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Pratte I, Braune BM, Hobson KA, Mallory ML. Variable sea-ice conditions influence trophic dynamics in an Arctic community of marine top predators. Ecol Evol 2019; 9:7639-7651. [PMID: 31346428 PMCID: PMC6635931 DOI: 10.1002/ece3.5313] [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: 02/20/2019] [Revised: 05/09/2019] [Accepted: 05/14/2019] [Indexed: 11/07/2022] Open
Abstract
Sea-ice coverage is a key abiotic driver of annual environmental conditions in Arctic marine ecosystems and could be a major factor affecting seabird trophic dynamics. Using stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) in eggs of thick-billed murres (Uria lomvia), northern fulmars (Fulmarus glacialis), glaucous gulls (Larus hyperboreus), and black-legged kittiwakes (Rissa tridactyla), we investigated the trophic ecology of prebreeding seabirds nesting at Prince Leopold Island, Nunavut, and its relationship with sea-ice conditions. The seabird community of Prince Leopold Island had a broader isotopic niche during lower sea-ice conditions, thus having a more divergent diet, while the opposite was observed during years with more extensive sea-ice conditions. Species' trophic position was influenced by sea ice; in years of lower sea-ice concentration, gulls and kittiwakes foraged at higher trophic levels while the opposite was observed for murres and fulmars. For murres and fulmars over a longer time series, there was no evidence of the effect of sea-ice concentration on species' isotopic niche. Results suggest a high degree of adaptation in populations of high Arctic species that cope with harsh and unpredictable conditions. Such different responses of the community isotopic niche also show that the effect of variable sea-ice conditions, despite being subtle at the species level, might have larger implications when considering the trophic ecology of the larger seabird community. Species-specific responses in foraging patterns, in particular trophic position in relation to sea ice, are critical to understanding effects of ecosystem change predicted for a changing climate.
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Affiliation(s)
| | - Birgit M. Braune
- Environment and Climate Change Canada, National Wildlife Research CentreCarleton UniversityOttawaOntarioCanada
| | - Keith A. Hobson
- Environment and Climate Change Canada, Department of BiologyUniversity of Western OntarioLondonUK
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Smith MA, Sullender BK, Koeppen WC, Kuletz KJ, Renner HM, Poe AJ. An assessment of climate change vulnerability for Important Bird Areas in the Bering Sea and Aleutian Arc. PLoS One 2019; 14:e0214573. [PMID: 30995250 PMCID: PMC6469780 DOI: 10.1371/journal.pone.0214573] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 03/15/2019] [Indexed: 11/19/2022] Open
Abstract
Recently available downscaled ocean climate models for the Bering Sea and Aleutian Arc offer the opportunity to assess climate vulnerability for upper trophic level consumers such as marine birds. We analyzed seasonal and annual spatial projections from three climate models for two physical climate variables (seawater temperature and sea ice) and three forage variables (large copepods, euphausiids, and benthic infauna), comparing projected conditions from a recent time period (2003–2012) to a future time period (2030–2039). We focused the analyses on core areas within globally significant Important Bird Areas, and developed indices of the magnitude of projected change and vulnerability agreement among models. All three climate models indicated a high degree of change for seawater temperature warming (highest in the central and eastern Aleutian Islands) and ice loss (most significant in the eastern Bering Sea) across scales, and we found those changes to be significant for every species and virtually every core area assessed. There was low model agreement for the forage variables; while the majority of core areas were identified as climate vulnerable by one or more models (72% for large copepods, 73% for euphausiids, and 94% for benthic infauna), very few were agreed upon by all three models (only 6% of euphausiid-forager core areas). Based on the magnitude-agreement score, euphausiid biomass decline affected core areas for fulmars, gulls, and auklets, especially along the outer shelf and Aleutian Islands. Benthic biomass decline affected eiders along the inner shelf, and large copepod decline was significant for storm-petrels and auklets in the western Aleutians. Overall, 12% of core areas indicated climate vulnerability for all variables assessed. Modeling and interpreting biological parameters to project future dynamics remains complex; the strong signal for projected physical changes raised concerns about lagged responses such as distribution shifts, breeding failures, mortality events, and population declines.
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Affiliation(s)
- Melanie A. Smith
- Audubon Alaska, Anchorage, Alaska, United States of America
- * E-mail:
| | | | | | - Kathy J. Kuletz
- US Fish and Wildlife Service, Anchorage, Alaska, United States of America
| | - Heather M. Renner
- Alaska Maritime National Wildlife Refuge, US Fish and Wildlife Service, Homer, Alaska, United States of America
| | - Aaron J. Poe
- US Fish and Wildlife Service, Anchorage, Alaska, United States of America
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Macias-Fauria M, Post E. Effects of sea ice on Arctic biota: an emerging crisis discipline. Biol Lett 2019; 14:rsbl.2017.0702. [PMID: 29563280 DOI: 10.1098/rsbl.2017.0702] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 02/22/2018] [Indexed: 11/12/2022] Open
Abstract
The rapid decline in Arctic sea ice (ASI) extent, area and volume during recent decades is occurring before we can understand many of the mechanisms through which ASI interacts with biological processes both at sea and on land. As a consequence, our ability to predict and manage the effects of this enormous environmental change is limited, making this a crisis discipline Here, we propose a framework to study these effects, defining direct effects as those acting on life-history events of Arctic biota, and indirect effects, where ASI acts upon biological systems through chains of events, normally involving other components of the physical system and/or biotic interactions. Given the breadth and complexity of ASI's effects on Arctic biota, Arctic research requires a truly multidisciplinary approach to address this issue. In the absence of effective global efforts to tackle anthropogenic global warming, ASI will likely continue to decrease, compromising the conservation of many ASI-related taxonomic groups and ecosystems. Mitigation actions will rely heavily on the knowledge acquired on the mechanisms and components involved with the biological effects of ASI.
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Affiliation(s)
- Marc Macias-Fauria
- School of Geography and the Environment, University of Oxford, Oxford OX1 3QY, UK
| | - Eric Post
- Department of Wildlife, Fish and Conservation Biology, University of California, Davis, CA 95616-8571, USA
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Springer AM, van Vliet GB, Bool N, Crowley M, Fullagar P, Lea MA, Monash R, Price C, Vertigan C, Woehler EJ. Transhemispheric ecosystem disservices of pink salmon in a Pacific Ocean macrosystem. Proc Natl Acad Sci U S A 2018; 115:E5038-E5045. [PMID: 29760093 PMCID: PMC5984504 DOI: 10.1073/pnas.1720577115] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Pink salmon (Oncorhynchus gorbuscha) in the North Pacific Ocean have flourished since the 1970s, with growth in wild populations augmented by rising hatchery production. As their abundance has grown, so too has evidence that they are having important effects on other species and on ocean ecosystems. In alternating years of high abundance, they can initiate pelagic trophic cascades in the northern North Pacific Ocean and Bering Sea and depress the availability of common prey resources of other species of salmon, resident seabirds, and other pelagic species. We now propose that the geographic scale of ecosystem disservices of pink salmon is far greater due to a 15,000-kilometer transhemispheric teleconnection in a Pacific Ocean macrosystem maintained by short-tailed shearwaters (Ardenna tenuirostris), seabirds that migrate annually between their nesting grounds in the South Pacific Ocean and wintering grounds in the North Pacific Ocean. Over this century, the frequency and magnitude of mass mortalities of shearwaters as they arrive in Australia, and their abundance and productivity, have been related to the abundance of pink salmon. This has influenced human social, economic, and cultural traditions there, and has the potential to alter the role shearwaters play in insular terrestrial ecology. We can view the unique biennial pulses of pink salmon as a large, replicated, natural experiment that offers basin-scale opportunities to better learn how these ecosystems function. By exploring trophic interaction chains driven by pink salmon, we may achieve a deeper conservation conscientiousness for these northern open oceans.
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Affiliation(s)
- Alan M Springer
- Institute of Marine Science, University of Alaska Fairbanks, Fairbanks, AK 99775;
| | | | - Natalie Bool
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7000, Australia
| | - Mike Crowley
- South Coast Region, State Forests of NSW, Australia, Moruya Heads, NSW 2537, Australia
| | - Peter Fullagar
- Commonwealth Scientific and Industrial Research Organization, Division of Wildlife Research, Australia, Belconnen, ACT 2617, Australia
| | - Mary-Anne Lea
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7000, Australia
- Antarctic Climate and Ecosystems CRC, Hobart, TAS 7000, Australia
| | - Ross Monash
- Marine Conservation Program, Department of Primary Industries, Parks, Water and Environment, Hobart, TAS 7001, Australia
| | - Cassandra Price
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7000, Australia
| | - Caitlin Vertigan
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7000, Australia
| | - Eric J Woehler
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7000, Australia
- BirdLife Tasmania, Hobart, TAS 7001, Australia
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