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Pessarrodona A, Grimaldi CM. On the ecology of Cystophora spp. forests. JOURNAL OF PHYCOLOGY 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] [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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2
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Liu OR, Gaines SD. Environmental context dependency in species interactions. Proc Natl Acad Sci U S A 2022; 119:e2118539119. [PMID: 36037344 PMCID: PMC9457591 DOI: 10.1073/pnas.2118539119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 07/17/2022] [Indexed: 11/28/2022] Open
Abstract
Ecological interactions are not uniform across time and can vary with environmental conditions. Yet, interactions among species are often measured with short-term controlled experiments whose outcomes can depend greatly on the particular environmental conditions under which they are performed. As an alternative, we use empirical dynamic modeling to estimate species interactions across a wide range of environmental conditions directly from existing long-term monitoring data. In our case study from a southern California kelp forest, we test whether interactions between multiple kelp and sea urchin species can be reliably reconstructed from time-series data and whether those interactions vary predictably in strength and direction across observed fluctuations in temperature, disturbance, and low-frequency oceanographic regimes. We show that environmental context greatly alters the strength and direction of species interactions. In particular, the state of the North Pacific Gyre Oscillation seems to drive the competitive balance between kelp species, asserting bottom-up control on kelp ecosystem dynamics. We show the importance of specifically studying variation in interaction strength, rather than mean interaction outcomes, when trying to understand the dynamics of complex ecosystems. The significant context dependency in species interactions found in this study argues for a greater utilization of long-term data and empirical dynamic modeling in studies of the dynamics of other ecosystems.
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Affiliation(s)
- Owen R. Liu
- Bren School of Environmental Science and Management, University of California, Santa Barbara, CA, 93106
| | - Steven D. Gaines
- Bren School of Environmental Science and Management, University of California, Santa Barbara, CA, 93106
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3
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Castorani MCN, Bell TW, Walter JA, Reuman D, Cavanaugh KC, Sheppard LW. Disturbance and nutrients synchronise kelp forests across scales through interacting Moran effects. Ecol Lett 2022; 25:1854-1868. [PMID: 35771209 PMCID: PMC9541195 DOI: 10.1111/ele.14066] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/20/2022] [Accepted: 06/02/2022] [Indexed: 11/30/2022]
Abstract
Spatial synchrony is a ubiquitous and important feature of population dynamics, but many aspects of this phenomenon are not well understood. In particular, it is largely unknown how multiple environmental drivers interact to determine synchrony via Moran effects, and how these impacts vary across spatial and temporal scales. Using new wavelet statistical techniques, we characterised synchrony in populations of giant kelp Macrocystis pyrifera, a widely distributed marine foundation species, and related synchrony to variation in oceanographic conditions across 33 years (1987-2019) and >900 km of coastline in California, USA. We discovered that disturbance (storm-driven waves) and resources (seawater nutrients)-underpinned by climatic variability-act individually and interactively to produce synchrony in giant kelp across geography and timescales. Our findings demonstrate that understanding and predicting synchrony, and thus the regional stability of populations, relies on resolving the synergistic and antagonistic Moran effects of multiple environmental drivers acting on different timescales.
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Affiliation(s)
- Max C. N. Castorani
- Department of Environmental SciencesUniversity of VirginiaCharlottesvilleVirginiaUSA
| | - Tom W. Bell
- Department of Applied Ocean Physics & EngineeringWoods Hole Oceanographic InstitutionWoods HoleMassachusettsUSA
- Earth Research InstituteUniversity of CaliforniaSanta BarbaraCaliforniaUSA
| | - Jonathan A. Walter
- Department of Environmental SciencesUniversity of VirginiaCharlottesvilleVirginiaUSA
| | - Daniel C. Reuman
- Department of Ecology and Evolutionary BiologyUniversity of KansasLawrenceKansasUSA
- Center for Ecological ResearchUniversity of KansasLawrenceKansasUSA
- Laboratory of PopulationsRockefeller UniversityNew YorkNew YorkUSA
| | - Kyle C. Cavanaugh
- Department of GeographyUniversity of CaliforniaLos AngelesCaliforniaUSA
| | - Lawrence W. Sheppard
- Department of Ecology and Evolutionary BiologyUniversity of KansasLawrenceKansasUSA
- Marine Biological Association of the United KingdomPlymouthUK
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4
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Effects of seawater temperature and seasonal irradiance on growth, reproduction, and survival of the endemic Antarctic brown alga Desmarestia menziesii (Phaeophyceae). Polar Biol 2022. [DOI: 10.1007/s00300-021-02991-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AbstractEndemic Antarctic macroalgae are especially adapted to live in extreme Antarctic conditions. Their potential biogeographic distribution niche is primarily controlled by the photoperiodic regime and seawater temperatures, since these parameters regulate growth, reproduction, and survival during the entire life cycle. Here we analyzed the upper survival temperature (UST) of juvenile sporophytes and the temperature range for sporophyte formation from gametophytes of Desmarestia menziesii, one of the dominant endemic Antarctic brown algal species. This process is a missing link to better evaluate the full biogeographical niche of this species. Two laboratory experiments were conducted. First, growth and maximum quantum yield of juvenile sporophytes were analyzed under a temperature gradient (0, 5, 10, 12, 13, 14, 15, and 16 °C) in a 16:8 h light:dark (LD) regime (Antarctic spring condition) for 2 weeks. Second, the formation of sporophytes from gametophytes (as a proxy of gametophyte reproduction) was evaluated during a 7 weeks period under a temperature gradient (0, 4, 8, 12, and 16 °C), and two different photoperiods: 6:18 h LD regime simulating winter conditions and a light regime simulating the Antarctic shift from winter to spring by gradually increasing the light period from 7.5:16.5 h LD (late winter) to 18.5:5.5 h LD (late spring). Sporophytes of D. menziesii were able to grow and survive up to 14 °C for 2 weeks without visible signs of morphological damage. Thus, this species shows the highest UST of all endemic Antarctic Desmarestiales species. In turn, gametophyte reproduction solely took place at 0 °C but not at 4–8 °C. The number of emerging sporophytes was six times higher under the light regime simulating the transition from winter to spring than under constant short day winter conditions. There was a negative relationship between the number of sporophytes formed and the gametophyte density at the beginning of the experiment, which provides evidence that gametophyte density exerts some control upon reproduction in D. menziesii. Results strongly indicate that although sporophytes and gametophytes may survive in warmer temperatures, the northernmost distribution limit of D. menziesii in South Georgia Islands is set by the low temperature requirements for gametophyte reproduction. Hence, global warming could have an impact on the distribution of this and other Antarctic species, by influencing their growth and reproduction.
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5
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Spiecker BJ, Menge BA. El Niño and marine heatwaves: Ecological impacts on Oregon rocky intertidal kelp communities at local to regional scales. ECOL MONOGR 2022. [DOI: 10.1002/ecm.1504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Bruce A. Menge
- Department of Integrative Biology Oregon State University Corvallis OR USA
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6
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Castorani MCN, Harrer SL, Miller RJ, Reed DC. Disturbance structures canopy and understory productivity along an environmental gradient. Ecol Lett 2021; 24:2192-2206. [PMID: 34339096 PMCID: PMC8518717 DOI: 10.1111/ele.13849] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 04/13/2021] [Accepted: 06/29/2021] [Indexed: 01/31/2023]
Abstract
Disturbances often disproportionately impact different vegetation layers in forests and other vertically stratified ecosystems, shaping community structure and ecosystem function. However, disturbance-driven changes may be mediated by environmental conditions that affect habitat quality and species interactions. In a decade-long field experiment, we tested how kelp forest net primary productivity (NPP) responds to repeated canopy loss along a gradient in grazing and substrate suitability. We discovered that habitat quality can mediate the effects of intensified disturbance on canopy and understory NPP. Experimental annual and quarterly disturbances suppressed total macroalgal NPP, but effects were strongest in high-quality habitats that supported dense kelp canopies that were removed by disturbance. Understory macroalgae partly compensated for canopy NPP losses and this effect magnified with increasing habitat quality. Disturbance-driven increases in understory NPP were still rising after 5-10 years of disturbance, demonstrating the value of long-term experimentation for understanding ecosystem responses to changing disturbance regimes.
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Affiliation(s)
- Max C. N. Castorani
- Department of Environmental SciencesUniversity of VirginiaCharlottesvilleVAUSA
| | | | - Robert J. Miller
- Marine Science InstituteUniversity of CaliforniaSanta BarbaraCAUSA
| | - Daniel C. Reed
- Marine Science InstituteUniversity of CaliforniaSanta BarbaraCAUSA
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7
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Yan J, Zhu Z, Zhou J, Chu X, Sui H, Cui B, van der Heide T. Saltmarsh resilience controlled by patch size and plant density of habitat-forming species that trap shells. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 778:146119. [PMID: 33725609 DOI: 10.1016/j.scitotenv.2021.146119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 02/10/2021] [Accepted: 02/23/2021] [Indexed: 06/12/2023]
Abstract
Habitat fragmentaion into small patches is regarded as a vital cause of biodiversity loss. Fragmentationof habitat-forming species is especially harmful, as patchiness of such species often controls ecosystem stability and resilience by density and patch size-dependent self-reinforcing feedbacks. Although fragmentation are expected to weaken or even break such feedbacks, it remains unclear how the resulting patchiness of habitat-forming species affect ecosystem resilience to environmental stresses. Here, using Spartian alterniflora, the habitat-forming species in saltmarshes as a model, we investigate how patch size, plant density, and shell aggregation interactively control the persistence of a degrading salt marsh that suffered from erosion induced by hydrodynamics. Our results demonstrate that large patches can trap more shells along the patch edge than the smaller ones, therefore significantly facilitating plant re-growth within the patch. Shell removal experiments further reveal that large patches trapping more shells along patch edges reinforce their own persistence by decreasing erosion and thus facilitating plant recovery. By contrast, small patches with lesser plants cannot persist as they trap less shells along patch edges but are able to accumulate more shells at interior locations where they hinder plant re-growth, indicating a critical threshold of patch size ~20 m2 below which ecosystem collapses. The current study highlights the importance to identify critical threshold of stress-resistant patch sizes in transition-prone ecosystems as early-warning to alert undesired ecosystem collapse and restoration practice.
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Affiliation(s)
- Jiaguo Yan
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing, China; Department of Estuarine and Delta Systems, NIOZ Royal Netherlands Institute for Sea Research, and Utrecht University, Yerseke, the Netherlands
| | - Zhenchang Zhu
- Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou 511458, China; Guangdong Provincial Key Laboratory of Water Quality Improvement and Ecological Restoration for Watersheds, Institute of Environmental and Ecological Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Jie Zhou
- Beijing Water Engineering Construction and Management Affairs Center, Beijing, China
| | - Xun Chu
- Beijing Guohuan Tsinghua Environmental Engineering Design & Research Institute Co., Ltd, China
| | - Haochen Sui
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing, China
| | - Baoshan Cui
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing, China.
| | - Tjisse van der Heide
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, Den Burg, Texel, the Netherlands; Conservation Ecology Group, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, the Netherlands
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8
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Lewis RD, Johnson CR, Wright JT. Demography of the Intertidal Fucoid Hormosira banksii: Importance of Recruitment to Local Abundance. JOURNAL OF PHYCOLOGY 2021; 57:664-676. [PMID: 33406291 DOI: 10.1111/jpy.13124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 12/07/2020] [Accepted: 12/08/2020] [Indexed: 06/12/2023]
Abstract
Canopy-forming macroalgae form the basis of diverse coastal ecosystems globally. The fucoid Hormosira banksii is often the dominant canopy-forming macroalga in the temperate intertidal of southern Australia and New Zealand, where it is commonly associated with an understory of coralline turf. Hormosira banksii is susceptible to both natural and anthropogenic disturbance and despite its abundance, few studies have examined the demography of this important species. This study determined the demographic response of H. banksii to different gradients of disturbance to both its canopy and to the understory coralline turf. We established plots in which the density of H. banksii and/or understory coralline turf was manipulated in a pulse perturbation to simulate a disturbance event. The manipulated plots contained eight treatments ranging from 100% removal of H. banksii to 100% removal of the understory coralline turf. We then measured recruitment and followed individual recruits for up to 18 months to determine growth and survivorship. We found that H. banksii recruitment was seasonally variable throughout the experiment and highest over summer, survivorship of recruits was generally high, and the species was slow-growing and long-lived. Moreover, the level of disturbance did not seem to affect recruitment, growth, or survivorship and post-recruitment mortality was independent of H. banksii density. In this system, it appears that H. banksii is a relatively long-lived perennial species whose demography is density-independent which appears to allow recovery from disturbance.
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Affiliation(s)
- Ryan D Lewis
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Private Bag 129, Hobart, Tasmania, 7001, Australia
| | - Craig R Johnson
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Private Bag 129, Hobart, Tasmania, 7001, Australia
| | - Jeffrey T Wright
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Private Bag 129, Hobart, Tasmania, 7001, Australia
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9
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Impacts of sub-micrometer sediment particles on early-stage growth and survival of the kelp Ecklonia bicyclis. Sci Rep 2020; 10:20689. [PMID: 33244042 PMCID: PMC7693333 DOI: 10.1038/s41598-020-75796-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 10/20/2020] [Indexed: 11/25/2022] Open
Abstract
Marine forests have declined in many urbanized regions in recent years. One cause is the inflow of fine particles into coastal rocky shores. We examined the influence of sub-micrometre (sub-micro) particles on the early growth stages of the large brown macrophyte Ecklonia bicyclis. The percentage of substrate attachment of zoospores decreased with an increase in sub-micro sediments. As the size of the particles decreased, the negative effect became greater. There was an increase in poor levels of gametophyte survival and growth as more and smaller sediment was deposited. We consider that the causes of these phenomena owing to increasing amounts of sediment is a decrease in availability of substrate for zoospore attachment and that of area for substance exchange on the gametophytes. We also evaluated the effects in sea areas, based on the amount and size distribution of seabed sediment in the algal communities deforested by particles, and found that the inhibition of zoospore attachment and gametophyte growth by sub-micro particles was remarkably large. The sub-micro sediment on the substrate has seriously negative effects on the early stages of macrophytes. Inflow of very fine particles to natural marine forests may result in severe degradation of rocky reef ecosystems.
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10
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de Caralt S, Verdura J, Vergés A, Ballesteros E, Cebrian E. Differential effects of pollution on adult and recruits of a canopy-forming alga: implications for population viability under low pollutant levels. Sci Rep 2020; 10:17825. [PMID: 33082390 PMCID: PMC7575554 DOI: 10.1038/s41598-020-73990-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 09/14/2020] [Indexed: 11/12/2022] Open
Abstract
Marine macroalgal forests are highly productive and iconic ecosystems, which are seriously threatened by number of factors such as habitat destruction, overgrazing, ocean warming, and pollution. The effect of chronic, but low levels of pollutants on the long-term survival of the canopy-forming algae is not well understood. Here we test the effects of low concentrations (found in good quality water-bodies) of nitrates, heavy metals copper (Cu) and lead (Pb), and herbicides (glyphosate) on both adults and recruits of Carpodesmia crinita, a Mediterranean canopy forming macroalga. We show that although adult biomass, height and photosynthetic yield remain almost unaffected in all the assays, low Cu levels of 30 µg/L completely suppress adult fertility. In addition, all the assays have a strong and negative impact on the survival and growth of recruits; in particular, glyphosate concentrations above 1 µg/L almost totally inhibit their survival. These results suggest that the long-term viability of C. crinita may be severely compromised by low pollutant levels that are not affecting adult specimens. Our results provide important data for a better understanding of the present-day threats to marine canopy-forming macroalgae and for the design of future management actions aimed at preserving macroalgal forests.
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Affiliation(s)
- Sònia de Caralt
- GRMAR, Institute of Aquatic Ecology (IEA), University of Girona (UdG), c/ Maria Aurèlia Capmany 69, 17003, Girona, Spain.
| | - Jana Verdura
- GRMAR, Institute of Aquatic Ecology (IEA), University of Girona (UdG), c/ Maria Aurèlia Capmany 69, 17003, Girona, Spain
| | - Alba Vergés
- GRMAR, Institute of Aquatic Ecology (IEA), University of Girona (UdG), c/ Maria Aurèlia Capmany 69, 17003, Girona, Spain
| | - Enric Ballesteros
- Centre for Advanced Studies of Blanes (CEAB), Spanish National Research Council (CSIC), c/ d'accés a la Cala St Francesc 14, 17300, Blanes, Spain
| | - Emma Cebrian
- GRMAR, Institute of Aquatic Ecology (IEA), University of Girona (UdG), c/ Maria Aurèlia Capmany 69, 17003, Girona, Spain.
- Centre for Advanced Studies of Blanes (CEAB), Spanish National Research Council (CSIC), c/ d'accés a la Cala St Francesc 14, 17300, Blanes, Spain.
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11
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Hamilton SL, Bell TW, Watson JR, Grorud-Colvert KA, Menge BA. Remote sensing: generation of long-term kelp bed data sets for evaluation of impacts of climatic variation. Ecology 2020; 101:e03031. [PMID: 32108936 DOI: 10.1002/ecy.3031] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 01/14/2020] [Accepted: 01/30/2020] [Indexed: 02/06/2023]
Abstract
A critical tool in assessing ecosystem change is the analysis of long-term data sets, yet such information is generally sparse and often unavailable for many habitats. Kelp forests are an example of rapidly changing ecosystems that are in most cases data poor. Because kelp forests are highly dynamic and have high intrinsic interannual variability, understanding how regional-scale drivers are driving kelp populations-and particularly how kelp populations are responding to climate change-requires long-term data sets. However, much of the work on kelp responses to climate change has focused on just a few, relatively long-lived, perennial, canopy-forming species. To understand how kelp populations with different life history traits are responding to climate-related variability, we leverage 35 yr of Landsat satellite imagery to track the population size of an annual, ruderal kelp, Nereocystis luetkeana, across Oregon. We found high levels of interannual variability in Nereocystis canopy area and varying population trajectories over the last 35 yr. Surprisingly, Oregon Nereocystis population sizes were unresponsive to a 2014 marine heat wave accompanied by increases in urchin densities that decimated northern California Nereocystis populations. Some Oregon Nereocystis populations have even increased in area relative to pre-2014 levels. Analysis of environmental drivers found that Nereocystis population size was negatively correlated with estimated nitrate levels and positively correlated with winter wave height. This pattern is the inverse of the predicted relationship based on extensive prior work on the perennial kelp Macrocystis pyrifera and may be related to the annual life cycle of Nereocystis. This article demonstrates (1) the value of novel remote sensing tools to create long-term data sets that may challenge our understanding of nearshore marine species and (2) the need to incorporate life history traits into our theory of how climate change will shape the ocean of the future.
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Affiliation(s)
- Sara L Hamilton
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, 97331, USA
| | - Tom W Bell
- Earth Research Institute, University of California, Santa Barbara, California, 93106, USA
| | - James R Watson
- Department of Geography, Oregon State University, Corvallis, Oregon, 97331, USA
| | | | - Bruce A Menge
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, 97331, USA
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12
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Ebbing A, Pierik R, Bouma T, Kromkamp JC, Timmermans K. How light and biomass density influence the reproduction of delayed Saccharina latissima gametophytes (Phaeophyceae). JOURNAL OF PHYCOLOGY 2020; 56:709-718. [PMID: 32108344 PMCID: PMC7318604 DOI: 10.1111/jpy.12976] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 01/03/2020] [Indexed: 06/10/2023]
Abstract
Kelp life-cycle transitions are complex and susceptible to various (a)biotic controls. Understanding the microscopic part of the kelp's lifecycle is of key importance, as gametophytes form a critical phase influencing, among others, the distributional limits of the species. Many environmental controls have been identified that affect kelp gametogenesis, whose interactive effects can be subtle and counterintuitive. Here we performed a fully factorial experiment on the (interactive) influences of light intensity, light quality, and the Initial Gametophyte Density (IGD) on Saccharina latissima reproduction and vegetative growth of delayed gametophytes. A total of 144 cultures were followed over a period of 21 d. The IGD was a key determinant for reproductive success, with increased IGDs (≥0.04 mg DW · mL-1 ) practically halting reproduction. Interestingly, the effects of IGDs were not affected by nutrient availability, suggesting a resource-independent effect of density on reproduction. The Photosynthetically Usable Radiation (PUR), overarching the quantitative contribution of both light intensity and light quality, correlated with both reproduction and vegetative growth. The PUR furthermore specifies that the contribution of light quality, as a lifecycle control, is a matter of absorbed photon flux instead of color signaling. We hypothesize that (i) the number of photons absorbed, independent of their specific wavelength, and (ii) IGD interactions, independent of nutrient availability, are major determinants of reproduction in S. latissima gametophytes. These insights help understand kelp gametophyte development and dispersal under natural conditions, while also aiding the control of in vitro gametophyte cultures.
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Affiliation(s)
- Alexander Ebbing
- Department of Estuarine and Delta SystemsNIOZ Royal Netherlands Institute for Sea ResearchPO Box 1404401 NTYersekeThe Netherlands
- Department Ocean EcosystemsUniversity of GroningenPO Box 729700 ABGroningenThe Netherlands
| | - Ronald Pierik
- Department of BiologyUtrecht UniversityPadualaan 83584 CHUtrechtThe Netherlands
| | - Tjeerd Bouma
- Department of Estuarine and Delta SystemsNIOZ Royal Netherlands Institute for Sea ResearchPO Box 1404401 NTYersekeThe Netherlands
- Department Ocean EcosystemsUniversity of GroningenPO Box 729700 ABGroningenThe Netherlands
| | - Jacco C. Kromkamp
- Department of Estuarine and Delta SystemsNIOZ Royal Netherlands Institute for Sea ResearchPO Box 1404401 NTYersekeThe Netherlands
- Department Ocean EcosystemsUniversity of GroningenPO Box 729700 ABGroningenThe Netherlands
| | - Klaas Timmermans
- Department of Estuarine and Delta SystemsNIOZ Royal Netherlands Institute for Sea ResearchPO Box 1404401 NTYersekeThe Netherlands
- Department Ocean EcosystemsUniversity of GroningenPO Box 729700 ABGroningenThe Netherlands
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13
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Eisaguirre JH, Eisaguirre JM, Davis K, Carlson PM, Gaines SD, Caselle JE. Trophic redundancy and predator size class structure drive differences in kelp forest ecosystem dynamics. Ecology 2020; 101:e02993. [PMID: 32002994 PMCID: PMC7317486 DOI: 10.1002/ecy.2993] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 11/22/2019] [Accepted: 12/05/2019] [Indexed: 11/07/2022]
Abstract
Ecosystems are changing at alarming rates because of climate change and a wide variety of other anthropogenic stressors. These stressors have the potential to cause phase shifts to less productive ecosystems. A major challenge for ecologists is to identify ecosystem attributes that enhance resilience and can buffer systems from shifts to less desirable alternative states. In this study, we used the Northern Channel Islands, California, as a model kelp forest ecosystem that had been perturbed from the loss of an important sea star predator due to a sea star wasting disease. To determine the mechanisms that prevent phase shifts from productive kelp forests to less productive urchin barrens, we compared pre- and postdisease predator assemblages as predictors of purple urchin densities. We found that prior to the onset of the disease outbreak, the sunflower sea star exerted strong predation pressures and was able to suppress purple urchin populations effectively. After the disease outbreak, which functionally extirpated the sunflower star, we found that the ecosystem response-urchin and algal abundances-depended on the abundance and/or size of remaining predator species. Inside Marine Protected Areas (MPAs), the large numbers and sizes of other urchin predators suppressed purple urchin populations resulting in kelp and understory algal growth. Outside of the MPAs, where these alternative urchin predators are fished, less abundant, and smaller, urchin populations grew dramatically in the absence of sunflower stars resulting in less kelp at these locations. Our results demonstrate that protected trophic redundancy inside MPAs creates a net of stability that could limit kelp forest ecosystem phase shifts to less desirable, alternative states when perturbed. This highlights the importance of harboring diversity and managing predator guilds.
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Affiliation(s)
- Jacob H. Eisaguirre
- Department of Environmental StudiesUniversity of CaliforniaSanta BarbaraCalifornia93106USA
- Marine Science InstituteUniversity of CaliforniaSanta BarbaraCalifornia93106USA
| | - Joseph M. Eisaguirre
- Department of Biology & WildlifeUniversity of Alaska FairbanksFairbanksAlaska99775USA
- Department of Mathematics & StatisticsUniversity of Alaska FairbanksFairbanksAlaska99775USA
| | - Kathryn Davis
- Marine Science InstituteUniversity of CaliforniaSanta BarbaraCalifornia93106USA
| | - Peter M. Carlson
- Marine Science InstituteUniversity of CaliforniaSanta BarbaraCalifornia93106USA
| | - Steven D. Gaines
- Bren School of Environmental Science and ManagementUniversity of CaliforniaSanta BarbaraCalifornia93106USA
| | - Jennifer E. Caselle
- Marine Science InstituteUniversity of CaliforniaSanta BarbaraCalifornia93106USA
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Gizzi F, Jiménez J, Schäfer S, Castro N, Costa S, Lourenço S, José R, Canning-Clode J, Monteiro J. Before and after a disease outbreak: Tracking a keystone species recovery from a mass mortality event. MARINE ENVIRONMENTAL RESEARCH 2020; 156:104905. [PMID: 32174333 DOI: 10.1016/j.marenvres.2020.104905] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 01/23/2020] [Accepted: 02/03/2020] [Indexed: 06/10/2023]
Abstract
Mass mortality events involving marine taxa are increasing worldwide. The long-spined sea urchin Diadema africanum is considered a keystone herbivore species in the northeastern Atlantic due to its control over the abundance and distribution of algae. After a first registered mass mortality in 2009, another event off the coasts of Madeira archipelago affected this ecologically important species in summer 2018. This study documented the 2018 D. africanum mass mortality event, and the progress of its populations on the southern coast of Madeira island. A citizen science survey was designed targeting marine stakeholders to understand the extent and intensity of the event around the archipelago. Underwater surveys on population density prior, during and after the mass mortality, permitted an evaluation of the severity and magnitude of the event as well as urchin population recovery. A preliminary assessment of causative agents of the mortality was performed. The event was reported in the principal islands of the archipelago reducing the populations up to 90%. However, a fast recovery was registered during the following months, suggesting that the reproductive success was not compromised. Microbiological analyses in symptomatic and asymptomatic individuals, during and after the event, was not conclusive. Nevertheless, the bacteria Aeromonas salmonicida, or the gram-negative bacteria, or the interaction of different types of bacteria may be responsible for the disease outbreak. Further studies are needed to assess the role of pathogens in sea urchin mass mortalities and the compound effects that sea urchins have in local habitats and ecological functioning of coastal marine ecosystems.
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Affiliation(s)
- Francesca Gizzi
- MARE - Marine and Environmental Sciences Centre, Agência Regional para o Desenvolvimento da Investigação, Tecnologia e Inovação (ARDITI), Edifício Madeira Tecnopolo, Caminho da Penteada, 9020-105, Funchal, Madeira, Portugal.
| | - Jesús Jiménez
- MARE - Marine and Environmental Sciences Centre, Agência Regional para o Desenvolvimento da Investigação, Tecnologia e Inovação (ARDITI), Edifício Madeira Tecnopolo, Caminho da Penteada, 9020-105, Funchal, Madeira, Portugal.
| | - Susanne Schäfer
- MARE - Marine and Environmental Sciences Centre, Agência Regional para o Desenvolvimento da Investigação, Tecnologia e Inovação (ARDITI), Edifício Madeira Tecnopolo, Caminho da Penteada, 9020-105, Funchal, Madeira, Portugal; GEOMAR, Marine Ecology Department, Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105, Kiel, Germany.
| | - Nuno Castro
- MARE - Marine and Environmental Sciences Centre, Agência Regional para o Desenvolvimento da Investigação, Tecnologia e Inovação (ARDITI), Edifício Madeira Tecnopolo, Caminho da Penteada, 9020-105, Funchal, Madeira, Portugal.
| | - Sónia Costa
- MARE - Marine and Environmental Sciences Centre, Agência Regional para o Desenvolvimento da Investigação, Tecnologia e Inovação (ARDITI), Edifício Madeira Tecnopolo, Caminho da Penteada, 9020-105, Funchal, Madeira, Portugal; OOM/ARDITI, Agência Regional para o Desenvolvimento da Investigação, Tecnologia e Inovação, Edifício Madeira Tecnopolo, Caminho da Penteada, 9020-105, Funchal, Madeira, Portugal.
| | - Silvia Lourenço
- MARE - Marine and Environmental Sciences Centre, Politécnico de Leiria, Edifício CETEMARES, Av. Porto de Pesca, 2520 - 630, Peniche, Portugal; CIIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos, S/N, 4450-208, Matosinhos, Portugal.
| | - Ricardo José
- Direcção Regional de Pescas, Centro de Maricultura da Calheta, Av. D. Manuel I, 9370-133, Calheta, Portugal.
| | - João Canning-Clode
- MARE - Marine and Environmental Sciences Centre, Agência Regional para o Desenvolvimento da Investigação, Tecnologia e Inovação (ARDITI), Edifício Madeira Tecnopolo, Caminho da Penteada, 9020-105, Funchal, Madeira, Portugal; Centre of IMAR of the University of the Azores, Department of Oceanography and Fisheries, Rua Prof. Dr. Frederico Machado, 4, PT-9901-862, Horta, Azores, Portugal; Smithsonian Environmental Research Center, 647 Contees Wharf Road, Edgewater, MD, 21037, USA.
| | - João Monteiro
- MARE - Marine and Environmental Sciences Centre, Agência Regional para o Desenvolvimento da Investigação, Tecnologia e Inovação (ARDITI), Edifício Madeira Tecnopolo, Caminho da Penteada, 9020-105, Funchal, Madeira, Portugal.
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15
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Wade R, Augyte S, Harden M, Nuzhdin S, Yarish C, Alberto F. Macroalgal germplasm banking for conservation, food security, and industry. PLoS Biol 2020; 18:e3000641. [PMID: 32058997 PMCID: PMC7046291 DOI: 10.1371/journal.pbio.3000641] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Revised: 02/27/2020] [Indexed: 01/02/2023] Open
Abstract
Ex situ seed banking was first conceptualized and implemented in the early 20th century to maintain and protect crop lines. Today, ex situ seed banking is important for the preservation of heirloom strains, biodiversity conservation and ecosystem restoration, and diverse research applications. However, these efforts primarily target microalgae and terrestrial plants. Although some collections include macroalgae (i.e., seaweeds), they are relatively few and have yet to be connected via any international, coordinated initiative. In this piece, we provide a brief introduction to macroalgal germplasm banking and its application to conservation, industry, and mariculture. We argue that concerted effort should be made globally in germline preservation of marine algal species via germplasm banking with an overview of the technical advances for feasibility and ensured success. Seaweed germplasm banking is an important resource for biodiversity conservation, human food security, and industry innovation. This Perspective article maintains that an international, coordinative initiative is needed to fully develop and capitalize on this resource.
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Affiliation(s)
- Rachael Wade
- University of Wisconsin Milwaukee, Milwaukee, Wisconsin, United States of America
- * E-mail:
| | - Simona Augyte
- University of Connecticut Stamford, Stamford, Connecticut, United States of America
| | - Maddelyn Harden
- University of Southern California, Los Angeles, California, United States of America
| | - Sergey Nuzhdin
- University of Southern California, Los Angeles, California, United States of America
| | - Charles Yarish
- University of Connecticut Stamford, Stamford, Connecticut, United States of America
| | - Filipe Alberto
- University of Wisconsin Milwaukee, Milwaukee, Wisconsin, United States of America
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16
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Communities and Attachment Networks Associated with Primary, Secondary and Alternative Foundation Species; A Case Study of Stressed and Disturbed Stands of Southern Bull Kelp. DIVERSITY-BASEL 2019. [DOI: 10.3390/d11040056] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Southern bull kelps (Durvillaea spp., Fucales) are ‘primary’ foundation species that control community structures and ecosystem functions on temperate wave-exposed rocky reefs. However, these large foundation species are threatened by disturbances and stressors, including invasive species, sedimentation and heatwaves. It is unknown whether ‘alternative’ foundation species can replace lost southern bull kelps and its associated communities and networks. We compared community structure (by quantifying abundances of different species) and attachment-interaction networks (by quantifying which species were attached to other species) among plots dominated by Durvillaea spp. and plots where Durvillaea spp. were lost either through long-term repeated experimental removals or by recent stress from a marine heatwave. Long-term experimental removal plots were dominated by ‘alternative’ foundation species, the canopy-forming Cystophora spp. (Fucales), whereas the recent heatwave stressed plots were dominated by the invasive kelp Undaria pinnatifida (Laminariales). A network analysis of attachment interactions showed that communities differed among plots dominated by either Durvillaea spp., Cystophora spp. or U. pinnatifida, with different relationships between the primary, or alternative, foundation species and attached epiphytic ‘secondary’ foundation species. For example, native Cystophora spp. were more important as hosts for secondary foundation species compared to Durvillaea spp. and U. pinnatifida. Instead, Durvillaea spp. facilitated encrusting algae, which in turn provided habitat for gastropods. We conclude that (a) repeated disturbances and strong stressors can reveal ecological differences between primary and alternative foundation species, (b) analyses of abundances and attachment-networks are supplementary methods to identify linkages between primary, alternative and secondary foundation species, and (c) interspersed habitats dominated by different types of foundation species increase system-level biodiversity by supporting different species-abundance patterns and species-attachment networks.
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17
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Muth AF, Graham MH, Lane CE, Harley CDG. Recruitment tolerance to increased temperature present across multiple kelp clades. Ecology 2019; 100:e02594. [PMID: 30615200 DOI: 10.1002/ecy.2594] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 11/17/2018] [Accepted: 12/20/2018] [Indexed: 11/08/2022]
Abstract
Kelp systems dominate nearshore marine environments in upwelling zones characterized by cold temperatures and high nutrients. Worldwide, kelp population persistence and recruitment success generally decreases with rising water temperatures coupled with low nutrients, making kelp populations vulnerable to impending warming of the oceans. This response to climate change at a global scale, however, may vary due to regional differences in temperature variability, acclimation, and differential responses of kelp species to changing conditions. Culture experiments were conducted on 12 eastern Pacific kelp taxa across geographic regions (British Columbia, central California, and southern California) under three nitrate levels (1, 5, and 10 μmol/L) and two temperatures (12°C and 18°C) to determine sporophyte production (i.e., recruitment success). For all taxa from all locations, sporophytes were always present in the 12°C treatment and when recruitment failure was observed, it always occurred at 18°C, regardless of nitrate level, indicating that temperature is the driving factor limiting recruitment, not nitrate. Rising ocean temperatures will undoubtedly cause recruitment failure for many kelp species; however, the ability of species to acclimatize or adapt to increased temperatures at the warmer edge of their species range may promote a resiliency of kelp systems to climate change at a global scale.
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Affiliation(s)
- Arley F Muth
- Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, California, 95039, USA
| | - Michael H Graham
- Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, California, 95039, USA
| | - Christopher E Lane
- College of Arts and Sciences, University of Rhode Island, Kingston, Rhode Island, 02881, USA
| | - Christopher D G Harley
- Department of Zoology, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
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18
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Dobkowski KA, Flanagan KD, Nordstrom JR. Factors influencing recruitment and appearance of bull kelp, Nereocystis luetkeana (phylum Ochrophyta). JOURNAL OF PHYCOLOGY 2019; 55:236-244. [PMID: 30565227 DOI: 10.1111/jpy.12814] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 11/09/2018] [Indexed: 06/09/2023]
Abstract
The dynamics of annual species are strongly tied to their capacity for recruitment each year. We examined how competition and propagule availability influence recruitment and appearance and tracked survivorship of an annual species of marine macroalgae, the bull kelp (Nereocystis luetkeana), which serves as major biogenic habitat in the Salish Sea of Washington State. We hypothesized that (i) juvenile N. luetkeana would exhibit a seasonal appearance as a cohort in the spring and (ii) competition for space would be more limiting than propagules (spores) to recruitment at sites adjacent to established N. luetkeana beds. We tagged N. luetkeana recruits in the field to track appearance and survivorship across seasons (spring, summer, fall, and winter), using a two-factor crossed design to assess effects of competition and propagule availability on appearance of new N. luetkeana sporophytes. Survivorship of N. luetkeana recruits was low and, whereas most new individuals arose in the spring, some appeared in every season. New N. luetkeana recruits also appeared the earliest (median 8 weeks vs. >20 weeks) after experimental "seeding" in the spring as compared to other seasons. Eliminating macroalgal competitors ("clearing") influenced the appearance of recruits more than enhancement of propagules in the spring. An improved understanding of factors regulating the seasonal appearance of new N. luetkeana sporophytes furthers our understanding of this crucial foundation species' appearance and persistence across seasons, which is increasingly important as global ocean conditions change, and highlights the importance of studying organisms with complex life histories across multiple stages and geographical regions.
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Affiliation(s)
- Katie A Dobkowski
- University of Washington, 1410 NE Campus Parkway, Seattle, Washington, 98195, USA
- Friday Harbor Laboratories, 620 University Rd, Friday Harbor, Washington, 98250, USA
| | - K Darby Flanagan
- University of Washington, 1410 NE Campus Parkway, Seattle, Washington, 98195, USA
- Friday Harbor Laboratories, 620 University Rd, Friday Harbor, Washington, 98250, USA
| | - Jessica R Nordstrom
- Friday Harbor Laboratories, 620 University Rd, Friday Harbor, Washington, 98250, USA
- Point Defiance Zoo and Aquarium, 5400 N Pearl St, Tacoma, Washington, 98407, USA
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19
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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] [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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20
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Verdura J, Sales M, Ballesteros E, Cefalì ME, Cebrian E. Restoration of a Canopy-Forming Alga Based on Recruitment Enhancement: Methods and Long-Term Success Assessment. FRONTIERS IN PLANT SCIENCE 2018; 9:1832. [PMID: 30619405 PMCID: PMC6295557 DOI: 10.3389/fpls.2018.01832] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 11/26/2018] [Indexed: 06/04/2023]
Abstract
Marine forests dominated by macroalgae have experienced noticeable regression along some temperate and subpolar rocky shores. Along continuously disturbed shores, where natural recovery is extremely difficult, these forests are often permanently replaced by less structured assemblages. Thus, implementation of an active restoration plan emerges as an option to ensure their conservation. To date, active transplantation of individuals from natural and healthy populations has been proposed as a prime vehicle for restoring habitat-forming species. However, given the threatened and critical conservation status of many populations, less invasive techniques are required. Some authors have experimentally explored the applicability of several non-destructive techniques based on recruitment enhancement for macroalgae restoration; however, these techniques have not been effectively applied to restore forest-forming fucoids. Here, for the first time, we successfully restored four populations of Cystoseira barbata (i.e., they established self-maintaining populations of roughly 25 m2) in areas from which they had completely disappeared at least 50 years ago using recruitment-enhancement techniques. We compared the feasibility and costs of active macroalgal restoration by means of in situ (wild-collected zygotes and recruits) and ex situ (provisioning of lab-cultured recruits) techniques. Mid/long-term monitoring of the restored and reference populations allowed us to define the best indicators of success for the different restoration phases. After 6 years, the densities and size structure distributions of the restored populations were similar and comparable to those of the natural reference populations. However, the costs of the in situ recruitment technique were considerably lower than those of the ex situ technique. The restoration method, monitoring and success indicators proposed here may have applicability for other macroalgal species, especially those that produce rapidly sinking zygotes. Recruitment enhancement should become an essential tool for preserving Cystoseira forests and their associated biodiversity.
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Affiliation(s)
- Jana Verdura
- Facultat de Ciències, Institut d’Ecologia Aquàtica, Universitat de Girona, Girona, Spain
| | - Marta Sales
- Estació d’Investigació Jaume Ferrer, Instituto Español de Oceanografía (IEO), Mahón, Spain
| | | | - Maria Elena Cefalì
- Estació d’Investigació Jaume Ferrer, Instituto Español de Oceanografía (IEO), Mahón, Spain
| | - Emma Cebrian
- Facultat de Ciències, Institut d’Ecologia Aquàtica, Universitat de Girona, Girona, Spain
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21
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Succession of sessile organisms on experimental plates immersed in Nabeta Bay, Izu Peninsula, Japan V. An integrated consideration on the definition and prediction of succession. Ecol Res 2018. [DOI: 10.1007/bf02348595] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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22
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Benedetti‐Cecchi L, Bulleri F, Dal Bello M, Maggi E, Ravaglioli C, Rindi L. Hybrid datasets: integrating observations with experiments in the era of macroecology and big data. Ecology 2018; 99:2654-2666. [DOI: 10.1002/ecy.2504] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 07/08/2018] [Accepted: 08/02/2018] [Indexed: 12/17/2022]
Affiliation(s)
| | - Fabio Bulleri
- Department of Biology CoNISMa University of Pisa Via Derna 1 56126 Pisa Italy
| | - Martina Dal Bello
- Physics of Living Systems Group Department of Physics Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA
| | - Elena Maggi
- Department of Biology CoNISMa University of Pisa Via Derna 1 56126 Pisa Italy
| | - Chiara Ravaglioli
- Department of Biology CoNISMa University of Pisa Via Derna 1 56126 Pisa Italy
| | - Luca Rindi
- Department of Biology CoNISMa University of Pisa Via Derna 1 56126 Pisa Italy
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23
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Witman JD, Lamb RW. Persistent differences between coastal and offshore kelp forest communities in a warming Gulf of Maine. PLoS One 2018; 13:e0189388. [PMID: 29298307 PMCID: PMC5751975 DOI: 10.1371/journal.pone.0189388] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 11/26/2017] [Indexed: 12/03/2022] Open
Abstract
Kelp forests provide important ecosystem services, yet coastal kelp communities are increasingly altered by anthropogenic impacts. Kelp forests in remote, offshore locations may provide an informative contrast due to reduced impacts from local stressors. We tested the hypothesis that shallow kelp assemblages (12-15 m depth) and associated fish and benthic communities in the coastal southwest Gulf of Maine (GOM) differed significantly from sites on Cashes Ledge, 145 km offshore by sampling five coastal and three offshore sites at 43.0 +/- 0.07° N latitude. Offshore sites on Cashes Ledge supported the greatest density (47.8 plants m2) and standing crop biomass (5.5 kg m2 fresh weight) of the foundation species Saccharina latissima kelp at this depth in the Western North Atlantic. Offshore densities of S. latissima were over 150 times greater than at coastal sites, with similar but lower magnitude trends for congeneric S. digitata. Despite these differences, S. latissima underwent a significant 36.2% decrease between 1987 and 2015 on Cashes Ledge, concurrent with a rapid warming of the GOM and invasion by the kelp-encrusting bryozoan Membranipora membranacea. In contrast to kelp, the invasive red alga Dasysiphonia japonica was significantly more abundant at coastal sites, suggesting light or dispersal limitation offshore. Spatial differences in fish abundance mirrored those of kelp, as the average biomass of all fish on Cashes Ledge was 305 times greater than at the coastal sites. Remote video censuses of cod (Gadus morhua), cunner (Tautaogolabrus adspersus), and pollock (Pollachius virens) corroborated these findings. Understory benthic communities also differed between regions, with greater abundance of sessile invertebrates offshore. Populations of kelp-consuming sea urchins Stronglyocentrotus droebachiensis, were virtually absent from Cashes Ledge while small urchins were abundant onshore, suggesting recruitment limitation offshore. Despite widespread warming of the GOM since 1987, extraordinary spatial differences in the abundance of primary producers (kelp), consumers (cod) and benthic communities between coastal and offshore sites have persisted. The shallow kelp forest communities offshore on Cashes Ledge represent an oasis of unusually high kelp and fish abundance in the region, and as such, comprise a persistent abundance hotspot that is functionally significant for sustained biological productivity of offshore regions of the Gulf of Maine.
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Affiliation(s)
- Jon D. Witman
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI, United States of America
| | - Robert W. Lamb
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI, United States of America
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24
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Lamy T, Reed DC, Rassweiler A, Siegel DA, Kui L, Bell TW, Simons RD, Miller RJ. Scale-specific drivers of kelp forest communities. Oecologia 2018; 186:217-233. [PMID: 29101467 DOI: 10.1007/s00442-017-3994-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 10/25/2017] [Indexed: 12/01/2022]
Abstract
Identifying spatial scales of variation in natural communities and the processes driving them is critical for obtaining a predictive understanding of biodiversity. In this study, we focused on diverse communities inhabiting productive kelp forests on shallow subtidal rocky reefs in southern California, USA. We combined long-term community surveys from 86 sites with detailed environmental data to determine what structures assemblages of fishes, invertebrates and algae at multiple spatial scales. We identified the spatial scales of variation in species composition using a hierarchical analysis based on eigenfunctions, and assessed how sea surface temperature (SST), water column chlorophyll, giant kelp biomass, wave exposure and potential propagule delivery strength contributed to community variation at each scale. Spatial effects occurring at multiple scales explained 60% of the variation in fish assemblages and 52% of the variation in the assemblages of invertebrates and algae. Most variation occurred over broad spatial scales (> 200 km) consistent with spatial heterogeneity in SST and potential propagule delivery strength, while the latter also explained community variation at medium scales (65-200 km). Small scale (1-65 km) community variation was substantial but not linked to any of the measured drivers. Conclusions were consistent for both reef fishes and benthic invertebrates and algae, despite sharp differences in their adult mobility. Our results demonstrate the scale dependence of environmental drivers on kelp forest communities, showing that most species were strongly sorted along oceanographic conditions over various spatial scales. Such spatial effects must be integrated into models assessing the response of marine ecosystems to climate change.
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Affiliation(s)
- Thomas Lamy
- Marine Science Institute, University of California, Santa Barbara, CA, 93106, USA.
| | - Daniel C Reed
- Marine Science Institute, University of California, Santa Barbara, CA, 93106, USA
| | - Andrew Rassweiler
- Marine Science Institute, University of California, Santa Barbara, CA, 93106, USA
- Department of Biological Science, Florida State University, Tallahassee, FL, 32304, USA
| | - David A Siegel
- Marine Science Institute, University of California, Santa Barbara, CA, 93106, USA
- Earth Research Institute, University of California, CA, 93106, Santa Barbara, USA
- Department of Geography, University of California, Santa Barbara, CA, 93106, USA
| | - Li Kui
- Marine Science Institute, University of California, Santa Barbara, CA, 93106, USA
| | - Tom W Bell
- Earth Research Institute, University of California, CA, 93106, Santa Barbara, USA
| | - Rachel D Simons
- Earth Research Institute, University of California, CA, 93106, Santa Barbara, USA
| | - Robert J Miller
- Marine Science Institute, University of California, Santa Barbara, CA, 93106, USA
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25
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Increased sediment load during a large-scale dam removal changes nearshore subtidal communities. PLoS One 2017; 12:e0187742. [PMID: 29220368 PMCID: PMC5722376 DOI: 10.1371/journal.pone.0187742] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 10/25/2017] [Indexed: 11/19/2022] Open
Abstract
The coastal marine ecosystem near the Elwha River was altered by a massive sediment influx—over 10 million tonnes—during the staged three-year removal of two hydropower dams. We used time series of bathymetry, substrate grain size, remotely sensed turbidity, scuba dive surveys, and towed video observations collected before and during dam removal to assess responses of the nearshore subtidal community (3 m to 17 m depth). Biological changes were primarily driven by sediment deposition and elevated suspended sediment concentrations. Macroalgae, predominantly kelp and foliose red algae, were abundant before dam removal with combined cover levels greater than 50%. Where persistent sediment deposits formed, macroalgae decreased greatly or were eliminated. In areas lacking deposition, macroalgae cover decreased inversely to suspended sediment concentration, suggesting impacts from light reduction or scour. Densities of most invertebrate and fish taxa decreased in areas with persistent sediment deposition; however, bivalve densities increased where mud deposited over sand, and flatfish and Pacific sand lance densities increased where sand deposited over gravel. In areas without sediment deposition, most invertebrate and fish taxa were unaffected by increased suspended sediment or the loss of algae cover associated with it; however, densities of tubeworms and flatfish, and primary cover of sessile invertebrates increased suggesting benefits of increased particulate matter or relaxed competition with macroalgae for space. As dam removal neared completion, we saw evidence of macroalgal recovery that likely owed to water column clearing, indicating that long-term recovery from dam removal effects may be starting. Our results are relevant to future dam removal projects in coastal areas and more generally to understanding effects of increased sedimentation on nearshore subtidal benthic communities.
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26
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Martins GM, Arenas F, Tuya F, Ramírez R, Neto AI, Jenkins SR. Successional convergence in experimentally disturbed intertidal communities. Oecologia 2017; 186:507-516. [PMID: 29189939 DOI: 10.1007/s00442-017-4022-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 11/22/2017] [Indexed: 11/29/2022]
Abstract
Determining the causes of variation in community assembly is a central question in ecology. Analysis of β-diversity can provide insight by relating the extent of regional to local variation in diversity, allowing inference of the relative importance of deterministic versus stochastic processes. We investigated the effects of disturbance timing on community assembly at three distinct regions with varying environmental conditions: Northern Portugal, Azores and Canaries. On the lower rocky intertidal, quadrats were experimentally cleared of biota at three distinct times of the year and community assembly followed for 1 year. Similar levels of α- and γ-diversity were found in all regions, which remained constant throughout succession. When Jaccard (incidence-based) and Bray-Curtis (abundance-based) metrics were used, β-diversity (the mean dissimilarity among plots cleared at the different times) was larger during early stages of community assembly but decreased over time. The adaptation of the Raup-Crick's metric, which accounts for changes in species richness, showed that the structure of assemblages disturbed at different times of the year was similar to the null model of random community assembly during early stages of succession but became more similar than expected by chance. This pattern was observed in all regions despite differences in the regional species pool, suggesting that priority effects are likely weak and deterministic processes determine community structure despite stochasticity during early stages of community assembly.
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Affiliation(s)
- Gustavo M Martins
- Faculdade de Ciências e Tecnologia, Departamento de Biologia, Universidade dos Açores, 9501-801, Ponta Delgada, Açores, Portugal. .,cE3c-Centre for Ecology, Evolution and Environmental Changes/Azorean Biodiversity Group, 9501-801, Ponta Delgada, Açores, Portugal.
| | - Francisco Arenas
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208, Matosinhos, Portugal
| | - Fernando Tuya
- Grupo en Biodiversidad y Conservación, IU-ECOAQUA, Universidad de Las Palmas de Gran Canaria, 35017, Las Palmas, Canary Islands, Spain
| | - Rubén Ramírez
- Grupo en Biodiversidad y Conservación, IU-ECOAQUA, Universidad de Las Palmas de Gran Canaria, 35017, Las Palmas, Canary Islands, Spain
| | - Ana I Neto
- Faculdade de Ciências e Tecnologia, Departamento de Biologia, Universidade dos Açores, 9501-801, Ponta Delgada, Açores, Portugal.,cE3c-Centre for Ecology, Evolution and Environmental Changes/Azorean Biodiversity Group, 9501-801, Ponta Delgada, Açores, Portugal
| | - Stuart R Jenkins
- School of Ocean Sciences, Bangor University, Menai Bridge, Anglesey, UK
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South PM, Floerl O, Forrest BM, Thomsen MS. A review of three decades of research on the invasive kelp Undaria pinnatifida in Australasia: An assessment of its success, impacts and status as one of the world's worst invaders. MARINE ENVIRONMENTAL RESEARCH 2017; 131:243-257. [PMID: 28958575 DOI: 10.1016/j.marenvres.2017.09.015] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 09/10/2017] [Accepted: 09/16/2017] [Indexed: 06/07/2023]
Abstract
Marine invasive macroalgae can have severe local-scale impacts on ecological communities. The kelp Undaria pinnatifida is one of the most successful marine invasive species worldwide, and is widely regarded as one of the worst. Here, we review research on Undaria in Australasia, where the kelp is established throughout much of New Zealand and south-eastern Australia. The presence of Undaria for at least three decades in these locations makes Australasia one of the longest-invaded bioregions globally, and a valuable case study for considering Undaria's invasion success and associated impacts. In Australasia, Undaria has primarily invaded open spaces, turf communities, and gaps in native canopies within a relatively narrow elevation band on rocky shores. Despite its high biomass, Undaria has relatively few direct impacts on native species, and can increase community-wide attributes such as primary productivity and the provision of biogenic habitat. Therefore, Australasian Undaria research provides an example of a decoupling between the success and impact of an invasive species. Undaria will most likely continue to spread along thousands of kilometres of rocky coastline in temperate Australasia, due to its tolerance to large variations in temperature, ability to exploit disturbances to local communities, and the continued transfer among regions via vessel movements and aquaculture activities. However, the spread of Undaria remains difficult to manage as eradication is challenging and seldom successful. Therefore, understanding potential invasion pathways, maintaining native canopy-forming species that limit Undaria success, and effectively managing anthropogenic vectors of Undaria spread, should be key management priorities.
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Affiliation(s)
- Paul M South
- Cawthron Institute, 98 Halifax Street East, Nelson 7010, New Zealand; Institute of Marine Science, University of Auckland, Private bag 92019, Auckland, New Zealand.
| | - Oliver Floerl
- Cawthron Institute, 98 Halifax Street East, Nelson 7010, New Zealand
| | - Barrie M Forrest
- Cawthron Institute, 98 Halifax Street East, Nelson 7010, New Zealand
| | - Mads S Thomsen
- Marine Ecology Research Group, School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, New Zealand; UWA Oceans Institute & School of Biological Sciences, University of Western Australia, Crawley, WA 6009, Australia
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28
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Menge BA, Bracken MES, Lubchenco J, Leslie HM. Alternative state? Experimentally induced
F
ucus
canopy persists 38 yr in an
A
scophyllum‐
dominated community. Ecosphere 2017. [DOI: 10.1002/ecs2.1725] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Bruce A. Menge
- Department of Integrative Biology Oregon State University Cordley Hall 3029 Corvallis Oregon 97331 USA
| | - Matthew E. S. Bracken
- Department of Ecology and Evolutionary Biology University of California 321 Steinhaus Hall Irvine California 92697 USA
| | - Jane Lubchenco
- Department of Integrative Biology Oregon State University Cordley Hall 3029 Corvallis Oregon 97331 USA
| | - Heather M. Leslie
- Darling Marine Center and School of Marine Sciences University of Maine 193 Clarks Cove Road Walpole Maine 04573 USA
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29
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Bertocci I, Domínguez Godino JA, Freitas C, Incera M, Bio A, Domínguez R. Compounded perturbations in coastal areas: contrasting responses to nutrient enrichment and the regime of storm‐related disturbance depend on life‐history traits. Funct Ecol 2017. [DOI: 10.1111/1365-2435.12815] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Iacopo Bertocci
- CIIMAR/CIMAR Centro Interdisciplinar de Investigação Marinha e Ambiental Terminal de Cruzeiros do Porto de Leixões Av. General Norton de Matos s/n 4450‐208 Matosinhos Portugal
- Stazione Zoologica Anton Dohrn Villa Comunale 80121 Naples Italy
| | - Jorge A. Domínguez Godino
- CIIMAR/CIMAR Centro Interdisciplinar de Investigação Marinha e Ambiental Terminal de Cruzeiros do Porto de Leixões Av. General Norton de Matos s/n 4450‐208 Matosinhos Portugal
- CCMAR CIMAR‐Laboratório Associado Universidade do Algarve Gambelas 8005‐139 Faro Portugal
| | - Cristiano Freitas
- CIIMAR/CIMAR Centro Interdisciplinar de Investigação Marinha e Ambiental Terminal de Cruzeiros do Porto de Leixões Av. General Norton de Matos s/n 4450‐208 Matosinhos Portugal
| | - Monica Incera
- CIIMAR/CIMAR Centro Interdisciplinar de Investigação Marinha e Ambiental Terminal de Cruzeiros do Porto de Leixões Av. General Norton de Matos s/n 4450‐208 Matosinhos Portugal
- Centro Tecnológico del Mar – Fundación CETMAR C/Eduardo Cabello s/n E‐36208 Bouzas Vigo Spain
| | - Ana Bio
- CIIMAR/CIMAR Centro Interdisciplinar de Investigação Marinha e Ambiental Terminal de Cruzeiros do Porto de Leixões Av. General Norton de Matos s/n 4450‐208 Matosinhos Portugal
| | - Rula Domínguez
- CIIMAR/CIMAR Centro Interdisciplinar de Investigação Marinha e Ambiental Terminal de Cruzeiros do Porto de Leixões Av. General Norton de Matos s/n 4450‐208 Matosinhos Portugal
- Departamento de Ecoloxía e Bioloxía Animal Faculdade de Ciencias do Mar Universidade de Vigo Vigo Spain
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30
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Castorani MCN, Reed DC, Raimondi PT, Alberto F, Bell TW, Cavanaugh KC, Siegel DA, Simons RD. Fluctuations in population fecundity drive variation in demographic connectivity and metapopulation dynamics. Proc Biol Sci 2017; 284:20162086. [PMID: 28123088 PMCID: PMC5310032 DOI: 10.1098/rspb.2016.2086] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 01/03/2017] [Indexed: 11/12/2022] Open
Abstract
Demographic connectivity is vital to sustaining metapopulations yet often changes dramatically through time due to variation in the production and dispersal of offspring. However, the relative importance of variation in fecundity and dispersal in determining the connectivity and dynamics of metapopulations is poorly understood due to the paucity of comprehensive spatio-temporal data on these processes for most species. We quantified connectivity in metapopulations of a marine foundation species (giant kelp Macrocystis pyrifera) across 11 years and approximately 900 km of coastline by estimating population fecundity with satellite imagery and propagule dispersal using a high-resolution ocean circulation model. By varying the temporal complexity of different connectivity measures and comparing their ability to explain observed extinction-colonization dynamics, we discovered that fluctuations in population fecundity, rather than fluctuations in dispersal, are the dominant driver of variation in connectivity and contribute substantially to metapopulation recovery and persistence. Thus, for species with high variability in reproductive output and modest variability in dispersal (most plants, many animals), connectivity measures ignoring fluctuations in fecundity may overestimate connectivity and likelihoods of persistence, limiting their value for understanding and conserving metapopulations. However, we demonstrate how connectivity measures can be simplified while retaining utility, validating a practical solution for data-limited systems.
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Affiliation(s)
- Max C N Castorani
- Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
| | - Daniel C Reed
- Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
| | - Peter T Raimondi
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95064, USA
| | - Filipe Alberto
- Department of Biological Sciences, University of Wisconsin, Milwaukee, WI 53211, USA
| | - Tom W Bell
- Earth Research Institute, University of California, Santa Barbara, CA 93106, USA
| | - Kyle C Cavanaugh
- Department of Geography, University of California, Los Angeles, CA 90095, USA
| | - David A Siegel
- Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
- Earth Research Institute, University of California, Santa Barbara, CA 93106, USA
| | - Rachel D Simons
- Earth Research Institute, University of California, Santa Barbara, CA 93106, USA
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31
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Krumhansl KA, Okamoto DK, Rassweiler A, Novak M, Bolton JJ, Cavanaugh KC, Connell SD, Johnson CR, Konar B, Ling SD, Micheli F, Norderhaug KM, Pérez-Matus A, Sousa-Pinto I, Reed DC, Salomon AK, Shears NT, Wernberg T, Anderson RJ, Barrett NS, Buschmann AH, Carr MH, Caselle JE, Derrien-Courtel S, Edgar GJ, Edwards M, Estes JA, Goodwin C, Kenner MC, Kushner DJ, Moy FE, Nunn J, Steneck RS, Vásquez J, Watson J, Witman JD, Byrnes JEK. Global patterns of kelp forest change over the past half-century. Proc Natl Acad Sci U S A 2016; 113:13785-13790. [PMID: 27849580 PMCID: PMC5137772 DOI: 10.1073/pnas.1606102113] [Citation(s) in RCA: 231] [Impact Index Per Article: 28.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Kelp forests (Order Laminariales) form key biogenic habitats in coastal regions of temperate and Arctic seas worldwide, providing ecosystem services valued in the range of billions of dollars annually. Although local evidence suggests that kelp forests are increasingly threatened by a variety of stressors, no comprehensive global analysis of change in kelp abundances currently exists. Here, we build and analyze a global database of kelp time series spanning the past half-century to assess regional and global trends in kelp abundances. We detected a high degree of geographic variation in trends, with regional variability in the direction and magnitude of change far exceeding a small global average decline (instantaneous rate of change = -0.018 y-1). Our analysis identified declines in 38% of ecoregions for which there are data (-0.015 to -0.18 y-1), increases in 27% of ecoregions (0.015 to 0.11 y-1), and no detectable change in 35% of ecoregions. These spatially variable trajectories reflected regional differences in the drivers of change, uncertainty in some regions owing to poor spatial and temporal data coverage, and the dynamic nature of kelp populations. We conclude that although global drivers could be affecting kelp forests at multiple scales, local stressors and regional variation in the effects of these drivers dominate kelp dynamics, in contrast to many other marine and terrestrial foundation species.
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Affiliation(s)
- Kira A Krumhansl
- School of Resource and Environmental Management, Hakai Institute, Simon Fraser University, Burnaby, BC, Canada V5A 1S6;
| | - Daniel K Okamoto
- School of Resource and Environmental Management, Hakai Institute, Simon Fraser University, Burnaby, BC, Canada V5A 1S6
| | - Andrew Rassweiler
- Department of Biological Science, Florida State University, Tallahassee, FL 32306
| | - Mark Novak
- Department of Integrative Biology, Oregon State University, Corvallis, OR 97331
| | - John J Bolton
- Department of Biological Sciences and Marine Research Institute, University of Cape Town, 7701 Rondebosch, South Africa
| | - Kyle C Cavanaugh
- Department of Geography, University of California, Los Angeles, CA 90095
| | - Sean D Connell
- Southern Seas Ecology Laboratories, The Environment Institute, The University of Adelaide, Adelaide, SA 5005, Australia
| | - Craig R Johnson
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, 7001 TAS, Australia
| | - Brenda Konar
- College of Fisheries and Ocean Sciences, University of Alaska, Fairbanks, AK 99775
| | - Scott D Ling
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, 7001 TAS, Australia
| | - Fiorenza Micheli
- Hopkins Marine Station, Stanford University, Pacific Grove, CA 93950
| | | | - Alejandro Pérez-Matus
- Subtidal Ecology Laboratory and Marine Conservation Center, Estación Costera de Investigaciones Marinas, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile
| | - Isabel Sousa-Pinto
- Interdisciplinary Centre for Marine and Environmental Research, 4450-208 Matosinhos, Portugal
- Department of Biology, Faculty of Sciences, University of Porto, 4169-007 Porto, Portugal
| | - Daniel C Reed
- Marine Science Institute, University of California, Santa Barbara, CA 93106
| | - Anne K Salomon
- School of Resource and Environmental Management, Hakai Institute, Simon Fraser University, Burnaby, BC, Canada V5A 1S6
| | - Nick T Shears
- Leigh Marine Laboratory, Institute of Marine Science, The University of Auckland, Auckland 0941, New Zealand
| | - Thomas Wernberg
- Oceans Institute, University of Western Australia, Perth, WA 6009, Australia
- School of Biological Sciences, University of Western Australia, Perth, WA 6009, Australia
| | - Robert J Anderson
- Department of Biological Sciences and Marine Research Institute, University of Cape Town, 7701 Rondebosch, South Africa
- Department of Agriculture, Forestry and Fisheries, Roggebaai 8012, South Africa
| | - Nevell S Barrett
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, 7001 TAS, Australia
| | - Alejandro H Buschmann
- Centro de Investigación y Desarrollo en Recursos y Ambientes Costeros, Universidad de Los Lagos, Puerto Montt 5480000, Chile
- Centro de Biotecnología y Bioingeniería, Universidad de Los Lagos, Puerto Montt 5480000, Chile
| | - Mark H Carr
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95064
| | - Jennifer E Caselle
- Marine Science Institute, University of California, Santa Barbara, CA 93106
| | - Sandrine Derrien-Courtel
- Muséum National d'Histoire Naturelle, Station Marine de Concarneau, 29182 Concarneau Cedex, France
| | - Graham J Edgar
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, 7001 TAS, Australia
| | - Matt Edwards
- Department of Biology, San Diego State University, San Diego, CA 92182
| | - James A Estes
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95064
| | - Claire Goodwin
- Centre for Environmental Data and Recording, National Museums Northern Ireland, Holywood, Co. Down BT18 0EU, United Kingdom
| | - Michael C Kenner
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95064
| | | | | | - Julia Nunn
- Centre for Environmental Data and Recording, National Museums Northern Ireland, Holywood, Co. Down BT18 0EU, United Kingdom
| | - Robert S Steneck
- School of Marine Sciences, University of Maine, Walpole, ME 04573
| | - Julio Vásquez
- Departamento de Biología Marina, Universidad Católica del Norte, Coquimbo 1781421, Chile
| | - Jane Watson
- Biology Department, Vancouver Island University, Nanaimo, BC, Canada V9R 5S5
| | - Jon D Witman
- Ecology and Evolutionary Biology, Brown University, Providence, RI 02912
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32
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Morris MM, Haggerty JM, Papudeshi BN, Vega AA, Edwards MS, Dinsdale EA. Nearshore Pelagic Microbial Community Abundance Affects Recruitment Success of Giant Kelp, Macrocystis pyrifera. Front Microbiol 2016; 7:1800. [PMID: 27895628 PMCID: PMC5107569 DOI: 10.3389/fmicb.2016.01800] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 10/26/2016] [Indexed: 11/22/2022] Open
Abstract
Marine microbes mediate key ecological processes in kelp forest ecosystems and interact with macroalgae. Pelagic and biofilm-associated microbes interact with macroalgal propagules at multiple stages of recruitment, yet these interactions have not been described for Macrocystis pyrifera. Here we investigate the influence of microbes from coastal environments on recruitment of giant kelp, M. pyrifera. Through repeated laboratory experiments, we tested the effects of altered pelagic microbial abundance on the settlement and development of the microscopic propagules of M. pyrifera during recruitment. M. pyrifera zoospores were reared in laboratory microcosms exposed to environmental microbial communities from seawater during the complete haploid stages of the kelp recruitment cycle, including zoospore release, followed by zoospore settlement, to gametophyte germination and development. We altered the microbial abundance states differentially in three independent experiments with repeated trials, where microbes were (a) present or absent in seawater, (b) altered in community composition, and (c) altered in abundance. Within the third experiment, we also tested the effect of nearshore versus offshore microbial communities on the macroalgal propagules. Distinct pelagic microbial communities were collected from two southern California temperate environments reflecting contrasting intensity of human influence, the nearshore Point Loma kelp forest and the offshore Santa Catalina Island kelp forest. The Point Loma kelp forest is a high impacted coastal region adjacent to the populous San Diego Bay; whereas the kelp forest at Catalina Island is a low impacted region of the Channel Islands, 40 km offshore the southern California coast, and is adjacent to a marine protected area. Kelp gametophytes reared with nearshore Point Loma microbes showed lower survival, growth, and deteriorated morphology compared to gametophytes with the offshore Catalina Island microbial community, and these effects were magnified under high microbial abundances. Reducing abundance of Point Loma microbes restored M. pyrifera propagule success. Yet an intermediate microbial abundance was optimal for kelp propagules reared with Catalina Island microbes, suggesting that microbes also have a beneficial influence on kelp. Our study shows that pelagic microbes from nearshore and offshore environments are differentially influencing kelp propagule success, which has significant implications for kelp recruitment and kelp forest ecosystem health.
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Affiliation(s)
- Megan M Morris
- Department of Biology, San Diego State University San Diego, CA, USA
| | - John M Haggerty
- Department of Biology, San Diego State University San Diego, CA, USA
| | - Bhavya N Papudeshi
- Bioinformatics and Medical Informatics, San Diego State University San Diego, CA, USA
| | - Alejandro A Vega
- Department of Biology, San Diego State University San Diego, CA, USA
| | - Matthew S Edwards
- Department of Biology, San Diego State University San Diego, CA, USA
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33
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KIM SANGIL, KANG YUNHEE, KIM TAEHOON, PARK SANGRUL. Recovery Pattern and Seasonal Dynamics of Kelp Species, Ecklonia cava Population Formed Following the Large-scale Disturbance. ACTA ACUST UNITED AC 2016. [DOI: 10.7850/jkso.2016.21.3.103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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34
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Watanabe H, Ito M, Matsumoto A, Arakawa H. Effects of sediment influx on the settlement and survival of canopy-forming macrophytes. Sci Rep 2016; 6:18677. [PMID: 26726051 PMCID: PMC4698636 DOI: 10.1038/srep18677] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 11/23/2015] [Indexed: 11/09/2022] Open
Abstract
Kelp forests on coastal rocky shores are negatively impacted by sudden sediment loads that can occur with storms and floods. Using laboratory experiments, we studied the effects of sediment deposition on the survival of the large brown alga Eisenia bicyclis juveniles (zoospores and gametophytes) to quantify the potential impacts of particulate matter on kelp forests. The zoospore adhesion rate and the gametophyte survival and growth rates all declined markedly with increasing sediment load, particularly with smaller particle diameter. Using experimental results, we derived an equation to calculate the rate of initial kelp depletion with sediment load based on the quantity and size distribution of sediment particles. The equation enabled the estimation of E. bicyclis depletion rates in the field by measurement of particle quantity and diameter distribution of sediments on the reef substrate.
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Affiliation(s)
- Hayato Watanabe
- Corporate Planning Department, Iwate Prefectural Government, 1-1 Youkacho, Kuji, Iwate 028-0064, Japan.,Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan
| | - Miku Ito
- Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan
| | - Akira Matsumoto
- Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan
| | - Hisayuki Arakawa
- Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan
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Castorani MCN, Reed DC, Alberto F, Bell TW, Simons RD, Cavanaugh KC, Siegel DA, Raimondi PT. Connectivity structures local population dynamics: a long-term empirical test in a large metapopulation system. Ecology 2015; 96:3141-52. [PMID: 26909421 DOI: 10.1890/15-0283.1] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
Ecological theory predicts that demographic connectivity structures the dynamics of local populations within metapopulation systems, but empirical support has been constrained by major limitations in data and methodology. We tested this prediction for giant kelp Macrocystis pyrifera, a key habitat-forming species in temperate coastal ecosystems worldwide, in southern California, USA. We combined a long-term (22 years), large-scale (~500 km coastline), high-resolution census of abundance with novel patch delineation methods and an innovative connectivity measure incorporating oceanographic transport and source fecundity. Connectivity strongly predicted local dynamics (well-connected patches had lower probabilities of extinction and higher probabilities of colonization, leading to greater likelihoods of occupancy) but this relationship was mediated by patch size. Moreover, the relationship between connectivity and local population dynamics varied over time, possibly due to temporal variation in oceanographic transport processes. Surprisingly, connectivity had a smaller influence on colonization relative to extinction, possibly because local ecological factors differ greatly between extinct and extant patches. Our results provide the first comprehensive evidence that southern California giant kelp populations function as a metapopulation system, challenging the view that populations of this important foundation species are governed exclusively by self-replenishment.
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36
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Witman JD, Lamb RW, Byrnes JEK. Towards an integration of scale and complexity in marine ecology. ECOL MONOGR 2015. [DOI: 10.1890/14-2265.1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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37
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Bennett S, Wernberg T, de Bettignies T, Kendrick GA, Anderson RJ, Bolton JJ, Rodgers KL, Shears NT, Leclerc JC, Lévêque L, Davoult D, Christie HC. Canopy interactions and physical stress gradients in subtidal communities. Ecol Lett 2015; 18:677-86. [PMID: 25975532 DOI: 10.1111/ele.12446] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 12/15/2014] [Accepted: 04/07/2015] [Indexed: 11/28/2022]
Abstract
Species interactions are integral drivers of community structure and can change from competitive to facilitative with increasing environmental stress. In subtidal marine ecosystems, however, interactions along physical stress gradients have seldom been tested. We observed seaweed canopy interactions across depth and latitudinal gradients to test whether light and temperature stress structured interaction patterns. We also quantified interspecific and intraspecific interactions among nine subtidal canopy seaweed species across three continents to examine the general nature of interactions in subtidal systems under low consumer pressure. We reveal that positive and neutral interactions are widespread throughout global seaweed communities and the nature of interactions can change from competitive to facilitative with increasing light stress in shallow marine systems. These findings provide support for the stress gradient hypothesis within subtidal seaweed communities and highlight the importance of canopy interactions for the maintenance of subtidal marine habitats experiencing environmental stress.
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Affiliation(s)
- Scott Bennett
- School of Plant Biology & UWA Oceans Institute, University of Western Australia, 39 Fairway, Crawley, 6009, WA, Australia
| | - Thomas Wernberg
- School of Plant Biology & UWA Oceans Institute, University of Western Australia, 39 Fairway, Crawley, 6009, WA, Australia
| | - Thibaut de Bettignies
- School of Plant Biology & UWA Oceans Institute, University of Western Australia, 39 Fairway, Crawley, 6009, WA, Australia
| | - Gary A Kendrick
- School of Plant Biology & UWA Oceans Institute, University of Western Australia, 39 Fairway, Crawley, 6009, WA, Australia
| | - Robert J Anderson
- Seaweed Research Unit, Department of Agriculture, forestry and Fisheries, Pvt Bag X2, Roggebaai, 8012, South Africa
- Department of Biological Sciences and Marine Research Institute, University of Cape Town, Rondebosch, 7701, South Africa
| | - John J Bolton
- Department of Biological Sciences and Marine Research Institute, University of Cape Town, Rondebosch, 7701, South Africa
| | - Kirsten L Rodgers
- Leigh Marine Laboratory, Institute of Marine Science, University of Auckland, PO Box 349, Warkworth, 0941, New Zealand
| | - Nick T Shears
- Leigh Marine Laboratory, Institute of Marine Science, University of Auckland, PO Box 349, Warkworth, 0941, New Zealand
| | - Jean-Charles Leclerc
- Sorbonne Universités, UPMC Univ Paris 6, Station Biologique, Place Georges Teissier, Roscoff, 29680, France
- CNRS, Station Biologique, Place Georges Teissier, UMR 7144, Roscoff, 29680, France
| | - Laurent Lévêque
- Sorbonne Universités, UPMC Univ Paris 6, Station Biologique, Place Georges Teissier, Roscoff, 29680, France
- CNRS, FR 2424, Station Biologique, Place Georges Teissier, Roscoff, 29680, France
| | - Dominique Davoult
- Sorbonne Universités, UPMC Univ Paris 6, Station Biologique, Place Georges Teissier, Roscoff, 29680, France
- CNRS, Station Biologique, Place Georges Teissier, UMR 7144, Roscoff, 29680, France
| | - Hartvig C Christie
- Section for Marine Biology, Norwegian Institute for Water Research, Oslo, Norway
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38
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Desmond MJ, Pritchard DW, Hepburn CD. Light Limitation within Southern New Zealand Kelp Forest Communities. PLoS One 2015; 10:e0123676. [PMID: 25902185 PMCID: PMC4406696 DOI: 10.1371/journal.pone.0123676] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 02/21/2015] [Indexed: 11/20/2022] Open
Abstract
Light is the fundamental driver of primary productivity in the marine environment. Reduced light availability has the potential to alter the distribution, community composition, and productivity of key benthic primary producers, potentially reducing habitat and energy provision to coastal food webs. We compared the underwater light environment of macroalgal dominated shallow subtidal rocky reef habitats on a coastline modified by human activities with a coastline of forested catchments. Key metrics describing the availability of photosynthetically active radiation (PAR) were determined over 295 days and were related to macroalgal depth distribution, community composition, and standing biomass patterns, which were recorded seasonally. Light attenuation was more than twice as high in shallow subtidal zones along the modified coast. Macroalgal biomass was 2-5 times greater within forested sites, and even in shallow water (2m) a significant difference in biomass was observed. Long-term light dose provided the best explanation for differences in observed biomass between modified and forested coasts, with light availability over the study period differing by 60 and 90 mol photons m-2 at 2 and 10 metres, respectively. Higher biomass on the forested coast was driven by the presence of larger individuals rather than species diversity or density. This study suggests that commonly used metrics such as species diversity and density are not as sensitive as direct measures of biomass when detecting the effects of light limitation within macroalgal communities.
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Marzinelli EM, Williams SB, Babcock RC, Barrett NS, Johnson CR, Jordan A, Kendrick GA, Pizarro OR, Smale DA, Steinberg PD. Large-scale geographic variation in distribution and abundance of Australian deep-water kelp forests. PLoS One 2015; 10:e0118390. [PMID: 25693066 PMCID: PMC4334971 DOI: 10.1371/journal.pone.0118390] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 01/15/2015] [Indexed: 11/21/2022] Open
Abstract
Despite the significance of marine habitat-forming organisms, little is known about their large-scale distribution and abundance in deeper waters, where they are difficult to access. Such information is necessary to develop sound conservation and management strategies. Kelps are main habitat-formers in temperate reefs worldwide; however, these habitats are highly sensitive to environmental change. The kelp Ecklonia radiate is the major habitat-forming organism on subtidal reefs in temperate Australia. Here, we provide large-scale ecological data encompassing the latitudinal distribution along the continent of these kelp forests, which is a necessary first step towards quantitative inferences about the effects of climatic change and other stressors on these valuable habitats. We used the Autonomous Underwater Vehicle (AUV) facility of Australia's Integrated Marine Observing System (IMOS) to survey 157,000 m2 of seabed, of which ca 13,000 m2 were used to quantify kelp covers at multiple spatial scales (10-100 m to 100-1,000 km) and depths (15-60 m) across several regions ca 2-6° latitude apart along the East and West coast of Australia. We investigated the large-scale geographic variation in distribution and abundance of deep-water kelp (>15 m depth) and their relationships with physical variables. Kelp cover generally increased with latitude despite great variability at smaller spatial scales. Maximum depth of kelp occurrence was 40-50 m. Kelp latitudinal distribution along the continent was most strongly related to water temperature and substratum availability. This extensive survey data, coupled with ongoing AUV missions, will allow for the detection of long-term shifts in the distribution and abundance of habitat-forming kelp and the organisms they support on a continental scale, and provide information necessary for successful implementation and management of conservation reserves.
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Affiliation(s)
- Ezequiel M. Marzinelli
- Sydney Institute of Marine Science, Mosman, New South Wales, Australia
- Centre for Marine Bio-Innovation and School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | - Stefan B. Williams
- Australian Centre for Field Robotics, University of Sydney, Sydney, New South Wales, Australia
| | | | - Neville S. Barrett
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
| | - Craig R. Johnson
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
| | - Alan Jordan
- Department of Primary Industries, New South Wales Government, Port Stephens Fisheries Institute, Nelson Bay, New South Wales, Australia
| | - Gary A. Kendrick
- Oceans Institute and School of Plant Biology, University of Western Australia, Perth, Western Australia, Australia
| | - Oscar R. Pizarro
- Australian Centre for Field Robotics, University of Sydney, Sydney, New South Wales, Australia
| | - Dan A. Smale
- Oceans Institute and School of Plant Biology, University of Western Australia, Perth, Western Australia, Australia
- Marine Biological Association of the United Kingdom, The Laboratory, Citadel Hill, Plymouth, United Kingdom
| | - Peter D. Steinberg
- Sydney Institute of Marine Science, Mosman, New South Wales, Australia
- Centre for Marine Bio-Innovation and School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, Australia
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Benes KM, Carpenter RC. Kelp canopy facilitates understory algal assemblage via competitive release during early stages of secondary succession. Ecology 2015; 96:241-51. [PMID: 26236909 DOI: 10.1890/14-0076.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
Kelps are conspicuous foundation species in marine ecosystems that alter the composition of understory algal assemblages. While this may be due to changes in the competitive interactions between algal species, how kelp canopies mediate propagule supply and establishment success of understory algae is not well known. In Southern California, USA, Eisenia arborea forms dense kelp canopies in shallow subtidal environments and is associated with an understory dominated by red algal species. In canopy-free areas, however, the algal assemblage is comprised of mostly brown algal species. We used a combination of mensurative and manipulative experiments to test whether Eisenia facilitates the understory assemblage by reducing competition between these different types of algae by changes in biotic interactions and/or recruitment. Our results show Eisenia facilitates a red algal assemblage via inhibition of brown algal settlement into the canopy zone, allowing recruitment to occur by vegetative means rather than establishment of new individuals. In the canopy-free zone, however, high settlement and recruitment rates suggest competitive interactions shape the community there. These results demonstrate that foundation species alter the distribution and abundance of associated organisms by affecting not only interspecific interactions but also propagule supply and recruitment limitation.
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The regime of climate-related disturbance and nutrient enrichment modulate macroalgal invasions in rockpools. Biol Invasions 2014. [DOI: 10.1007/s10530-014-0711-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Rebours C, Marinho-Soriano E, Zertuche-González JA, Hayashi L, Vásquez JA, Kradolfer P, Soriano G, Ugarte R, Abreu MH, Bay-Larsen I, Hovelsrud G, Rødven R, Robledo D. Seaweeds: an opportunity for wealth and sustainable livelihood for coastal communities. JOURNAL OF APPLIED PHYCOLOGY 2014; 26:1939-1951. [PMID: 25346571 PMCID: PMC4200322 DOI: 10.1007/s10811-014-0304-8] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Revised: 03/25/2014] [Accepted: 03/25/2014] [Indexed: 05/13/2023]
Abstract
The European, Canadian, and Latin American seaweed industries rely on the sustainable harvesting of natural resources. As several countries wish to increase their activity, the harvest should be managed according to integrated and participatory governance regimes to ensure production within a long-term perspective. Development of regulations and directives enabling the sustainable exploitation of natural resources must therefore be brought to the national and international political agenda in order to ensure environmental, social, and economic values in the coastal areas around the world. In Europe, Portugal requires an appraisal of seaweed management plans while Norway and Canada have developed and implemented coastal management plans including well-established and sustainable exploitation of their natural seaweed resources. Whereas, in Latin America, different scenarios of seaweed exploitation can be observed; each country is however in need of long-term and ecosystem-based management plans to ensure that exploitation is sustainable. These plans are required particularly in Peru and Brazil, while Chile has succeeded in establishing a sustainable seaweed-harvesting plan for most of the economically important seaweeds. Furthermore, in both Europe and Latin America, seaweed aquaculture is at its infancy and development will have to overcome numerous challenges at different levels (i.e., technology, biology, policy). Thus, there is a need for regulations and establishment of "best practices" for seaweed harvesting, management, and cultivation. Trained human resources will also be required to provide information and education to the communities involved, to enable seaweed utilization to become a profitable business and provide better income opportunities to coastal communities.
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Affiliation(s)
- Céline Rebours
- Bioforsk, Norwegian Institute for Agricultural and Environmental Research, Frederik A. Dahlsvei 20, 1430 Ås, Norway
- Present Address: Arctic Agriculture and Land Use Division, Bioforsk, NO-8049 Bodø, Norway
| | - Eliane Marinho-Soriano
- Department of Oceanography and Limnology, Federal University of Rio Grande do Norte, Via Costeira, Praia de Mãe Luiza, s/n, Natal, RN 59014-002 Brazil
| | - José A. Zertuche-González
- Instituto de Investigaciones Oceanológicas, Universidad Autónoma de Baja California, Km 107 Carretera Tijuana-Ensenada, 22860 Ensenada, BC Mexico
| | - Leila Hayashi
- Aquaculture Department, Federal University of Santa Catarina, Rod. Admar Gonzaga 1346, Itacorubi, Florianópolis, SC Brazil
| | - Julio A. Vásquez
- Facultad de Ciencias del Mar, Centro de Estudios Avanzados en Zonas Aridas, Universidad Católica del Norte, Coquimbo, Chile
| | - Paul Kradolfer
- PSW SA, Av. Paul Poblet Parcela D19 Lote 1, Lurín, Lima 16, Peru
| | | | - Raul Ugarte
- Acadian Seaplants Limited, 30 Brown Ave., Dartmouth, NS B3B-1X8 Canada
| | - Maria Helena Abreu
- ALGAPlus Lda, Travessa Alexandre da Conceição 3830-196, Ílhavo, Portugal
| | | | | | - Rolf Rødven
- Bioforsk, Norwegian Institute for Agricultural and Environmental Research, Frederik A. Dahlsvei 20, 1430 Ås, Norway
| | - Daniel Robledo
- Department of Marine Resources, CINVESTAV-IPN, Km 6 Carretera Ant. Progreso, 97310 Mérida, Yucatán Mexico
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Johansson ML, Raimondi PT, Reed DC, Coelho NC, Serrão EA, Alberto FA. Looking into the black box: simulating the role of self-fertilization and mortality in the genetic structure of Macrocystis pyrifera. Mol Ecol 2013; 22:4842-54. [PMID: 23962179 DOI: 10.1111/mec.12444] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 07/03/2013] [Indexed: 01/10/2024]
Abstract
Patterns of spatial genetic structure (SGS), typically estimated by genotyping adults, integrate migration over multiple generations and measure the effective gene flow of populations. SGS results can be compared with direct ecological studies of dispersal or mating system to gain additional insights. When mismatches occur, simulations can be used to illuminate the causes of these mismatches. Here, we report a SGS and simulation-based study of self-fertilization in Macrocystis pyrifera, the giant kelp. We found that SGS is weaker than expected in M. pyrifera and used computer simulations to identify selfing and early mortality rates for which the individual heterozygosity distribution fits that of the observed data. Only one (of three) population showed both elevated kinship in the smallest distance class and a significant negative slope between kinship and geographical distance. All simulations had poor fit to the observed data unless mortality due to inbreeding depression was imposed. This mortality could only be imposed for selfing, as these were the only simulations to show an excess of homozygous individuals relative to the observed data. Thus, the expected data consistently achieved nonsignificant differences from the observed data only under models of selfing with mortality, with best fits between 32% and 42% selfing. Inbreeding depression ranged from 0.70 to 0.73. The results suggest that density-dependent mortality of early life stages is a significant force in structuring Macrocystis populations, with few highly homozygous individuals surviving. The success of these results should help to validate simulation approaches even in data-poor systems, as a means to estimate otherwise difficult-to-measure life cycle parameters.
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Affiliation(s)
- Mattias L Johansson
- Department of Biological Sciences, University of Wisconsin - Milwaukee, PO Box 413, Milwaukee, WI, 53201, USA
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Carney LT, Bohonak AJ, Edwards MS, Alberto F. Genetic and experimental evidence for a mixed-age, mixed-origin bank of kelp microscopic stages in southern California. Ecology 2013; 94:1955-65. [PMID: 24279267 DOI: 10.1890/13-0250.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Laboratory studies have demonstrated that the microscopic stages of kelps can rapidly resume development from a delayed state. Like terrestrial seeds or aquatic resting eggs, banks of delayed kelp stages may supplement population recovery after periods of stress, playing an important role for kelp populations that experience adult sporophyte absences due to seasonal or interannual disturbances. We found that removing the microscopic stages from natural rock substratum could prevent the appearance of juvenile kelp sporophytes for three months and the establishment of a diverse kelp assemblage for over four months within a southern California kelp forest. Juveniles were observed within one month in plots where microscopic stages were left intact, which may confer an advantage for the resulting sporophytes as they attain larger sizes before later recruiting neighbors. Microsatellite diversity was high (expected heterozygosity HE approximately 0.9) for juveniles and adults within our sites. Using a microsatellite-based parentage analysis for the dominant kelp, Macrocystis pyrifera, we estimated that a portion of the new M. pyrifera sporophyte recruits had originated from their parents at least seven months after their parents had disappeared. Similar delay durations have been demonstrated in recent laboratory studies. Additionally, our results suggest that zoospore dispersal distances > 50 m may be supported by including additional microsatellite loci in the analysis. We propose a mixed-age and, potentially, a mixed-origin bank of M. pyrifera gametophytes promotes maximal genetic diversity in recovering populations and reduces population genetic subdivision and self-fertilization rates for intact populations by promoting the survival of zoospores dispersed > 10 m and during inhospitable environmental conditions.
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Affiliation(s)
- Laura T Carney
- Department of Biology, San Diego State University, 5500 Campanile Drive, San Diego, California 92182, USA.
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46
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Harrer SL, Reed DC, Holbrook SJ, Miller RJ. Patterns and controls of the dynamics of net primary production by understory macroalgal assemblages in giant kelp forests. JOURNAL OF PHYCOLOGY 2013; 49:248-257. [PMID: 27008514 DOI: 10.1111/jpy.12023] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2011] [Accepted: 10/23/2012] [Indexed: 06/05/2023]
Abstract
Macroalgae are important primary producers in many subtidal habitats, yet little information exists on the temporal and spatial dynamics of net primary production (NPP) by entire subtidal assemblages. This knowledge gap reflects the logistical challenges in measuring NPP of diverse macroalgal assemblages in shallow marine habitats. Here, we couple a simple primary production model with nondestructive estimates of taxon-specific biomass on subtidal reefs off Santa Barbara, California to produce a 4-year time series of net primary production by intact assemblages of understory macroalgae in giant kelp forests off Santa Barbara, California, USA. Daily bottom irradiance varied significantly throughout the year, and algal assemblages were on average exposed to saturating irradiance for only 1.3-4.5 h per day, depending on the time of year. Despite these variable light-limiting conditions, biomass rather than irradiance explained the vast majority of variation observed in daily NPP at all times of the year. Measurements of peak biomass in spring and summer proved to be good predictors of NPP for the entire year, explaining as much as 76% of the observed variation. In contrast, bottom irradiance was a poor predictor of NPP, explaining <10% of the variation in NPP when analyzed seasonally and ~2% when evaluated annually. Our finding that annual NPP by macroalgal assemblages can be predicted from a single, nondestructive measurement of biomass should prove useful for developing time series data that are necessary to evaluate natural and anthropogenic changes in NPP by one of the world's most productive ecosystems.
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Affiliation(s)
- Shannon L Harrer
- Department of Ecology Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, California, 93106, USA
- Marine Science Institute, University of California Santa Barbara, Santa Barbara, California, 93106, USA
| | - Daniel C Reed
- Marine Science Institute, University of California Santa Barbara, Santa Barbara, California, 93106, USA
| | - Sally J Holbrook
- Department of Ecology Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, California, 93106, USA
- Marine Science Institute, University of California Santa Barbara, Santa Barbara, California, 93106, USA
| | - Robert J Miller
- Marine Science Institute, University of California Santa Barbara, Santa Barbara, California, 93106, USA
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47
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Sea Urchins as Drivers of Shallow Benthic Marine Community Structure. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/b978-0-12-396491-5.00014-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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49
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Thrush SF, Hewitt JE, Lohrer AM. Interaction networks in coastal soft-sediments highlight the potential for change in ecological resilience. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2012; 22:1213-1223. [PMID: 22827129 DOI: 10.1890/11-1403.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Recent studies emphasize the role of indirect relationships and feedback loops in maintaining ecosystem resilience. Environmental changes that impact on the organisms involved in these processes have the potential to initiate threshold responses and fundamentally shift the interactions within an ecosystem. However, empirical studies are hindered by the difficulty of designing appropriate manipulative experiments to capture this complexity. Here we employ structural equation modeling to define and test the architecture of ecosystem interaction networks. Using survey data from 19 estuaries we investigate the interactions between biological (abundance of large bioturbating macrofauna, microphytobenthos, and detrital matter) and physical (sediment grain size) processes. We assess the potential for abrupt changes in the architecture of the network and the strength of interactions to occur across environmental gradients. Our analysis identified a potential threshold in the relationship between sediment mud content and benthic chlorophyll a, at -12 microg/g, using quantile regression. Below this threshold, the interaction network involved different variables and fewer feedbacks than above. This approach has potential to improve our empirical understanding of thresholds in ecological systems and our ability to design manipulative experiments that test how and when a threshold will be passed. It can also be used to indicate to resource managers that a particular system has the potential to exhibit threshold responses to environmental change, emphasizing precautionary management and facilitating a better understanding of how persistent multiple stressors threaten the resilience and long-term use of natural ecosystems.
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Affiliation(s)
- S F Thrush
- National Institute of Water and Atmospheric Research, P.O. Box 11-115, Hamilton 3251, New Zealand.
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Kawamata S. Experimental evaluation of the anti-attachment effect of microalgal mats on grazing activity of the sea urchin Strongylocentrotus nudus in oscillating flows. J Exp Biol 2012; 215:1464-71. [PMID: 22496282 DOI: 10.1242/jeb.068411] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Algal mats can hinder the adhesion of the tube feet of sea urchins. This leads to the hypothesis that the restriction of sea urchin feeding activity by wave action can potentially be enhanced by the presence of algal mats, which will facilitate the survival of kelp recruits at sites with wave action in urchin barrens. To evaluate the potential anti-attachment effect of algal mats on sea urchins, a laboratory tank experiment was performed on the movement of Strongylocentrotus nudus sea urchins and their grazing on juvenile kelp plants at the center of 30×30 cm flat test substrates with or without a thin-layer microalgal mat at four levels of oscillatory flow (maximum orbital velocity: 10, 20, 30 and 40 cm s(-1)). The grazing loss of kelp slightly increased with increasing velocity up to 30 cm s(-1) in the absence of microalgal mats, while in contrast the loss substantially decreased at 30 cm s(-1) in their presence. Sea urchins were dislodged more frequently at 20 cm s(-1) or higher velocities in the presence of microalgal mats. Mats were frequently abraded by scraping by the adoral spines during urchin movement at high velocities (30 and 40 cm s(-1)) but were subject to no or only slight urchin grazing in most cases. The results indicate that the overall decrease in grazing loss of kelp within the microalgal mats was attributable to the anti-attachment effect on urchins during incursions rather than due to urchins grazing on the mats.
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Affiliation(s)
- Shigeru Kawamata
- National Research Institute of Fisheries Engineering, Fisheries Research Agency, 7620-7 Hasaki, Kamisu City, Ibaraki 314-0408, Japan.
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