1
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Olsen EM, Karlsen Ø, Skjæraasen JE. Large females connect Atlantic cod spawning sites. Science 2023; 382:1181-1184. [PMID: 38060630 DOI: 10.1126/science.adi1826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 10/31/2023] [Indexed: 12/18/2023]
Abstract
The Earth's ecosystems are increasingly deprived of large animals. Global simulations suggest that this downsizing of nature has serious consequences for biosphere functioning. However, the historical loss of large animals means that it is now often impossible to secure empirical data revealing their true ecological importance. We tracked 465 mature Atlantic cod (Gadus morhua) during their winter spawning season and show that large females (up to 114 centimeters in length), which are still found in mid-Norway, were characterized by more complex movement networks compared with smaller females. Large males were sparse but displayed similar movement patterns. Our finding implies that management programs promoting large fish will have positive impacts on population resilience by facilitating the continued use of a diversity of spawning habitats and the connectivity between them.
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Affiliation(s)
- Esben Moland Olsen
- Institute of Marine Research; Flødevigen, Arendal 4817, Norway
- Centre for Coastal Research, Department of Natural Sciences, University of Agder; Kristiansand 4604, Norway
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2
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Galloway AWE, Gravem SA, Kobelt JN, Heady WN, Okamoto DK, Sivitilli DM, Saccomanno VR, Hodin J, Whippo R. Sunflower sea star predation on urchins can facilitate kelp forest recovery. Proc Biol Sci 2023; 290:20221897. [PMID: 36809801 PMCID: PMC9943640 DOI: 10.1098/rspb.2022.1897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 01/25/2023] [Indexed: 02/23/2023] Open
Abstract
The recent collapse of predatory sunflower sea stars (Pycnopodia helianthoides) owing to sea star wasting disease (SSWD) is hypothesized to have contributed to proliferation of sea urchin barrens and losses of kelp forests on the North American west coast. We used experiments and a model to test whether restored Pycnopodia populations may help recover kelp forests through their consumption of nutritionally poor purple sea urchins (Strongylocentrotus purpuratus) typical of barrens. Pycnopodia consumed 0.68 S. purpuratus d-1, and our model and sensitivity analysis shows that the magnitude of recent Pycnopodia declines is consistent with urchin proliferation after modest sea urchin recruitment, and even small Pycnopodia recoveries could generally lead to lower densities of sea urchins that are consistent with kelp-urchin coexistence. Pycnopodia seem unable to chemically distinguish starved from fed urchins and indeed have higher predation rates on starved urchins owing to shorter handling times. These results highlight the importance of Pycnopodia in regulating purple sea urchin populations and maintaining healthy kelp forests through top-down control. The recovery of this important predator to densities commonly found prior to SSWD, whether through natural means or human-assisted reintroductions, may therefore be a key step in kelp forest restoration at ecologically significant scales.
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Affiliation(s)
- A. W. E. Galloway
- Oregon Institute of Marine Biology, Department of Biology, University of Oregon, 63466 Boat Basin Road, Charleston OR 97420, USA
| | - S. A. Gravem
- Department of Integrative Biology and Partnership for Interdisciplinary Studies of Coastal Oceans, Oregon State University, 3029 Cordley Hall, Corvallis, OR 97331, USA
| | - J. N. Kobelt
- School of Aquatic and Fishery Sciences, University of Washington, 98195, Seattle WA, USA
| | - W. N. Heady
- The Nature Conservancy, Sacramento CA, 95811, USA
| | - D. K. Okamoto
- Department of Biological Science, Florida State University, Tallahassee, 32306 FL, USA
| | - D. M. Sivitilli
- Astrobiology Program, University of Washington, 98195, Seattle WA, USA
- Department of Psychology, University of Washington, 98195, Seattle WA, USA
| | | | - J. Hodin
- Friday Harbor Laboratories, University of Washington, 98195, Seattle WA, USA
| | - R. Whippo
- Oregon Institute of Marine Biology, Department of Biology, University of Oregon, 63466 Boat Basin Road, Charleston OR 97420, USA
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3
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Sørdalen TK, Halvorsen KT, Olsen EM. Protection from fishing improves body growth of an exploited species. Proc Biol Sci 2022; 289:20221718. [DOI: 10.1098/rspb.2022.1718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Hunting and fishing are often size-selective, which favours slow body growth. In addition, fast growth rate has been shown to be positively correlated with behavioural traits that increase encounter rates and catchability in passive fishing gears such as baited traps. This harvest-induced selection should be effectively eliminated in no-take marine-protected areas (MPAs) unless strong density dependence results in reduced growth rates. We compared body growth of European lobster (
Homarus gammarus
) between three MPAs and three fished areas. After 14 years of protection from intensive, size-selective lobster fisheries, the densities in MPAs have increased considerably, and we demonstrate that females moult more frequently and grow more during each moult in the MPAs. A similar, but weaker pattern was evident for males. This study suggests that MPAs can shield a wild population from slow-growth selection, which can explain the rapid recovery of size structure following implementation. If slow-growth selection is a widespread phenomenon in fisheries, the effectiveness of MPAs as a management tool can be higher than currently anticipated.
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Affiliation(s)
- Tonje Knutsen Sørdalen
- Centre for Coastal Research, Department of Natural Sciences, University of Agder, N-4604 Kristiansand, Norway
- Institute of Marine Research, Flødevigen, Nye Flødevigvei 20, N-4817 His, Norway
| | | | - Esben Moland Olsen
- Centre for Coastal Research, Department of Natural Sciences, University of Agder, N-4604 Kristiansand, Norway
- Institute of Marine Research, Flødevigen, Nye Flødevigvei 20, N-4817 His, Norway
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4
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Knight CJ, Dunn RP, Long JD. Conspecific cues, not starvation, mediate barren urchin response to predation risk. Oecologia 2022; 199:859-869. [PMID: 35907124 DOI: 10.1007/s00442-022-05225-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 07/20/2022] [Indexed: 11/30/2022]
Abstract
Prey state and prey density mediate antipredator responses that can shift community structure and alter ecosystem processes. For example, well-nourished prey at low densities (i.e., prey with higher per capita predation risk) should respond strongly to predators. Although prey state and density often co-vary across habitats, it is unclear if prey responses to predator cues are habitat-specific. We used mesocosms to compare the habitat-specific responses of purple sea urchins (Strongylocentrotus purpuratus) to waterborne cues from predatory lobsters (Panulirus interruptus). We predicted that urchins from kelp forests (i.e., in well-nourished condition) tested at low densities typically observed in this habitat would respond more strongly to predation risk than barren urchins (i.e., in less nourished condition) tested at high densities typically observed in this habitat. Indeed, when tested at densities associated with respective habitats, urchins from forests, but not barrens, reduced kelp grazing by 69% when exposed to lobster risk cues. Barren urchins that were unresponsive to predator cues at natural, high densities suddenly responded strongly to lobster cues when conspecific densities were reduced. Strong responses of low densities of barren urchins persisted across feeding history (i.e. 0-64 days of starvation). This suggests that barren urchins can respond to predators but typically do not because of high conspecific densities. Because high densities of urchins in barrens should weaken the non-consumptive effects of lobsters, urchins in these habitats may continue to graze in the presence of predators thereby providing a feedback that maintains urchin barrens.
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Affiliation(s)
- Christopher J Knight
- Biology Department, San Diego State University, 5500 Campanile Drive, San Diego, San Diego, CA, 92182, USA.
- Hopkins Marine Station, Department of Biology, Stanford University, 120 Ocean View Blvd, Pacific Grove, CA, 93950, USA.
| | - Robert P Dunn
- Biology Department, San Diego State University, 5500 Campanile Drive, San Diego, San Diego, CA, 92182, USA
- North Inlet-Winyah Bay National Estuarine Research Reserve, Georgetown, SC, 29440, USA
- Baruch Marine Field Laboratory, University of South Carolina, 2306 Crabhall Road Georgetown, Columbia, SC, 29440, USA
| | - Jeremy D Long
- Biology Department, San Diego State University, 5500 Campanile Drive, San Diego, San Diego, CA, 92182, USA
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5
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Grorud-Colvert K, Sullivan-Stack J, Roberts C, Constant V, Horta E Costa B, Pike EP, Kingston N, Laffoley D, Sala E, Claudet J, Friedlander AM, Gill DA, Lester SE, Day JC, Gonçalves EJ, Ahmadia GN, Rand M, Villagomez A, Ban NC, Gurney GG, Spalding AK, Bennett NJ, Briggs J, Morgan LE, Moffitt R, Deguignet M, Pikitch EK, Darling ES, Jessen S, Hameed SO, Di Carlo G, Guidetti P, Harris JM, Torre J, Kizilkaya Z, Agardy T, Cury P, Shah NJ, Sack K, Cao L, Fernandez M, Lubchenco J. The MPA Guide: A framework to achieve global goals for the ocean. Science 2021; 373:eabf0861. [PMID: 34516798 DOI: 10.1126/science.abf0861] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Kirsten Grorud-Colvert
- Department of Integrative Biology, Oregon State University, 3029 Cordley Hall, Corvallis, OR, USA.,Marine Conservation Institute, Seattle, WA 98103, USA
| | - Jenna Sullivan-Stack
- Department of Integrative Biology, Oregon State University, 3029 Cordley Hall, Corvallis, OR, USA
| | - Callum Roberts
- Department of Environment and Geography, University of York, York YO10 5DD, UK
| | - Vanessa Constant
- Department of Integrative Biology, Oregon State University, 3029 Cordley Hall, Corvallis, OR, USA
| | - Barbara Horta E Costa
- Center of Marine Sciences, CCMAR, University of Algarve, Campus de Gambelas, Faro, 8005-139, Portugal.,School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Elizabeth P Pike
- Marine Protection Atlas, Marine Conservation Institute, Seattle, WA, 98103-9090, USA.,Pew Bertarelli Ocean Legacy Project, The Pew Charitable Trusts, Washington, DC 20004-2008, USA
| | - Naomi Kingston
- Department of Integrative Biology, Oregon State University, 3029 Cordley Hall, Corvallis, OR, USA.,UN Environment Programme World Conservation Monitoring Centre, Cambridge, UK
| | - Dan Laffoley
- IUCN World Commission on Protected Areas, International Union for Conservation of Nature (IUCN), CH-1196 Gland, Switzerland.,School of Public Policy, Oregon State University, Corvallis, OR 97330, USA
| | - Enric Sala
- National Geographic Society, Washington, DC, USA.,Department of Geography, Florida State University, Tallahassee, FL 32306-2190, USA
| | - Joachim Claudet
- National Center for Scientific Research, PSL Université Paris, CRIOBE, USR 3278 CNRS-EPHE-UPVD, Maison des Océans, 75005 Paris, France.,Wildlife Conservation Society, 2300 Southern Blvd, Bronx, NY 10460, USA
| | - Alan M Friedlander
- Hawai'i Institute of Marine Biology, University of Hawaii, Kāne'ohe, HI 96744, USA.,Pristine Seas, National Geography Society, Washington, DC 20036, USA
| | - David A Gill
- Duke University Marine Laboratory, Nicholas School of the Environment, Duke University, Beaufort, NC 28516, USA
| | - Sarah E Lester
- Department of Integrative Biology, Oregon State University, 3029 Cordley Hall, Corvallis, OR, USA.,Department of Geography, Florida State University, Tallahassee, FL 32306-2190, USA
| | - Jon C Day
- ARC Centre of Excellence in Coral Reef Studies, James Cook University, Townsville QLD 4811, Australia
| | - Emanuel J Gonçalves
- Pristine Seas, National Geography Society, Washington, DC 20036, USA.,Duke University Marine Laboratory, Nicholas School of the Environment, Duke University, Beaufort, NC 28516, USA.,Marine and Environmental Sciences Centre (MARE), ISPA-Instituto Universitário, 1149-041 Lisbon, Portugal.,Oceano Azul Foundation, Oceanário de Lisboa, Esplanada D. Carlos I,1990-005 Lisbon, Portugal
| | - Gabby N Ahmadia
- Ocean Conservation, World Wildlife Fund, Washington, DC 20037, USA.,School of Environmental Studies, University of Victoria, Victoria, BC V8W 2Y2, Canada.,Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - Matt Rand
- IUCN World Commission on Protected Areas, International Union for Conservation of Nature (IUCN), CH-1196 Gland, Switzerland.,Pew Bertarelli Ocean Legacy Project, The Pew Charitable Trusts, Washington, DC 20004-2008, USA
| | - Angelo Villagomez
- IUCN World Commission on Protected Areas, International Union for Conservation of Nature (IUCN), CH-1196 Gland, Switzerland.,Pew Bertarelli Ocean Legacy Project, The Pew Charitable Trusts, Washington, DC 20004-2008, USA
| | - Natalie C Ban
- UN Environment Programme World Conservation Monitoring Centre, Cambridge, UK.,School of Environmental Studies, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - Georgina G Gurney
- Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia
| | - Ana K Spalding
- ARC Centre of Excellence in Coral Reef Studies, James Cook University, Townsville QLD 4811, Australia.,Marine and Environmental Sciences Centre (MARE), ISPA-Instituto Universitário, 1149-041 Lisbon, Portugal.,School of Public Policy, Oregon State University, Corvallis, OR 97330, USA.,Smithsonian Tropical Research Institute, Panama City, Panama; Coiba Scientific Station (Coiba AIP), Panama City, Panama.,Marine Conservation Institute, Seattle, WA 98103, USA
| | - Nathan J Bennett
- National Center for Scientific Research, PSL Université Paris, CRIOBE, USR 3278 CNRS-EPHE-UPVD, Maison des Océans, 75005 Paris, France.,The Peopled Seas Initiative, Vancouver, BC, Canada
| | - Johnny Briggs
- Pew Bertarelli Ocean Legacy Project, The Pew Charitable Trusts, Washington, DC 20004-2008, USA
| | | | - Russell Moffitt
- Marine Protection Atlas, Marine Conservation Institute, Seattle, WA, 98103-9090, USA.,Pew Bertarelli Ocean Legacy Project, The Pew Charitable Trusts, Washington, DC 20004-2008, USA
| | - Marine Deguignet
- UN Environment Programme World Conservation Monitoring Centre, Cambridge, UK
| | - Ellen K Pikitch
- National Geographic Society, Washington, DC, USA.,School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Emily S Darling
- School of Environmental Studies, University of Victoria, Victoria, BC V8W 2Y2, Canada.,Wildlife Conservation Society, 2300 Southern Blvd, Bronx, NY 10460, USA
| | - Sabine Jessen
- Marine Protection Atlas, Marine Conservation Institute, Seattle, WA, 98103-9090, USA.,National Ocean Program, Canadian Parks and Wilderness Society, Ottawa, ON K2P 0A4, Canada
| | - Sarah O Hameed
- The Peopled Seas Initiative, Vancouver, BC, Canada.,Blue Parks Program, Marine Conservation Institute, Seattle, WA 98103, USA
| | | | - Paolo Guidetti
- Department of Integrative Marine Ecology (EMI), Stazione Zoologica A. Dohrn-National Institute of Marine Biology, Ecology and Biotechnology, Villa Comunale, 80121 Naples, Italy.,National Research Council, Institute for the Study of Anthropic Impact and Sustainability in the Marine Environment (CNR-IAS), V16149 Genoa, Italy
| | - Jean M Harris
- Institute for Coastal and Marine Research (CMR), Nelson Mandela University, Gomeroy Avenue, Summerstrand, Port Elizabeth 6031, South Africa
| | - Jorge Torre
- Comunidad y Biodiversidad, A.C. Isla del Peruano 215, Col. Lomas de Miramar, Guaymas, Sonora, 85454, Mexico
| | - Zafer Kizilkaya
- Mediterranean Conservation Society, Bornova, Izmir 35100 Turkey
| | - Tundi Agardy
- Oceano Azul Foundation, Oceanário de Lisboa, Esplanada D. Carlos I,1990-005 Lisbon, Portugal.,Sound Seas, Colrain, MA 01340, USA
| | - Philippe Cury
- Center of Marine Sciences, CCMAR, University of Algarve, Campus de Gambelas, Faro, 8005-139, Portugal.,MARBEC, Montpellier University, CNRS, IRD, IFREMER, Sète, France
| | - Nirmal J Shah
- School of Public Policy, Oregon State University, Corvallis, OR 97330, USA.,Nature Seychelles, Centre for Environment and Education, Sanctuary at Roche Caiman, Mahe, Seychelles
| | - Karen Sack
- Ocean Conservation, World Wildlife Fund, Washington, DC 20037, USA.,Ocean Unite, Washington, DC 20007, USA
| | - Ling Cao
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 230000, China
| | - Miriam Fernandez
- Smithsonian Tropical Research Institute, Panama City, Panama; Coiba Scientific Station (Coiba AIP), Panama City, Panama.,Estación Costera de Investigaciones Marinas de Las Cruces and Departmento de Ecología, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Jane Lubchenco
- Department of Integrative Biology, Oregon State University, 3029 Cordley Hall, Corvallis, OR, USA.,Marine Conservation Institute, Seattle, WA 98103, USA
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6
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Smith JG, Tomoleoni J, Staedler M, Lyon S, Fujii J, Tinker MT. Behavioral responses across a mosaic of ecosystem states restructure a sea otter-urchin trophic cascade. Proc Natl Acad Sci U S A 2021; 118:e2012493118. [PMID: 33836567 PMCID: PMC7980363 DOI: 10.1073/pnas.2012493118] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Consumer and predator foraging behavior can impart profound trait-mediated constraints on community regulation that scale up to influence the structure and stability of ecosystems. Here, we demonstrate how the behavioral response of an apex predator to changes in prey behavior and condition can dramatically alter the role and relative contribution of top-down forcing, depending on the spatial organization of ecosystem states. In 2014, a rapid and dramatic decline in the abundance of a mesopredator (Pycnopodia helianthoides) and primary producer (Macrocystis pyrifera) coincided with a fundamental change in purple sea urchin (Strongylocentrotus purpuratus) foraging behavior and condition, resulting in a spatial mosaic of kelp forests interspersed with patches of sea urchin barrens. We show that this mosaic of adjacent alternative ecosystem states led to an increase in the number of sea otters (Enhydra lutris nereis) specializing on urchin prey, a population-level increase in urchin consumption, and an increase in sea otter survivorship. We further show that the spatial distribution of sea otter foraging efforts for urchin prey was not directly linked to high prey density but rather was predicted by the distribution of energetically profitable prey. Therefore, we infer that spatially explicit sea otter foraging enhances the resistance of remnant forests to overgrazing but does not directly contribute to the resilience (recovery) of forests. These results highlight the role of consumer and predator trait-mediated responses to resource mosaics that are common throughout natural ecosystems and enhance understanding of reciprocal feedbacks between top-down and bottom-up forcing on the regional stability of ecosystems.
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Affiliation(s)
- Joshua G Smith
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95060;
| | - Joseph Tomoleoni
- Santa Cruz Field Station, Western Ecological Research Center, US Geological Survey, Santa Cruz, CA 95060
| | - Michelle Staedler
- Department of Conservation Research, Monterey Bay Aquarium, Monterey, CA 93940
| | - Sophia Lyon
- Santa Cruz Field Station, Western Ecological Research Center, US Geological Survey, Santa Cruz, CA 95060
| | - Jessica Fujii
- Department of Conservation Research, Monterey Bay Aquarium, Monterey, CA 93940
| | - M Tim Tinker
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, CA 95060
- Santa Cruz Field Station, Western Ecological Research Center, US Geological Survey, Santa Cruz, CA 95060
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7
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Malakhoff KD, Miller RJ. After 15 years, no evidence for trophic cascades in marine protected areas. Proc Biol Sci 2021; 288:20203061. [PMID: 33593185 DOI: 10.1098/rspb.2020.3061] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In marine ecosystems, fishing often targets predators, which can drive direct and indirect effects on entire food webs. Marine reserves can induce trophic cascades by increasing predator density and body size, thereby increasing predation pressure on populations of herbivores, such as sea urchins. In California's northern Channel Islands, two species of sea urchins are abundant: the red urchin Mesocentrotus franciscanus, which is targeted by an economically valuable fishery, and the virtually unfished purple urchin Strongylocentrotus purpuratus. We hypothesized that urchin populations inside marine reserves would be depressed by higher predation, but that red urchins would be less affected due to fishing outside reserves. Instead, our analyses revealed that purple urchin populations were unaffected by reserves, and red urchin biomass significantly increased in response to protection. Therefore, urchin biomass overall has increased inside reserves, and we found no evidence that giant kelp is positively affected by reserves. Our results reveal the overwhelming direct effect of protecting fished species in marine reserves over indirect effects that are often predicted but seldom clearly documented. Indirect effects due to marine reserves may eventually occur in some cases, but very effective predators, large reserves or extended time periods may be needed to induce them.
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Affiliation(s)
- Katrina D Malakhoff
- Marine Science Institute, University of California Santa Barbara, Santa Barbara, CA 93106-9010, USA
| | - Robert J Miller
- Marine Science Institute, University of California Santa Barbara, Santa Barbara, CA 93106-9010, USA
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8
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Beas-Luna R, Micheli F, Woodson CB, Carr M, Malone D, Torre J, Boch C, Caselle JE, Edwards M, Freiwald J, Hamilton SL, Hernandez A, Konar B, Kroeker KJ, Lorda J, Montaño-Moctezuma G, Torres-Moye G. Geographic variation in responses of kelp forest communities of the California Current to recent climatic changes. GLOBAL CHANGE BIOLOGY 2020; 26:6457-6473. [PMID: 32902090 DOI: 10.1111/gcb.15273] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 05/06/2020] [Accepted: 06/18/2020] [Indexed: 06/11/2023]
Abstract
The changing global climate is having profound effects on coastal marine ecosystems around the world. Structure, functioning, and resilience, however, can vary geographically, depending on species composition, local oceanographic forcing, and other pressures from human activities and use. Understanding ecological responses to environmental change and predicting changes in the structure and functioning of whole ecosystems require large-scale, long-term studies, yet most studies trade spatial extent for temporal duration. We address this shortfall by integrating multiple long-term kelp forest monitoring datasets to evaluate biogeographic patterns and rates of change of key functional groups (FG) along the west coast of North America. Analysis of data from 469 sites spanning Alaska, USA, to Baja California, Mexico, and 373 species (assigned to 18 FG) reveals regional variation in responses to both long-term (2006-2016) change and a recent marine heatwave (2014-2016) associated with two atmospheric and oceanographic anomalies, the "Blob" and extreme El Niño Southern Oscillation (ENSO). Canopy-forming kelps appeared most sensitive to warming throughout their range. Other FGs varied in their responses among trophic levels, ecoregions, and in their sensitivity to heatwaves. Changes in community structure were most evident within the southern and northern California ecoregions, while communities in the center of the range were more resilient. We report a poleward shift in abundance of some key FGs. These results reveal major, ongoing region-wide changes in productive coastal marine ecosystems in response to large-scale climate variability, and the potential loss of foundation species. In particular, our results suggest that coastal communities that are dependent on kelp forests will be more impacted in the southern portion of the California Current region, highlighting the urgency of implementing adaptive strategies to sustain livelihoods and ensure food security. The results also highlight the value of multiregional integration and coordination of monitoring programs for improving our understanding of marine ecosystems, with the goal of informing policy and resource management in the future.
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Affiliation(s)
| | - Fiorenza Micheli
- Hopkins Marine Station, Stanford University, Pacific Grove, CA, USA
- Stanford Center for Ocean Solutions, Stanford University, Pacific Grove, CA, USA
| | - C Brock Woodson
- College of Engineering, University of Georgia, Athens, GA, USA
| | - Mark Carr
- University of California, Santa Cruz, CA, USA
| | - Dan Malone
- University of California, Santa Cruz, CA, USA
| | - Jorge Torre
- Comunidad y Biodiversidad A.C., La Paz, Mexico
| | - Charles Boch
- Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA
- Southwest Fisheries Science Center, NOAA, San Diego, CA, USA
| | - Jennifer E Caselle
- Marine Science Institute, University of California, Santa Barbara, CA, USA
| | | | - Jan Freiwald
- University of California, Santa Cruz, CA, USA
- Reef Check California, Marina del Rey, CA, USA
| | - Scott L Hamilton
- Moss Landing Marine Laboratories, San Jose State University, Moss Landing, CA, USA
| | | | | | | | - Julio Lorda
- Universidad Autónoma de Baja California, Ensenada, Mexico
- Tijuana River National Estuarine Research Reserve, Imperial Beach, CA, USA
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9
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Eisaguirre JH, Eisaguirre JM, Davis K, Carlson PM, Gaines SD, Caselle JE. Trophic redundancy and predator size class structure drive differences in kelp forest ecosystem dynamics. Ecology 2020; 101:e02993. [PMID: 32002994 PMCID: PMC7317486 DOI: 10.1002/ecy.2993] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 11/22/2019] [Accepted: 12/05/2019] [Indexed: 11/07/2022]
Abstract
Ecosystems are changing at alarming rates because of climate change and a wide variety of other anthropogenic stressors. These stressors have the potential to cause phase shifts to less productive ecosystems. A major challenge for ecologists is to identify ecosystem attributes that enhance resilience and can buffer systems from shifts to less desirable alternative states. In this study, we used the Northern Channel Islands, California, as a model kelp forest ecosystem that had been perturbed from the loss of an important sea star predator due to a sea star wasting disease. To determine the mechanisms that prevent phase shifts from productive kelp forests to less productive urchin barrens, we compared pre- and postdisease predator assemblages as predictors of purple urchin densities. We found that prior to the onset of the disease outbreak, the sunflower sea star exerted strong predation pressures and was able to suppress purple urchin populations effectively. After the disease outbreak, which functionally extirpated the sunflower star, we found that the ecosystem response-urchin and algal abundances-depended on the abundance and/or size of remaining predator species. Inside Marine Protected Areas (MPAs), the large numbers and sizes of other urchin predators suppressed purple urchin populations resulting in kelp and understory algal growth. Outside of the MPAs, where these alternative urchin predators are fished, less abundant, and smaller, urchin populations grew dramatically in the absence of sunflower stars resulting in less kelp at these locations. Our results demonstrate that protected trophic redundancy inside MPAs creates a net of stability that could limit kelp forest ecosystem phase shifts to less desirable, alternative states when perturbed. This highlights the importance of harboring diversity and managing predator guilds.
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Affiliation(s)
- Jacob H. Eisaguirre
- Department of Environmental StudiesUniversity of CaliforniaSanta BarbaraCalifornia93106USA
- Marine Science InstituteUniversity of CaliforniaSanta BarbaraCalifornia93106USA
| | - Joseph M. Eisaguirre
- Department of Biology & WildlifeUniversity of Alaska FairbanksFairbanksAlaska99775USA
- Department of Mathematics & StatisticsUniversity of Alaska FairbanksFairbanksAlaska99775USA
| | - Kathryn Davis
- Marine Science InstituteUniversity of CaliforniaSanta BarbaraCalifornia93106USA
| | - Peter M. Carlson
- Marine Science InstituteUniversity of CaliforniaSanta BarbaraCalifornia93106USA
| | - Steven D. Gaines
- Bren School of Environmental Science and ManagementUniversity of CaliforniaSanta BarbaraCalifornia93106USA
| | - Jennifer E. Caselle
- Marine Science InstituteUniversity of CaliforniaSanta BarbaraCalifornia93106USA
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10
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Jaco EM, Steele MA. Pre‐closure fishing pressure predicts effects of marine protected areas. J Appl Ecol 2019. [DOI: 10.1111/1365-2664.13541] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Erin M. Jaco
- Department of Biology California State University Northridge Northridge CA USA
| | - Mark A. Steele
- Department of Biology California State University Northridge Northridge CA USA
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11
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Olson AM, Trebilco R, Salomon AK. Expanded consumer niche widths may signal an early response to spatial protection. PLoS One 2019; 14:e0223748. [PMID: 31613924 PMCID: PMC6793880 DOI: 10.1371/journal.pone.0223748] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 09/29/2019] [Indexed: 11/19/2022] Open
Abstract
Marine management interventions are increasingly being implemented with the explicit goal of rebuilding ocean ecosystems, but early responses may begin with alterations in ecological interactions preceding detectable changes in population-level characteristics. To establish a baseline from which to monitor the effects of spatial protection on reef fish trophic ecology and track future ecosystem-level changes, we quantified temperate reef fish densities, size, biomass, diets and isotopic signatures at nine sites nested within two fished and one five-year old marine protected area (MPA) on the northwest coast of Canada. We calculated rockfish (Sebastes spp.) community and species-specific niche breadth for fished and protected areas based on δ13C and δ15N values. We found that rockfish community niche width was greater inside the MPA relative to adjacent fished reefs due to an expanded nitrogen range, possibly reflecting early changes in trophic interactions following five years of spatial protection. Our data also demonstrated that the MPA had a positive effect on the δ15N signature of rockfish (i.e., trophic position), but the effect of rockfish length on its own was not well-supported. In addition, we found a positive interaction between rockfish length and δ15N signature, such that δ15N signatures of rockfish caught within the MPA increased more rapidly with body size than those caught in fished areas. Differences in rockfish size structure and biomass among fished and unfished areas were not clearly evident. Species of rockfish and lingcod varied in trophic and size responses, indicating that life-history traits play an important role in predicting MPA effects. These results may suggest early changes in trophic behavior of slow-growing rockfish due to predation risk by faster growing higher trophic level predators such as lingcod inside MPAs established on temperate reefs. Consequently, spatial protection may restore both the trophic and behavioral roles of previously fished consumers earlier and in measurable ways sooner than observable changes in abundance and size.
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Affiliation(s)
- Angeleen M. Olson
- School of Resource and Environmental Management, Simon Fraser University, Faculty of Science, Burnaby, British Columbia, Canada
- Hakai Institute, Heriot Bay, British Columbia, Canada
- * E-mail: (AMO); (AKS)
| | - Rowan Trebilco
- School of Resource and Environmental Management, Simon Fraser University, Faculty of Science, Burnaby, British Columbia, Canada
- Antarctic Climate and Ecosystems CRC, University of Tasmania, Hobart, Tasmania, Australia
| | - Anne K. Salomon
- School of Resource and Environmental Management, Simon Fraser University, Faculty of Science, Burnaby, British Columbia, Canada
- Hakai Institute, Heriot Bay, British Columbia, Canada
- * E-mail: (AMO); (AKS)
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12
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Riquelme-Pérez N, Musrri CA, Stotz WB, Cerda O, Pino-Olivares O, Thiel M. Coastal fish assemblages and predation pressure in northern-central Chilean Lessonia trabeculata kelp forests and barren grounds. PeerJ 2019; 7:e6964. [PMID: 31223523 PMCID: PMC6571002 DOI: 10.7717/peerj.6964] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 04/15/2019] [Indexed: 01/03/2023] Open
Abstract
Kelp forests are declining in many parts of the globe, which can lead to the spreading of barren grounds. Increased abundances of grazers, mainly due to reduction of their predators, are among the causes of this development. Here, we compared the species richness (SR), frequency of occurrence (FO), and maximum abundance (MaxN) of predatory fish and their predation pressure between kelp forest and barren ground habitats of northern-central Chile. Sampling was done using baited underwater cameras with vertical and horizontal orientation. Two prey organisms were used as tethered baits, the black sea urchin Tetrapygus niger and the porcelanid crab Petrolisthes laevigatus. SR did not show major differences between habitats, while FO and MaxN were higher on barren grounds in vertical videos, with no major differences between habitats in horizontal videos. Predation pressure did not differ between habitats, but after 24 h consumption of porcelanid crabs was significantly higher than that of sea urchins. Scartichthys viridis/gigas was the main predator, accounting for 82% of the observed predation events on Petrolisthes laevigatus. Most of these attacks occurred on barren grounds. Scartichthys viridis/gigas was the only fish observed attacking (but not consuming) tethered sea urchins. High abundances of opportunistic predators (Scartichthys viridis/gigas) are probably related to low abundances of large predatory fishes. These results suggest that intense fishing activity on large predators, and their resulting low abundances, could result in low predation pressure on sea urchins, thereby contributing to the increase of T. niger abundances in subtidal rocky habitats.
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Affiliation(s)
| | - Catalina A Musrri
- Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile
| | - Wolfgang B Stotz
- Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile
| | - Osvaldo Cerda
- Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile
| | - Oscar Pino-Olivares
- Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile
| | - Martin Thiel
- Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile.,Millennium Nucleus Ecology and Sustainable Management of Oceanic Island (ESMOI), Coquimbo, Chile.,Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Coquimbo, Chile
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13
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Cheng BS, Altieri AH, Torchin ME, Ruiz GM. Can marine reserves restore lost ecosystem functioning? A global synthesis. Ecology 2019; 100:e02617. [DOI: 10.1002/ecy.2617] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 10/30/2018] [Accepted: 12/03/2018] [Indexed: 11/08/2022]
Affiliation(s)
- Brian S. Cheng
- Tennenbaum Marine Observatories Network Smithsonian Institution Washington District of Columbia 20013 USA
- Smithsonian Environmental Research Center Edgewater Maryland 21037 USA
- Department of Environmental Conservation University of Massachusetts Amherst Massachusetts 01003 USA
| | - Andrew H. Altieri
- Smithsonian Tropical Research Institute Apartado 0843‐03092 Balboa Republic of Panama
- Department of Environmental Engineering Sciences University of Florida Gainesville Florida 32611 USA
| | - Mark E. Torchin
- Smithsonian Tropical Research Institute Apartado 0843‐03092 Balboa Republic of Panama
| | - Gregory M. Ruiz
- Smithsonian Environmental Research Center Edgewater Maryland 21037 USA
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14
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Dunn RP, Hovel KA. Experiments reveal limited top-down control of key herbivores in southern California kelp forests. Ecology 2019; 100:e02625. [PMID: 30648729 DOI: 10.1002/ecy.2625] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 09/21/2018] [Accepted: 12/03/2018] [Indexed: 11/10/2022]
Abstract
Predator responses to gradients in prey density have important implications for population regulation and are a potential structuring force for subtidal marine communities, particularly on rocky reefs where herbivorous sea urchins can drive community state shifts. On rocky reefs in southern California where predatory sea otters have been extirpated, top-down control of sea urchins by alternative predators has been hypothesized but rarely tested experimentally. In laboratory feeding assays, predatory spiny lobsters (Panulirus interruptus) demonstrated a saturating functional response to urchin prey, whereby urchin proportional mortality was inversely density-dependent. In field experiments on rocky reefs near San Diego, California, predators (primarily the labrid fish California sheephead, Semicossyphus pulcher) inflicted highly variable mortality on purple urchin (Strongylocentrotus purpuratus) prey across all density levels. However, at low to moderate densities commonly observed within kelp forests, purple urchin mortality increased to a peak at a density of ~11 urchins/m2 . Above that level, at densities typical of urchin barrens, purple urchin mortality was density-independent. When larger red urchins (Mesocentrotus franciscanus) were offered to predators simultaneously with purple urchins, mortality was density-independent. Underwater videography revealed a positive relationship between purple urchin density and both the number and richness of fish predators, but these correlations were not observed when red urchins were present. Our results demonstrate highly variable mortality rates across prey densities in this system and suggest that top-down control of urchins can occur only under limited circumstances. Our findings provide insight into the dynamics of alternate community states observed on rocky reefs.
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Affiliation(s)
- Robert P Dunn
- Department of Biology, Coastal and Marine Institute, San Diego State University, San Diego, California, 92182, USA
- Department of Environmental Science and Policy, University of California Davis, Davis, California, 95616, USA
| | - Kevin A Hovel
- Department of Biology, Coastal and Marine Institute, San Diego State University, San Diego, California, 92182, USA
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15
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Dunn RP, Baskett ML, Hovel KA. Interactive effects of predator and prey harvest on ecological resilience of rocky reefs. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2017; 27:1718-1730. [PMID: 28581670 DOI: 10.1002/eap.1581] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 05/03/2017] [Accepted: 05/16/2017] [Indexed: 06/07/2023]
Abstract
A major goal of ecosystem-based fisheries management is to prevent fishery-induced shifts in community states. This requires an understanding of ecological resilience: the ability of an ecosystem to return to the same state following a perturbation, which can strongly depend on species interactions across trophic levels. We use a structured model of a temperate rocky reef to explore how multi-trophic level fisheries impact ecological resilience. Increasing fishing mortality of prey (urchins) has a minor effect on equilibrium biomass of kelp, urchins, and spiny lobster predators, but increases resilience by reducing the range of predator harvest rates at which alternative stable states are possible. Size-structured predation on urchins acts as the feedback maintaining each state. Our results demonstrate that the resilience of ecosystems strongly depends on the interactive effects of predator and prey harvest in multi-trophic level fisheries, which are common in marine ecosystems but are unaccounted for by traditional management.
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Affiliation(s)
- Robert P Dunn
- Coastal and Marine Institute & Department of Biology, San Diego State University, San Diego, California, 92182, USA
- Department of Environmental Science and Policy, University of California, Davis, Davis, California, 95616, USA
| | - Marissa L Baskett
- Department of Environmental Science and Policy, University of California, Davis, Davis, California, 95616, USA
| | - Kevin A Hovel
- Coastal and Marine Institute & Department of Biology, San Diego State University, San Diego, California, 92182, USA
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16
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Selden RL, Gaines SD, Hamilton SL, Warner RR. Protection of large predators in a marine reserve alters size-dependent prey mortality. Proc Biol Sci 2017; 284:20161936. [PMID: 28123086 PMCID: PMC5310031 DOI: 10.1098/rspb.2016.1936] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 01/03/2017] [Indexed: 11/12/2022] Open
Abstract
Where predator-prey interactions are size-dependent, reductions in predator size owing to fishing has the potential to disrupt the ecological role of top predators in marine ecosystems. In southern California kelp forests, we investigated the size-dependence of the interaction between herbivorous sea urchins and one of their predators, California sheephead (Semicossyphus pulcher). Empirical tests examined how differences in predator size structure between reserve and fished areas affected size-specific urchin mortality. Sites inside marine reserves had greater sheephead size and biomass, while empirical feeding trials indicated that larger sheephead were required to successfully consume urchins of increasing test diameter. Evaluations of the selectivity of sheephead for two urchin species indicated that shorter-spined purple urchins were attacked more frequently and successfully than longer-spined red urchins of the same size class, particularly at the largest test diameters. As a result of these size-specific interactions and the higher biomass of large sheephead inside reserves, urchin mortality rates were three times higher inside the reserve for both species. In addition, urchin mortality rates decreased with urchin size, and very few large urchins were successfully consumed in fished areas. The truncation of sheephead size structure that commonly occurs owing to fishing will probably result in reductions in urchin mortality, which may reduce the resilience of kelp beds to urchin barren formation. By contrast, the recovery of predator size structure in marine reserves may restore this resilience, but may be delayed until fish grow to sizes capable of consuming larger urchins.
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Affiliation(s)
- Rebecca L Selden
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106, USA
| | - Steven D Gaines
- Bren School of Environmental Science and Management, University of California, Santa Barbara, CA 93106, USA
| | - Scott L Hamilton
- Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, CA 95039, USA
| | - Robert R Warner
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106, USA
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