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Fernández Ajó A, Teixeira C, M D de Mello D, Dillon D, Rice JM, Buck CL, Hunt KE, Rogers MC, Torres LG. A longitudinal study of endocrinology and foraging ecology of subadult gray whales prior to death based on baleen analysis. Gen Comp Endocrinol 2024; 352:114492. [PMID: 38479678 DOI: 10.1016/j.ygcen.2024.114492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 03/04/2024] [Accepted: 03/06/2024] [Indexed: 03/18/2024]
Abstract
Individual-level assessments of wild animal health, vital rates, and foraging ecology are critical for understanding population-wide impacts of exposure to stressors. Large whales face multiple stressors, including, but not limited to, ocean noise, pollution, and ship strikes. Because baleen is a continuously growing keratinized structure, serial extraction, and quantification of hormones and stable isotopes along the length of baleen provide a historical record of whale physiology and foraging ecology. Furthermore, baleen analysis enables the investigation of dead specimens, even decades later, allowing comparisons between historic and modern populations. Here, we examined baleen of five sub-adult gray whales and observed distinct patterns of oscillations in δ15N values along the length of their baleen plates which enabled estimation of baleen growth rates and differentiation of isotopic niche widths of the whales during wintering and summer foraging. In contrast, no regular patterns were apparent in δ13C values. Prolonged elevation of cortisol in four individuals before death indicates that chronic stress may have impacted their health and survival. Triiodothyronine (T3) increased over months in the whales with unknown causes of death, simultaneous with elevations in cortisol, but both hormones remained stable in the one case of acute death attributed to killer whale predation. This parallel elevation of cortisol and T3 challenges the classic understanding of their interaction and might relate to increased energetic demands during exposure to stressors. Reproductive hormone profiles in subadults did not show cyclical trends, suggesting they had not yet reached sexual maturity. This study highlights the potential of baleen analysis to retrospectively assess gray whales' physiological status, exposure to stressors, reproductive status, and foraging ecology in the months or years leading up to their death, which can be a useful tool for conservation diagnostics to mitigate unusual mortality events.
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Affiliation(s)
- Alejandro Fernández Ajó
- Geospatial Ecology of Marine Megafauna Lab, Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Newport 97365, OR, USA.
| | - Clarissa Teixeira
- Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Newport 97365, OR, USA
| | - Daniela M D de Mello
- Department of Physiology, Institute of Bioscience, University of São Paulo, São Paulo 05508090, SP, Brazil
| | - Danielle Dillon
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA
| | - James M Rice
- Oregon Marine Mammal Stranding Network, Marine Mammal Institute, Oregon State University, Newport 97365, OR, USA
| | - C Loren Buck
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011, USA
| | - Kathleen E Hunt
- George Mason University & Smithsonian-Mason School of Conservation, 1500 Remount Rd, Front Royal, VA 22630, USA
| | - Matthew C Rogers
- NOAA, National Marine Fisheries Service, Alaska Fisheries Science Center Auke Bay Laboratories, Juneau, AK 99801, USA
| | - Leigh G Torres
- Geospatial Ecology of Marine Megafauna Lab, Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Newport 97365, OR, USA
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2
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Konishi K, Minamikawa S, Kleivane L, Takahashi M. Annual phenology and migration routes to breeding grounds in western-central North Pacific sei whales. Sci Rep 2024; 14:11212. [PMID: 38755300 PMCID: PMC11098811 DOI: 10.1038/s41598-024-61831-8] [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: 01/05/2024] [Accepted: 05/10/2024] [Indexed: 05/18/2024] Open
Abstract
The sei whale (Balaenoptera borealis) is an important species among baleen whales in the North Pacific and plays a significant role in the ecosystem. Despite the importance of this species, information regarding its migration patterns and breeding locations remains limited. To enhance the understanding of the phenology of North Pacific sei whales, we deployed satellite-monitored tags on these whales in the western and central North Pacific from 2017 to 2023. We fitted 55 sei whale tracks to a state-space model to describe the whales' seasonal movements at feeding grounds and their migratory behavior. The whales typically leave their feeding grounds between November and December, with migration pathways extending from off Japan to the west of the Hawaiian Islands. These southward transits converge in the waters of the Marshall Islands and north of Micronesia between 20° N and 7° N, which appear to be breeding grounds. After a brief stay at these breeding grounds, the whales migrate northward from January to February, reaching their feeding grounds around 30°N by March. To the best of our knowledge, this is the first study to present the phenology of feeding and breeding seasons and the migration pattern of North Pacific sei whales.
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Affiliation(s)
- Kenji Konishi
- The Institute of Cetacean Research, 4-5, Toyomi-cho, Chuo-ku, Tokyo, 104-0055, Japan.
| | - Shingo Minamikawa
- Fisheries Resources Institute, Japan Fisheries Research and Education Agency, 2-12-4, Fukuura, Kanazawa-ku, Yokohama-shi, Kanagawa, 236-8648, Japan
| | - Lars Kleivane
- LKARTS-Norway, Skutvik Landhandel, 8290, Skutvik, Norway
| | - Megumi Takahashi
- The Institute of Cetacean Research, 4-5, Toyomi-cho, Chuo-ku, Tokyo, 104-0055, Japan
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3
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García-Vernet R, Rita D, Bérubé M, Elgueta-Serra J, Pascual Guasch M, Víkingsson G, Ruiz-Sagalés M, Borrell A, Aguilar A. Order within chaos: potential migratory strategies and individual associations in fin whales feeding off Iceland. MOVEMENT ECOLOGY 2024; 12:36. [PMID: 38725038 PMCID: PMC11080271 DOI: 10.1186/s40462-024-00474-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Accepted: 04/10/2024] [Indexed: 05/12/2024]
Abstract
BACKGROUND The life cycle of most baleen whales involves annual migrations from low-latitude breeding grounds to high latitude feeding grounds. In most species, these migrations are traditionally considered to be carried out according to information acquired through vertical social learning during the first months of life and made individually. However, some recent studies have suggested a more complex scenario, particularly for the species of the Balaenoptera genus. METHODS Here, we studied the variation of δ15N and δ13C values along the growth axis of the baleen plate from 24 fin whales feeding off western Iceland to delve into their pattern of movements and to identify potential associations between individuals. The segment of baleen plate analyzed informed about at least two complete migratory cycles. We performed cluster analyses through two different methodologies and, whenever possible, we genotyped 20 microsatellite loci to determine potential existence of kinship. RESULTS Results of the of δ15N and δ13C values agree with a dispersion strategy in the winter breeding grounds. However, and despite the overall large variability, several pairs or groups of individuals with no kinship showed highly similar isotopic patterns for two consecutive years for both δ15N and δ13C values. CONCLUSIONS Our results suggest that, notably, some whales without kinship share the same migratory regime and destinations. We hypothesize that this could reflect either: (i) the sharing of particularly beneficial migratory regimes, and/or (ii) long-term association between individuals.
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Affiliation(s)
- Raquel García-Vernet
- Department of Evolutionary Biology, Ecology and Environmental Sciences, and IRBio, Faculty of Biology, University of Barcelona, Barcelona, 08028, Spain
| | - Diego Rita
- Department of Evolutionary Biology, Ecology and Environmental Sciences, and IRBio, Faculty of Biology, University of Barcelona, Barcelona, 08028, Spain
| | - Martine Bérubé
- Marine Evolution and Conservation, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, Groningen, 9747 AG, The Netherlands
- Center for Coastal Studies, 5 Holway Avenue, Provincetown, MA, 02657, USA
| | - Julia Elgueta-Serra
- Department of Evolutionary Biology, Ecology and Environmental Sciences, and IRBio, Faculty of Biology, University of Barcelona, Barcelona, 08028, Spain
| | - Marina Pascual Guasch
- Department of Evolutionary Biology, Ecology and Environmental Sciences, and IRBio, Faculty of Biology, University of Barcelona, Barcelona, 08028, Spain
| | - Gísli Víkingsson
- Marine and Freshwater Research Institute, PO Box 1390, Fornubúðum 5, 220, Hafnarfjörður, Iceland
| | - Marc Ruiz-Sagalés
- Department of Evolutionary Biology, Ecology and Environmental Sciences, and IRBio, Faculty of Biology, University of Barcelona, Barcelona, 08028, Spain
| | - Asunción Borrell
- Department of Evolutionary Biology, Ecology and Environmental Sciences, and IRBio, Faculty of Biology, University of Barcelona, Barcelona, 08028, Spain
| | - Alex Aguilar
- Department of Evolutionary Biology, Ecology and Environmental Sciences, and IRBio, Faculty of Biology, University of Barcelona, Barcelona, 08028, Spain.
- Reial Acadèmia de Ciències i Arts de Barcelona (RACAB), La Rambla 115, Barcelona, 08001, Spain.
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4
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Andrade D, García-Cegarra AM, Docmac F, Ñacari LA, Harrod C. Multiple stable isotopes (C, N & S) provide evidence for fin whale (Balaenoptera physalus) trophic ecology and movements in the Humboldt Current System of northern Chile. MARINE ENVIRONMENTAL RESEARCH 2023; 192:106178. [PMID: 37776807 DOI: 10.1016/j.marenvres.2023.106178] [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: 03/15/2023] [Revised: 09/04/2023] [Accepted: 09/11/2023] [Indexed: 10/02/2023]
Abstract
Reflecting the intense coastal upwelling and high primary productivity characteristic of the Humboldt Current System (HCS), the northern coast of Chile supports a diverse and productive community of marine consumers, including worldwide important pelagic fisheries resources. Although marine mammals are relatively understudied in the region, recent studies have demonstrated that fin whale (Balaenoptera physalus) is the most frequently encountered whale species, and forages in these waters year-round. However, a current lack of information limits our understanding of whether fin whales actively feed and/or remain resident in these waters or whether whales are observed feeding as they migrate along this part of the Pacific. Here, we use stable isotope ratios of carbon, nitrogen and sulphur of fin whale skin samples collected in early summer 2020 (n = 18) and in late winter 2021 (n = 22) to examine evidence of temporal isotopic shifts that could provide information on potential migratory movements and to estimate likely consumption patterns of putative prey (i.e. zooplankton, krill, pelagic fishes and Pleuroncodes sp.). We also analysed prey items in fin whale faecal plumes (n = 8) collected during the study period. Stable isotope data showed significant differences in the isotopic values of fin whales from summer and winter. On average, summer individuals were depleted in 15N and 34S relative to those sampled during winter. Whales sampled in summer showed greater isotopic variance than winter individuals, with several showing values that were atypical for consumers from the HCS. During winter, fin whales showed far less inter-individual variation in stable isotope values, and all individuals had values indicative of prey consumption in the region. Analysis of both stable isotopes and faeces indicated that fin whales sighted off the Mejillones Peninsula fed primarily on krill (SIA median contribution = 32%; IRI = 65%) and, to a lesser extent, zooplankton (SIA zooplankton = 29%; IRI copepod = 33%). These are the first isotopic-based data regarding the trophic ecology of fin whales in the north of Chile. They provide evidence that fin whales are seasonally resident in the area, including individuals with values that likely originated outside the study area. The information presented here serves as a baseline for future work. It highlights that many aspects of the ecology of fin whales in the Humboldt Current and wider SE Pacific still need to be clarified.
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Affiliation(s)
- Diego Andrade
- Programa de Magíster en Ecología de Sistemas Acuáticos, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta Chile, Chile; Instituto de Ciencias Naturales Alexander von Humboldt, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Chile
| | - Ana M García-Cegarra
- Instituto de Ciencias Naturales Alexander von Humboldt, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Chile; Laboratorio de Estudio de Megafauna Marina, CETALAB, Universidad de Antofagasta, Chile.
| | - Felipe Docmac
- Instituto de Ciencias Naturales Alexander von Humboldt, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Chile; Universidad de Antofagasta Stable Isotope Facility, Instituto Antofagasta, Universidad de Antofagasta, Chile; INVASAL, Concepción, Chile
| | - Luis A Ñacari
- Universidad de Antofagasta Stable Isotope Facility, Instituto Antofagasta, Universidad de Antofagasta, Chile; INVASAL, Concepción, Chile; Laboratorio de Ecología y Evolución de Parásitos, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Chile
| | - Chris Harrod
- Instituto de Ciencias Naturales Alexander von Humboldt, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Chile; Universidad de Antofagasta Stable Isotope Facility, Instituto Antofagasta, Universidad de Antofagasta, Chile; INVASAL, Concepción, Chile
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5
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Lippold A, Harju M, Aars J, Blévin P, Bytingsvik J, Gabrielsen GW, Kovacs KM, Lyche JL, Lydersen C, Rikardsen AH, Routti H. Occurrence of emerging brominated flame retardants and organophosphate esters in marine wildlife from the Norwegian Arctic. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 315:120395. [PMID: 36228858 DOI: 10.1016/j.envpol.2022.120395] [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: 04/08/2022] [Revised: 10/03/2022] [Accepted: 10/05/2022] [Indexed: 06/16/2023]
Abstract
To understand the exposure and potential sources of emerging brominated flame retardants (EBFR) and organophosphate esters (OPEs) in marine wildlife from the Norwegian Arctic, we investigated concentrations of EBFRs in 157 tissue samples from nine species of marine vertebrates and OPEs in 34 samples from three whale species. The samples, collected from a wide range of species with contrasting areal use and diets, included blubber of blue whales, fin whales, humpback whales, white whales, killer whales, walruses and ringed seals and adipose tissue and plasma from polar bears, as well as adipose tissue from glaucous gulls. Tris(2-ethylhexyl) phosphate (TEHP) and tris(2-chloroisopropyl) phosphate (TCIPP) ranged from <0.61 to 164 and < 0.8-41 ng/g lipid weight, respectively, in blue whales and fin whales. All other EBRFs and OPEs were below the detection limit or detected only at low concentration. In addition to the baseline information on the occurrence of EBFRs and OPEs in marine wildlife from the Arctic, we provide an in-depth discussion regarding potential sources of the detected compounds. This information is important for future monitoring and management of EBFRs and OPEs.
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Affiliation(s)
- Anna Lippold
- Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway
| | - Mikael Harju
- Norwegian Institute for Air Research, Fram Centre, Tromsø 9296, Norway
| | - Jon Aars
- Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway
| | | | | | | | - Kit M Kovacs
- Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway
| | | | | | | | - Heli Routti
- Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway.
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6
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Riekenberg PM, Camalich J, Svensson E, IJsseldijk LL, Brasseur SMJM, Witbaard R, Leopold MF, Rebolledo EB, Middelburg JJ, van der Meer MTJ, Sinninghe Damsté JS, Schouten S. Reconstructing the diet, trophic level and migration pattern of mysticete whales based on baleen isotopic composition. ROYAL SOCIETY OPEN SCIENCE 2021; 8:210949. [PMID: 34909214 PMCID: PMC8652277 DOI: 10.1098/rsos.210949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 10/28/2021] [Indexed: 06/14/2023]
Abstract
Baleen from mysticete whales is a well-preserved proteinaceous material that can be used to identify migrations and feeding habits for species whose migration pathways are unknown. Analysis of δ13C and δ15N values from bulk baleen have been used to infer migration patterns for individuals. However, this approach has fallen short of identifying migrations between regions as it is difficult to determine variations in isotopic shifts without temporal sampling of prey items. Here, we apply analysis of δ15N values of amino acids to five baleen plates belonging to three species, revealing novel insights on trophic position, metabolic state and migration between regions. Humpback and minke whales had higher reconstructed trophic levels than fin whales (3.7-3.8 versus 3-3.2, respectively) as expected due to different feeding specialization. Isotopic niche areas between baleen minima and maxima were well separated, indicating regional resource use for individuals during migration that aligned with isotopic gradients in Atlantic Ocean particulate organic matter. Phenylanine δ15N values confirmed regional separation between the niche areas for two fin whales as migrations occurred and elevated glycine and threonine δ15N values suggested physiological changes due to fasting. Simultaneous resolution of trophic level and physiological changes allow for identification of regional migrations in mysticetes.
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Affiliation(s)
- Philip M. Riekenberg
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, Den Hoorn 1790AB, The Netherlands
| | - Jaime Camalich
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, Den Hoorn 1790AB, The Netherlands
| | - Elisabeth Svensson
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, Den Hoorn 1790AB, The Netherlands
| | - Lonneke L. IJsseldijk
- Division of Pathology, Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3854 CL Utrecht, The Netherlands
| | - Sophie M. J. M. Brasseur
- Wageningen Marine Research, Wageningen University and Research, PO Box 57, 1780 AB Den Helder, The Netherlands
| | - Rob Witbaard
- Department of Estuarine and Delta Systems, NIOZ Royal Netherlands Institute for Sea Research, and Utrecht University, PO Box 140, 4400 AC Yerseke, The Netherlands
| | - Mardik F. Leopold
- Wageningen Marine Research, Wageningen University and Research, PO Box 57, 1780 AB Den Helder, The Netherlands
| | - Elisa Bravo Rebolledo
- Wageningen Marine Research, Wageningen University and Research, PO Box 57, 1780 AB Den Helder, The Netherlands
| | - Jack J. Middelburg
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Princetonlaan 8a, 3584 CB Utrecht, The Netherlands
| | - Marcel T. J. van der Meer
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, Den Hoorn 1790AB, The Netherlands
| | - Jaap S. Sinninghe Damsté
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, Den Hoorn 1790AB, The Netherlands
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Princetonlaan 8a, 3584 CB Utrecht, The Netherlands
| | - Stefan Schouten
- Department of Marine Microbiology and Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, Den Hoorn 1790AB, The Netherlands
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Princetonlaan 8a, 3584 CB Utrecht, The Netherlands
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7
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Eerkes‐Medrano D, Aldridge DC, Blix AS. North Atlantic minke whale ( Balaenoptera acutorostrata) feeding habits and migrations evaluated by stable isotope analysis of baleen. Ecol Evol 2021; 11:16344-16353. [PMID: 34824831 PMCID: PMC8601907 DOI: 10.1002/ece3.8224] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 07/06/2021] [Accepted: 07/09/2021] [Indexed: 11/16/2022] Open
Abstract
Isotopic analyses of the incrementally growing baleen in Mysticeti have been used to learn about their feeding and movement patterns. Using methods previously applied to Pacific minke whales, stable δ15N and δ13C isotope values were measured along the baleen plates of male and female minke whales from two locations in the Northeast Atlantic. The sample sizes used in this study are comparable to those previously used in the literature, and, although limited in size, the evidence suggests differences in isotopic signatures between whales caught at different locations. Both the δ15N and δ13C data suggest whales at the higher latitude site of Svalbard have a narrower diet than the whales from Lofoten/Vesterålen in Norway. Across all whales, the δ15N data indicate the whales primarily prey on fish for much of the year, only switching to zooplankton during the spring bloom. The δ13C data fail to confirm whether the whales migrate over long distances.
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Affiliation(s)
- Dafne Eerkes‐Medrano
- Aquatic Ecology Group, Department of ZoologyUniversity of CambridgeCambridgeUK
- Present address:
Marine LaboratoryMarine Scotland ScienceAberdeenUK
| | - David C. Aldridge
- Aquatic Ecology Group, Department of ZoologyUniversity of CambridgeCambridgeUK
- St. Catharine's CollegeCambridgeUK
| | - Arnoldus S. Blix
- St. Catharine's CollegeCambridgeUK
- Department of Arctic and Marine BiologyUiT‐The Arctic University of NorwayTromsøNorway
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8
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Troina GC, Riekenberg P, van der Meer MTJ, Botta S, Dehairs F, Secchi ER. Combining isotopic analysis of bulk-skin and individual amino acids to investigate the trophic position and foraging areas of multiple cetacean species in the western South Atlantic. ENVIRONMENTAL RESEARCH 2021; 201:111610. [PMID: 34224712 DOI: 10.1016/j.envres.2021.111610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 06/21/2021] [Accepted: 06/24/2021] [Indexed: 06/13/2023]
Abstract
We investigated the trophic structure and habitat use of ten cetacean species occurring in the oceanic waters of the western South Atlantic using naturally-occurring stable isotopes. We analysed δ15N in individual amino acids (AA) to estimate cetacean trophic position (TP) and to evaluate the spatial differences in baseline δ15N (source AAs). We adjusted cetacean bulk-skin δ13C and δ15N for the effect of trophic level using their estimated TPs, obtaining δ13CAdjusted and δ15NAdjusted, respectively. These values were applied to estimate the overlap in the niche areas of cetacean baseline sources. Our analyses showed spatial segregation between Steno bredanensis and the remaining odontocetes, and the high δ15N in this species reflects its occurrence in neritic waters of the southern region. The highest TPs were observed in Physeter macrocephalus, Stenella attenuata and Globicephala melas, while the lowest TPs were reported for S. longirostris, S. clymene and Orcinus orca. Overall, source AA-δ15N showed similar patterns as those of baseline-δ15N (zooplankton) and were higher in species sampled in the southernmost region of the study area (e.g., Delphinus delphis). Isotopic niche areas estimated using δ13CAdjusted and δ15NAdjusted suggested high overlap in foraging area between S. frontalis and Tursiops truncatus, with the latter occupying a higher TP. Our analyses of δ15N in AAs provide a unique insight into the trophic ecology, forage areas and spatial segregation in resource use among these cetacean populations. Additionally, our work provides AA-δ15N baseline for future studies on the trophic ecology and habitat use of marine organisms in the western South Atlantic.
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Affiliation(s)
- Genyffer C Troina
- Laboratório de Ecologia e Conservação da Megafauna Marinha (ECOMEGA), Instituto de Oceanografia, Universidade Federal do Rio Grande - FURG, Avenida Itália km 8, Rio Grande, RS, Brazil.
| | - Philip Riekenberg
- Department of Marine Microbiology & Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, Den Hoorn, 1790AB, the Netherlands
| | - Marcel T J van der Meer
- Department of Marine Microbiology & Biogeochemistry, NIOZ Royal Netherlands Institute for Sea Research, PO Box 59, Den Hoorn, 1790AB, the Netherlands
| | - Silvina Botta
- Laboratório de Ecologia e Conservação da Megafauna Marinha (ECOMEGA), Instituto de Oceanografia, Universidade Federal do Rio Grande - FURG, Avenida Itália km 8, Rio Grande, RS, Brazil
| | - Frank Dehairs
- Analytical, Environmental and Geo-Chemistry Department (AMGC), Vrije Universiteit Brussel (VUB), Pleinlaan 2, B-1050, Brussels, Belgium
| | - Eduardo R Secchi
- Laboratório de Ecologia e Conservação da Megafauna Marinha (ECOMEGA), Instituto de Oceanografia, Universidade Federal do Rio Grande - FURG, Avenida Itália km 8, Rio Grande, RS, Brazil
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9
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Jory C, Lesage V, Leclerc A, Giard J, Iverson S, Bérubé M, Michaud R, Nozais C. Individual and population dietary specialization decline in fin whales during a period of ecosystem shift. Sci Rep 2021; 11:17181. [PMID: 34433851 PMCID: PMC8387503 DOI: 10.1038/s41598-021-96283-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 07/28/2021] [Indexed: 11/25/2022] Open
Abstract
This study sought to estimate the effect of an anthropogenic and climate-driven change in prey availability on the degree of individual and population specialization of a large marine predator, the fin whale (Balaenoptera physalus). We examined skin biopsies from 99 fin whales sampled in the St. Lawrence Estuary (Canada) over a nine year period (1998–2006) during which environmental change was documented. We analyzed stable isotope ratios in skin and fatty acid signatures in blubber samples of whales, as well as in seven potential prey species, and diet was quantitatively assessed using Bayesian isotopic models. An abrupt change in fin whale dietary niche coincided with a decrease in biomass of their predominant prey, Arctic krill (Thysanoessa spp.). This dietary niche widening toward generalist diets occurred in nearly 60% of sampled individuals. The fin whale population, typically composed of specialists of either krill or lipid-rich pelagic fishes, shifted toward one composed either of krill specialists or true generalists feeding on various zooplankton and fish prey. This change likely reduced intraspecific competition. In the context of the current “Atlantification” of northern water masses, our findings emphasize the importance of considering individual-specific foraging tactics and not only population or group average responses when assessing population resilience or when implementing conservation measures.
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Affiliation(s)
- Cabrol Jory
- Maurice Lamontagne Institute, Fisheries and Oceans Canada, Mont-Joli, QC, Canada.
| | - Véronique Lesage
- Maurice Lamontagne Institute, Fisheries and Oceans Canada, Mont-Joli, QC, Canada.,Département de Biologie, Chimie et Géographie, Québec-Océan, Université du Québec à Rimouski, Rimouski, QC, Canada
| | - Alexandra Leclerc
- Maurice Lamontagne Institute, Fisheries and Oceans Canada, Mont-Joli, QC, Canada.,Département de Biologie, Chimie et Géographie, Québec-Océan, Université du Québec à Rimouski, Rimouski, QC, Canada
| | - Janie Giard
- Groupe de Recherche et d'Éducation sur les Mammifères Marins, Tadoussac, QC, Canada
| | - Sara Iverson
- Department of Biology, Dalhousie University, Halifax, NS, Canada
| | - Martine Bérubé
- Marine Evolution and Conservation, Groningen Institute of Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands.,Centre for Coastal Studies, Provincetown, MA, USA
| | - Robert Michaud
- Groupe de Recherche et d'Éducation sur les Mammifères Marins, Tadoussac, QC, Canada
| | - Christian Nozais
- Département de Biologie, Chimie et Géographie, Québec-Océan, Université du Québec à Rimouski, Rimouski, QC, Canada
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10
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Romagosa M, Pérez-Jorge S, Cascão I, Mouriño H, Lehodey P, Pereira A, Marques TA, Matias L, Silva MA. Food talk: 40-Hz fin whale calls are associated with prey biomass. Proc Biol Sci 2021; 288:20211156. [PMID: 34229495 PMCID: PMC8261222 DOI: 10.1098/rspb.2021.1156] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 06/09/2021] [Indexed: 11/12/2022] Open
Abstract
Animals use varied acoustic signals that play critical roles in their lives. Understanding the function of these signals may inform about key life-history processes relevant for conservation. In the case of fin whales (Balaenoptera physalus), that produce different call types associated with different behaviours, several hypotheses have emerged regarding call function, but the topic still remains in its infancy. Here, we investigate the potential function of two fin whale vocalizations, the song-forming 20-Hz call and the 40-Hz call, by examining their production in relation to season, year and prey biomass. Our results showed that the production of 20-Hz calls was strongly influenced by season, with a clear peak during the breeding months, and secondarily by year, likely due to changes in whale abundance. These results support the reproductive function of the 20-Hz song used as an acoustic display. Conversely, season and year had no effect on variation in 40-Hz calling rates, but prey biomass did. This is the first study linking 40-Hz call activity to prey biomass, supporting the previously suggested food-associated function of this call. Understanding the functions of animal signals can help identifying functional habitats and predict the negative effects of human activities with important implications for conservation.
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Affiliation(s)
- Miriam Romagosa
- Okeanos – Instituto de Investigação em Ciências do Mar, Universidade dos Açores & IMAR – Instituto do Mar, Horta, Portugal
| | - Sergi Pérez-Jorge
- Okeanos – Instituto de Investigação em Ciências do Mar, Universidade dos Açores & IMAR – Instituto do Mar, Horta, Portugal
| | - Irma Cascão
- Okeanos – Instituto de Investigação em Ciências do Mar, Universidade dos Açores & IMAR – Instituto do Mar, Horta, Portugal
| | - Helena Mouriño
- Centro de Matemática, Aplicações Fundamentais e Investigação Operacional, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
| | - Patrick Lehodey
- Collecte Localisation Satellite (CLS), Ramonville St Agne, France
| | - Andreia Pereira
- Instituto Dom Luiz (IDL), Universidade de Lisboa, Lisboa, Portugal
| | - Tiago A. Marques
- Centro de Estatística e Aplicações, Departamento de Biologia, Faculdade de Ciências, Universidade de Lisboa, Lisboa, Portugal
- Centre for Research into Ecological and Environmental Modelling, University of St Andrews, St Andrews, UK
| | - Luís Matias
- Instituto Dom Luiz (IDL), Universidade de Lisboa, Lisboa, Portugal
| | - Mónica A. Silva
- Okeanos – Instituto de Investigação em Ciências do Mar, Universidade dos Açores & IMAR – Instituto do Mar, Horta, Portugal
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11
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Bortoluzzi J, Darby J, Jackson AL. Technological advances in stable isotope analysis provide ever more insights into animal ecology. J Anim Ecol 2021; 90:1394-1397. [PMID: 34085716 DOI: 10.1111/1365-2656.13510] [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: 02/25/2021] [Accepted: 04/16/2021] [Indexed: 11/29/2022]
Abstract
In Focus: Whiteman J. P., Newsome S. D., Bustamante P., Cherel Y., Hobson K. A. (2021). Quantifying capital versus income breeding: New promise with stable isotope measurements of individual amino acids. Journal of Animal Ecology, 90, 1408-1418. The use of bulk stable isotope analysis (SIA) has become a staple in the field of ecology since the 1980s. This approach has proven its utility, but comes with limitations rooted in assumptions and confounding factors. Compound-specific SIA (CS-SIA) has the potential to address questions out of reach of bulk SIA by providing information on physiological pathways as well as dietary sources of consumer isotopes. Whiteman et al. (2021) provide an excellent example of the power of CS-SIA using amino acid stable isotopes to quantify the extent of capital versus income breeding involved in emperor penguin egg production. By doing so, they reframe an important life-history trait as a spectrum, rather than a dichotomy. This showcases the use of CS-SIA as a tool for investigating the resource allocation strategies employed by this species, and the potential for this technique to untangle the life-history strategies of a broad range of species.
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Affiliation(s)
- Jenny Bortoluzzi
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, College Green, Ireland
| | - Jamie Darby
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork, Ireland.,MaREI Centre for Energy, Climate and Marine, Environmental Research Institute, University College Cork, Cork, Ireland
| | - Andrew L Jackson
- Department of Zoology, School of Natural Sciences, Trinity College Dublin, College Green, Ireland
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12
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Mansouri F, Winfield ZC, Crain DD, Morris B, Charapata P, Sabin R, Potter CW, Hering AS, Fulton J, Trumble SJ, Usenko S. Evidence of multi-decadal behavior and ecosystem-level changes revealed by reconstructed lifetime stable isotope profiles of baleen whale earplugs. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 757:143985. [PMID: 33321341 DOI: 10.1016/j.scitotenv.2020.143985] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 11/11/2020] [Accepted: 11/14/2020] [Indexed: 06/12/2023]
Abstract
Biological time series datasets provide an unparalleled opportunity to investigate regional and global changes in the marine environment. Baleen whales are long-lived sentinel species and an integral part of the marine ecosystem. Increasing anthropogenic terrestrial and marine activities alter ocean systems, and such alterations could change foraging and feeding behavior of baleen whales. In this study, we analyzed δ13C and δ15N of baleen whale earplugs from three different species (N = 6 earplugs, n = 337 laminae) to reconstruct the first continuous stable isotope profiles with a six-month resolution. Results of our study provide an unprecedented opportunity to assess behavioral as well as ecological changes. Abrupt shifts and temporal variability observed in δ13C and δ15N profiles could be indicative of behavior change such as shift in foraging location and/or trophic level in response to natural or anthropogenic disturbances. Additionally, five out of six individuals demonstrated long-term declining trends in δ13C profiles, which could suggest influence of emission of depleted 13CO2 from fossil fuel combustion referred to as the Suess effect. After adjusting the δ13C values of earplugs for the estimated Suess effect and re-evaluating δ13C profiles, significant decline in δ13C values as well as different rate of depletion suggest contribution of other sources that could impact δ13C values at the base of the food web.
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Affiliation(s)
- Farzaneh Mansouri
- Department of Environmental Science, Baylor University, Waco, TX 76706, USA
| | - Zach C Winfield
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX 76706, USA
| | | | - Brooke Morris
- Department of Biology, Baylor University, Waco, TX 76706, USA
| | | | - Richard Sabin
- Division of Vertebrates, Department of Life Sciences, Natural History Museum, London SW7 5BD, UK
| | - Charles W Potter
- Department of Vertebrate Zoology, Smithsonian Institution National Museum of Natural History, Washington, DC 20013, USA
| | - Amanda S Hering
- Department of Statistical Science, Baylor University, Waco, TX 76706, USA
| | - James Fulton
- Department of Geoscience, Baylor University, Waco, TX 76706, USA
| | | | - Sascha Usenko
- Department of Environmental Science, Baylor University, Waco, TX 76706, USA; Department of Chemistry and Biochemistry, Baylor University, Waco, TX 76706, USA; Department of Biology, Baylor University, Waco, TX 76706, USA.
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13
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van den Berg GL, Vermeulen E, Valenzuela LO, Bérubé M, Ganswindt A, Gröcke DR, Hall G, Hulva P, Neveceralova P, Palsbøll PJ, Carroll EL. Decadal shift in foraging strategy of a migratory southern ocean predator. GLOBAL CHANGE BIOLOGY 2020; 27:1052-1067. [PMID: 33319502 DOI: 10.1111/gcb.15465] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 11/17/2020] [Accepted: 11/18/2020] [Indexed: 06/12/2023]
Abstract
Rapid anthropogenic environmental change is expected to impact a host of ecological parameters in Southern Ocean ecosystems. Of critical concern are the consequences of these changes on the range of species that show fidelity to migratory destinations, as philopatry is hypothesized to help or hinder adaptation to climate change depending on the circumstances. Many baleen whales show philopatry to feeding grounds and are also capital breeders that meet migratory and reproductive costs through seasonal energy intake. Southern right whales (Eubalaena australis, SRWs) are capital breeders that have a strong relationship between reproductive output and foraging success. The population dynamics of South Africa's population of SRWs are characterized by two distinct periods: the 1990s, a period of high calving rates; and the late 2010s, a period associated with lowered calving rates. Here we use analyses of stable carbon (δ13 C) and nitrogen (δ15 N) isotope values from SRW biopsy samples (n = 122) collected during these two distinct periods to investigate foraging ecology of the South African population of SRWs over a time period coincident with the demographic shift. We show that South African SRWs underwent a dramatic northward shift, and diversification, in foraging strategy from 1990s to 2010s. Bayesian mixing model results suggest that during the 1990s, South African SRWs foraged on prey isotopically similar to South Georgia/Islas Georgias del Sur krill. In contrast, in the 2010s, South African SRWs foraged on prey isotopically consistent with the waters of the Subtropical Convergence, Polar Front and Marion Island. We hypothesize that this shift represents a response to changes in preferred habitat or prey, for example, the decrease in abundance and southward range contraction of Antarctic krill. By linking reproductive decline to changing foraging strategies for the first time in SRWs, we show that altering foraging strategies may not be sufficient to adapt to a changing ocean.
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Affiliation(s)
- Gideon L van den Berg
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, South Africa
| | - Els Vermeulen
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, South Africa
| | - Luciano O Valenzuela
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Laboratorio de Ecología Evolutiva Humana (LEEH, Facultad de Ciencias Sociales, Unidad de Enseñanza Universitaria Quequén, UNCPBA, Buenos Aires, Argentina
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
- Instituto de Conservación de Ballenas, Buenos Aires, Argentina
| | - Martine Bérubé
- Marine Evolution and Conservation Group, Groningen Institute of Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
- Centre for Coastal Studies, Provincetown, MA, USA
| | - Andre Ganswindt
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, South Africa
| | - Darren R Gröcke
- Stable Isotope Biogeochemistry Laboratory (SIBL), Department of Earth Sciences, Durham University, Durham, UK
| | - Grant Hall
- Department of Zoology and Entomology, Mammal Research Institute, University of Pretoria, Pretoria, South Africa
| | - Pavel Hulva
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Petra Neveceralova
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
- Ivanhoe Sea Safaris, Gansbaai, South Africa
- Dyer Island Conservation Trust, Great White House, Kleinbaai, South Africa
| | - Per J Palsbøll
- Marine Evolution and Conservation Group, Groningen Institute of Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
- Centre for Coastal Studies, Provincetown, MA, USA
| | - Emma L Carroll
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
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14
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Lydersen C, Vacquié-Garcia J, Heide-Jørgensen MP, Øien N, Guinet C, Kovacs KM. Autumn movements of fin whales (Balaenoptera physalus) from Svalbard, Norway, revealed by satellite tracking. Sci Rep 2020; 10:16966. [PMID: 33046805 PMCID: PMC7550606 DOI: 10.1038/s41598-020-73996-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 09/18/2020] [Indexed: 11/16/2022] Open
Abstract
Insight into animal movements is essential for understanding habitat use by individuals as well as population processes and species life-history strategies. In this study, we instrumented 25 fin whales with ARGOS satellite-transmitters in Svalbard, Norway, to study their movement patterns and behaviour (Area Restricted Search (ARS), transiting or unknown) during boreal autumn/early winter. Ten of the whales stayed in the tagging area (most northerly location: 81.68°N) for their entire tracking periods (max 45 days). The other 15 whales moved in a south-westerly direction; the longest track ended off the coast of northern Africa (> 5000 km from the tagging location) after 96 days. The whales engaged in ARS behaviour intermittently throughout their southward migrations. During transit phases the whales moved quickly; one individual maintained an average horizontal speed of 9.3 km/h (travelling 223 km per day) for a period of a week. This study documents that: (1) some fin whales might remain at high latitudes during winter; (2) the whales that do migrate probably feed along the way; (3) they can maintain high transiting speed for long periods and; (4) one breeding area for this species is likely located in deep, warm water some 100 km west of Morocco.
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Affiliation(s)
| | - Jade Vacquié-Garcia
- Norwegian Polar Institute, Fram Centre, 9296, Tromsö, Norway
- CNRS, UMR CNRS - La Rochelle University, 7372, Villiers-en-Bois, France
| | | | - Nils Øien
- Institute of Marine Research, Nordnes, P.O. Box 1870, 5817, Bergen, Norway
| | - Christophe Guinet
- CNRS, UMR CNRS - La Rochelle University, 7372, Villiers-en-Bois, France
| | - Kit M Kovacs
- Norwegian Polar Institute, Fram Centre, 9296, Tromsö, Norway
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15
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Tartu S, Fisk AT, Götsch A, Kovacs KM, Lydersen C, Routti H. First assessment of pollutant exposure in two balaenopterid whale populations sampled in the Svalbard Archipelago, Norway. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 718:137327. [PMID: 32097839 DOI: 10.1016/j.scitotenv.2020.137327] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 02/12/2020] [Accepted: 02/13/2020] [Indexed: 06/10/2023]
Abstract
Pollutant concentrations are poorly known for the largest animals on Earth, blue whales Balaenoptera musculus and fin whales Balaenoptera physalus. In this study, concentrations of persistent organic pollutants (POPs) were determined in blubber biopsies and stable isotope values for nitrogen (δ15N) and carbon (δ13C) were measured using skin biopsies for 18 blue whales and 12 fin whales sampled in waters surrounding the Svalbard Archipelago, Norway. The samples were collected in summer during the period 2014-2018. POPs were dominated by DDTs, PCBs and toxaphenes, with median concentrations in blue/fin whales being 208/341, 127/275 and 133/233 ng/g lipid weight, respectively. Linear models indicated that pollutant concentrations were 1.6-3 times higher in fin whales than in blue whales, which is likely related to the higher trophic positions of fin whales, as indicated by their higher δ15N. Lower δ13C in fin whales suggests that they feed at higher latitudes than blue whales; these values were not correlated with pollutant concentrations. Pollutant levels were approximately twice as high in males compared to females (intraspecifically), which indicates that females of these species offload pollutants to their offspring during gestation and lactation, similar to many other mammalian species. Pollutant concentrations in balaenopterid whales from Svalbard waters were generally much lower than in conspecific whales from the Mediterranean Sea or the Gulf of California, but higher than those in conspecifics from the Antarctic Peninsula.
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Affiliation(s)
- Sabrina Tartu
- Norwegian Polar Institute, Fram Centre, Tromsø N-9296, Norway
| | - Aaron T Fisk
- School of the Environment, University of Windsor, Windsor, Ontario N9B 3P4, Canada
| | - Arntraut Götsch
- Norwegian Institute for Air Research (NILU), Fram Centre, Tromsø N-9296, Norway
| | - Kit M Kovacs
- Norwegian Polar Institute, Fram Centre, Tromsø N-9296, Norway
| | | | - Heli Routti
- Norwegian Polar Institute, Fram Centre, Tromsø N-9296, Norway.
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16
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Baleen whale acoustic presence and behaviour at a Mid-Atlantic migratory habitat, the Azores Archipelago. Sci Rep 2020; 10:4766. [PMID: 32179826 PMCID: PMC7075977 DOI: 10.1038/s41598-020-61849-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 03/03/2020] [Indexed: 11/15/2022] Open
Abstract
The identification of important areas during the annual life cycle of migratory animals, such as baleen whales, is vital for their conservation. In boreal springtime, fin and blue whales feed in the Azores on their way to northern latitudes while sei whales migrate through the archipelago with only occasional feeding. Little is known about their autumn or winter presence or their acoustic behaviour in temperate migratory habitats. This study used a 5-year acoustic data set collected by autonomous recorders in the Azores that were processed and analysed using an automated call detection and classification system. Fin and blue whales were acoustically present in the archipelago from autumn to spring with marked seasonal differences in the use of different call types. Diel patterns of calling activity were only found for fin whales with more calls during the day than night. Sei whales showed a bimodal distribution of acoustic presence in spring and autumn, corresponding to their expected migration patterns. Diel differences in sei whale calling varied with season and location. This work highlights the importance of the Azores as a migratory and wintering habitat for three species of baleen whales and provides novel information on their acoustic behaviour in a mid-Atlantic region.
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17
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Gauffier P, Borrell A, Silva MA, Víkingsson GA, López A, Giménez J, Colaço A, Halldórsson SD, Vighi M, Prieto R, de Stephanis R, Aguilar A. Wait your turn, North Atlantic fin whales share a common feeding ground sequentially. MARINE ENVIRONMENTAL RESEARCH 2020; 155:104884. [PMID: 32072986 DOI: 10.1016/j.marenvres.2020.104884] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 01/10/2020] [Accepted: 01/19/2020] [Indexed: 06/10/2023]
Abstract
Highly migratory marine species pose a challenge for the identification of management units due to the absence of clear oceanographic barriers. The population structure of North Atlantic fin whales has been investigated since the start of whaling operations but is still the subject of an ongoing scientific debate. Here we measured stable isotopes of carbon, nitrogen and oxygen in skin samples collected from 151 individuals from western Iceland, Galicia (NW Spain), the Azores archipelago and the Strait of Gibraltar (SoG). We found spatiotemporal differences in stable isotope ratios suggesting that fin whales sampled in these four areas may share a common feeding ground within the Northeast Atlantic at different times during the year. Our results also suggest that SoG whales use this common feeding ground in summer but exploit Mediterranean resources during the winter months, further supporting the existence of a limited but current exchange of individuals between these two basins.
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Affiliation(s)
- Pauline Gauffier
- CIRCE, Cabeza de Manzaneda, 3, 11390, Pelayo, Algeciras, Spain; Department of Evolutionary Biology, Ecology and Environmental Sciences, IRBio, Faculty of Biology, University of Barcelona, 08028, Barcelona, Spain.
| | - Asunción Borrell
- Department of Evolutionary Biology, Ecology and Environmental Sciences, IRBio, Faculty of Biology, University of Barcelona, 08028, Barcelona, Spain
| | - Mónica A Silva
- Okeanos Centre & Institute of Marine Research (IMAR), University of the Azores, 9901-862, Horta, Portugal; Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - Gísli A Víkingsson
- Marine and Freshwater Research Institute, Skúlagata 4, 101, Reykjavík, Iceland
| | - Alfredo López
- Departamento de Biologia & CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal; Coordinadora para o Estudo dos Mamíferos Mariños (CEMMA), P.O. Box 15, 36380, Pontevedra, Gondomar, Spain
| | - Joan Giménez
- Institut de Ciències del Mar (ICM-CSIC), Passeig Maritim 37-49, 08003, Barcelona, Spain; MaREI Centre for Marine and Renewable Energy, Environmental Research Institute, Beaufort Building, University College Cork, Ringaskiddy, P43 C573 Cork, Ireland; School of Biological, Earth, and Environmental Sciences (BEES), University College Cork, Distillery Fields, North Mall, T23 N73K Cork, Ireland
| | - Ana Colaço
- Okeanos Centre & Institute of Marine Research (IMAR), University of the Azores, 9901-862, Horta, Portugal
| | | | - Morgana Vighi
- Department of Evolutionary Biology, Ecology and Environmental Sciences, IRBio, Faculty of Biology, University of Barcelona, 08028, Barcelona, Spain
| | - Rui Prieto
- Okeanos Centre & Institute of Marine Research (IMAR), University of the Azores, 9901-862, Horta, Portugal; MARE - Marine and Environmental Sciences Centre and IMAR, Institute of Marine Research, University of the Azores, 9901-862, Horta, Portugal
| | - Renaud de Stephanis
- CIRCE, Cabeza de Manzaneda, 3, 11390, Pelayo, Algeciras, Spain; Instituto Español de Oceanografía, Centro Oceanográfico de Málaga, Puerto Pesquero s/n, 29640 Fuengirola, Málaga, Spain
| | - Alex Aguilar
- Department of Evolutionary Biology, Ecology and Environmental Sciences, IRBio, Faculty of Biology, University of Barcelona, 08028, Barcelona, Spain
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