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Lacombe RM, Martigny P, Pelletier D, Barst BD, Guillemette M, Amyot M, Elliott KH, Lavoie RA. Exploring the spatial variation of mercury in the Gulf of St. Lawrence using northern gannets as fish samplers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 927:172152. [PMID: 38575012 DOI: 10.1016/j.scitotenv.2024.172152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 03/22/2024] [Accepted: 03/30/2024] [Indexed: 04/06/2024]
Abstract
Mercury (Hg) is a ubiquitous and pervasive environmental contaminant with detrimental effects on wildlife, which originates from both natural and anthropogenic sources. Its distribution within ecosystems is influenced by various biogeochemical processes, making it crucial to elucidate the factors driving this variability. To explore these factors, we employed an innovative method to use northern gannets (Morus bassanus) as biological samplers of regurgitated fish in the Gulf of St. Lawrence. We assessed fish total Hg (THg) concentrations in relation to their geographical catch location as well as to pertinent biotic and anthropogenic factors. In small fish species, trophic position, calculated from compound-specific stable nitrogen isotopes in amino acids, emerged as the most influential predictor of THg concentrations. For large fish species, THg concentrations were best explained by δ13C, indicating higher concentrations in inshore habitats. No anthropogenic factors, such as pollution, shipping traffic, or coastal development, were significantly related to THg concentrations in fish. Moreover, previously published THg data in mussels sampled nearby were positively linked with THg concentrations in gannet prey, suggesting consistent mercury distribution across trophic levels in the Gulf of St. Lawrence. Our findings point to habitat-dependent variability in THg concentrations across multiple trophic levels. Our study could have many potential uses in the future, including the identification of vulnerability hotspots for fish populations and their predators, or assessing risk factors for seabirds themselves by using biologically relevant prey.
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Affiliation(s)
- R M Lacombe
- Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Rd, Sainte-Anne-de-Bellevue, Quebec H9X 3V9, Canada.
| | - P Martigny
- Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, 300 allée des Ursulines, Rimouski, Québec G5L 3A1, Canada.
| | - D Pelletier
- Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, 300 allée des Ursulines, Rimouski, Québec G5L 3A1, Canada; Département de Biologie, Cégep de Rimouski, 60 rue de l'Évêché O, Rimouski, Québec G5L 4H6, Canada.
| | - B D Barst
- Water and Environmental Research Center, University of Alaska Fairbanks, 1764 Tanana Loop, Fairbanks, AK 99775-5910, USA.
| | - M Guillemette
- Département de Biologie, Chimie et Géographie, Université du Québec à Rimouski, 300 allée des Ursulines, Rimouski, Québec G5L 3A1, Canada.
| | - M Amyot
- Department of Biological Sciences, University of Montreal, 1375 Avenue Thérèse-Lavoie-Roux, Montréal, Québec H2V 0B3, Canada.
| | - K H Elliott
- Department of Natural Resource Sciences, McGill University, 21111 Lakeshore Rd, Sainte-Anne-de-Bellevue, Quebec H9X 3V9, Canada.
| | - R A Lavoie
- Science and Technology Branch, Environment and Climate Change Canada, 1550 Av. D'Estimauville, Québec G1J 0C3, Canada.
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2
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Atkins K, Bearhop S, Bodey TW, Grecian WJ, Hamer K, Pereira JM, Meinertzhagen H, Mitchell C, Morgan G, Morgan L, Newton J, Sherley RB, Votier SC. Geolocator-tracking seabird migration and moult reveal large-scale, temperature-driven isoscapes in the NE Atlantic. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2023; 37:e9489. [PMID: 36775809 DOI: 10.1002/rcm.9489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 01/27/2023] [Accepted: 02/02/2023] [Indexed: 06/18/2023]
Abstract
RATIONALE By combining precision satellite-tracking with blood sampling, seabirds can be used to validate marine carbon and nitrogen isoscapes, but it is unclear whether a comparable approach using low-precision light-level geolocators (GLS) and feather sampling can be similarly effective. METHODS Here we used GLS to identify wintering areas of northern gannets (Morus bassanus) and sampled winter grown feathers (confirmed from image analysis of non-breeding birds) to test for spatial gradients in δ13 C and δ15 N in the NE Atlantic. RESULTS By matching winter-grown feathers with the non-breeding location of tracked birds we found latitudinal gradients in δ13 C and δ15 N in neritic waters. Moreover, isotopic patterns were best explained by sea surface temperature. Similar isotope gradients were found in fish muscle sampled at local ports. CONCLUSIONS Our study reveals the potential of using seabird GLS and feathers to reconstruct large-scale isotopic patterns.
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Affiliation(s)
- Kelly Atkins
- Centre for Ecology and Conservation, University of Exeter, Cornwall, UK
| | - Stuart Bearhop
- Centre for Ecology and Conservation, University of Exeter, Cornwall, UK
| | - Thomas W Bodey
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | | | - Keith Hamer
- School of Biology, University of Leeds, Leeds, UK
| | - Jorge M Pereira
- MARE - Marine and Environmental Sciences Centre/ARNET - Aquatic Research Network, Department of Life Sciences, University of Coimbra, Coimbra, Portugal
| | | | - Chris Mitchell
- Centre for Ecology and Conservation, University of Exeter, Cornwall, UK
| | | | | | - Jason Newton
- Natural Environment Research Council Life Sciences Mass Spectrometry Facility, Scottish Universities Environmental Research Centre, East Kilbride, UK
| | - Richard B Sherley
- Centre for Ecology and Conservation, University of Exeter, Cornwall, UK
| | - Stephen C Votier
- Lyell Centre, Institute for Life and Earth Sciences, Heriot-Watt University, Edinburgh, UK
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3
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Derville S, Torres LG, Newsome SD, Somes CJ, Valenzuela LO, Vander Zanden HB, Baker CS, Bérubé M, Busquets-Vass G, Carlyon K, Childerhouse SJ, Constantine R, Dunshea G, Flores PAC, Goldsworthy SD, Graham B, Groch K, Gröcke DR, Harcourt R, Hindell MA, Hulva P, Jackson JA, Kennedy AS, Lundquist D, Mackay AI, Neveceralova P, Oliveira L, Ott PH, Palsbøll PJ, Patenaude NJ, Rowntree V, Sironi M, Vermeuelen E, Watson M, Zerbini AN, Carroll EL. Long-term stability in the circumpolar foraging range of a Southern Ocean predator between the eras of whaling and rapid climate change. Proc Natl Acad Sci U S A 2023; 120:e2214035120. [PMID: 36848574 PMCID: PMC10013836 DOI: 10.1073/pnas.2214035120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 12/19/2022] [Indexed: 03/01/2023] Open
Abstract
Assessing environmental changes in Southern Ocean ecosystems is difficult due to its remoteness and data sparsity. Monitoring marine predators that respond rapidly to environmental variation may enable us to track anthropogenic effects on ecosystems. Yet, many long-term datasets of marine predators are incomplete because they are spatially constrained and/or track ecosystems already modified by industrial fishing and whaling in the latter half of the 20th century. Here, we assess the contemporary offshore distribution of a wide-ranging marine predator, the southern right whale (SRW, Eubalaena australis), that forages on copepods and krill from ~30°S to the Antarctic ice edge (>60°S). We analyzed carbon and nitrogen isotope values of 1,002 skin samples from six genetically distinct SRW populations using a customized assignment approach that accounts for temporal and spatial variation in the Southern Ocean phytoplankton isoscape. Over the past three decades, SRWs increased their use of mid-latitude foraging grounds in the south Atlantic and southwest (SW) Indian oceans in the late austral summer and autumn and slightly increased their use of high-latitude (>60°S) foraging grounds in the SW Pacific, coincident with observed changes in prey distribution and abundance on a circumpolar scale. Comparing foraging assignments with whaling records since the 18th century showed remarkable stability in use of mid-latitude foraging areas. We attribute this consistency across four centuries to the physical stability of ocean fronts and resulting productivity in mid-latitude ecosystems of the Southern Ocean compared with polar regions that may be more influenced by recent climate change.
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Affiliation(s)
- Solène Derville
- Marine Mammal Institute, Oregon State University, Newport, OR97365
- Unité Mixte de Recherche (UMR) Entropie, French Institute of Research for Sustainable Development, Nouméa98848, New Caledonia
| | - Leigh G. Torres
- Marine Mammal Institute, Oregon State University, Newport, OR97365
| | - Seth D. Newsome
- Biology Department, University of New Mexico, Albuquerque, NM87131-0001
| | | | - Luciano O. Valenzuela
- Consejo Nacional de Investigaciones Científicas y Técnicas, Laboratorio de Ecología Evolutiva Humana, Facultad de Ciencias Sociales de la Universidad Nacional del Centro de la Provincia de Buenos Aires (FACSO-UNCPBA), 7631Buenos Aires, Argentina
- Instituto de Conservación de Ballenas, Ing. Maschwitz, 1623 Buenos Aires, Argentina
- School of Biological Sciences, University of Utah, Salt Lake City, UT84112-0840
| | | | - C. Scott Baker
- Marine Mammal Institute, Oregon State University, Newport, OR97365
- Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Corvallis, OR97365
| | - Martine Bérubé
- Marine Evolution and Conservation Group, Groningen Institute of Evolutionary Life Sciences, University of Groningen, 9747 AGGroningen, The Netherlands
- Centre for Coastal Studies, Provincetown, MA02657
| | - Geraldine Busquets-Vass
- Biology Department, University of New Mexico, Albuquerque, NM87131-0001
- Laboratorio de Macroecología Marina, Centro de Investigación Científica y Educación Superior de Ensenada, Unidad La Paz, 23050La Paz, BCS, México
| | - Kris Carlyon
- Department of Natural Resources and Environment Tasmania, Hobart7001, Australia
| | | | - Rochelle Constantine
- School of Biological Sciences, University of Auckland Waipapa Taumata Rau, Auckland1010, AotearoaNew Zealand
| | - Glenn Dunshea
- Ecological Marine Services Pty. Ltd., Bundaberg4670, QLD, Australia
- Department of Natural History, NTNU University Museum, Norwegian University of Science and Technology, 7491Trondheim, Norway
| | - Paulo A. C. Flores
- Núcleo de Gestão Integrada ICMBio Florianópolis, Instituto Chico Mendes de Conservação da Biodiversidade, Ministério do Meio Ambiente, Florianópolis88053-700, Brazil
| | - Simon D. Goldsworthy
- South Australian Research and Development Institute, Primary Industries and Regions South Australia, Adelaide, SA5064, Australia
- School of Earth and Environmental Sciences University of Adelaide, Adelaide, SA5064, Australia
| | - Brittany Graham
- Environmental Law Initiative, Wellington6011, AotearoaNew Zealand
| | - Karina Groch
- Instituto Australis, Imbituba, SC88780-000, Brazil
| | - Darren R. Gröcke
- Stable Isotope Biogeochemistry Laboratory, Department of Earth Sciences, Durham University, DurhamDH1 3LE, United Kingdom
| | - Robert Harcourt
- School of Natural Sciences, Macquarie University, Sydney, NSW2000, Australia
| | - Mark A. Hindell
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7005, Australia
| | - Pavel Hulva
- Department of Zoology, Faculty of Science, Charles University, Prague116 36, Czech Republic
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava701 03, Czech Republic
| | | | - Amy S. Kennedy
- Cooperative Institute for Climate, Ecosystem and Ocean Studies, University of Washington & Marine Mammal Laboratory, Alaska Fisheries Science Center, National Oceanic and Atmospheric Administration (NOAA), Seattle, WA98112
| | - David Lundquist
- New Zealand Department of Conservation - Te Papa Atawhai, Wellington6011, AotearoaNew Zealand
| | - Alice I. Mackay
- South Australian Research and Development Institute, Primary Industries and Regions South Australia, Adelaide, SA5064, Australia
| | - Petra Neveceralova
- Department of Zoology, Faculty of Science, Charles University, Prague116 36, Czech Republic
- Ivanhoe Sea Safaris, Gansbaai7220, South Africa
- Dyer Island Conservation Trust, Great White House, Kleinbaai, Van Dyks Bay7220, South Africa
| | - Larissa Oliveira
- Grupo de Estudos de Mamíferos Aquáticos do Rio Grande do Sul, Torres, RS95560-000, Brazil
- Laboratório de Ecologia de Mamίferos, Universidade do Vale do Rio dos Sinos, Sao Leopoldo, RS93022-750, Brazil
| | - Paulo H. Ott
- Grupo de Estudos de Mamíferos Aquáticos do Rio Grande do Sul, Torres, RS95560-000, Brazil
- Universidade Estadual do Rio Grande do Sul, Osório, RS95520-000, Brazil
| | - Per J. Palsbøll
- Marine Evolution and Conservation Group, Groningen Institute of Evolutionary Life Sciences, University of Groningen, 9747 AGGroningen, The Netherlands
- Centre for Coastal Studies, Provincetown, MA02657
| | | | - Victoria Rowntree
- Instituto de Conservación de Ballenas, Ing. Maschwitz, 1623 Buenos Aires, Argentina
- School of Biological Sciences, University of Utah, Salt Lake City, UT84112-0840
- Ocean Alliance, Gloucester, MA01930
| | - Mariano Sironi
- Instituto de Conservación de Ballenas, Ing. Maschwitz, 1623 Buenos Aires, Argentina
- Diversidad Biológica IV, Universidad Nacional de Córdoba, CórdobaX5000HUA, Argentina
| | - Els Vermeuelen
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria0002, South Africa
| | - Mandy Watson
- Department of Environment, Land, Water and Planning, Warrnambool, VIC3280, Australia
| | - Alexandre N. Zerbini
- Cooperative Institute for Climate, Ecosystem and Ocean Studies, University of Washington & Marine Mammal Laboratory, Alaska Fisheries Science Center, National Oceanic and Atmospheric Administration (NOAA), Seattle, WA98112
- Marine Ecology and Telemetry Research & Cascadia Research Collective, Seabeck, WA98380
| | - Emma L. Carroll
- School of Biological Sciences, University of Auckland Waipapa Taumata Rau, Auckland1010, AotearoaNew Zealand
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Duckworth J, O'Brien S, Petersen IK, Petersen A, Benediktsson G, Johnson L, Lehikoinen P, Okill D, Väisänen R, Williams J, Williams S, Daunt F, Green JA. Winter locations of red-throated divers from geolocation and feather isotope signatures. Ecol Evol 2022; 12:e9209. [PMID: 36035269 PMCID: PMC9399444 DOI: 10.1002/ece3.9209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 07/18/2022] [Accepted: 07/26/2022] [Indexed: 12/03/2022] Open
Abstract
Migratory species have geographically separate distributions during their annual cycle, and these areas can vary between populations and individuals. This can lead to differential stress levels being experienced across a species range. Gathering information on the areas used during the annual cycle of red‐throated divers (RTDs; Gavia stellata) has become an increasingly pressing issue, as they are a species of concern when considering the effects of disturbance from offshore wind farms and the associated ship traffic. Here, we use light‐based geolocator tags, deployed during the summer breeding season, to determine the non‐breeding winter location of RTDs from breeding locations in Scotland, Finland, and Iceland. We also use δ15N and δ13C isotope signatures, from feather samples, to link population‐level differences in areas used in the molt period to population‐level differences in isotope signatures. We found from geolocator data that RTDs from the three different breeding locations did not overlap in their winter distributions. Differences in isotope signatures suggested this spatial separation was also evident in the molting period, when geolocation data were unavailable. We also found that of the three populations, RTDs breeding in Iceland moved the shortest distance from their breeding grounds to their wintering grounds. In contrast, RTDs breeding in Finland moved the furthest, with a westward migration from the Baltic into the southern North Sea. Overall, these results suggest that RTDs breeding in Finland are likely to encounter anthropogenic activity during the winter period, where they currently overlap with areas of future planned developments. Icelandic and Scottish birds are less likely to be affected, due to less ship activity and few or no offshore wind farms in their wintering distributions. We also demonstrate that separating the three populations isotopically is possible and suggest further work to allocate breeding individuals to wintering areas based solely on feather samples.
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Affiliation(s)
| | | | - Ib K Petersen
- Department of Bioscience Aarhus University Aarhus Denmark
| | | | | | | | - Petteri Lehikoinen
- Finnish Museum of Natural History University of Helsinki Helsinki Finland.,Avescapes Oy Helsinki Finland
| | | | | | | | | | - Francis Daunt
- UK Centre for Ecology & Hydrology Penicuik Midlothian UK
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5
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Schoombie S, Connan M, Dilley BJ, Davies D, Makhado AB, Ryan PG. Non-breeding distribution, activity patterns and moulting areas of Sooty Albatrosses (Phoebetria fusca) inferred from geolocators, satellite trackers and biochemical markers. Polar Biol 2021. [DOI: 10.1007/s00300-021-02969-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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6
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Rodríguez MA. Measurement error models reveal the scale of consumer movements along an isoscape gradient. Methods Ecol Evol 2021. [DOI: 10.1111/2041-210x.13544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Marco A. Rodríguez
- Département des sciences de l'environnement and Centre de Recherche sur les Interactions Bassins Versants – Écosystèmes Aquatiques (RIVE) Université du Québec à Trois‐Rivières Trois‐Rivières QC Canada
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7
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Carravieri A, Warner NA, Herzke D, Brault-Favrou M, Tarroux A, Fort J, Bustamante P, Descamps S. Trophic and fitness correlates of mercury and organochlorine compound residues in egg-laying Antarctic petrels. ENVIRONMENTAL RESEARCH 2021; 193:110518. [PMID: 33245882 DOI: 10.1016/j.envres.2020.110518] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 06/11/2023]
Abstract
Understanding the drivers and effects of exposure to contaminants such as mercury (Hg) and organochlorine compounds (OCs) in Antarctic wildlife is still limited. Yet, Hg and OCs have known physiological and fitness effects in animals, with consequences on their populations. Here we measured total Hg (a proxy of methyl-Hg) in blood cells and feathers, and 12 OCs (seven polychlorinated biphenyls, PCBs, and five organochlorine pesticides, OCPs) in plasma of 30 breeding female Antarctic petrels Thalassoica antarctica from one of the largest colonies in Antarctica (Svarthamaren, Dronning Maud Land). This colony is declining and there is poor documentation on the potential role played by contaminants on individual physiology and fitness. Carbon (δ13C) and nitrogen (δ15N) stable isotope values measured in the females' blood cells and feathers served as proxies of their feeding ecology during the pre-laying (austral spring) and moulting (winter) periods, respectively. We document feather Hg concentrations (mean ± SD, 2.41 ± 0.83 μg g-1 dry weight, dw) for the first time in this species. Blood cell Hg concentrations (1.38 ± 0.43 μg g-1 dw) were almost twice as high as those reported in a recent study, and increased with pre-laying trophic position (blood cell δ15N). Moulting trophic ecology did not predict blood Hg concentrations. PCB concentrations were very low (Σ7PCBs, 0.35 ± 0.31 ng g-1 wet weight, ww). Among OCPs, HCB (1.02 ± 0.36 ng g-1 ww) and p, p'-DDE (1.02 ± 1.49 ng g-1 ww) residues were comparable to those of ecologically-similar polar seabirds, while Mirex residues (0.72 ± 0.35 ng g-1 ww) were higher. PCB and OCP concentrations showed no clear relationship with pre-laying or moulting feeding ecology, indicating that other factors overcome dietary drivers. OC residues were inversely related to body condition, suggesting stronger release of OCs into the circulation of egg-laying females upon depletion of their lipid reserves. Egg volume, hatching success, chick body condition and survival were not related to maternal Hg or OC concentrations. Legacy contaminant exposure does not seem to represent a threat for the breeding fraction of this population over the short term. Yet, exposure to contaminants, especially Mirex, and other concurring environmental stressors should be monitored over the long-term in this declining population.
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Affiliation(s)
- Alice Carravieri
- Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS- La Rochelle Université, 2 Rue Olympe de Gouges, La Rochelle, 17000, France.
| | - Nicholas A Warner
- NILU-Norwegian Institute for Air Research, Fram Centre, Tromsø, NO-9296, Norway; UiT-The Arctic University of Norway, Department of Arctic and Marine Biology, Hansine Hansens veg 18, Tromsø, 9037, Norway
| | - Dorte Herzke
- NILU-Norwegian Institute for Air Research, Fram Centre, Tromsø, NO-9296, Norway; UiT-The Arctic University of Norway, Department of Arctic and Marine Biology, Hansine Hansens veg 18, Tromsø, 9037, Norway
| | - Maud Brault-Favrou
- Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS- La Rochelle Université, 2 Rue Olympe de Gouges, La Rochelle, 17000, France
| | - Arnaud Tarroux
- NINA-Norwegian Institute for Nature Research, Fram Centre, Tromsø, NO-9296, Norway
| | - Jérôme Fort
- Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS- La Rochelle Université, 2 Rue Olympe de Gouges, La Rochelle, 17000, France
| | - Paco Bustamante
- Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS- La Rochelle Université, 2 Rue Olympe de Gouges, La Rochelle, 17000, France; Institut Universitaire de France (IUF), 1 Rue Descartes, Paris, 75005, France
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Reisinger RR, Carpenter-Kling T, Connan M, Cherel Y, Pistorius PA. Foraging behaviour and habitat-use drives niche segregation in sibling seabird species. ROYAL SOCIETY OPEN SCIENCE 2020; 7:200649. [PMID: 33047027 PMCID: PMC7540780 DOI: 10.1098/rsos.200649] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 08/17/2020] [Indexed: 06/11/2023]
Abstract
To mediate competition, similar sympatric species are assumed to use different resources, or the same but geographically separated resources. The two giant petrels (Macronectes spp.) are intriguing in that they are morphologically similar seabirds with overlapping diets and distributions. To better understand the mechanisms allowing their coexistence, we investigated intra- and interspecific niche segregation at Marion Island (Southern Indian Ocean), one of the few localities where they breed in sympatry. We used GPS tracks from 94 individuals and remote-sensed environmental data to quantify habitat use, combined with blood carbon and nitrogen stable isotope ratios from 90 individuals to characterize their foraging habitat and trophic ecology. Females of both species made distant at-sea foraging trips and fed at a similar trophic level. However, they used distinct pelagic habitats. By contrast, males of both species mainly foraged on or near land, resulting in significant sexual segregation, but high interspecific habitat and diet overlap. However, some males showed flexible behavioural strategies, also making distant, pelagic foraging trips. Using contemporaneous tracking, environmental and stable isotope data we provide a clear example of how sympatric sibling species can be segregated along different foraging behaviour dimensions.
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Affiliation(s)
- Ryan R. Reisinger
- Marine Apex Predator Research Unit, Institute for Coastal and Marine Research and Department of Zoology, Nelson Mandela University, South Campus, Port Elizabeth 6031, South Africa
- Centre d'Etudes Biologiques de Chizé, UMR 7372 du CNRS-La Rochelle Université, 79360 Villiers-en-Bois, France
- Institute for Marine Sciences, University of California Santa Cruz, Santa Cruz, CA 95060, USA
| | - Tegan Carpenter-Kling
- Marine Apex Predator Research Unit, Institute for Coastal and Marine Research and Department of Zoology, Nelson Mandela University, South Campus, Port Elizabeth 6031, South Africa
- DST/NRF Centre of Excellence at the FitzPatrick Institute of African Ornithology, Department of Zoology, Nelson Mandela University, Port Elizabeth, South Africa
| | - Maëlle Connan
- Marine Apex Predator Research Unit, Institute for Coastal and Marine Research and Department of Zoology, Nelson Mandela University, South Campus, Port Elizabeth 6031, South Africa
| | - Yves Cherel
- Centre d'Etudes Biologiques de Chizé, UMR 7372 du CNRS-La Rochelle Université, 79360 Villiers-en-Bois, France
| | - Pierre A. Pistorius
- Marine Apex Predator Research Unit, Institute for Coastal and Marine Research and Department of Zoology, Nelson Mandela University, South Campus, Port Elizabeth 6031, South Africa
- DST/NRF Centre of Excellence at the FitzPatrick Institute of African Ornithology, Department of Zoology, Nelson Mandela University, Port Elizabeth, South Africa
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