 6009, Australia. Department of Environment and Agriculture, School of Science, Curtin University, Bentley, Western Australia 6102, Australia. Department of Global Change Research, Institut Mediterrani d'Estudis Avançats (Universitat de les Illes Balears - Consejo Superior de Investigaciones Científicas), Esporles, Spain
| | - Benjamin J Saunders
- Department of Environment and Agriculture, School of Science, Curtin University, Bentley, Western Australia 6102, Australia
| | - Dan A Smale
- School of Plant Biology and Oceans Institute, The University of Western Australia, 39 Fairway, Crawley, Western Australia 6009, Australia. School of Geography and Environmental Science, The University of Western Australia, 39 Fairway, Crawley, Western Australia 6009, Australia
| | - Mads S Thomsen
- School of Plant Biology and Oceans Institute, The University of Western Australia, 39 Fairway, Crawley, Western Australia 6009, Australia. Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth PL1 2PB, UK
| | - Chenae A Tuckett
- School of Plant Biology and Oceans Institute, The University of Western Australia, 39 Fairway, Crawley, Western Australia 6009, Australia
| | - Fernando Tuya
- Marine Ecology Group, School of Biological Sciences, The University of Canterbury, Private Bag 4800, Christchurch, New Zealand
| | - Mathew A Vanderklift
- CSIRO Oceans and Atmosphere Flagship, Private Bag 5, Wembley, Western Australia 6913, Australia
| | - Shaun Wilson
- School of Plant Biology and Oceans Institute, The University of Western Australia, 39 Fairway, Crawley, Western Australia 6009, Australia. Marine Science Program, Science Division, Department of Parks and Wildlife, Kensington, Western Australia 6151, Australia
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Koch K, Thiel M, Hagen W, Graeve M, Gómez I, Jofre D, Hofmann LC, Tala F, Bischof K. Short- and long-term acclimation patterns of the giant kelp Macrocystis pyrifera (Laminariales, Phaeophyceae) along a depth gradient. J Phycol 2016; 52:260-73. [PMID: 27037591 DOI: 10.1111/jpy.12394] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 01/11/2016] [Indexed: 06/05/2023]
Abstract
The giant kelp, Macrocystis pyrifera, is exposed to highly variable irradiance and temperature regimes across its geographic and vertical depth gradients. The objective of this study was to extend our understanding of algal acclimation strategies on different temporal scales to those varying abiotic conditions at various water depths. Different acclimation strategies to various water depths (0.2 and 4 m) between different sampling times (Jan/Feb and Aug/Sept 2012; long-term acclimation) and more rapid adjustments to different depths (0.2, 2 and 4 m; short-term acclimation) during 14 d of transplantation were found. Adjustments of variable Chl a fluorescence, pigment composition (Chl c, fucoxanthin), and the de-epoxidation state of the xanthophyll cycle pigments were responsible for the development of different physiological states with respect to various solar radiation and temperature climates. Interestingly, the results indicated that phlorotannins are important during long-term acclimation while antioxidants have a crucial role during short-term acclimation. Furthermore, the results suggested that modifications in total lipids and fatty acid compositions apparently also might play a role in depth acclimation. In Aug/Sept (austral winter), M. pyrifera responded to the transplantation from 4 m to 0.2 m depth with a rise in the degree of saturation and a switch from shorter- to longer-chain fatty acids. These changes seem to be essential for the readjustment of thylakoid membranes and might, thus, facilitate efficient photosynthesis under changing irradiances and temperatures. Further experiments are needed to disentangle the relative contribution of solar radiation, temperature and also other abiotic parameters in the observed physiological changes.
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Affiliation(s)
- Kristina Koch
- Marine Botany and Bremen Marine Ecology - Center for Research and Education (BreMarE), University of Bremen, Leobener Str. NW2, 28359, Bremen, Germany
| | - Martin Thiel
- Facultad de Ciencias del Mar, Universidad Católica del Norte and Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Larrondo 1281, Coquimbo, Chile
- Nucleus Ecology and Sustainable Management of Oceanic Island (ESMOI), Coquimbo, Chile
| | - Wilhelm Hagen
- Marine Zoology and Bremen Marine Ecology - Center for Research and Education (BreMarE), University of Bremen, Leobener Str. NW2, Bremen, 28359, Germany
| | - Martin Graeve
- Ecological Chemistry, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI), Am Handelshafen 12, Bremerhaven, 27570, Germany
| | - Iván Gómez
- Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Casilla 567, Valdivia, Chile
| | - David Jofre
- Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile
| | - Laurie C Hofmann
- Marine Botany and Bremen Marine Ecology - Center for Research and Education (BreMarE), University of Bremen, Leobener Str. NW2, 28359, Bremen, Germany
- Max Planck Institute for Marine Microbiology, Celsiusstr. 1, Bremen, 28359, Germany
| | - Fadia Tala
- Facultad de Ciencias del Mar, Universidad Católica del Norte and Centro de Investigación y Desarrollo Tecnológico en Algas (CIDTA), Larrondo 1281, Coquimbo, Chile
| | - Kai Bischof
- Marine Botany and Bremen Marine Ecology - Center for Research and Education (BreMarE), University of Bremen, Leobener Str. NW2, 28359, Bremen, Germany
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Starko S, Martone PT. Evidence of an evolutionary-developmental trade-off between drag avoidance and tolerance strategies in wave-swept intertidal kelps (Laminariales, Phaeophyceae). J Phycol 2016; 52:54-63. [PMID: 26987088 DOI: 10.1111/jpy.12368] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 10/13/2015] [Indexed: 06/05/2023]
Abstract
Kelps are a clade of morphologically diverse, ecologically important habitat-forming species. Many kelps live in wave-swept environments and are exposed to chronic flow-induced stress. In order to grow and survive in these harsh environments, kelps can streamline (reducing drag coefficient) to avoid drag or to increase attachment and breakage force to tolerate it. We aimed to quantify the drag tolerance and streamlining strategies of kelps from wave-swept intertidal habitats. We measured drag coefficient and tenacity of populations from eight kelp species over a wide range of sizes to determine whether kelps avoid dislodgement by reducing drag coefficient or by increasing tenacity as they grow, and whether these traits are traded off. We employed phylogenetic comparative methods to rule out potentially confounding effects of species' relatedness. There was a significant negative relationship between drag avoidance and tolerance strategies, even after incorporating phylogeny. Kelps that were more tenacious were less able to reduce drag, resulting in a continuum from "tolerators" to "streamliners," with some species demonstrating intermediate, mixed strategies. Drag and tenacity were correlated with geometric properties (i.e., second moment of area) of the stipe in large kelps. Results presented in this study suggest that kelps are either strong or streamlined, but not both. This continuum is consistent with avoidance and tolerance trade-offs that have been documented in many different biological systems and may have widespread implications for the evolution of large macroalgae, perhaps driving morphological diversity within this group.
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Affiliation(s)
- Samuel Starko
- Department of Botany and Beaty Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada, V6T1Z4
- Bamfield Marine Sciences Centre, 100 Pachena Road, Bamfield, British Columbia, Canada
| | - Patrick T Martone
- Department of Botany and Beaty Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada, V6T1Z4
- Bamfield Marine Sciences Centre, 100 Pachena Road, Bamfield, British Columbia, Canada
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50
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Abstract
The marine marbled rockfish Sebastiscus marmoratus is dependent on kelp beds and rocks for survival and reproduction. We found that sound production and hearing sensitivity in S. marmoratus are closely matched in the frequency domain. We also found that the juvenile rockfish prefers the habitat of the larger macroalgae Sargassum horueri rather than the habitat containing the smaller algae Ulva pertusa where the adult rockfish prefers to live. Our underwater noise recording data from these two habitats indicate that their spectra of the background noise have different values. The results suggest that the acoustic cues may be critical for pelagic larvae when selecting the preferential habitat in which to settle.
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Affiliation(s)
- Xuguang Zhang
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, 999 HuchengHuan Road, Lingang, Pudong New District, 201306, Shanghai, China.
- Institute for Marine Biosystem and Neuroscience, Shanghai Ocean University, 999 HuchengHuan Road, Lingang, Pudong New District, 201306, Shanghai, China.
- International Center for Marine Studies, Shanghai Ocean University, 999 HuchengHuan Road, Lingang, Pudong New District, 201306, Shanghai, China.
| | - Hongy Guo
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, 999 HuchengHuan Road, Lingang, Pudong New District, 201306, Shanghai, China.
- Institute for Marine Biosystem and Neuroscience, Shanghai Ocean University, 999 HuchengHuan Road, Lingang, Pudong New District, 201306, Shanghai, China.
- International Center for Marine Studies, Shanghai Ocean University, 999 HuchengHuan Road, Lingang, Pudong New District, 201306, Shanghai, China.
| | - Zhenhua Wang
- College of Marine Sciences, Shanghai Ocean University, 201306, Shanghai, China.
| | - Yingjie Pan
- International Center for Marine Studies, Shanghai Ocean University, 999 HuchengHuan Road, Lingang, Pudong New District, 201306, Shanghai, China.
| | - Jiakun Song
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Education, 999 HuchengHuan Road, Lingang, Pudong New District, 201306, Shanghai, China.
- Institute for Marine Biosystem and Neuroscience, Shanghai Ocean University, 999 HuchengHuan Road, Lingang, Pudong New District, 201306, Shanghai, China.
- International Center for Marine Studies, Shanghai Ocean University, 999 HuchengHuan Road, Lingang, Pudong New District, 201306, Shanghai, China.
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