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Linsky JMJ, Dunlop RA, Noad MJ, McMichael LA. Blubber gene expression and cortisol concentrations reveal changing physiological stress in a Southern ocean sentinel species. MARINE ENVIRONMENTAL RESEARCH 2024; 199:106596. [PMID: 38905865 DOI: 10.1016/j.marenvres.2024.106596] [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: 03/27/2024] [Revised: 05/21/2024] [Accepted: 06/06/2024] [Indexed: 06/23/2024]
Abstract
The health of migratory eastern Australian humpback whales (Megaptera novaeangliae) can reflect the condition of their remote polar foraging environments. This study used gene expression (LEP, LEPR, ADIQ, AhR, TNF-α, HSP-70), blubber hormone concentrations (cortisol, testosterone), and photogrammetric body condition to assess this sentinel species during a period of unprecedented changes to anthropogenic activity and natural processes. The results revealed higher cortisol concentrations in 2020 compared to 2021, suggesting a decline in physiological stress between years. Additionally, metabolic transcripts LEPR, and AhR, which is also linked to xenobiotic metabolism, were upregulated during the 2020 southbound migration. These differences suggest that one or more environmental stressors were reduced between 2020 and 2021, with upregulated AhR possibly indicating a Southern Ocean pollutant declined between the years. This research confirms a Southern Ocean-wide decrease in whale stress during the study period and informs efforts to identify key stressors on Antarctic marine ecosystems.
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Affiliation(s)
- Jacob M J Linsky
- School of the Environment, The University of Queensland, St Lucia, Queensland, 4072, Australia.
| | - Rebecca A Dunlop
- School of the Environment, The University of Queensland, St Lucia, Queensland, 4072, Australia
| | - Michael J Noad
- School of Veterinary Science, The University of Queensland, Gatton, Queensland, 4343, Australia; Centre for Marine Science, The University of Queensland, St. Lucia, QLD, 4072, Australia
| | - Lee A McMichael
- School of Veterinary Science, The University of Queensland, Gatton, Queensland, 4343, Australia
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2
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Pallin LJ, Garrigue C, Kellar NM, Baker CS, Bonneville CD, Derville S, Garland EC, Steel D, Friedlaender AS. Demographic and physiological signals of reproductive events in humpback whales on a southwest pacific breeding ground. CONSERVATION PHYSIOLOGY 2024; 12:coae038. [PMID: 38894754 PMCID: PMC11184982 DOI: 10.1093/conphys/coae038] [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: 12/21/2023] [Revised: 04/15/2024] [Accepted: 06/08/2024] [Indexed: 06/21/2024]
Abstract
The field of marine mammal conservation has dramatically benefited from the rapid advancement of methods to assess the reproductive physiology of individuals and populations from steroid hormones isolated from minimally invasive skin-blubber biopsy samples. Historically, this vital information was only available from complete anatomical and physiological investigations of samples collected during commercial or indigenous whaling. Humpback whales (Megaptera novaeangliae) are a migratory, cosmopolitan species that reproduce in warm, low-latitude breeding grounds. New Caledonia is seasonally visited by a small breeding sub-stock of humpback whales, forming part of the endangered Oceania subpopulation. To better understand the demographic and seasonal patterns of reproductive physiology in humpback whales, we quantified baseline measurements of reproductive hormones (progesterone-P4, testosterone-T and 17β-estradiol-E2) using an extensive archive of skin-blubber biopsy samples collected from female humpback whales in New Caledonia waters between 2016 and 2019 (n = 194). We observed significant differences in the P4, T and E2 concentrations across different demographic groups of female humpback whales, and we described some of the first evidence of the endocrine patterns of estrous in live free-ranging baleen whales. This study is fundamental in its methodological approach to a wild species that has a global distribution, with seasonally distinct life histories. This information will assist in monitoring, managing and conserving this population as global ecological changes continue to occur unhindered.
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Affiliation(s)
- Logan J Pallin
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA 95060, USA
- Department of Ocean Sciences, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA 95060, USA
| | - Claire Garrigue
- UMR ENTROPIE IRD, Université de La Réunion, Université de la Nouvelle-Calédonie, CNRS, IFREMER, Laboratoire d'excellence-CORAIL, 101 promenade Roger Laroque BP A5NOUMEA CEDEX5 Nouvelle Calédonie 98848, France
- Opération Cétacés, BP 12827, Nouvelle-Calédonie 98802, France
| | - Nicholas M Kellar
- Marine Mammal Turtle Division, , Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 8901 La Jolla Shores Drive, La Jolla, CA 92037, USA
| | - C Scott Baker
- Department of Fisheries, Wildlife, and Conservation Sciences, Marine Mammal Institute, Oregon State University, Hatfield Marine Science Center, 2030 SE Marine Science Drive, Newport, OR 97365, USA
| | - Claire D Bonneville
- UMR ENTROPIE IRD, Université de La Réunion, Université de la Nouvelle-Calédonie, CNRS, IFREMER, Laboratoire d'excellence-CORAIL, 101 promenade Roger Laroque BP A5NOUMEA CEDEX5 Nouvelle Calédonie 98848, France
- Opération Cétacés, BP 12827, Nouvelle-Calédonie 98802, France
| | - Solène Derville
- UMR ENTROPIE IRD, Université de La Réunion, Université de la Nouvelle-Calédonie, CNRS, IFREMER, Laboratoire d'excellence-CORAIL, 101 promenade Roger Laroque BP A5NOUMEA CEDEX5 Nouvelle Calédonie 98848, France
- Opération Cétacés, BP 12827, Nouvelle-Calédonie 98802, France
| | - Ellen C Garland
- Sea Mammal Research Unit, Scottish Oceans Institute, School of Biology, University of St. Andrews, W Sands Rd, St Andrews KY16 9XL, UK
| | - Debbie Steel
- Department of Fisheries, Wildlife, and Conservation Sciences, Marine Mammal Institute, Oregon State University, Hatfield Marine Science Center, 2030 SE Marine Science Drive, Newport, OR 97365, USA
| | - Ari S Friedlaender
- Department of Ocean Sciences, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA 95060, USA
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3
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Linsky JMJ, Dunlop RA, McMichael LA. A novel RT-qPCR health assay reveals differential expression of stress and immunoregulatory genes between the seasonal migrations of humpback whales (Megaptera novaeangliae). Mol Ecol 2024; 33:e17209. [PMID: 38018561 DOI: 10.1111/mec.17209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 10/24/2023] [Accepted: 11/03/2023] [Indexed: 11/30/2023]
Abstract
Health information is essential for the conservation management of whale species. However, assessing the health of free-ranging whales is challenging as samples are primarily limited to skin and blubber tissue. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) offers a method to measure health from blubber RNA, providing insights into energetic status, stress and immune activity. To identify changes in health, natural differences in baseline gene expression linked to an individual's sex, reproductive status and life-history stage must first be quantified. This study aimed to establish baseline gene expression indices of health in migrating humpback whales (Megaptera novaeangliae). To do this, we developed an assay to quantify seven health-related gene transcripts (Leptin, Leptin Receptor, Adiponectin, Aryl Hydrocarbon Receptor, Tumour Necrosis Factor-α, Interleukin-6, Heat Shock Protein-70) and used Bayesian mixed effect models to assess differential baseline expression based on sex, lactation status and migration stage (northbound to and southbound from the annual breeding grounds). Results showed no significant contribution of sex to differential baseline expression. However, lactating individuals exhibited downregulated AhR and HSP-70 compared to non-lactating conspecifics. Additionally, southbound individuals demonstrated significantly upregulated HSP-70 and downregulated TNF-alpha, suggesting a relationship between these inflammation-linked transcripts and migratory fasting. Our results suggest that baseline differences due to migratory stage and lactation status should be considered in health applications of this assay. Future monitoring efforts can use our baseline measurements to better understand how gene expression is tied to population-level impacts, such as reduced prey availability or migratory stressors.
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Affiliation(s)
- Jacob M J Linsky
- School of the Environment, The University of Queensland, St Lucia, Queensland, Australia
| | - Rebecca A Dunlop
- School of the Environment, The University of Queensland, St Lucia, Queensland, Australia
| | - Lee A McMichael
- School of Veterinary Science, The University of Queensland, Gatton, Queensland, Australia
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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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Fernandez Ajó A, Pirotta E, Bierlich KC, Hildebrand L, Bird CN, Hunt KE, Buck CL, New L, Dillon D, Torres LG. Assessment of a non-invasive approach to pregnancy diagnosis in gray whales through drone-based photogrammetry and faecal hormone analysis. ROYAL SOCIETY OPEN SCIENCE 2023; 10:230452. [PMID: 37476509 PMCID: PMC10354484 DOI: 10.1098/rsos.230452] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 06/26/2023] [Indexed: 07/22/2023]
Abstract
Knowledge of baleen whales' reproductive physiology is limited and requires long-term individual-based studies and innovative tools. We used 6 years of individual-level data on the Pacific Coast Feeding Group gray whales to evaluate the utility of faecal progesterone immunoassays and drone-based photogrammetry for pregnancy diagnosis. We explored the variability in faecal progesterone metabolites and body morphology relative to observed reproductive status and estimated the pregnancy probability for mature females of unknown reproductive status using normal mixture models. Individual females had higher faecal progesterone concentrations when pregnant than when presumed non-pregnant. Yet, at the population level, high overlap and variability in progesterone metabolite concentrations occurred between pregnant and non-pregnant groups, limiting this metric for accurate pregnancy diagnosis in gray whales. Alternatively, body width at 50% of the total body length (W50) correctly discriminated pregnant from non-pregnant females at individual and population levels, with high accuracy. Application of the model using W50 metric to mature females of unknown pregnancy status identified eight additional pregnancies with high confidence. Our findings highlight the utility of drone-based photogrammetry to non-invasively diagnose pregnancy in this group of gray whales, and the potential for improved data on reproductive rates for population management of baleen whales generally.
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Affiliation(s)
- A. Fernandez Ajó
- Geospatial Ecology of Marine Megafauna Lab, Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Newport 97365, OR, USA
| | - E. Pirotta
- Centre for Research into Ecological and Environmental Modelling, University of St Andrews, St Andrews, UK
| | - K. C. Bierlich
- Geospatial Ecology of Marine Megafauna Lab, Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Newport 97365, OR, USA
| | - L. Hildebrand
- Geospatial Ecology of Marine Megafauna Lab, Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Newport 97365, OR, USA
| | - C. N. Bird
- Geospatial Ecology of Marine Megafauna Lab, Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Newport 97365, OR, USA
| | - K. E. Hunt
- Smithsonian-Mason School of Conservation, Department of Biology, George Mason University, 1500 Remount Road, Front Royal, VA 22630, USA
| | - C. L. Buck
- Department of Biological Sciences, Northern Arizona University, 617 South Beaver Street, Flagstaff, AZ 86011, USA
| | - L. New
- Ursinus College, 601 East Main Street, Collegeville, PA 19426, USA
| | - D. Dillon
- Department of Biological Sciences, Northern Arizona University, 617 South Beaver Street, Flagstaff, AZ 86011, USA
| | - L. 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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Pallin LJ, Botero-Acosta N, Steel D, Baker CS, Casey C, Costa DP, Goldbogen JA, Johnston DW, Kellar NM, Modest M, Nichols R, Roberts D, Roberts M, Savenko O, Friedlaender AS. Variation in blubber cortisol levels in a recovering humpback whale population inhabiting a rapidly changing environment. Sci Rep 2022; 12:20250. [PMID: 36424421 PMCID: PMC9686265 DOI: 10.1038/s41598-022-24704-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 11/18/2022] [Indexed: 11/27/2022] Open
Abstract
Glucocorticoids are regularly used as biomarkers of relative health for individuals and populations. Around the Western Antarctic Peninsula (WAP), baleen whales have and continue to experience threats, including commercial harvest, prey limitations and habitat change driven by rapid warming, and increased human presence via ecotourism. Here, we measured demographic variation and differences across the foraging season in blubber cortisol levels of humpback whales (Megaptera novaeangliae) over two years around the WAP. Cortisol concentrations were determined from 305 biopsy samples of unique individuals. We found no significant difference in the cortisol concentration between male and female whales. However, we observed significant differences across demographic groups of females and a significant decrease in the population across the feeding season. We also assessed whether COVID-19-related reductions in tourism in 2021 along the WAP correlated with lower cortisol levels across the population. The decline in vessel presence in 2021 was associated with a significant decrease in humpback whale blubber cortisol concentrations at the population level. Our findings provide critical contextual data on how these hormones vary naturally in a population over time, show direct associations between cortisol levels and human presence, and will enable comparisons among species experiencing different levels of human disturbance.
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Affiliation(s)
- L. J. Pallin
- grid.205975.c0000 0001 0740 6917Present Address: Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA 95060 USA
| | - N. Botero-Acosta
- Fundación Macuáticos Colombia, Calle 27 # 79-167, Medellín, Colombia ,Programa Antártico Colombiano, Avenida Ciudad de Cali #51 - 66, Oficina 306, Edificio World Business Center – WBC, Bogotá, D.C. Colombia
| | - D. Steel
- grid.4391.f0000 0001 2112 1969Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Hatfield Marine Science Center, 2030 SE Marine Science Drive, Newport, OR 97365 USA
| | - C. S. Baker
- grid.4391.f0000 0001 2112 1969Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Hatfield Marine Science Center, 2030 SE Marine Science Drive, Newport, OR 97365 USA
| | - C. Casey
- grid.205975.c0000 0001 0740 6917Institute for Marine Science, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA 95060 USA ,California Ocean Alliance, 9099 Soquel Ave, Aptos, CA 95003 USA
| | - D. P. Costa
- grid.205975.c0000 0001 0740 6917Present Address: Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA 95060 USA
| | - J. A. Goldbogen
- grid.168010.e0000000419368956Department of Biology, Hopkins Marine Station, Stanford University, 120 Ocean View Blvd, Pacific Grove, CA 93950 USA
| | - D. W. Johnston
- grid.26009.3d0000 0004 1936 7961Division of Marine Science and Conservation, Nicholas School of the Environment, Duke University Marine Laboratory, 135 Duke Marine Lab Road, Beaufort, NC 28516 USA
| | - N. M. Kellar
- grid.422702.10000 0001 1356 4495Marine Mammal Turtle Division, Southwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 8901 La Jolla Shores Drive, La Jolla, CA 92037 USA
| | - M. Modest
- grid.205975.c0000 0001 0740 6917Present Address: Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA 95060 USA
| | - R. Nichols
- grid.205975.c0000 0001 0740 6917Department of Ocean Sciences, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA 95060 USA
| | - D. Roberts
- California Ocean Alliance, 9099 Soquel Ave, Aptos, CA 95003 USA
| | - M. Roberts
- California Ocean Alliance, 9099 Soquel Ave, Aptos, CA 95003 USA
| | - O. Savenko
- National Antarctic Scientific Center of Ukraine, 16 Taras Shevchenko Blvd., Kyiv, 01601 Ukraine ,grid.438834.0Ukrainian Scientific Center of Ecology of the Sea, 89 Frantsuzsky Blvd., Odesa, 65009 Ukraine
| | - A. S. Friedlaender
- California Ocean Alliance, 9099 Soquel Ave, Aptos, CA 95003 USA ,grid.205975.c0000 0001 0740 6917Department of Ocean Sciences, University of California Santa Cruz, Ocean Health Building, 115 McAllister Way, Santa Cruz, CA 95060 USA
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Melica V, Atkinson S, Calambokidis J, Gendron D, Lang A, Scordino J. Naturally stressed? Glucocorticoid profiles in blubber of blue and gray whales in response to life history parameters. MARINE MAMMAL SCIENCE 2022; 38:1524-1548. [PMID: 36619002 PMCID: PMC9815209 DOI: 10.1111/mms.12954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
The goal of the present study was to carry out a thorough methodological validation and describe baseline profiles for glucocorticoid hormones (cortisol and corticosterone) in blubber from blue (n = 77) and gray (n = 103) whales from the eastern North Pacific Ocean. For each species, we modelled cortisol and corticosterone concentrations in response to life history parameters (age, sex, reproductive status) and season or geographic location. In blue whales, cortisol concentrations did not vary significantly by age class, sex, or reproductive status, whereas corticosterone was significantly lower in immature than in adult females (p < .001). In gray whales, cortisol concentrations were significantly higher in lactating whales (p < .05), while corticosterone was significantly different between females and males (p = .001) and elevated in calves (p = .003). In gray whales, corticosterone concentrations were significantly lower in males sampled later in the year (August to November) compared to both sexes sampled between March and August (p = .05), but no seasonal trend occurred in blue whales. Our results indicate that glucocorticoid actions vary between species and sex in large whales. Analysis of multiple hormones improves our understanding of the physiology of maintaining metabolic homeostasis or coping with chronic stressors.
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Affiliation(s)
- Valentina Melica
- Fisheries Department, College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, Alaska
| | - Shannon Atkinson
- Fisheries Department, College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Juneau, Alaska
| | | | - Diane Gendron
- Instituto Politecnico Nacional, Centro Interdisciplinario de Ciencias Marina (IPN-CICIMAR), La Paz, Baja California Sur, Mexico
| | - Aimee Lang
- Ocean Associates Inc., on contract to NOAA Southwest Fisheries Science Center, La Jolla, California
| | - Jonathan Scordino
- Marine Mammal Program, Makah Fisheries Management, Neah Bay, Washington
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Edwards MJ, Stanley CR, Hosie CA, Richdon S, Price E, Wormell D, Smith TE. Social roles influence cortisol levels in captive Livingstone's fruit bats (Pteropus livingstonii). Horm Behav 2022; 144:105228. [PMID: 35772196 DOI: 10.1016/j.yhbeh.2022.105228] [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: 01/17/2022] [Revised: 05/03/2022] [Accepted: 06/21/2022] [Indexed: 11/16/2022]
Abstract
A critical component of conserving and housing species ex situ is an explicit scientific understanding of the physiological underpinnings of their welfare. Cortisol has been repeatedly linked to stress, and therefore used as an indicator of welfare for many species. In order to measure cortisol in the Livingstone's fruit bat (Pteropus livingstonii; a critically endangered keystone species) without disturbing the captive population, we have developed and validated a non-invasive, novel hormone extraction procedure and faecal glucocorticoid assay. A total of 92 faecal samples, 73 from the P. livingstonii breeding colony at Jersey Zoo, Channel Islands and 19 samples from P. livingstonii housed at Bristol Zoological Gardens, UK, have been collected and analyzed. Mixed-effect modelling of the influence of physiological state variables on cortisol concentration revealed that lactating females had higher cortisol levels than non-lactating females, indicating that our assay is measuring biologically relevant hormone concentrations. Males and older bats also had higher cortisol than non-lactating females and younger individuals. Further analysis applied social network methodology to compare the cortisol levels of bats with different social roles. We found that individuals that linked social groups possessed higher than average cortisol levels and conversely, individuals with high-quality, positive relationships had lower cortisol levels. These results demonstrate, for the first time in a bat species, social mediation of stress hormones. Lastly, the frequency of vocalisation was found to positively correlate with cortisol concentration in males, suggesting that this behaviour may be used by animal management as a visual indicator of a bat's hormonal status. Hence, this research has provided unique insights and empirical scientific knowledge regarding the relationship between the physiology and social behaviour of P. livingstonii, therefore allowing for recommendations to be made to optimise bat welfare at the individual level.
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Affiliation(s)
- Morgan J Edwards
- Animal Behaviour and Welfare Research Group, Department of Biological Sciences, University of Chester, Chester CH1 4BJ, UK.
| | - Christina R Stanley
- Animal Behaviour and Welfare Research Group, Department of Biological Sciences, University of Chester, Chester CH1 4BJ, UK.
| | - Charlotte A Hosie
- Animal Behaviour and Welfare Research Group, Department of Biological Sciences, University of Chester, Chester CH1 4BJ, UK.
| | - Sarah Richdon
- Institute of Conservation Science & Learning, Bristol Zoological Society, Clifton, Bristol BS8 3HA, UK.
| | - Eluned Price
- Durrell Wildlife Conservation Trust, Trinity, Jersey JE3 6AP, UK.
| | - Dominic Wormell
- Durrell Wildlife Conservation Trust, Trinity, Jersey JE3 6AP, UK.
| | - Tessa E Smith
- Animal Behaviour and Welfare Research Group, Department of Biological Sciences, University of Chester, Chester CH1 4BJ, UK.
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9
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Agusti C, Carbajal A, Olvera-Maneu S, Domingo M, Lopez-Bejar M. Blubber and serum cortisol concentrations as indicators of the stress response and overall health status in striped dolphins. Comp Biochem Physiol A Mol Integr Physiol 2022; 272:111268. [PMID: 35817193 DOI: 10.1016/j.cbpa.2022.111268] [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: 02/14/2022] [Revised: 07/04/2022] [Accepted: 07/05/2022] [Indexed: 11/30/2022]
Abstract
The impacts of environmental changes and anthropogenic threats in marine mammals are a growing concern for their conservation. In recent years, efforts have been directed to understand how marine mammals cope with stressors and to assess and validate stress biomarkers, mainly levels of glucocorticoid hormones (e.g. cortisol) in certain body tissues. The aims of this study were to assess the impact of different causes of stranding (chronically affected and bycaught striped dolphins) on cortisol concentrations in serum and in blubber; and to evaluate the association between cortisol levels in these tissues. Blubber and blood samples were collected from striped dolphins (n = 42) stranded on the Mediterranean coast between 2012 and 2018. Cortisol concentrations were measured by using enzyme immunoassay. A high correlation was found between circulating and blubber cortisol concentrations (R2 = 0.85, p < 0.01). Necropsies and pathological studies concluded that a third of the dolphins were bycaught in fishing nets and released by fishermen (Bycaught animals group), while the other two thirds were euthanized, or died, due to a disease or chronic condition (e.g. calves separated from the mother or animals infected with dolphin morbillivirus or Brucella ceti) that impeded survival (Chronically affected animals group). Cortisol concentrations (mean ± SD) were six times higher in chronically affected animals (35.3 ± 23 ng cortisol/g blubber and 6.63 ± 3.22 μg cortisol/dl serum) compared to those bycaught in fishing nets (6.2 ± 4.3 ng cortisol/g blubber and 1.15 ± 1.51 μg cortisol/dl serum). Results suggests that serum and blubber cortisol concentrations can contribute in inferring the overall health and welfare of free-ranging cetaceans. However, further research is required to understand better the kinetics of blubber cortisol incorporation and removal, the factors involved in these processes, and the local conversion of cortisol in the blubber.
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Affiliation(s)
- Clara Agusti
- Zoo Animal Welfare Education Centre (ZAWEC), Veterinary Faculty, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
| | - Annaïs Carbajal
- Department of Animal Health and Anatomy, Veterinary Faculty, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Sergi Olvera-Maneu
- Department of Animal Health and Anatomy, Veterinary Faculty, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain
| | - Mariano Domingo
- Department of Animal Health and Anatomy, Veterinary Faculty, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain; CRESA (Centre de Recerca en Sanitat Animal), Campus Universitat Autònoma de Barcelona (UAB), 08193 Bellaterra, Barcelona, Spain
| | - Manel Lopez-Bejar
- Department of Animal Health and Anatomy, Veterinary Faculty, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain; College of Veterinary Medicine, Western University of Health Sciences, Pomona 91766, CA, USA
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10
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Lowe CL, Hunt KE, Neilson JL, Gabriele CM, Teerlink SS, Buck CL. Reproductive Steroid Hormone Patterns in Baleen of Two Pregnant Humpback Whales (Megaptera Novaeangliae). Integr Comp Biol 2022; 62:152-163. [PMID: 35671163 DOI: 10.1093/icb/icac070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 05/16/2022] [Accepted: 05/19/2022] [Indexed: 11/14/2022] Open
Abstract
Understanding reproductive physiology in mysticetes has been slowed by the lack of repeated samples from individuals. Analysis of humpback whale baleen enables retrospective hormone analysis within individuals dating back three to five years before death. Using this method, we investigated differences in four steroid hormones involved in reproduction and mating during confirmed pregnant and non-pregnant periods in two female humpback whales (Megaptera novaeangliae) with known reproductive histories based on sightings and necropsy data. Cortisol, corticosterone, testosterone and estradiol concentrations were determined via enzyme immunoassay using subsamples of each baleen plate at 2 cm intervals. There were no significant differences in cortisol or corticosterone during pregnancy when compared to non-pregnancy (inter-calving interval), but there were significant differences between the two whales in average glucocorticoid concentrations, with the younger whale showing higher values overall. For testosterone, levels for the younger female peaked at parturition in one pregnancy, but also had spikes during nonpregnancy. The older female had three large spikes in testosterone, one of which was associated with parturition. Estradiol had large fluctuations in both whales but had generally lower concentrations during non-pregnancy than during pregnancy. There were peaks in estradiol before each pregnancy, possibly coinciding with ovulation, and peaks coinciding with the month of parturition. Both estradiol and testosterone could be useful for determining ovulation or impending birth. Using baleen to investigate retrospective steroid hormone profiles can be used for elucidating long-term patterns of physiological change during gestation.
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Affiliation(s)
- Carley L Lowe
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011USA
| | - Kathleen E Hunt
- Department of Biology, Smithsonian-Mason School of Conservation & George Mason University, Front Royal, VI 22630USA
| | - Janet L Neilson
- Humpback Whale Monitoring Program, Glacier Bay National Park & Preserve, Gustavus, AK 99826USA
| | - Christine M Gabriele
- Humpback Whale Monitoring Program, Glacier Bay National Park & Preserve, Gustavus, AK 99826USA
| | | | - C Loren Buck
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86011USA
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11
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Dalle Luche G, Boggs ASP, Kucklick JR, Hawker DW, Wisse JH, Bengtson Nash S. Steroid hormone profiles and body conditions of migrating male humpback whales (Megaptera novaeangliae). Gen Comp Endocrinol 2021; 313:113888. [PMID: 34425085 DOI: 10.1016/j.ygcen.2021.113888] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 08/08/2021] [Accepted: 08/18/2021] [Indexed: 11/21/2022]
Abstract
Simultaneous analysis of multiple steroid hormones from remotely obtained blubber biopsies has the potential to concurrently provide information regarding stress and reproductive status from free-swimming cetaceans, while also investigating correlations between hormone concentrations and other health biomarkers. In this study we measured blubber concentration profiles of eight reproductive and adrenal steroid hormones (17α-hydroxy-progesterone, testosterone, androstenedione, progesterone, cortisol, 11-deoxy-corticosterone, oestrone, and oestradiol) together with body condition, as determined by the inverse Adipocyte Index, of 101 male humpback whales. Whales were sampled randomly at two time points, while migrating to and from their northeast Australian breeding grounds, allowing for intra- and inter-seasonal profile analysis. Testosterone, progesterone and cortisol together with androstenedione 17α-hydroxyprogesterone, and oestrone concentrations (the latter quantified for the first time in live biopsied male humpback whales) decreased between the northward and southward migrations. Decreasing testosterone levels during the height of humpback whale conceptions suggests asynchronicity between blubber testosterone levels and the expected peak of male fertility. Statistically significant relationships between levels of certain steroid analytes were observed and appeared to change between the early and late breeding seasons. During the northward migration, testosterone, progesterone, androstenedione, oestrone and 17α-hydroxyprogesterone levels were positively correlated. Cortisol concentrations correlated positively with those of testosterone during the northward migration, but negatively during the southward migration. Androstenedione and testosterone were positively correlated with adiposity during the late breeding season. These hormone-hormone and hormone-adiposity correlations may be reflective of the activation of certain steroid hormone synthesis pathways, or alternatively, of concomitant physiological stimuli. As steroid hormones work in concert, information on multiple steroid hormones is needed to interpret endocrinological status and understand the relationships between these compounds and ancillary health markers. This study provides steroid hormone profiles of wild male humpback whales, as well as the first insight into seasonal male endocrinology as a function of adiposity.
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Affiliation(s)
- Greta Dalle Luche
- Environmental Futures Research Institute, Griffith University, Brisbane, QLD 4111, Australia.
| | - Ashley S P Boggs
- National Institute of Standards and Technology, Hollings Marine Laboratory, Charleston, SC 29412, USA
| | - John R Kucklick
- National Institute of Standards and Technology, Hollings Marine Laboratory, Charleston, SC 29412, USA
| | - Darryl W Hawker
- School of Environment and Science, Griffith University, Brisbane, QLD 4111, Australia
| | - Jillian H Wisse
- Nicholas School of the Environment, Duke University, Durham, NC 27710, USA
| | - Susan Bengtson Nash
- Environmental Futures Research Institute, Griffith University, Brisbane, QLD 4111, Australia
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12
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Melica V, Atkinson S, Gendron D, Calambokidis J, Mueter F. Blubber endocrine profiles provide insights into reproductive biology in blue whales from the eastern North Pacific Ocean. Gen Comp Endocrinol 2021; 310:113830. [PMID: 34087186 PMCID: PMC9167553 DOI: 10.1016/j.ygcen.2021.113830] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 05/26/2021] [Accepted: 05/31/2021] [Indexed: 01/07/2023]
Abstract
The goal of the present study was to complement existing data of testosterone and progesterone in blue whale (Balaenoptera musculus) blubber from the eastern North Pacific Ocean to evaluate effects of seasonality and location on these hormones and to better assess reproductive status of individuals. Physiological parameters regarding reproduction are fundamental for describing population dynamics, and hormones can be a valid tool to estimate those for wildlife populations. In this study, blubber tissue was validated for testosterone and progesterone assays. Hormone concentrations were measured in 69 (35 males and 34 females) blubber samples from live (n = 66) and stranded (n = 3) animals collected between 2002 and 2016 from a known winter reproductive ground in the Gulf of California (GoC) and summer feeding areas along the United States West Coast (USWC), specifically off the states of California and Oregon. Results were combined with sighting histories as a tool to determine reproductive status of individual whales. Testosterone concentrations in adult male blue whales were significantly higher (p < 0.05) in blubber biopsies sampled off the USWC between the months of June and November compared to those sampled in the GoC between February and April. Elevated testosterone concentrations likely indicate physiological preparation for reproductive activity while the animals were present off the USWC. Progesterone concentrations were significantly elevated in pregnant females, confirming progesterone as an indicator of pregnancy in blue whales. Probabilities of being pregnant were estimated for adult females with unknown sighting histories based on progesterone concentrations. Testosterone in females was detected and measured only in pregnant whales suggesting its biosynthesis or metabolism is altered during gestation. These results provide updated and new information on the reproductive cycle of blue whales in the eastern North Pacific, posing new milestones to better estimate the timing of the mating season for this endangered population.
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Affiliation(s)
- Valentina Melica
- University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, Fisheries Dept, Juneau Center, 17101 Pt. Lena Loop Road, Juneau, AK 99801, USA.
| | - Shannon Atkinson
- University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, Fisheries Dept, Juneau Center, 17101 Pt. Lena Loop Road, Juneau, AK 99801, USA.
| | - Diane Gendron
- Centro Interdisciplinario de Ciencias Marina (IPN-CICIMAR), Av. Instituto Politecnico Nacional s/n, playa Palo de Santa Rita, 23096 La Paz, B.C.S., Mexico
| | | | - Franz Mueter
- University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, Fisheries Dept, Juneau Center, 17101 Pt. Lena Loop Road, Juneau, AK 99801, USA
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13
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Pénitot A, Schwarz D, Nguyen Hong Duc P, Cazau D, Adam O. Bidirectional Interactions With Humpback Whale Singer Using Concrete Sound Elements. Front Psychol 2021; 12:654314. [PMID: 34177706 PMCID: PMC8225952 DOI: 10.3389/fpsyg.2021.654314] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 04/09/2021] [Indexed: 12/01/2022] Open
Abstract
We describe an art–science project called “Feral Interactions—The Answer of the Humpback Whale” inspired by humpback whale songs and interactions between individuals based on mutual influences, learning process, or ranking in the dominance hierarchy. The aim was to build new sounds that can be used to initiate acoustic interactions with these whales, not in a one-way direction, as playbacks do, but in real interspecies exchanges. Thus, we investigated how the humpback whales generate sounds in order to better understand their abilities and limits. By carefully listening to their emitted vocalizations, we also describe their acoustic features and temporal structure, in a scientific way and also with a musical approach as it is done with musique concrète, in order to specify the types and the morphologies of whale sounds. The idea is to highlight the most precise information to generate our own sounds that will be suggested to the whales. Based on the approach developed in musique concrète, similarities with the sounds produced by bassoon were identified and then were processed to become “concrete sound elements.” This analysis also brought us to design a new music interface that allows us to create adapted musical phrases in real-time. With this approach, interactions will be possible in both directions, from and to whales.
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Affiliation(s)
| | - Diemo Schwarz
- Sciences et Technologies de la Musique et du Son, UMR 9912, Ircam, CNRS, Ministère de la Culture, Sorbonne Université, Paris, France
| | - Paul Nguyen Hong Duc
- CNRS, Institut Jean Le Rond d'Alembert, UMR 7190, Sorbonne Université, Paris, France
| | - Dorian Cazau
- ENSTA Bretagne, CNRS, Lab-STICC, UMR 6285, Brest, France
| | - Olivier Adam
- CNRS, Institut Jean Le Rond d'Alembert, UMR 7190, Sorbonne Université, Paris, France.,CNRS, Institut des Neurosciences Paris-Saclay, UMR 9197, Université Paris-Saclay, Orsay, France
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14
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Graham KM, Burgess EA, Rolland RM. Stress and reproductive events detected in North Atlantic right whale blubber using a simplified hormone extraction protocol. CONSERVATION PHYSIOLOGY 2021; 9:coaa133. [PMID: 33489237 PMCID: PMC7808127 DOI: 10.1093/conphys/coaa133] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 10/16/2020] [Accepted: 12/14/2020] [Indexed: 06/12/2023]
Abstract
As studies quantifying steroid hormones in marine mammal blubber progress, methodological refinements may improve the utility and consistency of blubber hormone measurements. This study advances blubber extraction methodologies by testing a simplified extraction protocol that reduces time and complexity compared to a protocol widely used in cetacean blubber studies. Using blubber samples archived from remote biopsy (n = 21 live whales) and necropsy collection (n = 7 dead whales) of North Atlantic right whales (NARW; Eubalaena glacialis) of known life history states, we performed analytical and biological validations to assess the feasibility of measuring reproductive (testosterone, progesterone) and glucocorticoid (cortisol) hormones in blubber via enzyme immunoassay following the simplified extraction. Analytical validations (parallelism, accuracy, extraction efficiency, repeatability) showed the simplified extraction produced similar results to the extended protocol, offering a more efficient and consistent technique. In live, apparently healthy whales, blubber testosterone concentrations (mean ± SE) were significantly higher in males (2.02 ± 0.36 ng/g) compared to females (0.81 ± 0.15 ng/g). Blubber progesterone was highest in a confirmed pregnant female (60.3 ng/g), which was 12-fold greater than the mean concentration of non-pregnant females (4.56 ± 0.88 ng/g). Blubber cortisol concentrations in whales that died from anthropogenic causes averaged 5.31 ± 2.28 ng/g, whereas most live, healthy whales had cortisol values below 1 ng/g. Among living whales, a whale actively entangled in fishing gear had the highest blubber cortisol measurement (3.51 ng/g), exhibiting levels similar to whales that died from acute entanglement (2.88 ± 0.42 ng/g). Overall, the highest blubber cortisol concentration (18.0 ng/g) was measured in a dead whale with a severe chronic entanglement, approximately 30-fold greater than mean blubber cortisol of apparently healthy whales (0.58 ± 0.11 ng/g). The methodological approach presented here provides a reference for researchers interested in an alternative, streamlined technique for hormone extraction of cetacean blubber and contributes to the diverse tool set for stress and reproductive assessments of endangered NARWs.
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Affiliation(s)
- Katherine M Graham
- Anderson Cabot Center for Ocean Life at the New England Aquarium, Central Wharf, Boston, MA 02110, USA
| | - Elizabeth A Burgess
- Anderson Cabot Center for Ocean Life at the New England Aquarium, Central Wharf, Boston, MA 02110, USA
| | - Rosalind M Rolland
- Anderson Cabot Center for Ocean Life at the New England Aquarium, Central Wharf, Boston, MA 02110, USA
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15
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Lowe CL, Hunt KE, Robbins J, Seton RE, Rogers M, Gabriele CM, Neilson JL, Landry S, Teerlink SS, Buck CL. Patterns of cortisol and corticosterone concentrations in humpback whale ( Megaptera novaeangliae) baleen are associated with different causes of death. CONSERVATION PHYSIOLOGY 2021; 9:coab096. [PMID: 34987826 PMCID: PMC8710851 DOI: 10.1093/conphys/coab096] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 10/08/2021] [Accepted: 12/06/2021] [Indexed: 05/15/2023]
Abstract
Baleen whales are subject to a myriad of natural and anthropogenic stressors, but understanding how these stressors affect physiology is difficult. Measurement of adrenal glucocorticoid (GC) hormones involved in the vertebrate stress response (cortisol and corticosterone) in baleen could help fill this data gap. Baleen analysis is a powerful tool, allowing for a retrospective re-creation of multiple years of GC hormone concentrations at approximately a monthly resolution. We hypothesized that whales that died from acute causes (e.g. ship strike) would have lower levels of baleen GCs than whales that died from extended illness or injury (e.g. long-term entanglement in fishing gear). To test this hypothesis, we extracted hormones from baleen plates of four humpback whales (Megaptera novaeangliae) with well-documented deaths including multiple and chronic entanglements (n = 1, female), ship strike (n = 2, male and female) and chronic illness with nutritional stress (n = 1, male). Over ~3 years of baleen growth and during multiple entanglements, the entangled whale had average corticosterone levels of 80-187% higher than the other three whales but cortisol levels were similar to two of the other three whales. The nutritionally stressed and chronically ill whale showed a slow increase in both cortisol and corticosterone spanning ~3 years, followed by a sharp decline in both hormones before death, possibly indicative of adrenal failure in this moribund individual. This whale's correlation between cortisol and corticosterone was significant but there were no correlations in the other three whales. Our results show that cortisol and corticosterone concentrations vary according to the type and duration of illness or injury. Single-point GC concentrations should be interpreted with caution as low values can occur in whales experiencing pronounced stress and individual baselines can be highly variable. Baleen analysis is a promising tissue type for retrospective analyses of physiological responses to various stressors affecting baleen whales.
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Affiliation(s)
- Carley L Lowe
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86001, USA
- Corresponding author: Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86001, USA. Tel: 702-524-3667. Fax: 928-523-7500.
| | - Kathleen E Hunt
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86001, USA
- Smithsonian-Mason School of Conservation & George Mason University, Front Royal, VA 22630, USA
| | - Jooke Robbins
- Center for Coastal Studies, Provincetown, MA 02657, USA
| | - Rosemary E Seton
- Allied Whale, College of the Atlantic, Bar Harbor, ME 04609, USA
| | - Matthew Rogers
- NOAA Fisheries, Alaska Fisheries Science Center Auke Bay Laboratories, Juneau, AK 99801, USA
| | | | - Janet L Neilson
- Glacier Bay National Park & Preserve, Gustavus, AK 99826, USA
| | - Scott Landry
- Center for Coastal Studies, Provincetown, MA 02657, USA
| | - Suzie S Teerlink
- NOAA Fisheries, Alaska Regional Office, Protected Resources Division, Juneau AK, 99801 USA
| | - C Loren Buck
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ 86001, USA
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16
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Cates KA, Atkinson S, Pack AA, Straley JM, Gabriele CM, Yin S. Corticosterone in central North Pacific male humpback whales (Megaptera novaeangliae): Pairing sighting histories with endocrine markers to assess stress. Gen Comp Endocrinol 2020; 296:113540. [PMID: 32585212 DOI: 10.1016/j.ygcen.2020.113540] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 06/08/2020] [Accepted: 06/13/2020] [Indexed: 10/24/2022]
Abstract
Developing a better understanding of the stress response is critical to ensuring the health and sustainability of marine mammal populations. However, accurately measuring and interpreting a stress response in free-ranging, large cetaceans is a nascent field. Here, an enzyme immunoassay for corticosterone was validated for use in biopsy samples from male humpback whales (Megaptera novaeangliae). Analyses were conducted on 247 male North Pacific humpback whale blubber samples, including 238 non-calves and 9 calves that were collected on the Hawaiian breeding and Southeast Alaskan feeding grounds from 2004 to 2006. Significant relationships were found when corticosterone concentrations were examined by year, age class and distribution between locations. When examined by year, corticosterone concentrations for male humpback whales were higher in Hawaii in 2004 than in 2005 and 2006 (p < 0.05). Corticosterone concentration also varied by age class with initially high concentrations at birth which subsequently tapered off and remained relatively low until sexual maturity was reached around age 8-10 years. Corticosterone concentrations appeared to peak in male humpback whales around 15-25 years of age. Blubber biopsies from Alaska and Hawaii had similar mean corticosterone concentrations, yet the variability in these samples was much greater for whales located in Hawaii. It is clear that much work remains to be done in order to accurately define or monitor a stress response in male humpback whales and that specific attention is required when looking at age, sex, and yearly trends. Our results suggest that a stress response may be most impacted by age and yearly oceanographic conditions and needs to be initially examined at the individual level.
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Affiliation(s)
- Kelly A Cates
- University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, Fisheries Department, Juneau Center, 17101 Pt. Lena Loop Road, Juneau, Alaska 99801, USA.
| | - Shannon Atkinson
- University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, Fisheries Department, Juneau Center, 17101 Pt. Lena Loop Road, Juneau, Alaska 99801, USA
| | - Adam A Pack
- Departments of Psychology and Biology, University of Hawai'i at Hilo, 200 West Kawili Street, Hilo, Hawai'i 96720, USA; The Dolphin Institute, P.O. Box 6279, Hilo, Hawai'i 96720, USA
| | - Janice M Straley
- University of Alaska Southeast Sitka Campus, 1332 Seward Ave., Sitka, Alaska 99835, USA
| | | | - Suzanne Yin
- Hawai'i Marine Mammal Consortium, P.O. Box 6107, Kamuela, Hawai'i 96743, USA
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