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Michael PE, Hixson KM, Gleason JS, Haney JC, Satgé YG, Jodice PGR. Migration, breeding location, and seascape shape seabird assemblages in the northern Gulf of Mexico. PLoS One 2023; 18:e0287316. [PMID: 37352140 PMCID: PMC10289433 DOI: 10.1371/journal.pone.0287316] [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: 10/05/2022] [Accepted: 06/04/2023] [Indexed: 06/25/2023] Open
Abstract
The Gulf of Mexico supports many seabird species, yet data gaps describing species composition and habitat use are prevalent. We used vessel-based observations from the Gulf of Mexico Marine Assessment Program for Protected Species to identify and characterize distinct seabird assemblages in the northern Gulf of Mexico (within the U.S. Exclusive Economic Zone; nGoM). Using cluster analysis of 17 seabird species, we identified assemblages based on seabird relative density. Vessel-based surveys documented the location, species, and number of seabirds across the nGoM between 2017-2019. For each assemblage, we identified the (co-)dominant species, spatial distribution, and areas of greater relative density. We also assessed the relationship of the total relative density within each assemblage with environmental, spatial, and temporal covariates. Of the species assessed, 76% (n = 13) breed predominantly outside the nGoM basin. We identified four seabird assemblages. Two assemblages, one dominated by black tern and the other co-dominated by northern gannet/laughing gull, occurred on the continental shelf. An assemblage dominated by sooty tern occurred along the continental slope into pelagic waters. The fourth assemblage had no dominant species, was broadly distributed, and was composed of observations with low relative density ('singles' assemblage). Differentiation of assemblages was linked to migratory patterns, residency, and breeding location. The spatial distributions and relationships of the black tern and northern gannet/laughing gull assemblages with environmental covariates indicate associations with river outflows and ports. The sooty tern assemblage overlapped an area prone to mesoscale feature formation. The singles assemblage may reflect commuting and dispersive behaviors. These findings highlight the importance of seasonal migrations and dynamic features across the seascape, shaping seabird assemblages. Considering the potential far-ranging effects of interactions with seabirds in the nGoM, awareness of these unique patterns and potential links with other fauna could inform future monitoring, research, restoration, offshore energy, and aquaculture development in this highly industrialized sea.
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Affiliation(s)
- Pamela E. Michael
- South Carolina Cooperative Fish & Wildlife Research Unit, Department of Forestry and Environmental Conservation, Clemson University, Clemson, South Carolina, United States of America
| | - Kathy M. Hixson
- South Carolina Cooperative Fish & Wildlife Research Unit, Department of Forestry and Environmental Conservation, Clemson University, Clemson, South Carolina, United States of America
| | - Jeffery S. Gleason
- U.S. Fish and Wildlife Service, Migratory Bird Program/Science Applications, Chiefland, Florida, United States of America
| | - J. Christopher Haney
- Terra Mar Applied Sciences, Washington, District of Columbia, United States of America
| | - Yvan G. Satgé
- South Carolina Cooperative Fish & Wildlife Research Unit, Department of Forestry and Environmental Conservation, Clemson University, Clemson, South Carolina, United States of America
| | - Patrick G. R. Jodice
- U.S. Geological Survey, South Carolina Cooperative Fish and Wildlife Research Unit, Clemson University, Clemson, South Carolina, United States of America
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2
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Fennie HW, Grorud-Colvert K, Sponaugle S. Larval rockfish growth and survival in response to anomalous ocean conditions. Sci Rep 2023; 13:4089. [PMID: 36906710 PMCID: PMC10008550 DOI: 10.1038/s41598-023-30726-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 02/28/2023] [Indexed: 03/13/2023] Open
Abstract
Understanding how future ocean conditions will affect populations of marine species is integral to predicting how climate change will impact both ecosystem function and fisheries management. Fish population dynamics are driven by variable survival of the early life stages, which are highly sensitive to environmental conditions. As global warming generates extreme ocean conditions (i.e., marine heatwaves) we can gain insight into how larval fish growth and mortality will change in warmer conditions. The California Current Large Marine Ecosystem experienced anomalous ocean warming from 2014 to 2016, creating novel conditions. We examined the otolith microstructure of juveniles of the economically and ecologically important black rockfish (Sebastes melanops) collected from 2013 to 2019 to quantify the implications of changing ocean conditions on early growth and survival. Our results demonstrated that fish growth and development were positively related to temperature, but survival to settlement was not directly related to ocean conditions. Instead, settlement had a dome-shaped relationship with growth, suggesting an optimal growth window. Our results demonstrated that the dramatic change in water temperature caused by such extreme warm water anomalies increased black rockfish growth in the larval stage; however, without sufficient prey or with high predator abundance these extreme conditions contributed to reduced survival.
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Affiliation(s)
- H William Fennie
- Department of Integrative Biology, Oregon State University, Corvallis, OR, 97331, USA. .,Hatfield Marine Science Center, Oregon State University, Newport, OR, 97365, USA. .,NOAA Fisheries Service, Fisheries Resource Division Southwest Fisheries Science Center, La Jolla, CA, 92037, USA. .,Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, 95605, USA.
| | | | - Su Sponaugle
- Department of Integrative Biology, Oregon State University, Corvallis, OR, 97331, USA.,Hatfield Marine Science Center, Oregon State University, Newport, OR, 97365, USA
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3
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Fennie HW, Seary R, Muhling BA, Bograd SJ, Brodie S, Cimino MA, Hazen EL, Jacox MG, McHuron EA, Melin S, Santora JA, Suca JJ, Thayer JA, Thompson AR, Warzybok P, Tommasi D. An anchovy ecosystem indicator of marine predator foraging and reproduction. Proc Biol Sci 2023; 290:20222326. [PMID: 36750186 PMCID: PMC9904941 DOI: 10.1098/rspb.2022.2326] [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: 11/17/2022] [Accepted: 01/13/2023] [Indexed: 02/09/2023] Open
Abstract
Forage fishes are key energy conduits that transfer primary and secondary productivity to higher trophic levels. As novel environmental conditions caused by climate change alter ecosystems and predator-prey dynamics, there is a critical need to understand how forage fish control bottom-up forcing of food web dynamics. In the northeast Pacific, northern anchovy (Engraulis mordax) is an important forage species with high interannual variability in population size that subsequently impacts the foraging and reproductive ecology of marine predators. Anchovy habitat suitability from a species distribution model (SDM) was assessed as an indicator of the diet, distribution and reproduction of four predator species. Across 22 years (1998-2019), this anchovy ecosystem indicator (AEI) was significantly positively correlated with diet composition of all species and the distribution of common murres (Uria aalge), Brandt's cormorants (Phalacrocorax penicillatus) and California sea lions (Zalophus californianus), but not rhinoceros auklets (Cerorhinca monocerata). The capacity for the AEI to explain variability in predator reproduction varied by species but was strongest with cormorants and sea lions. The AEI demonstrates the utility of forage SDMs in creating ecosystem indicators to guide ecosystem-based management.
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Affiliation(s)
- H. William Fennie
- Institute of Marine Sciences, University of California-Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
- Fisheries Resources Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric and Administration, 8901 La Jolla Shores Drive, La Jolla, CA 92037-1508, USA
| | - Rachel Seary
- Institute of Marine Sciences, University of California-Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
- Environmental Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 99 Pacific Street, Suite 255A, Monterey, CA 93940-7200, USA
| | - Barbara A. Muhling
- Institute of Marine Sciences, University of California-Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
- Fisheries Resources Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric and Administration, 8901 La Jolla Shores Drive, La Jolla, CA 92037-1508, USA
| | - Steven J. Bograd
- Environmental Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 99 Pacific Street, Suite 255A, Monterey, CA 93940-7200, USA
| | - Stephanie Brodie
- Institute of Marine Sciences, University of California-Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
- Environmental Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 99 Pacific Street, Suite 255A, Monterey, CA 93940-7200, USA
| | - Megan A. Cimino
- Institute of Marine Sciences, University of California-Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
- Environmental Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 99 Pacific Street, Suite 255A, Monterey, CA 93940-7200, USA
| | - Elliott L. Hazen
- Environmental Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 99 Pacific Street, Suite 255A, Monterey, CA 93940-7200, USA
| | - Michael G. Jacox
- Environmental Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 99 Pacific Street, Suite 255A, Monterey, CA 93940-7200, USA
- Physical Sciences Division, Earth System Research Laboratory, National Oceanic and Atmospheric and Administration, 325 Broadway, Boulder, CO 80305, USA
| | - Elizabeth A. McHuron
- Cooperative Institute for Climate, Ocean and Ecosystem Studies, University of Washington, 3737 Brooklyn Avenue NE, Seattle, WA 98105, USA
| | - Sharon Melin
- California Current Ecosystems Program, Alaska Fisheries Science Center, National Marine Mammal Laboratory, National Oceanic and Atmospheric Administration, 7600 Sand Point Way NE, Seattle, WA 98115, USA
| | - Jarrod A. Santora
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 110 McAllister Way, Santa Cruz, CA 95060, USA
- Department of Applied Math, University of California-Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
| | - Justin J. Suca
- Institute of Marine Sciences, University of California-Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
- Environmental Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 99 Pacific Street, Suite 255A, Monterey, CA 93940-7200, USA
| | - Julie A. Thayer
- Institute of Marine Sciences, University of California-Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
- Farallon Institute for Advanced Ecosystem Research, 101 H Street, Suite Q, Petaluma, CA 94952, USA
| | - Andrew R. Thompson
- Fisheries Resources Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric and Administration, 8901 La Jolla Shores Drive, La Jolla, CA 92037-1508, USA
| | - Pete Warzybok
- Point Blue Conservation Science, 3820 Cypress Drive Suite 11, Petaluma, CA 94954, USA
| | - Desiree Tommasi
- Institute of Marine Sciences, University of California-Santa Cruz, 1156 High Street, Santa Cruz, CA 95064, USA
- Fisheries Resources Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric and Administration, 8901 La Jolla Shores Drive, La Jolla, CA 92037-1508, USA
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4
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Patterson A, Gilchrist HG, Benjaminsen S, Bolton M, Bonnet-Lebrun AS, Davoren GK, Descamps S, Erikstad KE, Frederiksen M, Gaston AJ, Gulka J, Hentati-Sundberg J, Huffeldt NP, Johansen KL, Labansen AL, Linnebjerg JF, Love OP, Mallory ML, Merkel FR, Montevecchi WA, Mosbech A, Olsson O, Owen E, Ratcliffe N, Regular PM, Reiertsen TK, Ropert-Coudert Y, Strøm H, Thórarinsson TL, Elliott KH. Foraging range scales with colony size in high-latitude seabirds. Curr Biol 2022; 32:3800-3807.e3. [PMID: 35870447 DOI: 10.1016/j.cub.2022.06.084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 02/26/2022] [Accepted: 06/28/2022] [Indexed: 11/28/2022]
Abstract
Density-dependent prey depletion around breeding colonies has long been considered an important factor controlling the population dynamics of colonial animals.1-4 Ashmole proposed that as seabird colony size increases, intraspecific competition leads to declines in reproductive success, as breeding adults must spend more time and energy to find prey farther from the colony.1 Seabird colony size often varies over several orders of magnitude within the same species and can include millions of individuals per colony.5,6 As such, colony size likely plays an important role in determining the individual behavior of its members and how the colony interacts with the surrounding environment.6 Using tracking data from murres (Uria spp.), the world's most densely breeding seabirds, we show that the distribution of foraging-trip distances scales to colony size0.33 during the chick-rearing stage, consistent with Ashmole's halo theory.1,2 This pattern occurred across colonies varying in size over three orders of magnitude and distributed throughout the North Atlantic region. The strong relationship between colony size and foraging range means that the foraging areas of some colonial species can be estimated from colony sizes, which is more practical to measure over a large geographic scale. Two-thirds of the North Atlantic murre population breed at the 16 largest colonies; by extrapolating the predicted foraging ranges to sites without tracking data, we show that only two of these large colonies have significant coverage as marine protected areas. Our results are an important example of how theoretical models, in this case, Ashmole's version of central-place-foraging theory, can be applied to inform conservation and management in colonial breeding species.
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Affiliation(s)
- Allison Patterson
- Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Boulevard, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada.
| | - H Grant Gilchrist
- National Wildlife Research Centre, Environment and Climate Change Canada, Ottawa, ON, Canada
| | - Sigurd Benjaminsen
- Norwegian Institute for Nature Research, Fram Centre, 9296 Tromsø, Norway
| | - Mark Bolton
- RSPB Centre for Conservation Science, Royal Society for the Protection of Birds, Sandy, UK
| | | | - Gail K Davoren
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Sébastien Descamps
- Norwegian Polar Institute, Fram Centre, PO Box 6606 Langnes, 9296 Tromsø, Norway
| | - Kjell Einar Erikstad
- Norwegian Institute for Nature Research, Fram Centre, 9296 Tromsø, Norway; Centre for Biodiversity Dynamics, Norwegian University of Science and Technology, Trondheim, Norway
| | - Morten Frederiksen
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Anthony J Gaston
- Laskeek Bay Conservation Society, Queen Charlotte, PO Box 867, Queen Charlotte, BC V0T 1S0, Canada
| | - Julia Gulka
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Jonas Hentati-Sundberg
- Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, Lysekil, Sweden
| | - Nicholas Per Huffeldt
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark; Greenland Institute of Natural Resources, Kivioq 2, 3900 Nuuk, Greenland
| | | | - Aili Lage Labansen
- Greenland Institute of Natural Resources, Kivioq 2, 3900 Nuuk, Greenland
| | | | - Oliver P Love
- Department of Integrative Biology, University of Windsor, 401 Sunset Avenue, Windsor, ON N9B 3P4, Canada
| | - Mark L Mallory
- Biology, Acadia University, 15 University Avenue, Wolfville, NS B4P 2R6, Canada
| | - Flemming Ravn Merkel
- Department of Bioscience, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark; Department of Aquatic Resources, Institute of Marine Research, Swedish University of Agricultural Sciences, Lysekil, Sweden
| | - William A Montevecchi
- Psychology and Biology Departments, Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada
| | - Anders Mosbech
- Centre for Biodiversity Dynamics, Norwegian University of Science and Technology, Trondheim, Norway
| | - Olof Olsson
- Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden
| | - Ellie Owen
- RSPB Centre for Conservation Science, Royal Society for the Protection of Birds, Sandy, UK
| | - Norman Ratcliffe
- British Antarctic Survey, High Cross, Madingley Road, Cambridge, UK
| | - Paul M Regular
- Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, St. John's, NL, Canada
| | | | - Yan Ropert-Coudert
- Centre d'Etudes Biologiques de Chizé, CNRS - La Rochelle Université, Villiers-en-Bois, France
| | - Hallvard Strøm
- Norwegian Polar Institute, Fram Centre, PO Box 6606 Langnes, 9296 Tromsø, Norway
| | | | - Kyle H Elliott
- Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Boulevard, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada
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5
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Huon M, Planque Y, Jessopp MJ, Cronin M, Caurant F, Vincent C. Fine-scale foraging habitat selection by two diving central place foragers in the Northeast Atlantic. Ecol Evol 2021; 11:12349-12363. [PMID: 34594504 PMCID: PMC8462179 DOI: 10.1002/ece3.7934] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 05/02/2021] [Accepted: 05/27/2021] [Indexed: 11/28/2022] Open
Abstract
Habitat selection and spatial usage are important components of animal behavior influencing fitness and population dynamic. Understanding the animal-habitat relationship is crucial in ecology, particularly in developing strategies for wildlife management and conservation. As this relationship is governed by environmental features and intra- and interspecific interactions, habitat selection of a population may vary locally between its core and edges. This is particularly true for central place foragers such as gray and harbor seals, where, in the Northeast Atlantic, the availability of habitat and prey around colonies vary at local scale. Here, we study how foraging habitat selection may vary locally under the influence of physical habitat features. Using GPS/GSM tags deployed at different gray and harbor seals' colonies, we investigated spatial patterns and foraging habitat selection by comparing trip characteristics and home-range similarities and fitting GAMMs to seal foraging locations and environmental data. To highlight the importance of modeling habitat selection at local scale, we fitted individual models to colonies as well as a global model. The global model suffered from issues of homogenization, while colony models showed that foraging habitat selection differed markedly between regions for both species. Despite being capable of undertaking far-ranging trips, both gray and harbor seals selected their foraging habitat depending on local availability, mainly based on distance from the last haul-out and bathymetry. Distance from shore and tidal current also influenced habitat preferences. Results suggest that local conditions have a strong influence on population spatial ecology, highlighting the relevance of processes occurring at fine geographical scale consistent with management within regional units.
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Affiliation(s)
- Mathilde Huon
- Centre d'Etudes Biologiques de ChizéUMR 7372 CNRS –La Rochelle UniversitéLa RochelleFrance
- Observatoire PelagisUMS 3462 CNRS ‐ La Rochelle Université, Pôle analytiqueLa RochelleFrance
| | - Yann Planque
- Centre d'Etudes Biologiques de ChizéUMR 7372 CNRS –La Rochelle UniversitéLa RochelleFrance
| | - Mark John Jessopp
- MaREI CentreEnvironmental Research InstituteUniversity College CorkCorkIreland
- School of Biological, Earth & Environmental SciencesUniversity College CorkCorkIreland
| | - Michelle Cronin
- MaREI CentreEnvironmental Research InstituteUniversity College CorkCorkIreland
| | - Florence Caurant
- Centre d'Etudes Biologiques de ChizéUMR 7372 CNRS –La Rochelle UniversitéLa RochelleFrance
- Observatoire PelagisUMS 3462 CNRS ‐ La Rochelle Université, Pôle analytiqueLa RochelleFrance
| | - Cécile Vincent
- Centre d'Etudes Biologiques de ChizéUMR 7372 CNRS –La Rochelle UniversitéLa RochelleFrance
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6
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Sydeman WJ, Schoeman DS, Thompson SA, Hoover BA, García-Reyes M, Daunt F, Agnew P, Anker-Nilssen T, Barbraud C, Barrett R, Becker PH, Bell E, Boersma PD, Bouwhuis S, Cannell B, Crawford RJM, Dann P, Delord K, Elliott G, Erikstad KE, Flint E, Furness RW, Harris MP, Hatch S, Hilwig K, Hinke JT, Jahncke J, Mills JA, Reiertsen TK, Renner H, Sherley RB, Surman C, Taylor G, Thayer JA, Trathan PN, Velarde E, Walker K, Wanless S, Warzybok P, Watanuki Y. Hemispheric asymmetry in ocean change and the productivity of ecosystem sentinels. Science 2021; 372:980-983. [PMID: 34045354 DOI: 10.1126/science.abf1772] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 04/20/2021] [Indexed: 11/02/2022]
Abstract
Climate change and other human activities are causing profound effects on marine ecosystem productivity. We show that the breeding success of seabirds is tracking hemispheric differences in ocean warming and human impacts, with the strongest effects on fish-eating, surface-foraging species in the north. Hemispheric asymmetry suggests the need for ocean management at hemispheric scales. For the north, tactical, climate-based recovery plans for forage fish resources are needed to recover seabird breeding productivity. In the south, lower-magnitude change in seabird productivity presents opportunities for strategic management approaches such as large marine protected areas to sustain food webs and maintain predator productivity. Global monitoring of seabird productivity enables the detection of ecosystem change in remote regions and contributes to our understanding of marine climate impacts on ecosystems.
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Affiliation(s)
| | - D S Schoeman
- Global-Change Ecology Research Group, School of Science, Technology and Engineering, University of the Sunshine Coast, Sippy Downs, Queensland, Australia.,Centre for African Conservation Ecology, Department of Zoology, Nelson Mandela University, Gqeberha, South Africa
| | | | | | | | - F Daunt
- UK Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian, UK
| | - P Agnew
- Oamaru Blue Penguin Colony, Oamaru, New Zealand
| | - T Anker-Nilssen
- Norwegian Institute for Nature Research (NINA), Trondheim, Norway
| | - C Barbraud
- Centre d'Etudes Biologiques de Chizé, CNRS UMR7372, Villiers en Bois, France
| | - R Barrett
- UiT The Arctic University of Norway, Tromsø, Norway
| | - P H Becker
- Institute of Avian Research, Wilhelmshaven, Germany
| | - E Bell
- Wildlife Management International, Blenheim, New Zealand
| | - P D Boersma
- Center for Ecosystem Sentinels, Department of Biology, University of Washington, Seattle, WA, USA
| | - S Bouwhuis
- Institute of Avian Research, Wilhelmshaven, Germany
| | - B Cannell
- Murdoch University, Murdoch, Western Australia, and University of Western Australia, Perth, Western Australia
| | - R J M Crawford
- Department of Environment, Forestry and Fisheries, Cape Town, South Africa
| | - P Dann
- Phillip Island Nature Parks, Cowes, Victoria, Australia
| | - K Delord
- Centre d'Etudes Biologiques de Chizé, CNRS UMR7372, Villiers en Bois, France
| | - G Elliott
- New Zealand Department of Conservation, Wellington, New Zealand
| | - K E Erikstad
- Norwegian Institute for Nature Research (NINA), FRAM Centre, Tromsø, Norway and Centre for Biodiversity Dynamics (CBD), Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - E Flint
- U.S. Fish and Wildlife Service, Honolulu, HI, USA
| | - R W Furness
- University of Glasgow, Glasgow, Scotland, UK
| | - M P Harris
- UK Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian, UK
| | - S Hatch
- Institute for Seabird Research and Conservation, Anchorage, AK, USA
| | - K Hilwig
- U.S. Fish and Wildlife Service, Anchorage, AK, USA
| | - J T Hinke
- Antarctic Ecosystem Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, La Jolla, CA, USA
| | - J Jahncke
- Point Blue Conservation Science, Petaluma, CA, USA
| | | | - T K Reiertsen
- Norwegian Institute for Nature Research (NINA), FRAM Centre, Tromsø, Norway
| | - H Renner
- U.S. Fish and Wildlife Service, Anchorage, AK, USA
| | - R B Sherley
- Centre for Ecology and Conservation, University of Exeter, Cornwall, UK
| | - C Surman
- Halfmoon Biosciences, Ocean Beach, Western Australia, Australia
| | - G Taylor
- New Zealand Department of Conservation, Wellington, New Zealand
| | | | | | - E Velarde
- Universidad Veracruzana, Veracruz, Mexico
| | - K Walker
- New Zealand Department of Conservation, Wellington, New Zealand
| | - S Wanless
- UK Centre for Ecology and Hydrology, Bush Estate, Penicuik, Midlothian, UK
| | - P Warzybok
- Point Blue Conservation Science, Petaluma, CA, USA
| | - Y Watanuki
- Hokkaido University, Hakodate, Hokkaido, Japan
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7
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Field JC, Miller RR, Santora JA, Tolimieri N, Haltuch MA, Brodeur RD, Auth TD, Dick EJ, Monk MH, Sakuma KM, Wells BK. Spatiotemporal patterns of variability in the abundance and distribution of winter-spawned pelagic juvenile rockfish in the California Current. PLoS One 2021; 16:e0251638. [PMID: 34043656 PMCID: PMC8158922 DOI: 10.1371/journal.pone.0251638] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 04/30/2021] [Indexed: 11/18/2022] Open
Abstract
Rockfish are an important component of West Coast fisheries and California Current food webs, and recruitment (cohort strength) for rockfish populations has long been characterized as highly variable for most studied populations. Research efforts and fisheries surveys have long sought to provide greater insights on both the environmental drivers, and the fisheries and ecosystem consequences, of this variability. Here, variability in the temporal and spatial abundance and distribution patterns of young-of-the-year (YOY) rockfishes are described based on midwater trawl surveys conducted throughout the coastal waters of California Current between 2001 and 2019. Results confirm that the abundance of winter-spawning rockfish taxa in particular is highly variable over space and time. Although there is considerable spatial coherence in these relative abundance patterns, there are many years in which abundance patterns are very heterogeneous over the scale of the California Current. Results also confirm that the high abundance levels of YOY rockfish observed during the 2014-2016 large marine heatwave were largely coastwide events. Species association patterns of pelagic YOY for over 20 rockfish taxa in space and time are also described. The overall results will help inform future fisheries-independent surveys, and will improve future indices of recruitment strength used to inform stock assessment models and marine ecosystem status reports.
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Affiliation(s)
- John C. Field
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Santa Cruz, CA, United States of America
- Institute of Marine Sciences, Fisheries Collaborative Program, University of California, Santa Cruz, CA, United States of America
| | - Rebecca R. Miller
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Santa Cruz, CA, United States of America
- Institute of Marine Sciences, Fisheries Collaborative Program, University of California, Santa Cruz, CA, United States of America
| | - Jarrod A. Santora
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Santa Cruz, CA, United States of America
- Institute of Marine Sciences, Fisheries Collaborative Program, University of California, Santa Cruz, CA, United States of America
| | - Nick Tolimieri
- Conservation Biology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, United States of America
| | - Melissa A. Haltuch
- Fisheries Research, Analysis and Monitoring Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Seattle, WA, United States of America
| | - Richard D. Brodeur
- Fish Ecology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Newport, OR, United States of America
| | - Toby D. Auth
- Pacific States Marine Fisheries Commission, Newport, OR, United States of America
| | - E. J. Dick
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Santa Cruz, CA, United States of America
| | - Melissa H. Monk
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Santa Cruz, CA, United States of America
| | - Keith M. Sakuma
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Santa Cruz, CA, United States of America
| | - Brian K. Wells
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Santa Cruz, CA, United States of America
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8
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Factors affecting the seasonal distribution and biomass of E. pacifica and T. spinifera along the Pacific coast of Canada: A spatiotemporal modelling approach. PLoS One 2021; 16:e0249818. [PMID: 33989288 PMCID: PMC8121349 DOI: 10.1371/journal.pone.0249818] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 03/26/2021] [Indexed: 11/19/2022] Open
Abstract
Euphausiids are a keystone species in coastal food webs due to their high lipid content and seasonally high biomass. Understanding the habitat and environmental drivers that lead to areas of high biomass, or ‘hotspots’, and their seasonal persistence, will support the identification of important foraging regions for mid- and upper- trophic level predators. We quantify the distribution of hotspots of the two dominant species of euphausiid in the north-east Pacific Ocean: Euphausia pacifica and Thysanoessa spinifera, as well as euphausiid larvae (mixed species). The Canadian coast encompasses the northern California Current Ecosystem and the transition zone to the Alaska current, and is a highly productive region for fisheries, marine mammals, and seabirds. We used spatiotemporal modelling to predict the distribution of these three euphausiid groups in relation to geomorphic and environmental variables during the important spring-summer months (April through September) when euphausiid biomass is highest. We quantified the area, intensity, and persistence of biomass hotspots across months according to specific oceanographic ecosections developed for marine spatial planning purposes. Persistent hotspots of both adult species were predicted to occur along the 200 m depth contour of the continental slope; however, differences were predicted on the shallower Dixon shelf, which was a key area for T. spinifera, and within the Juan de Fuca Eddy system where E. pacifica hotspots occurred. The continental slope along the west coast of Vancouver Island was the only persistent hotspot region common between both adult species and euphausiid larvae. Larval distribution was more correlated with T. spinifera than E. pacifica biomass. Hotspots of adults were more persistent across months than hotspots of euphausiid larvae, which were seasonally patchy. The persistence of biomass hotspots of forage species through periods of low overall biomass could maintain trophic connectivity through perturbation events and increase ecosystem resilience to climate change.
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9
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Fiechter J, Santora JA, Chavez F, Northcott D, Messié M. Krill Hotspot Formation and Phenology in the California Current Ecosystem. GEOPHYSICAL RESEARCH LETTERS 2020; 47:e2020GL088039. [PMID: 32728303 PMCID: PMC7380319 DOI: 10.1029/2020gl088039] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 05/28/2020] [Accepted: 06/04/2020] [Indexed: 06/11/2023]
Abstract
In the California Current Ecosystem, krill represent a key link between primary production and higher trophic level species owing to their central position in the food web and tendency to form dense aggregations. However, the strongly advective circulation associated with coastal upwelling may decouple the timing, occurrence, and persistence of krill hotspots from phytoplankton biomass and nutrient sources. Results from a coupled physical-biological model provide insights into fundamental mechanisms controlling the phenology of krill hotspots in the California Current Ecosystem, and their sensitivity to alongshore changes in coastal upwelling intensity. The simulation indicates that dynamics controlling krill hotspot formation, intensity, and persistence on seasonal and interannual timescales are strongly heterogeneous and related to alongshore variations in upwelling-favorable winds, primary production, and ocean currents. Furthermore, regions promoting persistent krill hotspot formation coincide with increased observed abundance of top predators, indicating that the model resolves important ecosystem complexity and function.
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Affiliation(s)
- Jerome Fiechter
- Ocean Sciences DepartmentUniversity of CaliforniaSanta CruzCAUSA
| | - Jarrod A. Santora
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries ServiceNational Oceanic and Atmospheric AdministrationSanta CruzCAUSA
- Department of Applied MathematicsUniversity of CaliforniaSanta CruzCAUSA
| | | | - Devon Northcott
- Monterey Bay Aquarium Research InstituteMoss LandingCAUSA
- Now at Scripps Institution of OceanographyUniversity of California, San DiegoLa JollaCAUSA
| | - Monique Messié
- Monterey Bay Aquarium Research InstituteMoss LandingCAUSA
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10
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Wilkinson BP, Haynes-Sutton AM, Meggs L, Jodice PGR. High spatial fidelity among foraging trips of Masked Boobies from Pedro Cays, Jamaica. PLoS One 2020; 15:e0231654. [PMID: 32340024 PMCID: PMC7186003 DOI: 10.1371/journal.pone.0231654] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 03/27/2020] [Indexed: 11/18/2022] Open
Abstract
In marine environments, tropical and subtropical habitats are considered to be inherently less productive than more temperate systems. As such, foraging site fidelity among vertebrate predators occupying low-latitude marine systems is generally low as a response to an increased unpredictability of resources. We investigated the foraging movements of Masked Boobies breeding on Middle Cay, Jamaica using GPS loggers to examine if the presence of a nearby bathymetric feature influenced foraging site fidelity in a tropical system, the Caribbean Sea. According to the movements of tracked individuals, this population of boobies shows a high degree of spatial fidelity in foraging site selection, concentrated on the northern edge of Pedro Bank. We suggest this feature as an important location for marine conservation in the region and demonstrate its utility to foraging boobies via habitat modeling using a maximum entropy approach of relevant habitat variables. Finally, we place this study into the global context of Masked Booby foraging by examining the published literature of relevant tracking studies for population-level similarity in foraging metrics. According to hierarchical clustering of foraging effort, Masked Boobies demonstrate a density-dependent response to foraging effort regardless of colony origin or oceanic basin consistent with the principles of Ashmole’s Halo.
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Affiliation(s)
- Bradley P. Wilkinson
- Department of Forestry and Environmental Conservation, South Carolina Cooperative Fish and Wildlife Research Unit, Clemson University, Clemson, South Carolina, United States of America
- * E-mail:
| | | | - Llewelyn Meggs
- Yardie Environmental Conservationists Limited, Kingston, Jamaica
| | - Patrick G. R. Jodice
- Department of Forestry and Environmental Conservation, U.S. Geological Survey South Carolina Cooperative Fish and Wildlife Research Unit, Clemson University, Clemson, South Carolina, United States of America
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11
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Habitat compression and ecosystem shifts as potential links between marine heatwave and record whale entanglements. Nat Commun 2020; 11:536. [PMID: 31988285 PMCID: PMC6985238 DOI: 10.1038/s41467-019-14215-w] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 12/13/2019] [Indexed: 12/03/2022] Open
Abstract
Climate change and increased variability and intensity of climate events, in combination with recovering protected species populations and highly capitalized fisheries, are posing new challenges for fisheries management. We examine socio-ecological features of the unprecedented 2014–2016 northeast Pacific marine heatwave to understand the potential causes for record numbers of whale entanglements in the central California Current crab fishery. We observed habitat compression of coastal upwelling, changes in availability of forage species (krill and anchovy), and shoreward distribution shift of foraging whales. We propose that these ecosystem changes, combined with recovering whale populations, contributed to the exacerbation of entanglements throughout the marine heatwave. In 2016, domoic acid contamination prompted an unprecedented delay in the opening of California’s Dungeness crab fishery that inadvertently intensified the spatial overlap between whales and crab fishery gear. We present a retroactive assessment of entanglements to demonstrate that cooperation of fishers, resource managers, and scientists could mitigate future entanglement risk by developing climate-ready fisheries approaches, while supporting thriving fishing communities. Climate-driven extreme events may have strong local impacts on marine organisms and fisheries. Here the authors report increased whale entanglements in the northeast Pacific following a marine heatwave, and propose compression of coastal upwelling habitat as the potential driver.
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12
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Ryan JP, Cline DE, Joseph JE, Margolina T, Santora JA, Kudela RM, Chavez FP, Pennington JT, Wahl C, Michisaki R, Benoit-Bird K, Forney KA, Stimpert AK, DeVogelaere A, Black N, Fischer M. Humpback whale song occurrence reflects ecosystem variability in feeding and migratory habitat of the northeast Pacific. PLoS One 2019; 14:e0222456. [PMID: 31525231 PMCID: PMC6746543 DOI: 10.1371/journal.pone.0222456] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 08/30/2019] [Indexed: 11/20/2022] Open
Abstract
This study examines the occurrence of humpback whale (Megaptera novaeangliae) song in the northeast Pacific from three years of continuous recordings off central California (36.713°N, 122.186°W). Song is prevalent in this feeding and migratory habitat, spanning nine months of the year (September-May), peaking in winter (November-January), and reaching a maximum of 86% temporal coverage (during November 2017). From the rise of song in fall through the end of peak occurrence in winter, song length increases significantly from month to month. The seasonal peak in song coincides with the seasonal trough in day length and sighting-based evidence of whales leaving Monterey Bay, consistent with seasonal migration. During the seasonal song peak, diel variation shows maximum occurrence at night (69% of the time), decreasing during dawn and dusk (52%), and further decreasing with increasing solar elevation during the day, reaching a minimum near solar noon (30%). Song occurrence increased 44% and 55% between successive years. Sighting data within the acoustic detection range of the hydrophone indicate that variation in local population density was an unlikely cause of this large interannual variation. Hydrographic data and modeling of acoustic transmission indicate that changes in neither habitat occupancy nor acoustic transmission were probable causes. Conversely, the positive interannual trend in song paralleled major ecosystem variations, including similarly large positive trends in wind-driven upwelling, primary productivity, and krill abundance. Further, the lowest song occurrence during the first year coincided with anomalously warm ocean temperatures and an extremely toxic harmful algal bloom that affected whales and other marine mammals in the region. These major ecosystem variations may have influenced the health and behavior of humpback whales during the study period.
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Affiliation(s)
- John P. Ryan
- Monterey Bay Aquarium Research Institute, Moss Landing, California, United States of America
| | - Danelle E. Cline
- Monterey Bay Aquarium Research Institute, Moss Landing, California, United States of America
| | - John E. Joseph
- Department of Oceanography, Naval Postgraduate School, Monterey, California, United States of America
| | - Tetyana Margolina
- Department of Oceanography, Naval Postgraduate School, Monterey, California, United States of America
| | - Jarrod A. Santora
- Department of Applied Mathematics, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Raphael M. Kudela
- Ocean Sciences Department, University of California Santa Cruz, Santa Cruz, California, United States of America
| | - Francisco P. Chavez
- Monterey Bay Aquarium Research Institute, Moss Landing, California, United States of America
| | - J. Timothy Pennington
- Monterey Bay Aquarium Research Institute, Moss Landing, California, United States of America
| | - Christopher Wahl
- Monterey Bay Aquarium Research Institute, Moss Landing, California, United States of America
| | - Reiko Michisaki
- Monterey Bay Aquarium Research Institute, Moss Landing, California, United States of America
| | - Kelly Benoit-Bird
- Monterey Bay Aquarium Research Institute, Moss Landing, California, United States of America
| | - Karin A. Forney
- Marine Mammal & Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, NOAA, Moss Landing, California, United States of America
- Moss Landing Marine Laboratories, San Jose State University, Moss Landing, California, United States of America
| | - Alison K. Stimpert
- Bioacoustics/Vertebrate Ecology, San Jose State University, Moss Landing Marine Laboratories, Moss Landing, California, United States of America
| | - Andrew DeVogelaere
- Monterey Bay National Marine Sanctuary, National Ocean Service, National Oceanic and Atmospheric Administration, Monterey, California, United States of America
| | - Nancy Black
- Monterey Bay Whale Watch, Monterey, California, United States of America
| | - Mark Fischer
- Aguasonic Acoustics, Santa Clara, California, United States of America
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13
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Boyd C, Barlow J, Becker EA, Forney KA, Gerrodette T, Moore JE, Punt AE. Estimation of population size and trends for highly mobile species with dynamic spatial distributions. DIVERS DISTRIB 2017. [DOI: 10.1111/ddi.12663] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Charlotte Boyd
- School of Aquatic and Fishery Sciences; University of Washington; Seattle WA USA
- Southwest Fisheries Science Center; National Marine Fisheries Service; National Oceanic and Atmospheric Administration; La Jolla CA USA
| | - Jay Barlow
- Southwest Fisheries Science Center; National Marine Fisheries Service; National Oceanic and Atmospheric Administration; La Jolla CA USA
| | - Elizabeth A. Becker
- Marine Mammal and Turtle Division; Southwest Fisheries Science Center; National Marine Fisheries Service; National Oceanic and Atmospheric Administration; Moss Landing CA USA
| | - Karin A. Forney
- Marine Mammal and Turtle Division; Southwest Fisheries Science Center; National Marine Fisheries Service; National Oceanic and Atmospheric Administration; Moss Landing CA USA
- Moss Landing Marine Laboratories; Moss Landing CA USA
| | - Tim Gerrodette
- Southwest Fisheries Science Center; National Marine Fisheries Service; National Oceanic and Atmospheric Administration; La Jolla CA USA
| | - Jeffrey E. Moore
- Southwest Fisheries Science Center; National Marine Fisheries Service; National Oceanic and Atmospheric Administration; La Jolla CA USA
| | - André E. Punt
- School of Aquatic and Fishery Sciences; University of Washington; Seattle WA USA
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14
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Santora JA, Sydeman WJ, Schroeder ID, Field JC, Miller RR, Wells BK. Persistence of trophic hotspots and relation to human impacts within an upwelling marine ecosystem. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2017; 27:560-574. [PMID: 27862556 DOI: 10.1002/eap.1466] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 09/23/2016] [Accepted: 10/25/2016] [Indexed: 06/06/2023]
Abstract
Human impacts (e.g., fishing, pollution, and shipping) on pelagic ecosystems are increasing, causing concerns about stresses on marine food webs. Maintaining predator-prey relationships through protection of pelagic hotspots is crucial for conservation and management of living marine resources. Biotic components of pelagic, plankton-based, ecosystems exhibit high variability in abundance in time and space (i.e., extreme patchiness), requiring investigation of persistence of abundance across trophic levels to resolve trophic hotspots. Using a 26-yr record of indicators for primary production, secondary (zooplankton and larval fish), and tertiary (seabirds) consumers, we show distributions of trophic hotspots in the southern California Current Ecosystem result from interactions between a strong upwelling center and a productive retention zone with enhanced nutrients, which concentrate prey and predators across multiple trophic levels. Trophic hotspots also overlap with human impacts, including fisheries extraction of coastal pelagic and groundfish species, as well as intense commercial shipping traffic. Spatial overlap of trophic hotspots with fisheries and shipping increases vulnerability of the ecosystem to localized depletion of forage fish, ship strikes on marine mammals, and pollution. This study represents a critical step toward resolving pelagic areas of high conservation interest for planktonic ecosystems and may serve as a model for other ocean regions where ecosystem-based management and marine spatial planning of pelagic ecosystems is warranted.
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Affiliation(s)
- Jarrod A Santora
- Department of Applied Mathematics and Statistics, Center for Stock Assessment Research, University of California, Santa Cruz, 1156 High Street, Santa Cruz, California, 96060, USA
| | - William J Sydeman
- Farallon Institute for Advanced Ecosystem Research, 101 H Street, Suite Q, Petaluma, California, 94952, USA
| | - Isaac D Schroeder
- Cooperative Institute for Marine Ecosystems and Climate (CIMEC), University of California, Santa Cruz, Santa Cruz, California, 95060, USA
- Environmental Research Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 99 Pacific Street, Suite 255A, Monterey, California, 93940, USA
| | - John C Field
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 110 Shaffer Road, Santa Cruz, California, 95060, USA
| | - Rebecca R Miller
- Cooperative Institute for Marine Ecosystems and Climate (CIMEC), University of California, Santa Cruz, Santa Cruz, California, 95060, USA
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 110 Shaffer Road, Santa Cruz, California, 95060, USA
| | - Brian K Wells
- Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 110 Shaffer Road, Santa Cruz, California, 95060, USA
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15
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Fleming AH, Clark CT, Calambokidis J, Barlow J. Humpback whale diets respond to variance in ocean climate and ecosystem conditions in the California Current. GLOBAL CHANGE BIOLOGY 2016; 22:1214-24. [PMID: 26599719 DOI: 10.1111/gcb.13171] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 10/20/2015] [Accepted: 11/02/2015] [Indexed: 05/26/2023]
Abstract
Large, migratory predators are often cited as sentinel species for ecosystem processes and climate-related changes, but their utility as indicators is dependent upon an understanding of their response to environmental variability. Documentation of the links between climate variability, ecosystem change and predator dynamics is absent for most top predators. Identifying species that may be useful indicators and elucidating these mechanistic links provides insight into current ecological dynamics and may inform predictions of future ecosystem responses to climatic change. We examine humpback whale response to environmental variability through stable isotope analysis of diet over a dynamic 20-year period (1993-2012) in the California Current System (CCS). Humpback whale diets captured two major shifts in oceanographic and ecological conditions in the CCS. Isotopic signatures reflect a diet dominated by krill during periods characterized by positive phases of the North Pacific Gyre Oscillation (NPGO), cool sea surface temperature (SST), strong upwelling and high krill biomass. In contrast, humpback whale diets are dominated by schooling fish when the NPGO is negative, SST is warmer, seasonal upwelling is delayed and anchovy and sardine populations display increased biomass and range expansion. These findings demonstrate that humpback whales trophically respond to ecosystem shifts, and as a result, their foraging behavior is a synoptic indicator of oceanographic and ecological conditions across the CCS. Multi-decadal examination of these sentinel species thus provides insight into biological consequences of interannual climate fluctuations, fundamental to advancing ecosystem predictions related to global climate change.
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Affiliation(s)
- Alyson H Fleming
- Center for Marine Biodiversity & Conservation, Scripps Institution of Oceanography, La Jolla, CA, 92037, USA
- NOAA, National Marine Fisheries Service, Southwest Fisheries Science Center, La Jolla, CA, 92037, USA
| | - Casey T Clark
- School of Fisheries and Ocean Sciences, University of Alaska Fairbanks, PO Box 757220, Fairbanks, AK, 99775, USA
| | | | - Jay Barlow
- NOAA, National Marine Fisheries Service, Southwest Fisheries Science Center, La Jolla, CA, 92037, USA
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16
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Santora JA, Sydeman WJ. Persistence of hotspots and variability of seabird species richness and abundance in the southern California Current. Ecosphere 2015. [DOI: 10.1890/es14-00434.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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