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Godard RD, Wilson CM, Amstutz CG, Badawy N, Richardson B. Impacts of hurricanes and disease on Diadema antillarum in shallow water reef and mangrove locations in St John, USVI. PLoS One 2024; 19:e0297026. [PMID: 38359027 PMCID: PMC10868783 DOI: 10.1371/journal.pone.0297026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 12/26/2023] [Indexed: 02/17/2024] Open
Abstract
The 1983-1984 mortality event of the long-spined sea urchin Diadema antillarum reduced their population by up to 99% and was accompanied by a phase shift from coral dominated to algal dominated reefs in the Caribbean. Modest rebounds of D. antillarum populations in the Caribbean have been noted, and here we document the impacts of two major hurricanes (2017, Irma and Maria) and the 2022 disease outbreak on populations of D. antillarum found by targeted surveys in the urchin zone at nine fringing reef and three mangrove sites on St. John, USVI. D. antillarum populations at the reef sites had declined by 66% five months after the hurricanes but showed significant recovery just one year later. The impact of recent disease on these populations was much more profound, with all reef populations exhibiting a significant decline (96.4% overall). Fifteen months after the disease was first noted, D. antillarum at reef sites exhibited a modest yet significant recovery (15% pre-disease density). D. antillarum populations in mangrove sites were impacted by the hurricanes but exhibited much higher density than reef sites after the disease outbreak, suggesting that at D. antillarum in some locations may be less vulnerable to disease.
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Affiliation(s)
- Renee D. Godard
- Departments of Biology and Environmental Studies, Hollins University, Roanoke, Va, United States of America
| | - C. Morgan Wilson
- Departments of Biology and Environmental Studies, Hollins University, Roanoke, Va, United States of America
| | | | - Natalie Badawy
- Departments of Biology and Environmental Studies, Hollins University, Roanoke, Va, United States of America
| | - Brittany Richardson
- Departments of Biology and Environmental Studies, Hollins University, Roanoke, Va, United States of America
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de Breuyn M, van der Last AJ, Klokman OJ, Hylkema A. Diurnal predators of restocked lab-reared and wild Diadema antillarum near artificial reefs in Saba. PeerJ 2023; 11:e16189. [PMID: 37846309 PMCID: PMC10576963 DOI: 10.7717/peerj.16189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 09/06/2023] [Indexed: 10/18/2023] Open
Abstract
The long-spined sea urchin Diadema antillarum controls reef dynamics by grazing on algae and increasing coral recruitment. Populations of Diadema never recovered after a mass-die off in 1983 and 1984, and numbers were further reduced by a more recent die-off in 2022. To restore grazing pressure and thereby the resilience of Caribbean coral reefs, multiple Diadema restocking efforts have been performed. Although results vary, relatively low retention is one of the reasons restocking is not considered more often. If causes for the low retention can be identified, suitable measures may be able to increase restocking success. In this study, we monitored restocked lab-reared and wild juvenile Diadema on artificial reefs around Saba, Caribbean Netherlands. To assess the retention of Diadema over time, we conducted diver surveys and used underwater photo time lapse during daylight. Retention of uncaged lab-reared and wild Diadema decreased steadily with less than 30% surviving after 10 days. In total, 138 predator-prey interactions were recorded, of which 99% involved the queen triggerfish Balistes vetula, although other potential predators were present in the area. None of the recorded predator-prey interactions was successful, which suggests that artificial reefs with incorporated shelters may be suitable for juveniles as daytime refuge. However, Diadema that were more often attacked during the day were more likely to be absent the next morning. Because queen triggerfish often visited the experimental site in the first or last hour of daylight, it could be that they were more successful in their attacks when it was too dark to see anything on the photos and when Diadema came out to feed or to look for better shelter opportunities. If Diadema migrated off the artificial reef, they were probably predated during the process, because no Diadema were found on surrounding reefs. Wild Diadema were attacked significantly more often than lab-reared Diadema, possibly because the wild urchins were larger, but this did not significantly affect retention. Future restocking should be performed on natural or artificial reefs with deeper shelters, so Diadema can retract farther into their crevice, and should include night-time monitoring to identify the remaining unknown factors that cause low retention, including migration and nocturnal predation. This knowledge is urgently needed to coral reef managers so they can increase Diadema restocking success by selecting reefs with a lower predator density, protect urchins during an acclimatization period and/or conduct temporary predator control measures.
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Affiliation(s)
- Mareike de Breuyn
- Van Hall Larenstein University of Applied Sciences, Leeuwarden, Friesland, The Netherlands
| | - Alex J. van der Last
- Van Hall Larenstein University of Applied Sciences, Leeuwarden, Friesland, The Netherlands
| | - Oliver J. Klokman
- Van Hall Larenstein University of Applied Sciences, Leeuwarden, Friesland, The Netherlands
| | - Alwin Hylkema
- Van Hall Larenstein University of Applied Sciences, Leeuwarden, Friesland, The Netherlands
- Marine Animal Ecology group, Wageningen University, Wageningen University & Research, Wageningen, Gelderland, The Netherlands
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Arroyo-Esquivel J, Baskett ML, McPherson M, Hastings A. How far to build it before they come? Analyzing the use of the Field of Dreams hypothesis in bull kelp restoration. Ecol Appl 2023; 33:e2850. [PMID: 36942610 DOI: 10.1002/eap.2850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 03/03/2023] [Accepted: 03/10/2023] [Indexed: 05/19/2023]
Abstract
In restoration ecology, the Field of Dreams hypothesis posits that restoration efforts that create a suitable environment could lead to the eventual recovery of the remaining aspects of the ecosystem through natural processes. Natural processes following partial restoration has led to ecosystem recovery in both terrestrial and aquatic systems. However, understanding the efficacy of a "Field of Dreams" approach requires a comparison of different approaches to partial restoration in terms of spatial, temporal, and ecological scale with what would happen given more comprehensive restoration efforts. We explore the relative effect of partial restoration and ongoing recovery on restoration efficacy with a dynamical model based on temperate rocky reefs in Northern California. We analyze our model for both the ability and rate of bull kelp forest recovery under different restoration strategies. We compare the efficacy of a partial restoration approach with a more comprehensive restoration effort by exploring how kelp recovery likelihood and rate change with varying intensities of urchin removal and kelp outplanting over different time periods and spatial scales. We find that, in the case of bull kelp forests, setting more favorable initial conditions for kelp recovery by implementing both urchin harvesting and kelp outplanting at the start of the restoration project has a bigger impact on the kelp recovery rate than applying restoration efforts through a longer period of time. Therefore, partial restoration efforts, in terms of spatial and temporal scale, can be significantly more effective when applied across multiple ecological scales in terms of both the capacity and rate for achieving the target outcomes.
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Affiliation(s)
| | - Marissa L Baskett
- Department of Environmental Science and Policy, University of California, Davis, California, USA
| | - Meredith McPherson
- Department of Ocean Sciences, University of California, Santa Cruz, California, USA
| | - Alan Hastings
- Department of Environmental Science and Policy, University of California, Davis, California, USA
- Santa Fe Institute, Santa Fe, New Mexico, USA
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Bodmer MDV, Wheeler PM, Anand P, Cameron SE, Hintikka S, Cai W, Borcsok AO, Exton DA. The ecological importance of habitat complexity to the Caribbean coral reef herbivore Diadema antillarum: three lines of evidence. Sci Rep 2021; 11:9382. [PMID: 33931650 DOI: 10.1038/s41598-021-87232-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 03/25/2021] [Indexed: 02/02/2023] Open
Abstract
When Caribbean long-spined sea urchins, Diadema antillarum, are stable at high population densities, their grazing facilitates scleractinian coral dominance. Today, populations remain suppressed after a mass mortality in 1983-1984 caused a loss of their ecosystem functions, and led to widespread declines in ecosystem health. This study provides three lines of evidence to support the assertion that a lack of habitat complexity on Caribbean coral reefs contributes to their recovery failure. Firstly, we extracted fractal dimension (D) measurements, used as a proxy for habitat complexity, from 3D models to demonstrate that urchins preferentially inhabit areas of above average complexity at ecologically relevant spatial scales. Secondly, controlled behaviour experiments showed that an energetically expensive predator avoidance behaviour is reduced by 52% in complex habitats, potentially enabling increased resource allocation to reproduction. Thirdly, we deployed a network of simple and cost-effective artificial structures on a heavily degraded reef system in Honduras. Over a 24-month period the adult D. antillarum population around the artificial reefs increased by 320% from 0.05 ± 0.01 to 0.21 ± 0.04 m-2 and the juvenile D. antillarum population increased by 750% from 0.08 ± 0.02 to 0.68 ± 0.07 m-2. This study emphasises the important role of habitat structure in the ecology of D. antillarum and as a barrier to its widespread recovery.
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Delgado GA, Sharp WC. Does artificial shelter have a place in Diadema antillarum restoration in the Florida Keys? Tests of habitat manipulation and sheltering behavior. Glob Ecol Conserv 2021. [DOI: 10.1016/j.gecco.2021.e01502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Precht WF, Aronson RB, Gardner TA, Gill JA, Hawkins JP, Hernández-Delgado EA, Jaap WC, McClanahan TR, McField MD, Murdoch TJT, Nugues MM, Roberts CM, Schelten CK, Watkinson AR, Côté IM. The timing and causality of ecological shifts on Caribbean reefs. Adv Mar Biol 2020; 87:331-360. [PMID: 33293016 DOI: 10.1016/bs.amb.2020.08.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Caribbean reefs have experienced unprecedented changes in the past four decades. Of great concern is the perceived widespread shift from coral to macroalgal dominance and the question of whether it represents a new, stable equilibrium for coral-reef communities. The primary causes of the shift-grazing pressure (top-down), nutrient loading (bottom-up) or direct coral mortality (side-in)-still remain somewhat controversial in the coral-reef literature. We have attempted to tease out the relative importance of each of these causes. Four insights emerge from our analysis of an early regional dataset of information on the benthic composition of Caribbean reefs spanning the years 1977-2001. First, although three-quarters of reef sites have experienced coral declines concomitant with macroalgal increases, fewer than 10% of the more than 200 sites studied were dominated by macroalgae in 2001, by even the most conservative definition of dominance. Using relative dominance as the threshold, a total of 49 coral-to-macroalgae shifts were detected. This total represents ~35% of all sites that were dominated by coral at the start of their monitoring periods. Four shifts (8.2%) occurred because of coral loss with no change in macroalgal cover, 15 (30.6%) occurred because of macroalgal gain without coral loss, and 30 (61.2%) occurred owing to concomitant coral decline and macroalgal increase. Second, the timing of shifts at the regional scale is most consistent with the side-in model of reef degradation, which invokes coral mortality as a precursor to macroalgal takeover, because more shifts occurred after regional coral-mortality events than expected by chance. Third, instantaneous observations taken at the start and end of the time-series for individual sites showed these reefs existed along a continuum of coral and macroalgal cover. The continuous, broadly negative relationship between coral and macroalgal cover suggests that in some cases coral-to-macroalgae phase shifts may be reversed by removing sources of perturbation or restoring critical components such as the herbivorous sea urchin Diadema antillarum to the system. The five instances in which macroalgal dominance was reversed corroborate the conclusion that macroalgal dominance is not a stable, alternative community state as has been commonly assumed. Fourth, the fact that the loss in regional coral cover and concomitant changes to the benthic community are related to punctuated, discrete events with known causes (i.e. coral disease and bleaching), lends credence to the hypothesis that coral reefs of the Caribbean have been under assault from climate-change-related maladies since the 1970s.
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Affiliation(s)
- William F Precht
- Marine and Coastal Programs, Dial Cordy and Associates, Miami, FL, United States.
| | - Richard B Aronson
- Department of Ocean Engineering and Marine Sciences, Florida Institute of Technology, Melbourne, FL, United States
| | | | - Jennifer A Gill
- Centre for Ecology, Evolution and Conservation, School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
| | - Julie P Hawkins
- Environment Department, University of York, York, United Kingdom
| | - Edwin A Hernández-Delgado
- Department of Environmental Sciences and Center for Applied Tropical Ecology and Conservation, Applied Marine Ecology Laboratory, University of Puerto Rico, San Juan, Puerto Rico
| | - Walter C Jaap
- Lithophyte Research LLC, Saint Petersburg, FL, United States
| | - Tim R McClanahan
- Wildlife Conservation Society, Marine Programs, Bronx, NY, United States
| | | | | | - Maggy M Nugues
- EPHE, Laboratoire d'Excellence "CORAIL", PSL Research University, UPVD, CNRS, USR, Perpignan, France
| | - Callum M Roberts
- Environment Department, University of York, York, United Kingdom
| | | | - Andrew R Watkinson
- Living with Environmental Change, School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom
| | - Isabelle M Côté
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
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Caballero-aragón H, Perera-valderrama S, Cerdeira-estrada S, Martell-dubois R, Rosique-de la Cruz L, Álvarez-filip L, Pérez-cervantes E, Estrada-saldívar N, Ressl R. Puerto Morelos Coral Reefs, Their Current State and Classification by a Scoring System. Diversity 2020; 12:272. [DOI: 10.3390/d12070272] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Marine protected areas have been established as essential components for managing and protecting coral reefs to mitigate natural and anthropogenic stressors. One noteworthy example within the Mexican Caribbean is the Arrecife de Puerto Morelos National Park (APMNP), where several studies on the coral communities have been carried out since 2006. In June 2019, we conducted a study in eight sites of the APMNP applying a coral reef assessment method based on biological indicators of both the benthos and the fish communities. In this paper, we present the quantitative results of our study and provide a qualitative criterion assessing seven condition indexes through a scoring system. We also present a statistical comparison with a previous study carried out in 2016. The general status of coral reefs was classified as regular due to the low values of coral recruitment rate and biomass of key commercial fish species. However, living coral cover average was above 20%, with a slight dominance of framework building coral species and the presence of low values of fleshy algae cover, these being positive indicators. Our study found a higher proportion of reef promoter elements and a lower proportion of detractors, compared to a previous study carried out in 2016.
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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. Mar Environ Res 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] [What about the content of this article? (0)] [Affiliation(s)] [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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Ling SD, Kriegisch N, Woolley B, Reeves SE. Density-dependent feedbacks, hysteresis, and demography of overgrazing sea urchins. Ecology 2019; 100:e02577. [PMID: 30707451 DOI: 10.1002/ecy.2577] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 09/13/2018] [Accepted: 10/08/2018] [Indexed: 01/10/2024]
Abstract
Sea urchin grazing can result in regime shift from productive kelp beds to sea urchin barren grounds that represent an alternative and stable reef state. Here we examine the stability of urchin barrens by defining the demographics of the Australian urchin Heliocidaris erythrogramma during regime shift to, and maintenance of, barrens. Inverse-logistic modeling of calibrated in situ annual growth increments for five urchin populations, two from kelp beds and three from barrens, demonstrate slowing of urchin growth as availability and consumption of standing and/or drift kelp declines. Population age structures were predicted from observed sizes over four years (2012-2015, n = 5,864 individuals), which indicated stable age distributions for populations both maintaining barrens and actively grazing among kelp beds. Younger age distributions occurred on barrens whereas more mature populations existed within kelp beds, indicating that high recruitment facilitates maintenance of barrens while overgrazing appeared more reliant on adult urchins grazing from the edges of kelp beds, as opposed to juvenile recruitment among kelp. Leslie-matrix projections indicated potential for unchecked population growth for all study populations, but which varied depending on whether local or regional recruitment rates were modeled. Ultimately, strong density dependence was observed to check population growth; with high-recruitment/high-density populations offset by reduced growth rates and decreased longevity. Increasing disease rates among older urchins in high-density populations were consistent with observed density-dependent mortality, while tethering of healthy urchins revealed highest predation on small urchins within kelp beds, suggesting some remnant resilience of declining kelp habitat. Results demonstrate that the greatest opportunity for urchin population control is when reefs exist in the kelp bed state, at which point urchin populations are prone to negative feedback. Conversely, control of urchins on barrens is demonstrably difficult given positive density-dependent feedbacks that act to stabilize population size and which evidently underpin the hysteresis effect governing the persistence of this alternative stable state.
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Affiliation(s)
- S D Ling
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia
| | - N Kriegisch
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia
| | - B Woolley
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia
| | - S E Reeves
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, 7001, Australia
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Abstract
Rarity is a population characteristic that is usually associated with a high risk of extinction. We argue here, however, that chronically rare species (those with low population densities over many generations across their entire ranges) may have individual-level traits that make populations more resistant to extinction. The major obstacle to persistence at low density is successful fertilisation (union between egg and sperm), and chronically rare species are more likely to survive when (1) fertilisation occurs inside or close to an adult, (2) mate choice involves long-distance signals, (3) adults or their surrogate gamete dispersers are highly mobile, or (4) the two sexes are combined in a single individual. In contrast, external fertilisation and wind- or water-driven passive dispersal of gametes, or sluggish or sedentary adult life habits in the absence of gamete vectors, appear to be incompatible with sustained rarity. We suggest that the documented increase in frequency of these traits among marine genera over geological time could explain observed secular decreases in rates of background extinction. Unanswered questions remain about how common chronic rarity actually is, which traits are consistently associated with chronic rarity, and how chronically rare species are distributed among taxa, and among the world's ecosystems and regions.
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Affiliation(s)
- Geerat J Vermeij
- Department of Earth and Planetary Sciences, University of California, Davis, Davis, CA, 95616, USA
| | - Richard K Grosberg
- Department of Evolution and Ecology, Coastal and Marine Sciences Institute, University of California, Davis, Davis, CA, 95616, USA
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Walsh JJ, Lenes JM, Weisberg RH, Zheng L, Hu C, Fanning KA, Snyder R, Smith J. More surprises in the global greenhouse: Human health impacts from recent toxic marine aerosol formations, due to centennial alterations of world-wide coastal food webs. Mar Pollut Bull 2017; 116:9-40. [PMID: 28111002 DOI: 10.1016/j.marpolbul.2016.12.053] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 12/17/2016] [Accepted: 12/18/2016] [Indexed: 06/06/2023]
Abstract
Reductions of zooplankton biomasses and grazing pressures were observed during overfishing-induced trophic cascades and concurrent oil spills at global scales. Recent phytoplankton increments followed, once Fe-, P-, and N-nutrient limitations of commensal diazotrophs and dinoflagellates were also eliminated by respective human desertification, deforestation, and eutrophication during climate changes. Si-limitation of diatoms instead ensued during these last anthropogenic perturbations of agricultural effluents and sewage loadings. Consequently, ~15% of total world-wide annual asthma trigger responses, i.e. amounting to ~45 million adjacent humans during 2004, resulted from brevetoxin and palytoxin poisons in aerosol forms of western boundary current origins. They were denoted by greater global harmful algal bloom [HAB] abundances and breathing attacks among sea-side children during prior decadal surveys of asthma prevalence, compiled here in ten paired shelf ecosystems of western and eutrophied boundary currents. Since 1965, such inferred onshore fluxes of aerosolized DOC poisons of HABs may have served as additional wind-borne organic carriers of toxic marine MeHg, phthalate, and DDT/DDE vectors, traced by radio-iodine isotopes to potentially elicit carcinomas. During these exchanges, as much as 40% of mercury poisonings may instead have been effected by inhalation of collateral HAB-carried marine neurotoxic aerosols of MeHg, not just from eating marine fish. Health impacts in some areas were additional asthma and pneumonia episodes, as well as endocrine disruptions among the same adjacent humans, with known large local rates of thyroid cancers, physician-diagnosed pulmonary problems, and ubiquitous high indices of mercury in hair, pesticides in breast milk, and phthalates in urine.
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Affiliation(s)
- J J Walsh
- College of Marine Science, University of South Florida, St. Petersberg, FL 33701, United States.
| | - J M Lenes
- College of Marine Science, University of South Florida, St. Petersberg, FL 33701, United States
| | - R H Weisberg
- College of Marine Science, University of South Florida, St. Petersberg, FL 33701, United States
| | - L Zheng
- College of Marine Science, University of South Florida, St. Petersberg, FL 33701, United States
| | - C Hu
- College of Marine Science, University of South Florida, St. Petersberg, FL 33701, United States
| | - K A Fanning
- College of Marine Science, University of South Florida, St. Petersberg, FL 33701, United States
| | - R Snyder
- Virginia Institute of Marine Science Eastern Shore Laboratory, Wachapreague, VA 23480, United States
| | - J Smith
- Department of Radiology, School of Medicine, University of Alabama, Birmingham, AL 35294, United States
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12
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Burge CA, Friedman CS, Getchell R, House M, Lafferty KD, Mydlarz LD, Prager KC, Sutherland KP, Renault T, Kiryu I, Vega-Thurber R. Complementary approaches to diagnosing marine diseases: a union of the modern and the classic. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150207. [PMID: 26880839 PMCID: PMC4760137 DOI: 10.1098/rstb.2015.0207] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/21/2015] [Indexed: 01/01/2023] Open
Abstract
Linking marine epizootics to a specific aetiology is notoriously difficult. Recent diagnostic successes show that marine disease diagnosis requires both modern, cutting-edge technology (e.g. metagenomics, quantitative real-time PCR) and more classic methods (e.g. transect surveys, histopathology and cell culture). Here, we discuss how this combination of traditional and modern approaches is necessary for rapid and accurate identification of marine diseases, and emphasize how sole reliance on any one technology or technique may lead disease investigations astray. We present diagnostic approaches at different scales, from the macro (environment, community, population and organismal scales) to the micro (tissue, organ, cell and genomic scales). We use disease case studies from a broad range of taxa to illustrate diagnostic successes from combining traditional and modern diagnostic methods. Finally, we recognize the need for increased capacity of centralized databases, networks, data repositories and contingency plans for diagnosis and management of marine disease.
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Affiliation(s)
- Colleen A Burge
- Institute of Marine and Environmental Technology, University of Maryland Baltimore County, 701 E Pratt Street, Baltimore, MD 21202, USA
| | - Carolyn S Friedman
- School of Aquatic and Fishery Sciences, University of Washington, Box 355020, Seattle, WA 98195, USA
| | - Rodman Getchell
- Department of Microbiology and Immunology, C4-177 Vet Med Center, College of Veterinary Medicine, Cornell University, 930 Campus Road, Ithaca, NY 14853, USA
| | - Marcia House
- Northwest Indian Fisheries Commission, 6730 Martin Way East, Olympia, WA 98516, USA
| | - Kevin D Lafferty
- US Geological Survey, Western Ecological Research Center, c/o Marine Science Institute, University of California, Santa Barbara, CA 93106, USA
| | - Laura D Mydlarz
- Department of Biology, University of Texas Arlington, 501 South Nedderman, Arlington, TX 76019, USA
| | - Katherine C Prager
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90095, USA Fogarty International Center, National Institutes of Health, Bethesda, MD 20892, USA
| | | | - Tristan Renault
- Ifremer, Département Ressources Biologiques et Environnement, rue de l'Ile d'Yeu, 44311 Nantes Cedex 03, France
| | - Ikunari Kiryu
- National Research Institute of Aquaculture, Fisheries Research Agency, Mie 516-0193, Japan
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Abstract
In 1983-1984, the sea urchin Diadema antillarum suffered mass mortality throughout the Caribbean, Florida, and Bermuda. The demise of this herbivore contributed to a phase shift of Caribbean reefs from coral-dominated to alga-dominated communities. A compilation of published data of D. antillarum population densities shows that there has been moderate recovery since 1983, with the highest rates on islands of the eastern Caribbean. On the average the current population densities are approximately 12% of those before the die-off, apparently because of recruitment limitation, but the exact factors that are constraining the recovery are unclear. Scattered D. antillarum cohorts in some localities and aggregation of settled individuals in shallow water have created zones of higher herbivory in which juvenile coral recruitment, survivorship, and growth are higher than they are in alga-dominated areas. Unlike other stressors on Caribbean coral reefs, recent changes in D. antillarum populations progress toward aiding the recovery of coral cover.
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Affiliation(s)
- H A Lessios
- Smithsonian Tropical Research Institute, Balboa, Panama;
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15
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Abstract
The massive die-off of the long-spined sea urchin, Diadema antillarum, a significant reef grazer, in the mid 1980s was followed by phase shifts from coral dominated to macroalgae dominated reefs in the Caribbean. While Diadema populations have recovered in some reefs with concomitant increases in coral cover, the additional threat of increasing temperatures due to global climate change has not been investigated in adult sea urchins. In this study, I measured acute thermal tolerance of D. antillarum and that of a sympatric sea urchin not associated with coral cover, Echinometra lucunter, over winter, spring, and summer, thus exposing them to substantial natural thermal variation. Animals were taken from the wild and placed in laboratory tanks in room temperature water (∼22 °C) that was then heated at 0.16-0.3 °C min(-1) and the righting behavior of individual sea urchins was recorded. I measured both the temperature at which the animal could no longer right itself (T LoR) and the righting time at temperatures below the T LoR. In all seasons, D. antillarum exhibited a higher mean T LoR than E. lucunter. The mean T LoR of each species increased with increasing environmental temperature revealing that both species acclimatize to seasonal changes in temperatures. The righting times of D. antillarum were much shorter than those of E. lucunter. The longer relative spine length of Diadema compared to that of Echinometra may contribute to their shorter righting times, but does not explain their higher T LoR. The thermal safety margin (the difference between the mean collection temperature and the mean T LoR) was between 3.07-3.66 °C for Echinometra and 3.79-5.67 °C for Diadema. While these thermal safety margins exceed present day temperatures, they are modest compared to those of temperate marine invertebrates. If sea temperatures increase more rapidly than can be accommodated by the sea urchins (either by genetic adaptation, phenotypic plasticity, or both), this will have important consequences for the structure of coral reefs.
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Affiliation(s)
- Elizabeth Sherman
- Department of Natural Sciences, Bennington College , Bennington, VT , USA
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