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Erftemeijer PLA, van Gils J, Fernandes MB, Daly R, van der Heijden L, Herman PMJ. Habitat suitability modelling to improve understanding of seagrass loss and recovery and to guide decisions in relation to coastal discharge. MARINE POLLUTION BULLETIN 2023; 186:114370. [PMID: 36459773 DOI: 10.1016/j.marpolbul.2022.114370] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 09/09/2022] [Accepted: 11/11/2022] [Indexed: 06/17/2023]
Abstract
Habitat suitability modelling was used to test the relationship between coastal discharges and seagrass occurrence based on data from Adelaide (South Australia). Seven variables (benthic light including epiphyte shading, temperature, salinity, substrate, wave exposure, currents and tidal exposure) were simulated using a coupled hydrodynamic-biogeochemical model and interrogated against literature-derived thresholds for nine local seagrass species. Light availability was the most critical driver across the study area but wave exposure played a key role in shallow nearshore areas. Model validation against seagrass mapping data showed 86 % goodness-of-fit. Comparison against later mapping data suggested that modelling could predict ~745 ha of seagrass recovery in areas previously classified as 'false positives'. These results suggest that habitat suitability modelling is reliable to test scenarios and predict seagrass response to reduction of land-based loads, providing a useful tool to guide (investment) decisions to prevent loss and promote recovery of seagrasses.
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Affiliation(s)
- Paul L A Erftemeijer
- School of Biological Sciences and Oceans Institute, University of Western Australia, Crawley, WA 6009, Australia.
| | - Jos van Gils
- Deltares, Department of Marine and Coastal Systems, PO Box 170, 2600 MH Delft, the Netherlands
| | - Milena B Fernandes
- SA Water, GPO Box 1751, Adelaide, SA 5001, Australia; College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia
| | - Rob Daly
- SA Water, GPO Box 1751, Adelaide, SA 5001, Australia
| | - Luuk van der Heijden
- Deltares, Department of Marine and Coastal Systems, PO Box 170, 2600 MH Delft, the Netherlands
| | - Peter M J Herman
- Deltares, Department of Marine and Coastal Systems, PO Box 170, 2600 MH Delft, the Netherlands
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2
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Lebrasse MC, Schaeffer BA, Zimmerman RC, Hill VJ, Coffer MM, Whitman PJ, Salls WB, Graybill DD, Osburn CL. Simulated response of St. Joseph Bay, Florida, seagrass meadows and their belowground carbon to anthropogenic and climate impacts. MARINE ENVIRONMENTAL RESEARCH 2022; 179:105694. [PMID: 35850077 PMCID: PMC9924051 DOI: 10.1016/j.marenvres.2022.105694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 06/22/2022] [Accepted: 06/23/2022] [Indexed: 05/26/2023]
Abstract
Seagrass meadows are degraded globally and continue to decline in areal extent due to human pressures and climate change. This study used the bio-optical model GrassLight to explore the impact of climate change and anthropogenic stressors on seagrass extent, leaf area index (LAI) and belowground organic carbon (BGC) in St. Joseph Bay, Florida, using water quality data and remotely-sensed sea surface temperature (SST) from 2002 to 2020. Model predictions were compared with satellite-derived measurements of seagrass extent and shoot density from the Landsat images for the same period. The GrassLight-derived area of potential seagrass habitat ranged from 36.2 km2 to 39.2 km2, averaging 38.0 ± 0.8 km2 compared to an observed seagrass extent of 23.0 ± 3.0 km2 derived from Landsat (range = 17.9-27.4 km2). GrassLight predicted a mean seagrass LAI of 2.7 m2 leaf m-2 seabed, compared to a mean LAI of 1.9 m2 m-2 estimated from Landsat, indicating that seagrass density in St. Joseph Bay may have been below its light-limited ecological potential. Climate and anthropogenic change simulations using GrassLight predicted the impact of changes in temperature, pH, chlorophyll a, chromophoric dissolved organic matter and turbidity on seagrass meadows. Simulations predicted a 2-8% decline in seagrass extent with rising temperatures that was offset by a 3-11% expansion in seagrass extent in response to ocean acidification when compared to present conditions. Simulations of water quality impacts showed that a doubling of turbidity would reduce seagrass extent by 18% and total leaf area by 21%. Combining climate and water quality scenarios showed that ocean acidification may increase seagrass productivity to offset the negative effects of both thermal stress and declining water quality on the seagrasses growing in St. Joseph Bay. This research highlights the importance of considering multiple limiting factors in understanding the effects of environmental change on seagrass ecosystems.
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Affiliation(s)
- Marie Cindy Lebrasse
- Oak Ridge Institute for Science and Education, U.S. Environmental Protection Agency, Durham, NC, USA; Department of Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, NC, USA.
| | - Blake A Schaeffer
- U.S. Environmental Protection Agency, Office of Research and Development, Durham, NC, USA
| | - Richard C Zimmerman
- Department of Ocean and Earth Sciences, Old Dominion University, Norfolk, VA, USA
| | - Victoria J Hill
- Department of Ocean and Earth Sciences, Old Dominion University, Norfolk, VA, USA
| | - Megan M Coffer
- Oak Ridge Institute for Science and Education, U.S. Environmental Protection Agency, Durham, NC, USA
| | - Peter J Whitman
- Oak Ridge Institute for Science and Education, U.S. Environmental Protection Agency, Durham, NC, USA
| | - Wilson B Salls
- U.S. Environmental Protection Agency, Office of Research and Development, Durham, NC, USA
| | - David D Graybill
- Oak Ridge Institute for Science and Education, U.S. Environmental Protection Agency, Durham, NC, USA
| | - Christopher L Osburn
- Department of Marine, Earth and Atmospheric Sciences, North Carolina State University, Raleigh, NC, USA
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Kaikkonen L, Venesjärvi R, Nygård H, Kuikka S. Assessing the impacts of seabed mineral extraction in the deep sea and coastal marine environments: Current methods and recommendations for environmental risk assessment. MARINE POLLUTION BULLETIN 2018; 135:1183-1197. [PMID: 30301017 DOI: 10.1016/j.marpolbul.2018.08.055] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 07/02/2018] [Accepted: 08/27/2018] [Indexed: 05/27/2023]
Abstract
Mineral extraction from the seabed has experienced a recent surge of interest from both the mining industry and marine scientists. While improved methods of geological investigation have enabled the mapping of new seafloor mineral reserves, the ecological impacts of mining in both the deep sea and the shallow seabed are poorly known. This paper presents a synthesis of the empirical evidence from experimental seabed mining and parallel industries to infer the effects of seabed mineral extraction on marine ecosystems, focusing on polymetallic nodules and ferromanganese concretions. We use a problem-structuring framework to evaluate causal relationships between pressures caused by nodule extraction and the associated changes in marine ecosystems. To ensure that the rationale behind impact assessments is clear, we propose that future impact assessments use pressure-specific expert elicitation. We further discuss integrating ecosystem services in the impact assessments and the implications of current methods for environmental risk assessments.
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Affiliation(s)
- Laura Kaikkonen
- Ecosystems and Environment Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, P.O. Box 65, FI-00014 Helsinki, Finland.
| | - Riikka Venesjärvi
- Biosociety and Environment Unit, Natural Resource Institute Finland, Latokartanonkaari 9, FI-00790 Helsinki, Finland
| | - Henrik Nygård
- Marine Research Centre, Finnish Environment Institute, P.O. Box 140, FI-00251 Helsinki, Finland
| | - Sakari Kuikka
- Ecosystems and Environment Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, P.O. Box 65, FI-00014 Helsinki, Finland
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Fernandes MB, Gils J, Erftemeijer PLA, Daly R, Gonzalez D, Rouse K. A novel approach to determining dynamic nitrogen thresholds for seagrass conservation. J Appl Ecol 2018. [DOI: 10.1111/1365-2664.13252] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Milena B. Fernandes
- SA Water Adelaide South Australia Australia
- College of Science and EngineeringFlinders University Adelaide South Australia Australia
| | | | - Paul L. A. Erftemeijer
- School of Biological Sciences and Oceans InstituteUniversity of Western Australia Crawley Western Australia Australia
| | - Rob Daly
- SA Water Adelaide South Australia Australia
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Wu PPY, McMahon K, Rasheed MA, Kendrick GA, York PH, Chartrand K, Caley MJ, Mengersen K. Managing seagrass resilience under cumulative dredging affecting light: Predicting risk using dynamic Bayesian networks. J Appl Ecol 2017. [DOI: 10.1111/1365-2664.13037] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Paul Pao-Yen Wu
- Australian Research Council; Centre of Excellence in Mathematical and Statistical Frontiers; Brisbane Qld Australia
- School of Mathematical Sciences, Science and Engineering Faculty; Queensland University of Technology; Brisbane Qld Australia
| | - Kathryn McMahon
- The Western Australian Marine Science Institution; Crawley WA Australia
- School of Natural Sciences; Edith Cowan University; Joondalup WA Australia
| | - Michael A. Rasheed
- Centre for Tropical Water & Aquatic Ecosystem Research; James Cook University; Townsville Qld Australia
| | - Gary A. Kendrick
- The Western Australian Marine Science Institution; Crawley WA Australia
- UWA Oceans Institute and School of Plant Biology; University of Western Australia; Perth WA Australia
| | - Paul H. York
- Centre for Tropical Water & Aquatic Ecosystem Research; James Cook University; Townsville Qld Australia
| | - Kathryn Chartrand
- Centre for Tropical Water & Aquatic Ecosystem Research; James Cook University; Townsville Qld Australia
| | - M. Julian Caley
- Australian Research Council; Centre of Excellence in Mathematical and Statistical Frontiers; Brisbane Qld Australia
- School of Mathematical Sciences, Science and Engineering Faculty; Queensland University of Technology; Brisbane Qld Australia
| | - Kerrie Mengersen
- Australian Research Council; Centre of Excellence in Mathematical and Statistical Frontiers; Brisbane Qld Australia
- School of Mathematical Sciences, Science and Engineering Faculty; Queensland University of Technology; Brisbane Qld Australia
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Wu PPY, Mengersen K, McMahon K, Kendrick GA, Chartrand K, York PH, Rasheed MA, Caley MJ. Timing anthropogenic stressors to mitigate their impact on marine ecosystem resilience. Nat Commun 2017; 8:1263. [PMID: 29093493 PMCID: PMC5665875 DOI: 10.1038/s41467-017-01306-9] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 09/08/2017] [Indexed: 11/09/2022] Open
Abstract
Better mitigation of anthropogenic stressors on marine ecosystems is urgently needed to address increasing biodiversity losses worldwide. We explore opportunities for stressor mitigation using whole-of-systems modelling of ecological resilience, accounting for complex interactions between stressors, their timing and duration, background environmental conditions and biological processes. We then search for ecological windows, times when stressors minimally impact ecological resilience, defined here as risk, recovery and resistance. We show for 28 globally distributed seagrass meadows that stressor scheduling that exploits ecological windows for dredging campaigns can achieve up to a fourfold reduction in recovery time and 35% reduction in extinction risk. Although the timing and length of windows vary among sites to some degree, global trends indicate favourable windows in autumn and winter. Our results demonstrate that resilience is dynamic with respect to space, time and stressors, varying most strongly with: (i) the life history of the seagrass genus and (ii) the duration and timing of the impacting stress.
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Affiliation(s)
- Paul Pao-Yen Wu
- Australian Research Council Centre of Excellence in Mathematical and Statistical Frontiers, University of Melbourne, Melbourne, VIC, 3010, Australia.
- School of Mathematical Sciences, Queensland University of Technology, GPO Box 2434, 2 George Street, Brisbane, QLD, 4001, Australia.
| | - Kerrie Mengersen
- Australian Research Council Centre of Excellence in Mathematical and Statistical Frontiers, University of Melbourne, Melbourne, VIC, 3010, Australia
- School of Mathematical Sciences, Queensland University of Technology, GPO Box 2434, 2 George Street, Brisbane, QLD, 4001, Australia
| | - Kathryn McMahon
- School of Sciences and Centre for Marine Ecosystems Research, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027, Australia
- WAMSI Headquarters, M095, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia
| | - Gary A Kendrick
- WAMSI Headquarters, M095, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia
- UWA Oceans Institute and School of Biological Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia
| | - Kathryn Chartrand
- Centre for Tropical Water & Aquatic Ecosystem Research, James Cook University, PO Box 6811, 14-88 McGregor Road, Cairns, QLD, 4870, Australia
| | - Paul H York
- Centre for Tropical Water & Aquatic Ecosystem Research, James Cook University, PO Box 6811, 14-88 McGregor Road, Cairns, QLD, 4870, Australia
| | - Michael A Rasheed
- Centre for Tropical Water & Aquatic Ecosystem Research, James Cook University, PO Box 6811, 14-88 McGregor Road, Cairns, QLD, 4870, Australia
| | - M Julian Caley
- Australian Research Council Centre of Excellence in Mathematical and Statistical Frontiers, University of Melbourne, Melbourne, VIC, 3010, Australia
- School of Mathematical Sciences, Queensland University of Technology, GPO Box 2434, 2 George Street, Brisbane, QLD, 4001, Australia
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7
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Evans SM, Vergés A, Poore AGB. Genotypic Diversity and Short-term Response to Shading Stress in a Threatened Seagrass: Does Low Diversity Mean Low Resilience? FRONTIERS IN PLANT SCIENCE 2017; 8:1417. [PMID: 28855915 PMCID: PMC5557787 DOI: 10.3389/fpls.2017.01417] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 07/31/2017] [Indexed: 06/07/2023]
Abstract
Seagrasses that are predominantly clonal often have low levels of genetic variation within populations and predicting their response to changing conditions requires an understanding of whether genetic variation confers increased resistance to environmental stressors. A higher level of genetic diversity is assumed to benefit threatened species due to the increased likelihood of those populations having genotypes that can persist under environmental change. To test this idea, we conducted an in situ shading experiment with six geographically distinct meadows of the threatened seagrass Posidonia australis that vary in genetic diversity. Different genotypes within meadows varied widely in their physiological and growth responses to reduced light during a simulated short-term turbidity event. The majority of meadows were resistant to the sudden reduction in light availability, but a small subset of meadows with low genotypic diversity were particularly vulnerable to the early effects of shading, showing substantially reduced growth rates after only 3 weeks. Using the photosynthetic performance (maximum quantum yield) of known genotypes, we simulated meadows of varying genetic diversity to show that higher diversity can increase meadow resilience to stress by ensuring a high probability of including a high-performing genotype. These results support the hypothesis that complementarity among genotypes enhances the adaptive capacity of a population, and have significant implications for the conservation of declining P. australis meadows close to the species range edge on the east coast of Australia, where the genotypic diversity is low.
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Affiliation(s)
- Suzanna M. Evans
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, SydneyNSW, Australia
- Centre for Marine Bio-Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, SydneyNSW, Australia
| | - Adriana Vergés
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, SydneyNSW, Australia
- Centre for Marine Bio-Innovation, School of Biological, Earth and Environmental Sciences, University of New South Wales, SydneyNSW, Australia
- Sydney Institute of Marine Science, MosmanNSW, Australia
| | - Alistair G. B. Poore
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, SydneyNSW, Australia
- Sydney Institute of Marine Science, MosmanNSW, Australia
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8
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Wu PP, Julian Caley M, Kendrick GA, McMahon K, Mengersen K. Dynamic Bayesian network inferencing for non‐homogeneous complex systems. J R Stat Soc Ser C Appl Stat 2017. [DOI: 10.1111/rssc.12228] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Paul P.‐Y. Wu
- Queensland University of Technology, and Australian Research Council Centre of Excellence in Mathematical and Statistical Frontiers Brisbane Australia
| | - M. Julian Caley
- Queensland University of Technology, and Australian Research Council Centre of Excellence in Mathematical and Statistical Frontiers Brisbane Australia
| | - Gary A. Kendrick
- University of Western Australia, Crawley, and Western Australia Marine Science Institution Perth Australia
| | - Kathryn McMahon
- Edith Cowan University, Joondalup, and Western Australia Marine Science Institution Perth Australia
| | - Kerrie Mengersen
- Queensland University of Technology, and Australian Research Council Centre of Excellence in Mathematical and Statistical Frontiers Brisbane Australia
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9
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Barletta M, Cysneiros FJA, Lima ARA. Effects of dredging operations on the demersal fish fauna of a South American tropical-subtropical transition estuary. JOURNAL OF FISH BIOLOGY 2016; 89:890-920. [PMID: 27241214 DOI: 10.1111/jfb.12999] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 04/12/2016] [Indexed: 06/05/2023]
Abstract
Changes in the environment and in the composition of fish assemblages in the Paranaguá Estuary (South Brazil) were assessed by comparisons made before, during and after dredging operations, in the same months and areas studied in the previous year. Interactions between year and month were observed for salinity. During the dredging year fish total density was 2 individuals m(-2) and with a total biomass of 104 g m(-2) (among 31 species captured). For the same period the year before, 0·3 individuals m(-2) and 3 g m(-2) were captured (38 species). The number of species showed significant time v. month interactions, assuming that fish species composition varied for both year and month. Total mean density and biomass showed significant differences for interaction time v. month, and density and biomass in the dredging month September 2001 in the main channel were scientifically different from other months. Interaction times v. area were significant for Cathorops spixii (increased biomass), Aspistor luniscutis (increased density), Menticirrhus americanus (decreased biomass) and Cynoscion leiarchus (decreased density and biomass). This suggests that during the dredging process there is a change in the structure of the demersal fish assemblage. The impact (damage and mortality) induced by dredging on the macrobenthic animals along the dredge path attracted adults of C. spixii that reached densities 10 times greater than in the year before. On the other hand, sciaenid species practically disappeared. To contribute to the conservation of the estuarine fish fauna, and maintain fisheries production of the Paranaguá Estuary and surrounding areas, it is recommended that, dredging should be done from the late rainy season to the early dry season. Decisions must take into account the ecological cycles of socio-economically important fish species and prioritize the safe disposal of dredged spoils.
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Affiliation(s)
- M Barletta
- Laboratório de Ecologia e Gerenciamento de Ecossistemas Costeiros e Estuarinos (LEGECE), Departmento de Oceanografia, Universidade Federal de Pernambuco, Cidade Universitária, 50740-550, Recife, Pernambuco, Brazil
| | - F J A Cysneiros
- Departamento de Estatística, Universidade Federal de Pernambuco, Cidade Universitária, 50740-550, Recife, Pernambuco, Brazil
| | - A R A Lima
- Laboratório de Ecologia e Gerenciamento de Ecossistemas Costeiros e Estuarinos (LEGECE), Departmento de Oceanografia, Universidade Federal de Pernambuco, Cidade Universitária, 50740-550, Recife, Pernambuco, Brazil
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10
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Hovey RK, Statton J, Fraser MW, Ruiz-Montoya L, Zavala-Perez A, Rees M, Stoddart J, Kendrick GA. Strategy for assessing impacts in ephemeral tropical seagrasses. MARINE POLLUTION BULLETIN 2015; 101:594-599. [PMID: 26541985 DOI: 10.1016/j.marpolbul.2015.10.054] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 10/19/2015] [Accepted: 10/22/2015] [Indexed: 06/05/2023]
Abstract
We investigated the phenology and spatial patterns in Halophila decipiens by assessing biomass, reproduction and seed density in ~400 grab samples collected across nine sites (8 to 14 m water depth) between June 2011 and December 2012. Phenology correlated with light climate which is governed by the summer monsoon (wet period). During the wet period, sedimentary seed banks prevailed, varying spatially at both broad and fine scales, presenting a source of propagules for re-colonisation following the unfavourable growing conditions of the monsoon. Spatial patterns in H. decipiens biomass following monsoon conditions were highly variable within a landscape that largely comprised potential seagrass habitat. Management strategies for H. decipiens and similar transient species must recognise the high temporal and spatial variability of these populations and be underpinned by a framework that emphasises vulnerability assessments of different life stages instead of relying solely on thresholds for standing stock at fixed reference sites.
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Affiliation(s)
- Renae K Hovey
- Ocean's Institute, University of Western Australia, Crawley, Western Australia 6009, Australia; School Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia.
| | - John Statton
- Ocean's Institute, University of Western Australia, Crawley, Western Australia 6009, Australia; School Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Matthew W Fraser
- Ocean's Institute, University of Western Australia, Crawley, Western Australia 6009, Australia; School Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Leonardo Ruiz-Montoya
- Ocean's Institute, University of Western Australia, Crawley, Western Australia 6009, Australia; School Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Andrea Zavala-Perez
- Ocean's Institute, University of Western Australia, Crawley, Western Australia 6009, Australia; School Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia
| | - Max Rees
- MScience Pty Ltd., Nedlands, Western Australia 6009, Australia
| | - James Stoddart
- Ocean's Institute, University of Western Australia, Crawley, Western Australia 6009, Australia; MScience Pty Ltd., Nedlands, Western Australia 6009, Australia
| | - Gary A Kendrick
- Ocean's Institute, University of Western Australia, Crawley, Western Australia 6009, Australia; School Plant Biology, University of Western Australia, Crawley, Western Australia 6009, Australia
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11
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Gartner A, Lavery PS, Lonzano-Montes H. Trophic implications and faunal resilience following one-off and successive disturbances to an Amphibolis griffithii seagrass system. MARINE POLLUTION BULLETIN 2015; 94:131-143. [PMID: 25840868 DOI: 10.1016/j.marpolbul.2015.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 02/26/2015] [Accepted: 03/01/2015] [Indexed: 06/04/2023]
Abstract
Disturbances in seagrass systems often lead to considerable loss of seagrass fauna. We examined the capacity for seagrass fauna, across multiple trophic levels, to recover from disturbances, using empirical and modelling techniques. Model outputs, using Ecosim with Ecopath (EwE), were consistent with the results of field investigations, highlighting the models robustness. Modelled outcomes suggest second and third order consumers are likely to be negatively effected by disturbances in the seagrass canopy. Particularly piscivores, which once disturbed, appear unlikely to recover following severe declines in primary productivity. EwE also revealed the complex interaction between the duration and intensity of disturbances on seagrass fauna, which may differentially affect higher order consumers. Further, modelling predicted a variable capacity of higher order consumers to recover from successive disturbances, suggesting taxa with comparatively fast reproductive cycles and short generation terms would be more resilient than taxa with comparatively long generation terms and slow reproductive cycles.
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12
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Coulon F, Azéma N. Morpho-granular approach to characterize harbour sediments and their agglomeration/dispersion behaviour. POWDER TECHNOL 2015. [DOI: 10.1016/j.powtec.2015.01.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Mestres M, Sierra JP, Mösso C, Sánchez-Arcilla A, Hernáez M, Morales J. Numerical assessment of the dispersion of overspilled sediment from a dredge barge and its sensitivity to various parameters. MARINE POLLUTION BULLETIN 2014; 79:225-235. [PMID: 24365453 DOI: 10.1016/j.marpolbul.2013.12.009] [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: 10/30/2013] [Revised: 11/25/2013] [Accepted: 12/02/2013] [Indexed: 06/03/2023]
Abstract
Marine dredging operations are not uncommon in coastal waters since they are necessary for several beneficial uses, such as harbour maintenance, beach nourishment or removal/capping of pollutants, amongst others. They also constitute a significant risk for the environment, changing its physical, chemical and biological characteristics, as evidenced by many authors. In this study, two numerical models are used to simulate the dispersion pattern of fine suspended sediment spilled from a dredge barge, considering different hydrodynamic scenarios, particle sizes and dredging tracks in a mesotidal environment. The results show that, in this particular case, the currents (largely induced by the tide) are the main responsible for the final disposition of the settled particles, being the other variables of secondary importance.
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Affiliation(s)
- Marc Mestres
- Centre Internacional d'Investigació dels Recursos Costaners (CIIRC), c/Jordi Girona 1-3, Mòdul D1, 08034 Barcelona, Spain.
| | - Joan Pau Sierra
- Centre Internacional d'Investigació dels Recursos Costaners (CIIRC), c/Jordi Girona 1-3, Mòdul D1, 08034 Barcelona, Spain; Laboratori d'Enginyeria Marítima (LIM-UPC), Universitat Politècnica de Catalunya, c/Jordi Girona 1-3, Mòdul D1, 08034 Barcelona, Spain
| | - César Mösso
- Centre Internacional d'Investigació dels Recursos Costaners (CIIRC), c/Jordi Girona 1-3, Mòdul D1, 08034 Barcelona, Spain; Laboratori d'Enginyeria Marítima (LIM-UPC), Universitat Politècnica de Catalunya, c/Jordi Girona 1-3, Mòdul D1, 08034 Barcelona, Spain
| | - Agustín Sánchez-Arcilla
- Centre Internacional d'Investigació dels Recursos Costaners (CIIRC), c/Jordi Girona 1-3, Mòdul D1, 08034 Barcelona, Spain; Laboratori d'Enginyeria Marítima (LIM-UPC), Universitat Politècnica de Catalunya, c/Jordi Girona 1-3, Mòdul D1, 08034 Barcelona, Spain
| | - Mario Hernáez
- Autoridad Portuaria de Bilbao, Campo Volantín, 37, 48007 Bilbao, Spain
| | - Jorge Morales
- Autoridad Portuaria de Bilbao, Campo Volantín, 37, 48007 Bilbao, Spain
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15
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Chronic exposure of corals to fine sediments: lethal and sub-lethal impacts. PLoS One 2012; 7:e37795. [PMID: 22662225 PMCID: PMC3360596 DOI: 10.1371/journal.pone.0037795] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 04/26/2012] [Indexed: 11/19/2022] Open
Abstract
Understanding the sedimentation and turbidity thresholds for corals is critical in assessing the potential impacts of dredging projects in tropical marine systems. In this study, we exposed two species of coral sampled from offshore locations to six levels of total suspended solids (TSS) for 16 weeks in the laboratory, including a 4 week recovery period. Dose-response relationships were developed to quantify the lethal and sub-lethal thresholds of sedimentation and turbidity for the corals. The sediment treatments affected the horizontal foliaceous species (Montipora aequituberculata) more than the upright branching species (Acropora millepora). The lowest sediment treatments that caused full colony mortality were 30 mg l−1 TSS (25 mg cm−2 day−1) for M. aequituberculata and 100 mg l−1 TSS (83 mg cm−2 day−1) for A. millepora after 12 weeks. Coral mortality generally took longer than 4 weeks and was closely related to sediment accumulation on the surface of the corals. While measurements of damage to photosystem II in the symbionts and reductions in lipid content and growth indicated sub-lethal responses in surviving corals, the most reliable predictor of coral mortality in this experiment was long-term sediment accumulation on coral tissue.
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