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Houskeeper HF, Rosenthal IS, Cavanaugh KC, Pawlak C, Trouille L, Byrnes JEK, Bell TW, Cavanaugh KC. Automated satellite remote sensing of giant kelp at the Falkland Islands (Islas Malvinas). PLoS One 2022; 17:e0257933. [PMID: 34990455 PMCID: PMC8735600 DOI: 10.1371/journal.pone.0257933] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 12/20/2021] [Indexed: 11/30/2022] Open
Abstract
Giant kelp populations that support productive and diverse coastal ecosystems at temperate and subpolar latitudes of both hemispheres are vulnerable to changing climate conditions as well as direct human impacts. Observations of giant kelp forests are spatially and temporally uneven, with disproportionate coverage in the northern hemisphere, despite the size and comparable density of southern hemisphere kelp forests. Satellite imagery enables the mapping of existing and historical giant kelp populations in understudied regions, but automating the detection of giant kelp using satellite imagery requires approaches that are robust to the optical complexity of the shallow, nearshore environment. We present and compare two approaches for automating the detection of giant kelp in satellite datasets: one based on crowd sourcing of satellite imagery classifications and another based on a decision tree paired with a spectral unmixing algorithm (automated using Google Earth Engine). Both approaches are applied to satellite imagery (Landsat) of the Falkland Islands or Islas Malvinas (FLK), an archipelago in the southern Atlantic Ocean that supports expansive giant kelp ecosystems. The performance of each method is evaluated by comparing the automated classifications with a subset of expert-annotated imagery (8 images spanning the majority of our continuous timeseries, cumulatively covering over 2,700 km of coastline, and including all relevant sensors). Using the remote sensing approaches evaluated herein, we present the first continuous timeseries of giant kelp observations in the FLK region using Landsat imagery spanning over three decades. We do not detect evidence of long-term change in the FLK region, although we observe a recent decline in total canopy area from 2017-2021. Using a nitrate model based on nearby ocean state measurements obtained from ships and incorporating satellite sea surface temperature products, we find that the area of giant kelp forests in the FLK region is positively correlated with the nitrate content observed during the prior year. Our results indicate that giant kelp classifications using citizen science are approximately consistent with classifications based on a state-of-the-art automated spectral approach. Despite differences in accuracy and sensitivity, both approaches find high interannual variability that impedes the detection of potential long-term changes in giant kelp canopy area, although recent canopy area declines are notable and should continue to be monitored carefully.
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Affiliation(s)
- Henry F. Houskeeper
- Department of Geography, University of California Los Angeles, Los Angeles, California, United States of America
| | - Isaac S. Rosenthal
- School for the Environment, University of Massachusetts Boston, Boston, Massachusetts, United States of America
| | - Katherine C. Cavanaugh
- Department of Geography, University of California Los Angeles, Los Angeles, California, United States of America
| | - Camille Pawlak
- Department of Geography, University of California Los Angeles, Los Angeles, California, United States of America
| | - Laura Trouille
- The Adler Planetarium, Chicago, Illinois, United States of America
| | - Jarrett E. K. Byrnes
- Department of Biology, University of Massachusetts Boston, Boston, Massachusetts, United States of America
| | - Tom W. Bell
- Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
| | - Kyle C. Cavanaugh
- Department of Geography, University of California Los Angeles, Los Angeles, California, United States of America
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McPherson ML, Finger DJI, Houskeeper HF, Bell TW, Carr MH, Rogers-Bennett L, Kudela RM. Large-scale shift in the structure of a kelp forest ecosystem co-occurs with an epizootic and marine heatwave. Commun Biol 2021; 4:298. [PMID: 33674760 PMCID: PMC7935997 DOI: 10.1038/s42003-021-01827-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 02/09/2021] [Indexed: 01/31/2023] Open
Abstract
Climate change is responsible for increased frequency, intensity, and duration of extreme events, such as marine heatwaves (MHWs). Within eastern boundary current systems, MHWs have profound impacts on temperature-nutrient dynamics that drive primary productivity. Bull kelp (Nereocystis luetkeana) forests, a vital nearshore habitat, experienced unprecedented losses along 350 km of coastline in northern California beginning in 2014 and continuing through 2019. These losses have had devastating consequences to northern California communities, economies, and fisheries. Using a suite of in situ and satellite-derived data, we demonstrate that the abrupt ecosystem shift initiated by a multi-year MHW was preceded by declines in keystone predator population densities. We show strong evidence that northern California kelp forests, while temporally dynamic, were historically resilient to fluctuating environmental conditions, even in the absence of key top predators, but that a series of coupled environmental and biological shifts between 2014 and 2016 resulted in the formation of a persistent, altered ecosystem state with low primary productivity. Based on our findings, we recommend the implementation of ecosystem-based and adaptive management strategies, such as (1) monitoring the status of key ecosystem attributes: kelp distribution and abundance, and densities of sea urchins and their predators, (2) developing management responses to threshold levels of these attributes, and (3) creating quantitative restoration suitability indices for informing kelp restoration efforts.
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Affiliation(s)
- Meredith L McPherson
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA, USA.
| | - Dennis J I Finger
- Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, CA, USA
| | - Henry F Houskeeper
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
- Department of Geography, University of California Los Angeles, Los Angeles, CA, USA
| | - Tom W Bell
- Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
- Earth Research Institute, University of California Santa Barbara, Santa Barbara, CA, USA
| | - Mark H Carr
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Laura Rogers-Bennett
- Coastal Marine Science Institute, Karen C. Drayer Wildlife Health Center, University of California Davis and California Department of Fish and Wildlife, Bodega Marine Laboratory, Bodega Bay, CA, USA
| | - Raphael M Kudela
- Department of Ocean Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
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3
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Berry HD, Mumford TF, Christiaen B, Dowty P, Calloway M, Ferrier L, Grossman EE, VanArendonk NR. Long-term changes in kelp forests in an inner basin of the Salish Sea. PLoS One 2021; 16:e0229703. [PMID: 33596204 PMCID: PMC7888675 DOI: 10.1371/journal.pone.0229703] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 01/18/2021] [Indexed: 11/30/2022] Open
Abstract
Kelp forests form an important biogenic habitat that responds to natural and human drivers. Global concerns exist about threats to kelp forests, yet long-term information is limited and research suggests that trends are geographically distinct. We examined distribution of the bull kelp Nereocystis luetkeana over 145 years in South Puget Sound (SPS), a semi-protected inner basin in a fjord estuary complex in the northeast Pacific Ocean. We synthesized 48 historical and modern Nereocystis surveys and examined presence/absence within 1-km segments along 452 km of shoreline. Compared to the earliest baseline in 1878, Nereocystis extent in 2017 decreased 63%, with individual sub-basins showing up to 96% loss. Losses have persisted for decades, across a range of climate conditions. In recent decades, Nereocystis predominantly occurred along shorelines with intense currents and mixing, where temperature and nutrient concentrations did not reach thresholds for impacts to Nereocystis performance, and high current speeds likely excluded grazers. Losses predominated in areas with elevated temperature, lower nutrient concentrations, and relatively low current velocities. The pattern of long-term losses in SPS contrasts with stability in floating kelp abundance during the last century in an area of the Salish Sea with greater wave exposure and proximity to oceanic conditions. These findings support the hypothesis that kelp beds along wave-sheltered shorelines exhibit greater sensitivity to environmental stressors. Additionally, shorelines with strong currents and deep-water mixing may provide refugia within sheltered systems.
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Affiliation(s)
- Helen D. Berry
- Washington State Department of Natural Resources, Olympia, WA, United States of America
| | | | - Bart Christiaen
- Washington State Department of Natural Resources, Olympia, WA, United States of America
| | - Pete Dowty
- Washington State Department of Natural Resources, Olympia, WA, United States of America
| | - Max Calloway
- Washington State Department of Natural Resources, Olympia, WA, United States of America
| | - Lisa Ferrier
- Washington State Department of Natural Resources, Olympia, WA, United States of America
| | - Eric E. Grossman
- U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA, United States of America
| | - Nathan R. VanArendonk
- U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA, United States of America
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Oyarzo-Miranda C, Latorre N, Meynard A, Rivas J, Bulboa C, Contreras-Porcia L. Coastal pollution from the industrial park Quintero bay of central Chile: Effects on abundance, morphology, and development of the kelp Lessonia spicata (Phaeophyceae). PLoS One 2020; 15:e0240581. [PMID: 33057390 PMCID: PMC7561192 DOI: 10.1371/journal.pone.0240581] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 09/30/2020] [Indexed: 01/04/2023] Open
Abstract
The industrial park of Quintero Bay (QB) in the central coast of Chile was established in the 1960s, presents high levels of pollution due to the industrial activity, and it is known as one of the five Chilean "sacrifice zones". Lessonia spicata is the most important habitat-forming kelp species in the intertidal along the central and south shores of Chile, and currently there are no morphometric and population studies of L. spicata (or other seaweed species) nor studies about the effects of pollution on its development in QB and neighbouring sites. In this context, the aims of this study were (i) to register the abundance and morphological features of L. spicata populations from Ventanas, Horcón and Cachagua (sites with different pollution histories and located only up to 40 km from the QB); ii) to determine the heavy metals (HMs) concentration in seawater and marine sediments; and (iii) to evaluate in vitro the effects of exposure to seawater from the three sampling sites on spore release and early developmental stages, up to the juvenile sporophyte. Results showed that the chronically exposed Ventanas kelp population had the smallest adult individuals in comparison with the other sites. Ventanas and Horcón registered high HMs concentration in the seawater and marine sediments exceeding the international permissible limits (e.g in seawater Cu 20-859 μg L-1; sediments Cu > 50,000 μg kg-1). Unexpectedly in Cachagua, a site often considered unpolluted, high concentrations of Cu and As were also registered in the seawater (859 and 1,484 μg L-1, respectively) and of As in marine sediments (20,895 μg kg-1). Exposure of gametophytes to the seawater from Ventanas resulted in a developmental delay compared to the other treatments; however, low sporophyte production was determined in all treatments. Our results indicate that QB, more notably Ventanas, induce highly negative effects on individual development, and consequently on seaweed populations, which suggest a long-term negative impact on the community structure of these marine zones. Furthermore, the high concentrations of HMs reported here at Cachagua suggest a recent expansion of pollution along the central coast of Chile, evidencing effects on the marine ecosystem health even on sites far from the pollution source.
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Affiliation(s)
- Carolina Oyarzo-Miranda
- Departamento de Ecología y Biodiversidad, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
- Centro de Investigación Marina Quintay (CIMARQ), Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
| | - Nicolás Latorre
- Departamento de Ecología y Biodiversidad, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
- Centro de Investigación Marina Quintay (CIMARQ), Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
- Programa de Doctorado Medicina de la Conservación, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Andrés Meynard
- Departamento de Ecología y Biodiversidad, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
- Centro de Investigación Marina Quintay (CIMARQ), Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
| | - Jorge Rivas
- Departamento de Ecología y Biodiversidad, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
- Centro de Investigación Marina Quintay (CIMARQ), Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Cristian Bulboa
- Departamento de Ecología y Biodiversidad, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
- Centro de Investigación Marina Quintay (CIMARQ), Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
| | - Loretto Contreras-Porcia
- Departamento de Ecología y Biodiversidad, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
- Centro de Investigación Marina Quintay (CIMARQ), Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES), Santiago, Chile
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5
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Abstract
Extreme events are increasing globally with devastating ecological consequences, but the impacts on underlying genetic diversity and structure are often cryptic and poorly understood, hindering assessment of adaptive capacity and ecosystem vulnerability to future change. Using very rare "before" data we empirically demonstrate that an extreme marine heatwave caused a significant poleward shift in genetic clusters of kelp forests whereby alleles characteristic of cool water were replaced by those that predominated in warm water across 200 km of coastline. This "genetic tropicalisation" was facilitated by significant mortality of kelp and other co-occurring seaweeds within the footprint of the heatwave that opened space for rapid local proliferation of surviving kelp genotypes or dispersal and recruitment of spores from warmer waters. Genetic diversity declined and inbreeding increased in the newly tropicalised site, but these metrics were relative stable elsewhere within the footprint of the heatwave. Thus, extreme events such as marine heatwaves not only lead to significant mortality and population loss but can also drive significant genetic change in natural populations.
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Affiliation(s)
- Melinda A Coleman
- New South Wales Fisheries, National Marine Science Centre, 2 Bay Drive, Coffs Harbour, NSW, 2450, Australia.
- Southern Cross University, National Marine Science Centre, 2 Bay Drive, Coffs Harbour, NSW, 2450, Australia.
- Oceans Institute and School of Biological Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia.
| | - Antoine J P Minne
- Southern Cross University, National Marine Science Centre, 2 Bay Drive, Coffs Harbour, NSW, 2450, Australia
- Oceans Institute and School of Biological Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia
| | - Sofie Vranken
- Oceans Institute and School of Biological Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia
| | - Thomas Wernberg
- Oceans Institute and School of Biological Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA, 6009, Australia
- Department of Science and Environment, Roskilde University, 4000, Roskilde, Denmark
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6
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Gregr EJ, Christensen V, Nichol L, Martone RG, Markel RW, Watson JC, Harley CDG, Pakhomov EA, Shurin JB, Chan KMA. Cascading social-ecological costs and benefits triggered by a recovering keystone predator. Science 2020; 368:1243-1247. [PMID: 32527830 DOI: 10.1126/science.aay5342] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 05/05/2020] [Indexed: 01/10/2024]
Abstract
Predator recovery often leads to ecosystem change that can trigger conflicts with more recently established human activities. In the eastern North Pacific, recovering sea otters are transforming coastal systems by reducing populations of benthic invertebrates and releasing kelp forests from grazing pressure. These changes threaten established shellfish fisheries and modify a variety of other ecosystem services. The diverse social and economic consequences of this trophic cascade are unknown, particularly across large regions. We developed and applied a trophic model to predict these impacts on four ecosystem services. Results suggest that sea otter presence yields 37% more total ecosystem biomass annually, increasing the value of finfish [+9.4 million Canadian dollars (CA$)], carbon sequestration (+2.2 million CA$), and ecotourism (+42.0 million CA$). To the extent that these benefits are realized, they will exceed the annual loss to invertebrate fisheries (-$7.3 million CA$). Recovery of keystone predators thus not only restores ecosystems but can also affect a range of social, economic, and ecological benefits for associated communities.
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Affiliation(s)
- Edward J Gregr
- Institute for Resources Environment, and Sustainability, University of British Columbia, 2202 Main Mall, Vancouver, BC V6T 1Z4, Canada.
- SciTech Environmental Consulting, 2136 Napier St., Vancouver, BC V5L 2N9, Canada
| | - Villy Christensen
- Institute for the Oceans and Fisheries, University of British Columbia, 2202 Main Mall, Vancouver, BC V6T 1Z4, Canada
| | - Linda Nichol
- Fisheries and Oceans Canada, Pacific Biological Station, 3190 Hammond Bay Rd., Nanaimo, BC V9T 6N7, Canada
| | - Rebecca G Martone
- Institute for Resources Environment, and Sustainability, University of British Columbia, 2202 Main Mall, Vancouver, BC V6T 1Z4, Canada
- Outer Shores Expeditions, P.O. Box 361, Cobble Hill, BC V0R 1L0, Canada
| | - Russell W Markel
- Institute for Resources Environment, and Sustainability, University of British Columbia, 2202 Main Mall, Vancouver, BC V6T 1Z4, Canada
- Outer Shores Expeditions, P.O. Box 361, Cobble Hill, BC V0R 1L0, Canada
| | - Jane C Watson
- Biology Department, Vancouver Island University, 900 5th St. Nanaimo, BC V9R 5S5, Canada
| | - Christopher D G Harley
- Institute for the Oceans and Fisheries, University of British Columbia, 2202 Main Mall, Vancouver, BC V6T 1Z4, Canada
- Department of Zoology, University of British Columbia, 6270 University Blvd., Vancouver, BC V6T 1Z4, Canada
- Hakai Institute, P.O. Box 309, Heriot Bay, BC V0P 1H0, Canada
| | - Evgeny A Pakhomov
- Institute for the Oceans and Fisheries, University of British Columbia, 2202 Main Mall, Vancouver, BC V6T 1Z4, Canada
- Hakai Institute, P.O. Box 309, Heriot Bay, BC V0P 1H0, Canada
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, 2207 Main Mall, Vancouver, BC V6T 1Z4, Canada
| | - Jonathan B Shurin
- Section of Ecology, Behavior and Evolution, University of California, San Diego, 9500 Gilman Dr. #0116, La Jolla, CA 92093, USA
| | - Kai M A Chan
- Institute for Resources Environment, and Sustainability, University of British Columbia, 2202 Main Mall, Vancouver, BC V6T 1Z4, Canada
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Jiang Z, Liu J, Li S, Chen Y, Du P, Zhu Y, Liao Y, Chen Q, Shou L, Yan X, Zeng J, Chen J. Kelp cultivation effectively improves water quality and regulates phytoplankton community in a turbid, highly eutrophic bay. Sci Total Environ 2020; 707:135561. [PMID: 31972904 DOI: 10.1016/j.scitotenv.2019.135561] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 11/11/2019] [Accepted: 11/14/2019] [Indexed: 06/10/2023]
Abstract
Coastal eutrophication and its associated harmful algal blooms have emerged as one of the most severe environmental problems worldwide. Seaweed cultivation has been widely encouraged to control eutrophication and algal blooms. Among them, cultivated kelp (Saccharina japonica) dominates primarily by production and area. However, the responses of water quality and phytoplankton community to kelp farming remain unclear. Here, thirteen cruises were conducted in the kelp farms and control areas in the turbid, highly eutrophic Xiangshan Bay of the East China Sea from 2008 to 2015. Results indicated that kelp cultivation slightly increased dissolved oxygen and pH, but reduced dissolved inorganic nitrogen and phosphorus. We estimated that kelp harvesting would remove 297 t of nitrogen and 42 t of phosphorus from this bay annually. Because of decreased flow velocity, turbulence, and sediment resuspension, kelp farming greatly reduced suspended solids and increased transparency, resulting in increases in phytoplankton chlorophyll a and abundance. Additionally, kelp farming appreciably increased phytoplankton species number, Marglef richness, and Shannon-Wiener diversity indices by 51.6%, 40.1%, and 13.1%, respectively. Analysis of similarity and similarity percentages demonstrated that phytoplankton community composition differed significantly between the farm and control area, which was mostly attributed to long-chained diatoms and single-celled dinoflagellates. However, after the kelp harvesting, all measurements of water quality and phytoplankton biomass, diversity, and community composition exhibited no significant difference. Our study highlights that kelp cultivation alleviates eutrophication and acidification and enhances phytoplankton diversity, thus providing guidance for macroalgal aquaculture and remediation in eutrophic waters.
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Affiliation(s)
- Zhibing Jiang
- Key Laboratory of Marine Ecosystem and Biogeochemistry, State Oceanic Administration & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China; Function Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China; State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Jingjing Liu
- Key Laboratory of Marine Ecosystem and Biogeochemistry, State Oceanic Administration & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Shanglu Li
- Marine Monitoring and Forecasting Center of Zhejiang Province, Hangzhou, China
| | - Yue Chen
- Key Laboratory of Marine Ecosystem and Biogeochemistry, State Oceanic Administration & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Ping Du
- Key Laboratory of Marine Ecosystem and Biogeochemistry, State Oceanic Administration & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China; Function Laboratory for Marine Fisheries Science and Food Production Processes, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, China
| | - Yuanli Zhu
- Key Laboratory of Marine Ecosystem and Biogeochemistry, State Oceanic Administration & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Yibo Liao
- Key Laboratory of Marine Ecosystem and Biogeochemistry, State Oceanic Administration & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China; State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Quanzhen Chen
- Key Laboratory of Marine Ecosystem and Biogeochemistry, State Oceanic Administration & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Lu Shou
- Key Laboratory of Marine Ecosystem and Biogeochemistry, State Oceanic Administration & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Xiaojun Yan
- Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Marine College of Ningbo University, Ningbo, China
| | - Jiangning Zeng
- Key Laboratory of Marine Ecosystem and Biogeochemistry, State Oceanic Administration & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China.
| | - Jianfang Chen
- Key Laboratory of Marine Ecosystem and Biogeochemistry, State Oceanic Administration & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China; State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
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8
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Edwards M, Konar B, Kim JH, Gabara S, Sullaway G, McHugh T, Spector M, Small S. Marine deforestation leads to widespread loss of ecosystem function. PLoS One 2020; 15:e0226173. [PMID: 32130220 PMCID: PMC7055868 DOI: 10.1371/journal.pone.0226173] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 02/13/2020] [Indexed: 01/02/2023] Open
Abstract
Trophic interactions can result in changes to the abundance and distribution of habitat-forming species that dramatically reduce ecosystem functioning. In the coastal zone of the Aleutian Archipelago, overgrazing by herbivorous sea urchins that began in the 1990s resulted in widespread deforestation of the region's kelp forests, which led to lower macroalgal abundances and higher benthic irradiances. We examined how this deforestation impacted ecosystem function by comparing patterns of net ecosystem production (NEP), gross primary production (GPP), ecosystem respiration (Re), and the range between GPP and Re in remnant kelp forests, urchin barrens, and habitats that were in transition between the two habitat types at nine islands that spanned more than 1000 kilometers of the archipelago. Our results show that deforestation, on average, resulted in a 24% reduction in GPP, a 26% reduction in Re, and a 24% reduction in the range between GPP and Re. Further, the transition habitats were intermediate to the kelp forests and urchin barrens for these metrics. These opposing metabolic processes remained in balance; however, which resulted in little-to-no changes to NEP. These effects of deforestation on ecosystem productivity, however, were highly variable between years and among the study islands. In light of the worldwide declines in kelp forests observed in recent decades, our findings suggest that marine deforestation profoundly affects how coastal ecosystems function.
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Affiliation(s)
- Matthew Edwards
- Department of Biology, San Diego State University, San Diego, CA, United States of America
| | - Brenda Konar
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America
| | - Ju-Hyoung Kim
- Marine Applied Biosciences, Kunsan National University, Gunsan, South Korea
| | - Scott Gabara
- Department of Biology, San Diego State University, San Diego, CA, United States of America
- Department of Environmental Science and Policy, University of California, Davis, California, United States of America
| | - Genoa Sullaway
- Department of Biology, San Diego State University, San Diego, CA, United States of America
| | - Tristin McHugh
- Department of Biology, San Diego State University, San Diego, CA, United States of America
| | - Michael Spector
- Department of Biology, San Diego State University, San Diego, CA, United States of America
| | - Sadie Small
- Department of Biology, San Diego State University, San Diego, CA, United States of America
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9
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Hasselström L, Thomas JB, Nordström J, Cervin G, Nylund GM, Pavia H, Gröndahl F. Socioeconomic prospects of a seaweed bioeconomy in Sweden. Sci Rep 2020; 10:1610. [PMID: 32005872 PMCID: PMC6994625 DOI: 10.1038/s41598-020-58389-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 01/08/2020] [Indexed: 11/17/2022] Open
Abstract
Seaweed cultivation is a large industry worldwide, but production in Europe is small compared to production in Asian countries. In the EU, the motivations for seaweed farming may be seen from two perspectives; one being economic growth through biomass production and the other being the provisioning of ecosystem services such as mitigating eutrophication. In this paper, we assess the economic potential of large-scale cultivation of kelp, Saccharina latissima, along the Swedish west coast, including the value of externalities. The findings suggest that seaweed farming has the potential of becoming a profitable industry in Sweden. Furthermore, large-scale seaweed farming can sequester a significant share of annual anthropogenic nitrogen and phosphorus inflows to the basins of the Swedish west coast (8% of N and 60% of P). Concerning the valuation of externalities, positive values generated from sequestration of nitrogen and phosphorus are potentially counteracted by negative values from interference with recreational values. Despite the large N and P uptake, the socioeconomic value of this sequestration is only a minor share of the potential financial value from biomass production. This suggests that e.g. payment schemes for nutrient uptake based on the socioeconomic values generated is not likely to be a tipping point for the industry. Additionally, seaweed cultivation is not a cost-efficient measure in itself to remove nutrients. Policy should thus be oriented towards industry development, as the market potential of the biomass will be the driver that may unlock these bioremediation opportunities.
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Affiliation(s)
- Linus Hasselström
- KTH Royal Institute of Technology, Department of Sustainable Development, Environmental Science and Engineering. Teknikringen 10B, SE-133 31, Stockholm, Sweden.
- Anthesis. Barnhusgatan 4, SE-111 23, Stockholm, Sweden.
| | - Jean-Baptiste Thomas
- KTH Royal Institute of Technology, Department of Sustainable Development, Environmental Science and Engineering. Teknikringen 10B, SE-133 31, Stockholm, Sweden
| | - Jonas Nordström
- University of Copenhagen, Department of Food and Resource Economics, Rolighedsvej 25, DK-1958 Frederiksberg C, Denmark and Lund University School of Economics and Management, Agrifood Economics Centre, Box 7080, SE-220 07, Lund, Sweden
| | - Gunnar Cervin
- Department of Marine Sciences - Tjärnö, University of Gothenburg, Tjärnö Marine Laboratory, SE-452 96, Strömstad, Sweden
| | - Göran M Nylund
- Department of Marine Sciences - Tjärnö, University of Gothenburg, Tjärnö Marine Laboratory, SE-452 96, Strömstad, Sweden
| | - Henrik Pavia
- Department of Marine Sciences - Tjärnö, University of Gothenburg, Tjärnö Marine Laboratory, SE-452 96, Strömstad, Sweden
| | - Fredrik Gröndahl
- KTH Royal Institute of Technology, Department of Sustainable Development, Environmental Science and Engineering. Teknikringen 10B, SE-133 31, Stockholm, Sweden
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10
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Tala F, López BA, Velásquez M, Jeldres R, Macaya EC, Mansilla A, Ojeda J, Thiel M. Long-term persistence of the floating bull kelp Durvillaea antarctica from the South-East Pacific: Potential contribution to local and transoceanic connectivity. Mar Environ Res 2019; 149:67-79. [PMID: 31154063 DOI: 10.1016/j.marenvres.2019.05.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/16/2019] [Accepted: 05/18/2019] [Indexed: 05/06/2023]
Abstract
Current knowledge about the performance of floating seaweeds as dispersal vectors comes mostly from mid latitudes (30°-40°), but phylogeographic studies suggest that long-distance dispersal (LDD) is more common at high latitudes (50°-60°). To test this hypothesis, long-term field experiments with floating southern bull kelp Durvillaea antarctica were conducted along a latitudinal gradient (30°S, 37°S and 54°S) in austral winter and summer. Floating time exceeded 200d in winter at the high latitudes but in summer it dropped to 90d, being still higher than at low latitudes (<45d). Biomass variations were due to loss of buoyant fronds. Reproductive activity diminished during long floating times. Physiological changes included mainly a reduction in photosynthetic (Fv/Fm and pigments) rather than in defence variables (phlorotannins and antioxidant activity). The observed long floating persistence and long-term acclimation responses at 54°S support the hypothesis of LDD by kelp rafts at high latitudes.
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Affiliation(s)
- Fadia Tala
- Departamento de Biología Marina, Universidad Católica del Norte, Larrondo, 1281, Coquimbo, Chile; Centro de Investigación y Desarrollo Tecnológico en Algas (CIDTA), Facultad de Ciencias del Mar, Universidad Católica del Norte, Larrondo 1281, Coquimbo, Chile.
| | - Boris A López
- Departamento de Acuicultura y Recursos Agroalimentarios, Universidad de Los Lagos, Avenida Fuchslocher, 1305, Osorno, Chile
| | - Marcel Velásquez
- Laboratorio de Macroalgas Antárticas y Subantárticas (LMAS), Universidad de Magallanes, Facultad de Ciencias, Casilla 113-D, Punta Arenas, Chile; Instituto de Ecología y Biodiversidad, IEB-Chile, Universidad de Chile, Santiago, Chile
| | - Ricardo Jeldres
- Departamento de Oceanografía, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile; Centro FONDAP de Investigaciones en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Chile
| | - Erasmo C Macaya
- Departamento de Oceanografía, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile; Centro FONDAP de Investigaciones en Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Chile; Millennium Nucleus Ecology and Sustainable Management of Oceanic Island (ESMOI), Coquimbo, Chile
| | - Andrés Mansilla
- Laboratorio de Macroalgas Antárticas y Subantárticas (LMAS), Universidad de Magallanes, Facultad de Ciencias, Casilla 113-D, Punta Arenas, Chile; Instituto de Ecología y Biodiversidad, IEB-Chile, Universidad de Chile, Santiago, Chile
| | - Jaime Ojeda
- Laboratorio de Macroalgas Antárticas y Subantárticas (LMAS), Universidad de Magallanes, Facultad de Ciencias, Casilla 113-D, Punta Arenas, Chile; Instituto de Ecología y Biodiversidad, IEB-Chile, Universidad de Chile, Santiago, Chile; School of Environmental Studies, University of Victoria, Victoria, British Columbia, Canada
| | - Martin Thiel
- Departamento de Biología Marina, Universidad Católica del Norte, Larrondo, 1281, Coquimbo, Chile; Millennium Nucleus Ecology and Sustainable Management of Oceanic Island (ESMOI), Coquimbo, Chile; Centro de Estudios Avanzados en Zonas Áridas, Coquimbo, Chile
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11
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Feehan CJ, Grace SP, Narvaez CA. Ecological feedbacks stabilize a turf-dominated ecosystem at the southern extent of kelp forests in the Northwest Atlantic. Sci Rep 2019; 9:7078. [PMID: 31068664 PMCID: PMC6506546 DOI: 10.1038/s41598-019-43536-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 04/26/2019] [Indexed: 11/09/2022] Open
Abstract
Temperate marine ecosystems globally are undergoing regime shifts from dominance by habitat-forming kelps to dominance by opportunistic algal turfs. While the environmental drivers of shifts to turf are generally well-documented, the feedback mechanisms that stabilize novel turf-dominated ecosystems remain poorly resolved. Here, we document a decline of kelp Saccharina latissima between 1980 and 2018 at sites at the southernmost extent of kelp forests in the Northwest Atlantic and their replacement by algal turf. We examined the drivers of a shift to turf and feedback mechanisms that stabilize turf reefs. Kelp replacement by turf was linked to a significant multi-decadal increase in sea temperature above an upper thermal threshold for kelp survival. In the turf-dominated ecosystem, 45% of S. latissima were attached to algal turf rather than rocky substrate due to preemption of space. Turf-attached kelp required significantly (2 to 4 times) less force to detach from the substrate, with an attendant pattern of lower survival following 2 major wave events as compared to rock-attached kelp. Turf-attached kelp allocated a significantly greater percentage of their biomass to the anchoring structure (holdfast), with a consequent energetic trade-off of slower growth. The results indicate a shift in community dominance from kelp to turf driven by thermal stress and stabilized by ecological feedbacks of lower survival and slower growth of kelp recruited to turf.
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Affiliation(s)
- Colette J Feehan
- Department of Biology, Montclair State University, Montclair, NJ, 07043, USA.
| | - Sean P Grace
- Department of Biology and Werth Center for Coastal and Marine Studies, Southern Connecticut State University, New Haven, CT, 06515, USA
| | - Carla A Narvaez
- Department of Biology, Villanova University, Villanova, PA, 19085, USA
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12
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Gao X, Kim JH, Park SK, Yu OH, Kim YS, Choi HG. Diverse responses of sporophytic photochemical efficiency and gametophytic growth for two edible kelps, Saccharina japonica and Undaria pinnatifida, to ocean acidification and warming. Mar Pollut Bull 2019; 142:315-320. [PMID: 31232310 DOI: 10.1016/j.marpolbul.2019.03.063] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 03/25/2019] [Accepted: 03/30/2019] [Indexed: 06/09/2023]
Abstract
Ocean acidification and warming represent major environmental threats to kelp mariculture. In this study, sporophytic photochemical efficiency and gametophytic growth of Saccharina japonica and Undaria pinnatifida were evaluated under different pCO2 levels (360, 720, and 980 ppmv) and temperatures (5, 10, 15, and 20 °C for sporophytes; 15 and 20 °C for gametophytes). Sporophytic photochemical efficiencies of both kelps were significantly greater at 720 ppmv than at 360 and 980 ppmv. Female gametophytes of both kelps grew significantly better at 360 ppmv than at higher pCO2 levels. The growth of U. pinnatifida gametophytes was significantly greater at 20 °C than at 15 °C, while no significant difference was observed for the growth of S. japonica. These results indicate that increased pCO2 stimulated sporophytic photochemical efficiency while inhibited gametophytic growth of these kelps, which might negatively affect their seedling cultivation. U. pinnatifida exhibited higher productivity in warmer ocean than S. japonica.
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Affiliation(s)
- Xu Gao
- Faculty of Biological Science and Sea & Biotech, Wonkwang University, Iksan 54538, Republic of Korea
| | - Ju-Hyoung Kim
- Faculty of Marine Applied Biosciences, Kunsan National University, Gunsan 54150, Republic of Korea
| | - Seo Kyoung Park
- Faculty of Biological Science and Sea & Biotech, Wonkwang University, Iksan 54538, Republic of Korea
| | - Ok Hwan Yu
- Marine Ecosystem Research Center, Korea Institute of Ocean Science & Technology, Busan 49111, Republic of Korea
| | - Young Sik Kim
- Department of Marine Biotechnology, Kunsan National University, Gunsan 54150, Republic of Korea
| | - Han Gil Choi
- Faculty of Biological Science and Sea & Biotech, Wonkwang University, Iksan 54538, Republic of Korea.
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13
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Pan Z, Gao QF, Dong SL, Wang F, Li HD, Zhao K, Jiang XY. Effects of abalone (Haliotis discus hannai Ino) and kelp (Saccharina japonica) mariculture on sources, distribution, and preservation of sedimentary organic carbon in Ailian Bay, China: Identified by coupling stable isotopes (δ 13C and δ 15N) with C/N ratio analyses. Mar Pollut Bull 2019; 141:387-397. [PMID: 30955748 DOI: 10.1016/j.marpolbul.2019.02.053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 02/23/2019] [Accepted: 02/23/2019] [Indexed: 06/09/2023]
Abstract
To investigate the effects of mariculture on the sources, distribution and preservation of sedimentary organic carbon (SOC), sediments from an mariculture area in Ailian Bay, China, and a control area were analyzed for grain size composition, total organic carbon (TOC), total nitrogen (TN), carbon/nitrogen (C/N) ratio, and stable carbon and nitrogen isotopic composition (δ13C and δ15N). The sedimentary type of sediments in study area was clay silt. TOC, TN, C/N, δ13C, and δ15N ranged from 0.58 to 1.21%, 0.06-0.17%, 6.29-9.82, -23.20 to -18.50‰, and 6.17-7.38‰, respectively, and followed similar spatial patterns. TOC, TN and δ13C were higher in mariculture area than in control area. Biodeposit and kelp OC contributions greater of SOC in mariculture area than the control area (biodeposits: 20.10 ± 4.84 to 6.2 ± 1.3%; kelp: 15.3 ± 6.63 to 5.2 ± 0.84%). Overall, mariculture activities significantly influence the sources, distribution and preservation of SOC.
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Affiliation(s)
- Zhe Pan
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, Shandong Province 266003, China; Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong Province 266100, China
| | - Qin-Feng Gao
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, Shandong Province 266003, China; Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong Province 266100, China.
| | - Shuang-Lin Dong
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, Shandong Province 266003, China; Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong Province 266100, China
| | - Fang Wang
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, Shandong Province 266003, China; Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong Province 266100, China
| | - Hai-Dong Li
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, Shandong Province 266003, China; Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong Province 266100, China
| | - Kun Zhao
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, Shandong Province 266003, China; Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong Province 266100, China
| | - Xu-Yang Jiang
- Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao, Shandong Province 266003, China; Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong Province 266100, China
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14
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Yang X, Lin C, Song X, Xu M, Yang H. Effects of artificial reefs on the meiofaunal community and benthic environment - A case study in Bohai Sea, China. Mar Pollut Bull 2019; 140:179-187. [PMID: 30803633 DOI: 10.1016/j.marpolbul.2018.12.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 12/12/2018] [Accepted: 12/13/2018] [Indexed: 05/25/2023]
Abstract
Artificial reefs are widely deployed for fishery enhancement and marine conservation. A comprehensive assessment on the effects of artificial reefs could minimize the negative consequence of blindly developing artificial reefs. We examined the meiofaunal community and benthic environment adjacent to and <5 m from artificial reefs in Xiangyun Bay, Bohai Sea, China. We found the highest total meiofaunal abundance beside the artificial reef. Shannon-Wiener and Pielou indexes had no significant difference among different distances from the artificial reefs. The presence of artificial reefs impeded the surrounding flow and provided additional substrate for bivalves and kelps, which could cause finer sediment and organic enrichment around it. Sediment grain size and total organic matter were the most important parameters influencing the meiofauna. We suggest that the shape, material, configuration and location of artificial reefs should be related with a specific goal to avoid mindless proliferation.
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Affiliation(s)
- Xinyuan Yang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Chenggang Lin
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China.
| | - Xiaoyue Song
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Min Xu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Hongsheng Yang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China.
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15
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Burnett NP, Koehl MAR. Mechanical properties of the wave-swept kelp Egregia menziesii change with season, growth rate and herbivore wounds. J Exp Biol 2019; 222:jeb190595. [PMID: 30679240 DOI: 10.1242/jeb.190595] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 01/17/2019] [Indexed: 11/20/2022]
Abstract
The resistance of macroalgae to damage by hydrodynamic forces depends on the mechanical properties of their tissues. Although factors such as water-flow environment, algal growth rate and damage by herbivores have been shown to influence various material properties of macroalgal tissues, the interplay of these factors as they change seasonally and affect algal mechanical performance has not been worked out. We used the perennial kelp Egregia menziesii to study how the material properties of the rachis supporting a frond changed seasonally over a 2 year period, and how those changes correlated with seasonal patterns of the environment, growth rate and herbivore load. Rachis tissue became stiffer, stronger and less extensible with age (distance from the meristem). Thus, slowly growing rachises were stiffer, stronger and tougher than rapidly growing ones. Growth rates were highest in spring and summer when upwelling and long periods of daylight occurred. Therefore, rachis tissue was most resistant to damage in the winter, when waves were large as a result of seasonal storms. Herbivory was greatest during summer, when rachis growth rates were high. Unlike other macroalgae, E. menziesii did not respond to herbivore damage by increasing rachis tissue strength, but rather by growing in width so that the cross-sectional area of the wounded rachis was increased. The relative timing of environmental factors that affect growth rates (e.g. upwelling supply of nutrients, daylight duration) and of those that can damage macroalgae (e.g. winter storms, summer herbivore outbreaks) can influence the material properties and thus the mechanical performance of macroalgae.
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Affiliation(s)
- Nicholas P Burnett
- Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, CA 95616, USA
| | - M A R Koehl
- Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
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16
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Layton C, Shelamoff V, Cameron MJ, Tatsumi M, Wright JT, Johnson CR. Resilience and stability of kelp forests: The importance of patch dynamics and environment-engineer feedbacks. PLoS One 2019; 14:e0210220. [PMID: 30682047 PMCID: PMC6347235 DOI: 10.1371/journal.pone.0210220] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 12/17/2018] [Indexed: 12/02/2022] Open
Abstract
Habitat forming 'ecosystem engineers' such as kelp species create complex habitats that support biodiverse and productive communities. Studies of the resilience and stability of ecosystem engineers have typically focussed on the role of external factors such as disturbance. However, their population dynamics are also likely to be influenced by internal processes, such that the environmental modifications caused by engineer species feedback to affect their own demography (e.g. recruitment, survivorship). In numerous regions globally, kelp forests are declining and experiencing reductions in patch size and kelp density. To explore how resilience and stability of kelp habitats is influenced by this habitat degradation, we created an array of patch reefs of various sizes and supporting adult Ecklonia radiata kelp transplanted at different densities. This enabled testing of how sub-canopy abiotic conditions change with reductions in patch size and adult kelp density, and how this influenced demographic processes of microscopic and macroscopic juvenile kelp. We found that ecosystem engineering by adult E. radiata modified the environment to reduce sub-canopy water flow, sedimentation, and irradiance. However, the capacity of adult kelp canopy to engineer abiotic change was dependent on patch size, and to a lesser extent, kelp density. Reductions in patch size and kelp density also impaired the recruitment, growth and survivorship of microscopic and macroscopic juvenile E. radiata, and even after the provisioning of established juveniles, demographic processes were impaired in the absence of sufficient adult kelp. These results are consistent with the hypothesis that ecosystem engineering by adult E. radiata facilitates development of juvenile conspecifics. Habitat degradation seems to impair the ability of E. radiata to engineer abiotic change, causing breakdown of positive intraspecific feedback and collapse of demographic functions, and overall, leading to reductions in ecosystem stability and resilience well before local extirpation.
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Affiliation(s)
- Cayne Layton
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Victor Shelamoff
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Matthew J. Cameron
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Masayuki Tatsumi
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Jeffrey T. Wright
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Craig R. Johnson
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
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17
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González CP, Edding M, Torres R, Manríquez PH. Increased temperature but not pCO 2 levels affect early developmental and reproductive traits of the economically important habitat-forming kelp Lessonia trabeculata. Mar Pollut Bull 2018; 135:694-703. [PMID: 30301088 DOI: 10.1016/j.marpolbul.2018.07.072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 07/23/2018] [Accepted: 07/26/2018] [Indexed: 06/08/2023]
Abstract
The effects of ocean warming and ocean acidification on developmental and reproductive traits of Lessonia trabeculata were evaluated. Meiospores were cultured for 35 days in an experimental mesocosm where temperature (~15 and 19 °C) and partial CO2 pressure (pCO2, ~400 and 1300 μatm) were controlled. The results indicate that germination was reduced at 19 °C, whereas the increase of pCO2 only had effects at 15 °C. Likewise, the increase in temperature significantly affected the vegetative growth of female gametophytes. Sex ratio was not affected significantly by any of the variables studied. Fertility and reproductive success decreased by about 50% at 19 °C. The pCO2 levels had no significant effects on most early developmental traits. The results suggest that ocean warming or periodic warming events (e.g. an El Niño event) might affect the recruiting capacity of this or other similar species by affecting their early developmental stages.
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Affiliation(s)
- Claudio P González
- Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Coquimbo, Chile; Laboratorio de Ecología y Conducta de la Ontogenia Temprana (LECOT), Coquimbo, Chile; Laboratorio de Botánica Marina, Departamento de Biología Marina, Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile
| | - Mario Edding
- Centro de Investigación y Desarrollo Tecnológico en Algas (CIDTA), Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile; Laboratorio de Botánica Marina, Departamento de Biología Marina, Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile
| | - Rodrigo Torres
- Centro de Investigación en Ecosistemas de la Patagonia (CIEP), Coyhaique, Chile; Centro de Investigación: Dinámica de Ecosistemas Marinos de Altas Latitudes (IDEAL), Punta Arenas, Chile
| | - Patricio H Manríquez
- Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Coquimbo, Chile; Laboratorio de Ecología y Conducta de la Ontogenia Temprana (LECOT), Coquimbo, Chile.
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18
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Liggan LM, Martone PT. Under pressure: biomechanical limitations of developing pneumatocysts in the bull kelp (Nereocystis luetkeana, Phaeophyceae). J Phycol 2018; 54:608-615. [PMID: 30098020 DOI: 10.1111/jpy.12776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 07/16/2018] [Indexed: 06/08/2023]
Abstract
Maintaining buoyancy with gas-filled floats (pneumatocysts) is essential for some subtidal kelps to achieve an upright stature and compete for light . However, as these kelps grow up through the water column, pneumatocysts are exposed to substantial changes in hydrostatic pressure, which could cause complications as internal gases may expand or contract, potentially causing them to rupture, flood, and lose buoyancy. In this study, we investigate how pneumatocysts of Nereocystis luetkeana resist biomechanical stress and maintain buoyancy as they develop across a hydrostatic gradient. We measured internal pressure, material properties, and pneumatocyst geometry across a range of thallus sizes and collection depths to identify strategies used to resist pressure-induced mechanical failure. Contrary to expectations, all pneumatocysts had internal pressures less than atmospheric pressure, ensuring that thalli are always exposed to a positive pressure gradient and compressional loads, indicating that they are more likely to buckle than rupture at all depths. Small pneumatocysts collected from depths between 1 and 9 m (inner radius = 0.4-1.0 cm) were demonstrated to have elevated wall stresses under high compressive loads and are at greatest risk of buckling. Although small kelps do not adjust pneumatocyst material properties or geometry to reduce wall stress as they grow, they are ~3.4 times stronger than they need to be to resist hydrostatic buckling. When tested, pneumatocysts buckled around 35 m depth, which agrees with previous measures of lower limits due to light attenuation, suggesting that hydrostatic pressure may also define the lower limit of Nereocystis in the field.
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Affiliation(s)
- Lauran M Liggan
- Department of Botany and Beaty Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada, V6T1Z4
- Bamfield Marine Sciences Centre, 100 Pachena Road, Bamfield, British Columbia, Canada, V0R1B0
| | - Patrick T Martone
- Department of Botany and Beaty Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada, V6T1Z4
- Bamfield Marine Sciences Centre, 100 Pachena Road, Bamfield, British Columbia, Canada, V0R1B0
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19
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Minich JJ, Morris MM, Brown M, Doane M, Edwards MS, Michael TP, Dinsdale EA. Elevated temperature drives kelp microbiome dysbiosis, while elevated carbon dioxide induces water microbiome disruption. PLoS One 2018; 13:e0192772. [PMID: 29474389 PMCID: PMC5825054 DOI: 10.1371/journal.pone.0192772] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 01/30/2018] [Indexed: 01/23/2023] Open
Abstract
Global climate change includes rising temperatures and increased pCO2 concentrations in the ocean, with potential deleterious impacts on marine organisms. In this case study we conducted a four-week climate change incubation experiment, and tested the independent and combined effects of increased temperature and partial pressure of carbon dioxide (pCO2), on the microbiomes of a foundation species, the giant kelp Macrocystis pyrifera, and the surrounding water column. The water and kelp microbiome responded differently to each of the climate stressors. In the water microbiome, each condition caused an increase in a distinct microbial order, whereas the kelp microbiome exhibited a reduction in the dominant kelp-associated order, Alteromondales. The water column microbiomes were most disrupted by elevated pCO2, with a 7.3 fold increase in Rhizobiales. The kelp microbiome was most influenced by elevated temperature and elevated temperature in combination with elevated pCO2. Kelp growth was negatively associated with elevated temperature, and the kelp microbiome showed a 5.3 fold increase Flavobacteriales and a 2.2 fold increase alginate degrading enzymes and sulfated polysaccharides. In contrast, kelp growth was positively associated with the combination of high temperature and high pCO2 'future conditions', with a 12.5 fold increase in Planctomycetales and 4.8 fold increase in Rhodobacteriales. Therefore, the water and kelp microbiomes acted as distinct communities, where the kelp was stabilizing the microbiome under changing pCO2 conditions, but lost control at high temperature. Under future conditions, a new equilibrium between the kelp and the microbiome was potentially reached, where the kelp grew rapidly and the commensal microbes responded to an increase in mucus production.
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Affiliation(s)
- Jeremiah J. Minich
- Department of Biology, San Diego State University, San Diego, CA, United States of America
| | - Megan M. Morris
- Department of Biology, San Diego State University, San Diego, CA, United States of America
| | - Matt Brown
- Department of Biology, San Diego State University, San Diego, CA, United States of America
| | - Michael Doane
- Department of Biology, San Diego State University, San Diego, CA, United States of America
| | - Matthew S. Edwards
- Department of Biology, San Diego State University, San Diego, CA, United States of America
| | | | - Elizabeth A. Dinsdale
- Department of Biology, San Diego State University, San Diego, CA, United States of America
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20
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Pfister CA, Betcher SP. Climate drivers and animal host use determine kelp performance over decadal scales in the kelp Pleurophycus gardneri (Laminariales, Phaeophyceae). J Phycol 2018; 54:1-11. [PMID: 29072316 DOI: 10.1111/jpy.12601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Accepted: 09/13/2017] [Indexed: 06/07/2023]
Abstract
Primary producers respond to climate directly and indirectly due to effects on their consumers. In the temperate coastal ocean, the highly productive brown algae known as kelp have both strong climate and grazer linkages. We analyzed the demographic response of the kelp Pleurophycus gardneri over a 25-year span to determine the interaction between ocean climate indicators and invertebrate infestation rates. Pleurophycus hosts amphipod species that burrow in the stipe, increasing mortality. Although kelp performance is generally greater with more negative values of the Pacific Decadal Oscillation (PDO) and colder seawater temperatures, Pleurophycus showed the opposite pattern. When we compared the 1990s, a period of positive values for the PDO and warmer sea surface temperatures, with the following decade, a period characterized by negative PDO values, we documented a contradictory outcome for proxies of kelp fitness. In the 1990s, Pleurophycus unexpectedly showed greater longevity, faster growth, greater reproductive effort, and a trend toward decreased amphipod infestation compared with the 2006-2012 period. In contrast, the period from 2006 to 2012 showed opposite kelp performance patterns and with a trend toward greater amphipod infestation. Pleurophycus performance metrics suggest that some coastal primary producers will respond differently to climate drivers, particularly if they interact strongly with grazers.
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Affiliation(s)
- Catherine A Pfister
- Department of Ecology and Evolution, University of Chicago, 1101 E 57th St, Chicago, Illinois, USA
| | - Samuel P Betcher
- The College, University of Chicago, 1101 E 57th St, Chicago, Illinois, USA
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21
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Wernberg T, Coleman MA, Bennett S, Thomsen MS, Tuya F, Kelaher BP. Genetic diversity and kelp forest vulnerability to climatic stress. Sci Rep 2018; 8:1851. [PMID: 29382916 PMCID: PMC5790012 DOI: 10.1038/s41598-018-20009-9] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 01/11/2018] [Indexed: 12/01/2022] Open
Abstract
Genetic diversity confers adaptive capacity to populations under changing conditions but its role in mediating impacts of climate change remains unresolved for most ecosystems. This lack of knowledge is particularly acute for foundation species, where impacts may cascade throughout entire ecosystems. We combined population genetics with eco-physiological and ecological field experiments to explore relationships among latitudinal patterns in genetic diversity, physiology and resilience of a kelp ecosystem to climate stress. A subsequent 'natural experiment' illustrated the possible influence of latitudinal patterns of genetic diversity on ecosystem vulnerability to an extreme climatic perturbation (marine heatwave). There were strong relationships between physiological versatility, ecological resilience and genetic diversity of kelp forests across latitudes, and genetic diversity consistently outperformed other explanatory variables in contributing to the response of kelp forests to the marine heatwave. Population performance and vulnerability to a severe climatic event were thus strongly related to latitudinal patterns in genetic diversity, with the heatwave extirpating forests with low genetic diversity. Where foundation species control ecological structure and function, impacts of climatic stress can cascade through the ecosystem and, consequently, genetic diversity could contribute to ecosystem vulnerability to climate change.
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Affiliation(s)
- Thomas Wernberg
- UWA Oceans Institute (M470) and School of Biological Sciences, University of Western Australia, Crawley, 6009 WA, Australia.
| | - Melinda A Coleman
- Department of Primary Industries, NSW Fisheries, PO Box 4321, Coffs Harbour, NSW 2450, Australia
- National Marine Science Centre & Centre for Coastal Biogeochemistry Research, School of Environment, Science and Engineering, Southern Cross University, PO Box 4321, Coffs Harbour, NSW 2450, Australia
| | - Scott Bennett
- UWA Oceans Institute (M470) and School of Biological Sciences, University of Western Australia, Crawley, 6009 WA, Australia
- Department of Global Change Research, Institut Mediterrani d'Estudis Avançats (Universitat de les Illes Balears-Consejo Superior de Investigaciones Científicas), Esporles, Spain
| | - Mads S Thomsen
- UWA Oceans Institute (M470) and School of Biological Sciences, University of Western Australia, Crawley, 6009 WA, Australia
- Marine Ecology Research Group and Centre for Integrative Ecology, School of Biological Sciences, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
| | - Fernando Tuya
- IU-ECOAQUA, Universidad de Las Palmas de Gran Canaria, 35017, Las Palmas, Canary Islands, Spain
| | - Brendan P Kelaher
- National Marine Science Centre & Centre for Coastal Biogeochemistry Research, School of Environment, Science and Engineering, Southern Cross University, PO Box 4321, Coffs Harbour, NSW 2450, Australia
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22
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Walls AM, Kennedy R, Edwards MD, Johnson MP. Impact of kelp cultivation on the Ecological Status of benthic habitats and Zostera marina seagrass biomass. Mar Pollut Bull 2017; 123:19-27. [PMID: 28751026 DOI: 10.1016/j.marpolbul.2017.07.048] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 07/06/2017] [Accepted: 07/19/2017] [Indexed: 06/07/2023]
Abstract
The Ecological Status of subtidal benthic communities within a commercial kelp farm on the southwest coast of Ireland was not impacted by macroalgal cultivation. Additionally, there was no effect on the biomass of Zostera marina, a key habitat under the EU Habitats Directive and OSPAR Commission. However, sediment grain size and total organic matter (TOM) were influenced by abiotic and biotic aspects of the farm. A temporal effect on univariate and multivariate species data, Infaunal Quality Index (IQI) and Z. marina biomass was observed. This effect was likely a community response to high storm disturbance in winter 2013/14. The use of IQI to assess the impact of macroalgal cultivation on benthic communities is a novel approach. This study supports a view that environmental impacts of macroalgal cultivation are relatively benign compared to other forms of aquaculture. Further research must be conducted to understand all interactions between aquaculture activities and the environment.
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Affiliation(s)
- A M Walls
- Irish Seaweed Research Group, Ryan Institute, National University of Ireland, Galway, Ireland.
| | - R Kennedy
- Marine Ecosystem Research Laboratory, Zoology, Ryan Institute, National University of Ireland, Galway, Ireland
| | - M D Edwards
- Irish Seaweed Research Group, Ryan Institute, National University of Ireland, Galway, Ireland
| | - M P Johnson
- Irish Seaweed Research Group, Ryan Institute, National University of Ireland, Galway, Ireland
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23
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Leal PP, Hurd CL, Fernández PA, Roleda MY. Ocean acidification and kelp development: Reduced pH has no negative effects on meiospore germination and gametophyte development of Macrocystis pyrifera and Undaria pinnatifida. J Phycol 2017; 53:557-566. [PMID: 28164308 DOI: 10.1111/jpy.12518] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 12/28/2016] [Indexed: 06/06/2023]
Abstract
The absorption of anthropogenic CO2 by the oceans is causing a reduction in the pH of the surface waters termed ocean acidification (OA). This could have substantial effects on marine coastal environments where fleshy (non-calcareous) macroalgae are dominant primary producers and ecosystem engineers. Few OA studies have focused on the early life stages of large macroalgae such as kelps. This study evaluated the effects of seawater pH on the ontogenic development of meiospores of the native kelp Macrocystis pyrifera and the invasive kelp Undaria pinnatifida, in south-eastern New Zealand. Meiospores of both kelps were released into four seawater pH treatments (pHT 7.20, extreme OA predicted for 2300; pHT 7.65, OA predicted for 2100; pHT 8.01, ambient pH; and pHT 8.40, pre-industrial pH) and cultured for 15 d. Meiospore germination, germling growth rate, and gametophyte size and sex ratio were monitored and measured. Exposure to reduced pHT (7.20 and 7.65) had positive effects on germling growth rate and gametophyte size in both M. pyrifera and U. pinnatifida, whereas, higher pHT (8.01 and 8.40) reduced the gametophyte size in both kelps. Sex ratio of gametophytes of both kelps was biased toward females under all pHT treatments, except for U. pinnatifida at pHT 7.65. Germling growth rate under OA was significantly higher in M. pyrifera compared to U. pinnatifida but gametophyte development was equal for both kelps under all seawater pHT treatments, indicating that the microscopic stages of the native M. pyrifera and the invasive U. pinnatifida will respond similarly to OA.
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Affiliation(s)
- Pablo P Leal
- Department of Botany, University of Otago, 479 Great King Street, Dunedin, 9016, New Zealand
- Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Hobart, Tasmania, 7004, Australia
| | - Catriona L Hurd
- Department of Botany, University of Otago, 479 Great King Street, Dunedin, 9016, New Zealand
- Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Hobart, Tasmania, 7004, Australia
| | - Pamela A Fernández
- Department of Botany, University of Otago, 479 Great King Street, Dunedin, 9016, New Zealand
- Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Hobart, Tasmania, 7004, Australia
| | - Michael Y Roleda
- Department of Botany, University of Otago, 479 Great King Street, Dunedin, 9016, New Zealand
- Norwegian Institute of Bioeconomy Research, Kudalsveien 6, 8049, Bodø, Norway
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24
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Murúa P, Müller DG, Patiño DJ, Westermeier R. Giant kelp vegetative propagation: Adventitious holdfast elements rejuvenate senescent individuals of the Macrocystis pyrifera "integrifolia" ecomorph. J Phycol 2017; 53:230-234. [PMID: 27878814 DOI: 10.1111/jpy.12493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 10/27/2016] [Indexed: 06/06/2023]
Abstract
Recent findings on holdfast development in the giant kelp highlighted its key importance for Macrocystis vegetative propagation. We report here for the first time the development of adventitious holdfasts from Macrocystis stipes. Swellings emerge spontaneously from different areas of the stipes, especially in senescent or creeping individuals. After being manually fastened to solid substrata, these swellings elongated into haptera, which became strongly attached after 1 month. Within 4 months, new thalli increased in size and vitality, and developed reproductive fronds. Our results suggest the usage of these structures for auxiliary attachment techniques. These could act as a backup, when primary holdfasts are weak, and thus improve the survival rate of the giant kelp in natural beds.
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Affiliation(s)
- Pedro Murúa
- Instituto de Acuicultura, Universidad Austral de Chile, Sede Puerto Montt, PO Box 1327, Puerto Montt, Chile
- Oceanlab, University of Aberdeen, Main Street, Newburgh, AB41 6AA, UK
- The Scottish Association for Marine Science, Scottish Marine Institute, Culture Collection for Algae and Protozoa, Oban, Argyll, PA37 1QA, UK
| | - Dieter G Müller
- Fachbereich Biologie der Universität Konstanz, D-78457, Konstanz, Germany
| | - David J Patiño
- Instituto de Acuicultura, Universidad Austral de Chile, Sede Puerto Montt, PO Box 1327, Puerto Montt, Chile
| | - Renato Westermeier
- Instituto de Acuicultura, Universidad Austral de Chile, Sede Puerto Montt, PO Box 1327, Puerto Montt, Chile
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25
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Provost EJ, Kelaher BP, Dworjanyn SA, Russell BD, Connell SD, Ghedini G, Gillanders BM, Figueira W, Coleman MA. Climate-driven disparities among ecological interactions threaten kelp forest persistence. Glob Chang Biol 2017; 23:353-361. [PMID: 27392308 DOI: 10.1111/gcb.13414] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 05/18/2016] [Accepted: 06/23/2016] [Indexed: 06/06/2023]
Abstract
The combination of ocean warming and acidification brings an uncertain future to kelp forests that occupy the warmest parts of their range. These forests are not only subject to the direct negative effects of ocean climate change, but also to a combination of unknown indirect effects associated with changing ecological landscapes. Here, we used mesocosm experiments to test the direct effects of ocean warming and acidification on kelp biomass and photosynthetic health, as well as climate-driven disparities in indirect effects involving key consumers (urchins and rock lobsters) and competitors (algal turf). Elevated water temperature directly reduced kelp biomass, while their turf-forming competitors expanded in response to ocean acidification and declining kelp canopy. Elevated temperatures also increased growth of urchins and, concurrently, the rate at which they thinned kelp canopy. Rock lobsters, which are renowned for keeping urchin populations in check, indirectly intensified negative pressures on kelp by reducing their consumption of urchins in response to elevated temperature. Overall, these results suggest that kelp forests situated towards the low-latitude margins of their distribution will need to adapt to ocean warming in order to persist in the future. What is less certain is how such adaptation in kelps can occur in the face of intensifying consumptive (via ocean warming) and competitive (via ocean acidification) pressures that affect key ecological interactions associated with their persistence. If such indirect effects counter adaptation to changing climate, they may erode the stability of kelp forests and increase the probability of regime shifts from complex habitat-forming species to more simple habitats dominated by algal turfs.
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Affiliation(s)
- Euan J Provost
- National Marine Science Centre & Centre for Coastal Biogeochemistry Research, School of Environment, Science and Engineering, Southern Cross University, Coffs Harbour, NSW, Australia
| | - Brendan P Kelaher
- National Marine Science Centre & Centre for Coastal Biogeochemistry Research, School of Environment, Science and Engineering, Southern Cross University, Coffs Harbour, NSW, Australia
| | - Symon A Dworjanyn
- National Marine Science Centre & Centre for Coastal Biogeochemistry Research, School of Environment, Science and Engineering, Southern Cross University, Coffs Harbour, NSW, Australia
| | - Bayden D Russell
- The Swire Institute of Marine Science and School of Biological Sciences, The University of Hong Kong, Hong Kong, Hong Kong SAR
- Southern Seas Ecology Laboratories, School of Biological Sciences & Environment Institute, University of Adelaide, Adelaide, SA, Australia
| | - Sean D Connell
- Southern Seas Ecology Laboratories, School of Biological Sciences & Environment Institute, University of Adelaide, Adelaide, SA, Australia
| | - Giulia Ghedini
- Southern Seas Ecology Laboratories, School of Biological Sciences & Environment Institute, University of Adelaide, Adelaide, SA, Australia
| | - Bronwyn M Gillanders
- Southern Seas Ecology Laboratories, School of Biological Sciences & Environment Institute, University of Adelaide, Adelaide, SA, Australia
| | - WillIAM Figueira
- Marine Ecology Laboratories, School of Biological Sciences, University of Sydney, Sydney, NSW, Australia
| | - Melinda A Coleman
- National Marine Science Centre & Centre for Coastal Biogeochemistry Research, School of Environment, Science and Engineering, Southern Cross University, Coffs Harbour, NSW, Australia
- Department of Primary Industries, New South Wales Fisheries, PO Box 4321, Coffs Harbour, NSW, Australia
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26
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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27
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Vergés A, Doropoulos C, Malcolm HA, Skye M, Garcia-Pizá M, Marzinelli EM, Campbell AH, Ballesteros E, Hoey AS, Vila-Concejo A, Bozec YM, Steinberg PD. Long-term empirical evidence of ocean warming leading to tropicalization of fish communities, increased herbivory, and loss of kelp. Proc Natl Acad Sci U S A 2016; 113:13791-13796. [PMID: 27849585 PMCID: PMC5137712 DOI: 10.1073/pnas.1610725113] [Citation(s) in RCA: 169] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Some of the most profound effects of climate change on ecological communities are due to alterations in species interactions rather than direct physiological effects of changing environmental conditions. Empirical evidence of historical changes in species interactions within climate-impacted communities is, however, rare and difficult to obtain. Here, we demonstrate the recent disappearance of key habitat-forming kelp forests from a warming tropical-temperate transition zone in eastern Australia. Using a 10-y video dataset encompassing a 0.6 °C warming period, we show how herbivory increased as kelp gradually declined and then disappeared. Concurrently, fish communities from sites where kelp was originally abundant but subsequently disappeared became increasingly dominated by tropical herbivores. Feeding assays identified two key tropical/subtropical herbivores that consumed transplanted kelp within hours at these sites. There was also a distinct increase in the abundance of fishes that consume epilithic algae, and much higher bite rates by this group at sites without kelp, suggesting a key role for these fishes in maintaining reefs in kelp-free states by removing kelp recruits. Changes in kelp abundance showed no direct relationship to seawater temperatures over the decade and were also unrelated to other measured abiotic factors (nutrients and storms). Our results show that warming-mediated increases in fish herbivory pose a significant threat to kelp-dominated ecosystems in Australia and, potentially, globally.
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Affiliation(s)
- Adriana Vergés
- Centre for Marine Bio-Innovation, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia;
- Evolution and Ecology Research Centre, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
- Sydney Institute of Marine Science, Mosman, NSW 2088, Australia
| | - Christopher Doropoulos
- Centre for Marine Bio-Innovation, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
- Commonwealth Scientific and Industrial Research Organization Oceans and Atmosphere, Dutton Park, QLD 4102, Australia
- Marine Spatial Ecology Lab, Australian Research Council Centre of Excellence for Coral Reef Studies, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Hamish A Malcolm
- Marine Ecosystem Research, Fisheries NSW, Department of Primary Industries, Coffs Harbour, NSW 2450, Australia
| | - Mathew Skye
- Centre for Marine Bio-Innovation, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
- Evolution and Ecology Research Centre, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Marina Garcia-Pizá
- Centre for Marine Bio-Innovation, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
- Evolution and Ecology Research Centre, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Ezequiel M Marzinelli
- Centre for Marine Bio-Innovation, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
- Evolution and Ecology Research Centre, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
- Sydney Institute of Marine Science, Mosman, NSW 2088, Australia
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technical University, Singapore 637551, Singapore
| | - Alexandra H Campbell
- Centre for Marine Bio-Innovation, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
- Evolution and Ecology Research Centre, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
- Sydney Institute of Marine Science, Mosman, NSW 2088, Australia
| | - Enric Ballesteros
- Centre d'Estudis Avançats de Blanes (Consejo Superior de Investigaciones Científicas), 17300 Blanes, Girona, Spain
| | - Andrew S Hoey
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia
| | - Ana Vila-Concejo
- Geocoastal Research Group, School of Geosciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Yves-Marie Bozec
- Marine Spatial Ecology Lab, Australian Research Council Centre of Excellence for Coral Reef Studies, School of Biological Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD 4811, Australia
| | - Peter D Steinberg
- Centre for Marine Bio-Innovation, School of Biological, Earth, and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia
- Sydney Institute of Marine Science, Mosman, NSW 2088, Australia
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technical University, Singapore 637551, Singapore
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Müller DG, Maier I, Marie D, Westermeier R. Nuclear DNA level and life cycle of kelps: Evidence for sex-specific polyteny in Macrocystis (Laminariales, Phaeophyceae). J Phycol 2016; 52:157-60. [PMID: 27037581 DOI: 10.1111/jpy.12380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Giant kelp, Macrocystis pyrifera (Linnaeus) C. Agardh, is the subject of intense breeding studies for marine biomass production and conservation of natural resources. In this context, six gametophyte pairs and a sporophyte offspring of Macrocystis from South America were analyzed by flow cytometry. Minimum relative DNA content per cell (1C) was found in five males. Unexpectedly, nuclei of all female gametophytes contained approximately double the DNA content (2C) of males; the male gametophyte from one locality also contained 2C, likely a spontaneous natural diploid variant. The results illustrate a sex-specific difference in nuclear DNA content among Macrocystis gametophytes, with the chromosomes of the females in a polytenic condition. This correlates with significantly larger cell sizes in female gametophytes compared to males and resource allocation in oogamous reproduction. The results provide key information for the interpretation of DNA measurements in kelp life cycle stages and prompt further research on the regulation of the cell cycle, metabolic activity, sex determination, and sporophyte development.
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Affiliation(s)
- Dieter G Müller
- Fakultät für Biologie der Universität Konstanz, Konstanz, D-78464, Germany
| | - Ingo Maier
- MABIOLA, Hochgratweg 12, Amtzell, D-88279, Germany
| | - Dominique Marie
- Station Biologique de Roscoff, Roscoff, Cedex, 29682, France
| | - Renato Westermeier
- Universidad Austral de Chile, Sede Puerto Montt, PO Box 1327, Puerto Montt, Chile
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Li X, Zhang Z, Qu S, Liang G, Sun J, Zhao N, Cui C, Cao Z, Li Y, Pan J, Yu S, Wang Q, Li X, Luo S, Song S, Guo L, Yang G. Improving seedless kelp (Saccharina japonica) during its domestication by hybridizing gametophytes and seedling-raising from sporophytes. Sci Rep 2016; 6:21255. [PMID: 26887644 PMCID: PMC4757934 DOI: 10.1038/srep21255] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 01/20/2016] [Indexed: 11/09/2022] Open
Abstract
Dongfang no.7 (Saccharina japonica) was bred and maintained by hybridizing gametophytes, self-crossing the best individuals, selecting the best self-crossing line and seedling-raising from yearly reconstructed sporophytes. It increased the air dry yield by 43.2% in average over 2 widely farmed controls. Dongfang no.7 was seedling-raised from bulked sporophytes reconstructed from its representative gametophyte clones. Such strategy ensured it against variety contamination due to possible cross fertilization and occasional mixing and inbred depletion due to self-crossing number-limited sporophytes year after year. It derived from an intraspecific hybrid through 4 rounds of self-crossing and selection and retained a certain degree of genetic heterozygosity, thus being immune to inbred depletion due to purification of unknown detrimental alleles. Most importantly, it can be farmed in currently available system as the seedlings for large scale culture can be raised from reconstructed Dongfang no.7 sporophytes. Breeding and maintaining Dongfang no.7 provided a model that other varieties of kelp (S. japonica) and brown algae may follow during their domestication.
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Affiliation(s)
- Xiaojie Li
- National Engineering Science Research & Development Center of Algae and Sea Cucumbers of China, Yantai, Shandong 264003, PR China
- Provincial Key Laboratory of Genetic Improvement & Efficient Culture of Marine Algae of Shandong, Yantai, Shandong 264003, PR China
- Shandong Oriental Ocean Sci-tech Co., Ltd., Yantai, Shandong 264003, PR China
| | - Zhuangzhi Zhang
- National Engineering Science Research & Development Center of Algae and Sea Cucumbers of China, Yantai, Shandong 264003, PR China
- Provincial Key Laboratory of Genetic Improvement & Efficient Culture of Marine Algae of Shandong, Yantai, Shandong 264003, PR China
- Shandong Oriental Ocean Sci-tech Co., Ltd., Yantai, Shandong 264003, PR China
| | - Shancun Qu
- National Engineering Science Research & Development Center of Algae and Sea Cucumbers of China, Yantai, Shandong 264003, PR China
- Provincial Key Laboratory of Genetic Improvement & Efficient Culture of Marine Algae of Shandong, Yantai, Shandong 264003, PR China
- Shandong Oriental Ocean Sci-tech Co., Ltd., Yantai, Shandong 264003, PR China
| | - Guangjin Liang
- National Engineering Science Research & Development Center of Algae and Sea Cucumbers of China, Yantai, Shandong 264003, PR China
- Provincial Key Laboratory of Genetic Improvement & Efficient Culture of Marine Algae of Shandong, Yantai, Shandong 264003, PR China
- Shandong Oriental Ocean Sci-tech Co., Ltd., Yantai, Shandong 264003, PR China
| | - Juan Sun
- National Engineering Science Research & Development Center of Algae and Sea Cucumbers of China, Yantai, Shandong 264003, PR China
- Provincial Key Laboratory of Genetic Improvement & Efficient Culture of Marine Algae of Shandong, Yantai, Shandong 264003, PR China
- Shandong Oriental Ocean Sci-tech Co., Ltd., Yantai, Shandong 264003, PR China
| | - Nan Zhao
- National Engineering Science Research & Development Center of Algae and Sea Cucumbers of China, Yantai, Shandong 264003, PR China
- Provincial Key Laboratory of Genetic Improvement & Efficient Culture of Marine Algae of Shandong, Yantai, Shandong 264003, PR China
- Shandong Oriental Ocean Sci-tech Co., Ltd., Yantai, Shandong 264003, PR China
| | - Cuiju Cui
- National Engineering Science Research & Development Center of Algae and Sea Cucumbers of China, Yantai, Shandong 264003, PR China
- Provincial Key Laboratory of Genetic Improvement & Efficient Culture of Marine Algae of Shandong, Yantai, Shandong 264003, PR China
- Shandong Oriental Ocean Sci-tech Co., Ltd., Yantai, Shandong 264003, PR China
| | - Zengmei Cao
- National Engineering Science Research & Development Center of Algae and Sea Cucumbers of China, Yantai, Shandong 264003, PR China
- Provincial Key Laboratory of Genetic Improvement & Efficient Culture of Marine Algae of Shandong, Yantai, Shandong 264003, PR China
- Shandong Oriental Ocean Sci-tech Co., Ltd., Yantai, Shandong 264003, PR China
| | - Yan Li
- National Engineering Science Research & Development Center of Algae and Sea Cucumbers of China, Yantai, Shandong 264003, PR China
- Provincial Key Laboratory of Genetic Improvement & Efficient Culture of Marine Algae of Shandong, Yantai, Shandong 264003, PR China
- Shandong Oriental Ocean Sci-tech Co., Ltd., Yantai, Shandong 264003, PR China
| | - Jinhua Pan
- National Engineering Science Research & Development Center of Algae and Sea Cucumbers of China, Yantai, Shandong 264003, PR China
- Provincial Key Laboratory of Genetic Improvement & Efficient Culture of Marine Algae of Shandong, Yantai, Shandong 264003, PR China
- Shandong Oriental Ocean Sci-tech Co., Ltd., Yantai, Shandong 264003, PR China
| | - Shenhui Yu
- National Engineering Science Research & Development Center of Algae and Sea Cucumbers of China, Yantai, Shandong 264003, PR China
- Provincial Key Laboratory of Genetic Improvement & Efficient Culture of Marine Algae of Shandong, Yantai, Shandong 264003, PR China
- Shandong Oriental Ocean Sci-tech Co., Ltd., Yantai, Shandong 264003, PR China
| | - Qingyan Wang
- National Engineering Science Research & Development Center of Algae and Sea Cucumbers of China, Yantai, Shandong 264003, PR China
- Provincial Key Laboratory of Genetic Improvement & Efficient Culture of Marine Algae of Shandong, Yantai, Shandong 264003, PR China
- Shandong Oriental Ocean Sci-tech Co., Ltd., Yantai, Shandong 264003, PR China
| | - Xia Li
- National Engineering Science Research & Development Center of Algae and Sea Cucumbers of China, Yantai, Shandong 264003, PR China
- Provincial Key Laboratory of Genetic Improvement & Efficient Culture of Marine Algae of Shandong, Yantai, Shandong 264003, PR China
- Shandong Oriental Ocean Sci-tech Co., Ltd., Yantai, Shandong 264003, PR China
| | - Shiju Luo
- National Engineering Science Research & Development Center of Algae and Sea Cucumbers of China, Yantai, Shandong 264003, PR China
- Provincial Key Laboratory of Genetic Improvement & Efficient Culture of Marine Algae of Shandong, Yantai, Shandong 264003, PR China
- Shandong Oriental Ocean Sci-tech Co., Ltd., Yantai, Shandong 264003, PR China
| | - Shaofeng Song
- National Engineering Science Research & Development Center of Algae and Sea Cucumbers of China, Yantai, Shandong 264003, PR China
- Provincial Key Laboratory of Genetic Improvement & Efficient Culture of Marine Algae of Shandong, Yantai, Shandong 264003, PR China
- Shandong Oriental Ocean Sci-tech Co., Ltd., Yantai, Shandong 264003, PR China
| | - Li Guo
- Laboratory of Marine Genetics and Breeding, Ocean University of China, Qingdao 266003, PR China
- Institutes of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, PR China
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, PR China
| | - Guanpin Yang
- Laboratory of Marine Genetics and Breeding, Ocean University of China, Qingdao 266003, PR China
- Institutes of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, PR China
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, PR China
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Mertens NL, Russell BD, Connell SD. Escaping herbivory: ocean warming as a refuge for primary producers where consumer metabolism and consumption cannot pursue. Oecologia 2015; 179:1223-9. [PMID: 26363905 DOI: 10.1007/s00442-015-3438-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Accepted: 08/30/2015] [Indexed: 10/23/2022]
Abstract
Ocean warming is anticipated to strengthen the persistence of turf-forming habitat, yet the concomitant elevation of grazer metabolic rates may accelerate per capita rates of consumption to counter turf predominance. Whilst this possibility of strong top-down control is supported by the metabolic theory of ecology (MTE), it assumes that consumer metabolism and consumption keep pace with increasing production. This assumption was tested by quantifying the metabolic rates of turfs and herbivorous gastropods under a series of elevated temperatures in which the ensuing production and consumption were observed. We discovered that as temperature increases towards near-future levels (year 2100), consumption rates of gastropods peak earlier than the rate of growth of producers. Hence, turfs have greater capacity to persist under near-future temperatures than the capacity for herbivores to counter their growth. These results suggest that whilst MTE predicts stronger top-down control, understanding whether consumer-producer responses are synchronous is key to assessing the future strength of top-down control.
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Affiliation(s)
- Nicole L Mertens
- Southern Seas Ecology Laboratories, School of Biological Sciences, University of Adelaide, Adelaide, SA, 5005, Australia
| | - Bayden D Russell
- Southern Seas Ecology Laboratories, School of Biological Sciences, University of Adelaide, Adelaide, SA, 5005, Australia
- Swire Institute of Marine Science and School of Biological Sciences, University of Hong Kong, Hong Kong SAR, China
| | - Sean D Connell
- Southern Seas Ecology Laboratories, School of Biological Sciences, University of Adelaide, Adelaide, SA, 5005, Australia.
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31
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Miller RJ, Page HM, Reed DC. Trophic versus structural effects of a marine foundation species, giant kelp (Macrocystis pyrifera). Oecologia 2015; 179:1199-209. [PMID: 26358195 DOI: 10.1007/s00442-015-3441-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 08/30/2015] [Indexed: 10/23/2022]
Abstract
Foundation species create milieus in which ecosystems evolve, altering species abundances and distribution often to a dramatic degree. Although much descriptive work supports their importance, there remains little definitive information on the mechanisms by which foundation species alter their environment. These mechanisms fall into two basic categories: provision of food or other materials, and modification of the physical environment. Here, we manipulated the abundance of a marine foundation species, the giant kelp Macrocystis pyrifera, in 40 × 40-m plots at Mohawk Reef off Santa Barbara, California and found that its biomass had a strong positive effect on the abundance of bottom-dwelling sessile invertebrates. We examined the carbon (C) stable isotope values of seven species of sessile invertebrates in the treatment plots to test the hypothesis that this positive effect resulted from a nutritional supplement of small suspended particles of kelp detritus, as many studies have posited. We found no evidence from stable isotope analyses to support the hypothesis that kelp detritus is an important food source for sessile suspension-feeding invertebrates. The isotope composition of invertebrates varied with species and season, but was not affected by kelp biomass, with the exception of two species: the tunicate Styela montereyensis, which exhibited a slight enrichment in C stable isotope composition with increasing kelp biomass, and the hydroid Aglaophenia sp., which showed the opposite effect. These results suggest that modification of the physical habitat, rather than nutritional subsidy by kelp detritus, likely accounts for increased abundance of sessile invertebrates within giant kelp forests.
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Affiliation(s)
- Robert J Miller
- Marine Science Institute, University of California, Santa Barbara, CA, USA.
| | - Henry M Page
- Marine Science Institute, University of California, Santa Barbara, CA, USA
| | - Daniel C Reed
- Marine Science Institute, University of California, Santa Barbara, CA, USA
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32
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Krumhansl KA, Demes KW, Carrington E, Harley CDG. Divergent growth strategies between red algae and kelps influence biomechanical properties. Am J Bot 2015; 102:1938-44. [PMID: 26546127 DOI: 10.3732/ajb.1500289] [Citation(s) in RCA: 3] [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] [Received: 06/19/2015] [Accepted: 10/01/2015] [Indexed: 06/05/2023]
Abstract
PREMISE OF THE STUDY Morphology and material properties are the main components of the mechanical design of organisms, with species groups developing different optimization strategies in the context of their physical environment. For intertidal and subtidal seaweeds, possessing highly flexible and extensible tissues allows individuals to bend and reconfigure in flow, thereby reducing drag. Previous research has shown that aging may compromise these qualities. Tissue age increases with distance from the blade's meristem, which differs in its position on kelps and red algae. Here, we assess whether longitudinal patterns of blade material properties differ between these two algal groups according to tissue age. METHODS We performed tensile tests on tissues samples excised from various positions along the extent of blades in nine kelp species (basal growth) and 15 species of red algae (apical growth). KEY RESULTS We found that older tissues were less flexible and extensible than younger tissues in all species tested. As predicted, tissue near the basal meristem in kelp was more flexible and extensible than older tissue at the blade's distal end. The opposite pattern was observed for red algae, with the most flexible and extensible tissues found near the apical meristem at the distal ends of blades. CONCLUSIONS We propose that divergent patterns in the distribution of material properties along blades may have different consequences for the performance of kelps and red algae. The positioning of younger tissues at the blade base for kelps may enable these species to attain larger body sizes in wave-swept habitats.
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Affiliation(s)
- Kira A Krumhansl
- Department of Resource and Environmental Management, Simon Fraser University, 622 Strand Hall Annex 8888 University Dr. Burnaby, B.C. Canada V5A 1S6 Hakai Institute, PO Box 309, Heriot Bay, B.C. Canada V0P 1H0
| | - Kyle W Demes
- Hakai Institute, PO Box 309, Heriot Bay, B.C. Canada V0P 1H0 Department of Zoology, University of British Columbia, 6270 University Blvd. Vancouver, B.C. Canada V6T 1Z4
| | - Emily Carrington
- Department of Biology and Friday Harbor Laboratories, University of Washington, 620 University Road. Friday Harbor, WA USA 98250
| | - Christopher D G Harley
- Department of Zoology, University of British Columbia, 6270 University Blvd. Vancouver, B.C. Canada V6T 1Z4
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Carnell PE, Keough MJ. Spatially variable synergistic effects of disturbance and additional nutrients on kelp recruitment and recovery. Oecologia 2014; 175:409-16. [PMID: 24604540 DOI: 10.1007/s00442-014-2907-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 02/13/2014] [Indexed: 10/25/2022]
Abstract
Understanding the impact of multiple stressors on ecosystems is of pronounced importance, particularly when one or more of those stressors is anthropogenic. Here we investigated the role of physical disturbance and increased nutrients on reefs dominated by the canopy-forming kelp Ecklonia radiata. We combined experimental kelp canopy removals and additional nutrient at three different locations in a large embayment in temperate southeastern Australia. Over the following winter recruitment season, Ecklonia recruitment was unaffected by increased nutrients alone, but tripled at all sites where the canopy had been removed. At one site, the combination of disturbance and increased nutrients resulted in more than four times the recruitment of the introduced kelp Undaria pinnatifida. Six months after disturbance, the proliferation of the Undaria canopy in the canopy-removal and nutrient-addition treatment negatively influenced the recovery of the native kelp Ecklonia. Given the otherwise competitive dominance of adult Ecklonia, this provides a mechanism whereby Undaria could maintain open space for the following recruitment season. This interplay between disturbance, nutrients and the response of native and invasive species makes a compelling case for how a combination of factors can influence species dynamics.
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Affiliation(s)
- Paul E Carnell
- Department of Zoology, The University of Melbourne, Parkville, VIC, 3010, Australia,
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Mohring MB, Kendrick GA, Wernberg T, Rule MJ, Vanderklift MA. Environmental influences on kelp performance across the reproductive period: an ecological trade-off between gametophyte survival and growth? PLoS One 2013; 8:e65310. [PMID: 23755217 PMCID: PMC3670881 DOI: 10.1371/journal.pone.0065310] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 04/28/2013] [Indexed: 11/18/2022] Open
Abstract
Most kelps (order Laminariales) exhibit distinct temporal patterns in zoospore production, gametogenesis and gametophyte reproduction. Natural fluctuations in ambient environmental conditions influence the intrinsic characteristics of gametes, which define their ability to tolerate varied conditions. The aim of this work was to document seasonal patterns in reproduction and gametophyte growth and survival of Ecklonia radiata (C. Agardh) J. Agardh in south-western Australia. These results were related to patterns in local environmental conditions in an attempt to ascertain which factors explain variation throughout the season. E. radiata was fertile (produced zoospores) for three and a half months over summer and autumn. Every two weeks during this time, gametophytes were grown in a range of temperatures (16-22 °C) in the laboratory. Zoospore densities were highly variable among sample periods; however, zoospores released early in the season produced gametophytes which had greater rates of growth and survival, and these rates declined towards the end of the reproductive season. Growth rates of gametophytes were positively related to day length, with the fastest growing recruits released when the days were longest. Gametophytes consistently survived best in the lowest temperature (16 °C), yet exhibited optimum growth in higher culture temperatures (20-22 °C). These results suggest that E. radiata releases gametes when conditions are favourable for growth, and E. radiata gametophytes are tolerant of the range of temperatures observed at this location. E. radiata releases the healthiest gametophytes when day length and temperature conditions are optimal for better germination, growth, and sporophyte production, perhaps as a mechanism to help compete against other species for space and other resources.
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Affiliation(s)
- Margaret B Mohring
- School of Plant Biology and UWA Oceans Institute, The University of Western Australia, Crawley, Western Australia, Australia.
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Oppliger LV, Correa JA, Engelen AH, Tellier F, Vieira V, Faugeron S, Valero M, Gomez G, Destombe C. Temperature effects on gametophyte life-history traits and geographic distribution of two cryptic kelp species. PLoS One 2012; 7:e39289. [PMID: 22723987 PMCID: PMC3377671 DOI: 10.1371/journal.pone.0039289] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Accepted: 05/21/2012] [Indexed: 11/19/2022] Open
Abstract
A major determinant of the geographic distribution of a species is expected to be its physiological response to changing abiotic variables over its range. The range of a species often corresponds to the geographic extent of temperature regimes the organism can physiologically tolerate. Many species have very distinct life history stages that may exhibit different responses to environmental factors. In this study we emphasized the critical role of the haploid microscopic stage (gametophyte) of the life cycle to explain the difference of edge distribution of two related kelp species. Lessonia nigrescens was recently identified as two cryptic species occurring in parapatry along the Chilean coast: one located north and the other south of a biogeographic boundary at latitude 29-30°S. Six life history traits from microscopic stages were identified and estimated under five treatments of temperature in eight locations distributed along the Chilean coast in order to (1) estimate the role of temperature in the present distribution of the two cryptic L. nigrescens species, (2) compare marginal populations to central populations of the two cryptic species. In addition, we created a periodic matrix model to estimate the population growth rate (λ) at the five temperature treatments. Differential tolerance to temperature was demonstrated between the two species, with the gametophytes of the Northern species being more tolerant to higher temperatures than gametophytes from the south. Second, the two species exhibited different life history strategies with a shorter haploid phase in the Northern species contrasted with considerable vegetative growth in the Southern species haploid stage. These results provide strong ecological evidence for the differentiation process of the two cryptic species and show local adaptation of the life cycle at the range limits of the distribution. Ecological and evolutionary implications of these findings are discussed.
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Affiliation(s)
- L. Valeria Oppliger
- Center for Advanced Studies in Ecology and Biodiversity, Facultad de Ciencias Biologicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- UPMC Station Biologique de Roscoff, Equipe Biologie Evolutive et Diversité Marine, “BEDIM”, UMR 7144, BP 74, Roscoff, France
- CNRS Station Biologique de Roscoff, Equipe Biologie Evolutive et Diversité Marine, “BEDIM”, UMR 7144, BP 74, Roscoff, France
| | - Juan A. Correa
- Center for Advanced Studies in Ecology and Biodiversity, Facultad de Ciencias Biologicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Aschwin H. Engelen
- Centre of Marine Sciences (CCMAR), CIMAR – Laboratório Associado, Universidade do Algarve, Campus de Gambelas, Faro, Portugal
| | - Florence Tellier
- Departamento de Ecología, Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Concepción, Chile
| | - Vasco Vieira
- Centre of Marine Sciences (CCMAR), CIMAR – Laboratório Associado, Universidade do Algarve, Campus de Gambelas, Faro, Portugal
| | - Sylvain Faugeron
- Center for Advanced Studies in Ecology and Biodiversity, Facultad de Ciencias Biologicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Myriam Valero
- UPMC Station Biologique de Roscoff, Equipe Biologie Evolutive et Diversité Marine, “BEDIM”, UMR 7144, BP 74, Roscoff, France
- CNRS Station Biologique de Roscoff, Equipe Biologie Evolutive et Diversité Marine, “BEDIM”, UMR 7144, BP 74, Roscoff, France
| | - Gonzalo Gomez
- Center for Advanced Studies in Ecology and Biodiversity, Facultad de Ciencias Biologicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Christophe Destombe
- UPMC Station Biologique de Roscoff, Equipe Biologie Evolutive et Diversité Marine, “BEDIM”, UMR 7144, BP 74, Roscoff, France
- CNRS Station Biologique de Roscoff, Equipe Biologie Evolutive et Diversité Marine, “BEDIM”, UMR 7144, BP 74, Roscoff, France
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Falkenberg LJ, Russell BD, Connell SD. Stability of strong species interactions resist the synergistic effects of local and global pollution in kelp forests. PLoS One 2012; 7:e33841. [PMID: 22439005 PMCID: PMC3306304 DOI: 10.1371/journal.pone.0033841] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2011] [Accepted: 02/17/2012] [Indexed: 11/30/2022] Open
Abstract
Foundation species, such as kelp, exert disproportionately strong community effects and persist, in part, by dominating taxa that inhibit their regeneration. Human activities which benefit their competitors, however, may reduce stability of communities, increasing the probability of phase-shifts. We tested whether a foundation species (kelp) would continue to inhibit a key competitor (turf-forming algae) under moderately increased local (nutrient) and near-future forecasted global pollution (CO(2)). Our results reveal that in the absence of kelp, local and global pollutants combined to cause the greatest cover and mass of turfs, a synergistic response whereby turfs increased more than would be predicted by adding the independent effects of treatments (kelp absence, elevated nutrients, forecasted CO(2)). The positive effects of nutrient and CO(2) enrichment on turfs were, however, inhibited by the presence of kelp, indicating the competitive effect of kelp was stronger than synergistic effects of moderate enrichment of local and global pollutants. Quantification of physicochemical parameters within experimental mesocosms suggests turf inhibition was likely due to an effect of kelp on physical (i.e. shading) rather than chemical conditions. Such results indicate that while forecasted climates may increase the probability of phase-shifts, maintenance of intact populations of foundation species could enable the continued strength of interactions and persistence of communities.
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Affiliation(s)
| | | | - Sean D. Connell
- Southern Seas Ecology Laboratories, School of Earth and Environmental Sciences, University of Adelaide, South Australia, Australia
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Adams JMM, Ross AB, Anastasakis K, Hodgson EM, Gallagher JA, Jones JM, Donnison IS. Seasonal variation in the chemical composition of the bioenergy feedstock Laminaria digitata for thermochemical conversion. Bioresour Technol 2011; 102:226-34. [PMID: 20685112 DOI: 10.1016/j.biortech.2010.06.152] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Revised: 06/17/2010] [Accepted: 06/25/2010] [Indexed: 05/25/2023]
Abstract
To avoid negative impacts on food production, novel non-food biofuel feedstocks need to be identified and utilised. One option is to utilise marine biomass, notably fast-growing, large marine 'plants' such as the macroalgal kelps. This paper reports on the changing composition of Laminaria digitata throughout it growth cycle as determined by new technologies. The potential of Laminaria sp. as a feedstock for biofuel production and future biorefining possibilities was assessed through proximate and ultimate analysis, initial pyrolysis rates using thermo-gravimetric analysis (TGA), metals content and pyrolysis gas chromatography-mass spectrometry. Samples harvested in March contained the lowest proportion of carbohydrate and the highest ash and alkali metal content, whereas samples harvested in July contained the highest proportions of carbohydrate, lowest alkali metals and ash content. July was therefore considered the most suitable month for harvesting kelp biomass for thermochemical conversion to biofuels.
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Affiliation(s)
- J M M Adams
- Bioenergy and Biorenewables, Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Gogerddan, Aberystwyth SY23 3EB, United Kingdom
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Connell SD, Russell BD. The direct effects of increasing CO2 and temperature on non-calcifying organisms: increasing the potential for phase shifts in kelp forests. Proc Biol Sci 2010; 277:1409-15. [PMID: 20053651 PMCID: PMC2871943 DOI: 10.1098/rspb.2009.2069] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Accepted: 12/09/2009] [Indexed: 01/08/2023] Open
Abstract
Predictions about the ecological consequences of oceanic uptake of CO(2) have been preoccupied with the effects of ocean acidification on calcifying organisms, particularly those critical to the formation of habitats (e.g. coral reefs) or their maintenance (e.g. grazing echinoderms). This focus overlooks the direct effects of CO(2) on non-calcareous taxa, particularly those that play critical roles in ecosystem shifts. We used two experiments to investigate whether increased CO(2) could exacerbate kelp loss by facilitating non-calcareous algae that, we hypothesized, (i) inhibit the recovery of kelp forests on an urbanized coast, and (ii) form more extensive covers and greater biomass under moderate future CO(2) and associated temperature increases. Our experimental removal of turfs from a phase-shifted system (i.e. kelp- to turf-dominated) revealed that the number of kelp recruits increased, thereby indicating that turfs can inhibit kelp recruitment. Future CO(2) and temperature interacted synergistically to have a positive effect on the abundance of algal turfs, whereby they had twice the biomass and occupied over four times more available space than under current conditions. We suggest that the current preoccupation with the negative effects of ocean acidification on marine calcifiers overlooks potentially profound effects of increasing CO(2) and temperature on non-calcifying organisms.
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Affiliation(s)
- Sean D Connell
- Southern Seas Ecology Laboratories, School of Earth and Environmental Sciences, University of Adelaide, South Australia, Australia.
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Lincoln T. Ecology: Kelp in postglacial time. Nature 2009; 461:1066. [PMID: 19847253 DOI: 10.1038/4611066a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Spilmont N, Denis L, Artigas LF, Caloin F, Courcot L, Créach A, Desroy N, Gevaert F, Hacquebart P, Hubas C, Janquin MA, Lemoine Y, Luczak C, Migné A, Rauch M, Davoult D. Impact of the Phaeocystis globosa spring bloom on the intertidal benthic compartment in the eastern English Channel: a synthesis. Mar Pollut Bull 2009; 58:55-63. [PMID: 18947841 DOI: 10.1016/j.marpolbul.2008.09.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2008] [Revised: 09/08/2008] [Accepted: 09/10/2008] [Indexed: 05/27/2023]
Abstract
From 1999 to 2005, studies carried out in the frame of regional and national French programs aimed to determine whether the Phaeocystis globosa bloom affected the intertidal benthic communities of the French coast of the eastern English Channel in terms of composition and/or functioning. Study sites were chosen to cover most of the typical shore types encountered on this coast (a rocky shore, an exposed sandy beach and a small estuary). Both the presence of active Phaeocystis cells and their degradation product (foam) did have a significant impact on the studied shores. The primary production and growth rates of the kelp Saccharina latissima decreased during the bloom because of a shortage of light and nutrient for the macroalgae. On sandy sediments, the benthic metabolism (community respiration and community primary production), as well as the nitrification rate, were enhanced during foam deposits, in relation with the presence of bacteria and active pelagic cells within the decaying colonies. In estuarine sediments, the most impressive impact was the formation of a crust at the sediment surface due to drying foam. This led to anoxic conditions in the surface sediment and resulted in a high mortality among the benthic community. Some organisms also tended to migrate upward and were then directly accessible to the higher trophic level represented by birds. Phaeocystis then created a shortcut in the estuarine trophic network. Most of these modifications lasted shortly and all the systems considered came back to their regular properties and activities a few weeks after the end of the bloom, except for the most impacted estuarine area.
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Affiliation(s)
- Nicolas Spilmont
- Université des Sciences et Technologies de Lille, Laboratoire d'Océanologie et de Géosciences, CNRS UMR 8187 LOG, Station Marine de Wimereux, Wimereux, France.
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Salomon AK, Shears NT, Langlois TJ, Babcock RC. Cascading effects of fishing can alter carbon flow through a temperate coastal ecosystem. Ecol Appl 2008; 18:1874-87. [PMID: 19263885 DOI: 10.1890/07-1777.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Mounting evidence suggests that fishing can trigger trophic cascades and alter food web dynamics, yet its effects on ecosystem function remain largely unknown. We used the large-scale experimental framework of four marine reserves, spanning an oceanographic gradient in northeastern New Zealand, to test the extent to which the exploitation of reef predators can alter kelp carbon flux and secondary production. We provide evidence that the reduction of predatory snapper (Pagrus auratus) and lobster (Jasus edwardsii) can lead to an increase in sea urchins (Evechinus chloroticus) and indirect declines in kelp biomass in some locations but not others. Stable carbon isotope ratios (delta13C) of oysters (Crassostrea gigas) and mussels (Perna canaliculus) transplanted in reserve and fished sites within four locations revealed that fishing indirectly reduced the proportion of kelp-derived organic carbon assimilated by filter feeders in two locations where densities of actively grazing sea urchins were 23.7 and 8.3 times higher and kelp biomass was an order of magnitude lower than in non-fished reserve sites. In contrast, in the two locations where fishing had no effect on urchin density or kelp biomass, we detected no effect of fishing on the carbon signature of filter feeders. We show that the effects of fishing on nearshore trophic structure and carbon flux are context-dependent and hinge on large-scale, regional oceanographic factors. Where cascading effects of fishing on kelp biomass were documented, enhanced assimilation of kelp carbon did not result in the magnification of secondary production. Instead, a strong regional gradient in filter feeder growth emerged, best predicted by chlorophyll a. Estimates of kelp contribution to the diet of transplanted consumers averaged 56.9% +/- 6.2% (mean +/- SE) for mussels and 33.8% +/- 7.3% for oysters, suggesting that organic carbon fixed by kelp is an important food source fueling northeastern New Zealand's nearshore food webs. The importance of predators in mediating benthic primary production and organic carbon flux suggests that overfishing can have profound consequences on ecosystem functioning particularly where pelagic primary production is limiting. Our results underscore the broader ecosystem repercussions of overfishing and its context-dependent effects.
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Affiliation(s)
- Anne K Salomon
- Department of Biology, University of Washington, P.O. Box 351800, Seattle, Washington 98195-1800, USA.
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Shears NT, Babcock RC, Salomon AK. Context-dependent effects of fishing: variation in trophic cascades across environmental gradients. Ecol Appl 2008; 18:1860-73. [PMID: 19263884 DOI: 10.1890/07-1776.1] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Marine reserves provide a large-scale experimental framework to investigate the effects of fishing on food web dynamics and how they vary with environmental context. Because marine reserves promote the recovery of previously fished predators, spatial comparisons between reserve and fished sites are often made to infer such effects; however, alternative explanations for differences between reserve and fished sites are seldom tested (e.g., environmental variation among sites). We investigated the context dependency of the predator-urchin-kelp trophic cascade reported in northeastern New Zealand by comparing the abundance of herbivorous sea urchins (Evechinus chloroticus), the extent of urchin barrens habitat, and macroalgal biomass between reserve and fished sites within six locations that span an environmental gradient in wave exposure, sedimentation, and water clarity. At depths where differences in urchin abundance or macroalgal biomass were found between reserve and fished sites we used a model selection approach to identify which variables (fishing or environmental factors) best explained the variation among sites. Differences between reserve and fished sites were not ubiquitous across the locations examined and were highly depth specific. At sheltered locations, urchins were rare and barrens absent at both reserve and fished sites. At moderately exposed coastal locations, actively grazing urchins were most abundant at 4-6 m depth, and significant differences in macroalgal biomass between reserve and fished sites were observed. In contrast, at offshore island locations, urchins extended into deeper water, and differences between reserve and fished sites were found at 4-9 m depth. These differences could only be attributed to trophic cascades associated with protection from fishing in two of the six locations examined. In other cases, variation between reserve and fished sites was equally well explained by differences in sediment or wave exposure among sites. These results suggest that trophic cascades are not ubiquitous to northeastern New Zealand's subtidal reefs and the importance of sea urchins, and indirectly predators, in controlling macroalgal biomass will vary at local and regional scales in relation to abiotic factors. A better mechanistic understanding of how environmental variation affects the strength of species interactions across multiple spatial scales is needed to predict the ecosystem-level effects of fishing.
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Affiliation(s)
- Nick T Shears
- Leigh Marine Laboratory, University of Auckland, P.O. Box 349, Warkworth, New Zealand.
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Abstract
It has been suggested that microcarnivorous reef fishes may play an important role in giant kelp forest communities by preventing infestations of mesograzers that could severely impact or potentially destroy recovering kelp forests after extreme disturbance events. However, these trophic linkages, specifically the direct and indirect effects of fishes on the biomass of mesograzers, grazing intensity, and the performance of giant kelp, have not been sufficiently quantified and evaluated as to their importance and in the absence of such disturbance events. We examined experimentally the effects of mesograzers on the growth and performance of giant kelp in the presence and absence of their fish predators near Santa Catalina Island, California (U.S.A.). Mesograzer biomass and grazing intensity were significantly higher when fishes were excluded from giant kelp, which in turn, lowered kelp performance. This pattern was consistent both on experimental plots of kelp as habitat isolates, and on a continuous reef. Moreover, the abundance of mesograzers was inversely related to the abundance of kelp perch among several kelp-forested reefs, suggesting that these effects can occur at larger spatial scales. Because of differences in the diet and behavior of two microcarnivorous fishes, the kelp perch and señorita, we conducted an experiment manipulating each species and its density independently to determine their separate effects on mesograzers and kelp performance. Concurrently we examined the growth and mortality of juvenile kelp. Grazing intensity decreased, estimates of kelp performance increased, and the growth of juvenile kelp increased with increasing densities of fish but with no detectable effects between fishes. Our results demonstrate that these microcarnivorous fishes have positive indirect effects on kelp performance by reducing mesograzer biomass and grazing intensity, and the early life stages of other fishes also may be important. More specifically, these fishes have a positive effect on the density of fronds of giant kelp that can result in greater recruitment success and the abundance of kelp-associated invertebrates and fishes. Indeed, this study suggests that mesograzers have the potential to be one of the most important herbivores in kelp forest ecosystems.
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Affiliation(s)
- Andrew C Davenport
- Department of Biology, San Diego State University, San Diego, California 92182-4614, USA
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Contreras L, Medina MH, Andrade S, Oppliger V, Correa JA. Effects of copper on early developmental stages of Lessonia nigrescens Bory (Phaeophyceae). Environ Pollut 2007; 145:75-83. [PMID: 16720066 DOI: 10.1016/j.envpol.2006.03.051] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2006] [Revised: 03/23/2006] [Accepted: 03/29/2006] [Indexed: 05/09/2023]
Abstract
Copper effects on the early developmental gametophytic and sporophytic stages of the kelp Lessonia nigrescens were tested in gradients of increasing concentrations of ASV-labile copper. The results demonstrated a high sensitivity to copper of all life-history stages of the alga, where even the lowest tested concentration affected spore release as well as their subsequent settlement. More significant, concentrations higher than 7.87 microg L(-1) totally interrupted the development of the spores after they settle. This effect led to a failure in the formation of male and female gametophytes and, as a consequence, to a complete disruption of the normal life cycle of the kelp. Thus, we suggest that the absence of L. nigrescens from copper-enriched environments results from the high sensitivity of its early life cycle stages, which limits growth and maturation of the gametophytic microscopic phase and, as a consequence, prevents development of the macroscopic sporophytic phase.
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Affiliation(s)
- Loretto Contreras
- Departamento de Ecología, Center for Advanced Studies in Ecology and Biodiversity, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, Santiago, Chile
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Gao J, Zhang Y, Wang H, Qin S. Suspension culture of gametophytes of transgenic kelp in a photobioreactor. Biotechnol Lett 2005; 27:1025-8. [PMID: 16132848 DOI: 10.1007/s10529-005-8098-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2005] [Accepted: 05/20/2005] [Indexed: 10/25/2022]
Abstract
Transgenic Laminaria japonica gametophytes producing a recombinant tissue-type plasminogen activator (rtPA) protein, which is an effective third-generation thrombolytic agent for acute myocardial infarction (AMI), were cultured in an illuminated bubble column bioreactor. A maximum final dry cell weight of 1120 mg l(-1) was obtained in batch culture with an initial dry cell weight of 126 mg l(-1) and with aeration rate of 1.2 l air min(-1 )l(-1) culture, nitrate at 1.5 mM: and phosphate at 0.17 mM: . The yield of rtPA was 56 microg g(-1) dry cell wt. This is the first report regarding cultivation of a transgenic macroalga in a bioreactor.
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Affiliation(s)
- Jiangtao Gao
- Institute of Oceanology, Chinese Academy of Sciences, 266071, Qingdao, P.R. China
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Edwards MS. Estimating scale-dependency in disturbance impacts: El Niños and giant kelp forests in the northeast Pacific. Oecologia 2004; 138:436-47. [PMID: 14673640 DOI: 10.1007/s00442-003-1452-8] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2003] [Accepted: 11/07/2003] [Indexed: 11/28/2022]
Abstract
Recent discussions on scaling issues in ecology have emphasized that processes acting at a wide range of spatial and temporal scales influence ecosystems and thus there is no appropriate single scale at which ecological processes should be studied. This may be particularly true for environmental disturbances (e.g. El Niño) that occur over large geographic areas and encompass a wide range of scales relevant to ecosystem function. However, it may be possible to identify the scale(s) at which ecosystems are most strongly impacted by disturbances, and thus provide a measure by which their impacts can be most clearly described, by assessing scale-dependent changes in the patterns of variability in species abundance and distribution. This, in turn, may yield significant insight into the relative importance of the various forcing factors responsible for generating these impacts. The 1997-98 El Niño was one of the strongest El Niños ever recorded. I examined how this event impacted giant kelp populations in the northeast Pacific Ocean at 90 sites ranging from central Baja California, Mexico to central California, USA. These sites spanned the geographic range of giant kelp in the Northeast Pacific and were surveyed just before, immediately following, several months after, more than 1 year after, and nearly 2 years after the El Niño. I used a hierarchical sample design to compare these impacts at five spatial scales spanning six orders of magnitude, from a few meters to more than 1,000 km. Variance Components Analyses revealed that the El Niño shifted control over giant kelp abundance from factors acting at the scale of a few meters (local control) to factors operating over hundreds to thousands of kilometers (regional control). Moreover, El Niño resulted in the near-complete loss of all giant kelp throughout one-half of the species' range in the northeast Pacific Ocean. Giant kelp recovery following El Niño was far more complex and variable at multiple spatial scales, presumably driven by numerous factors acting at those scales. Recovery returned local control of giant kelp populations within 6 months in southern California, and within 2 years in Baja California.
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Affiliation(s)
- Matthew S Edwards
- Department of Biology, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USA.
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