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Ciccone C, Kante F, Folkow LP, Hazlerigg DG, West AC, Wood SH. Circadian coupling of mitochondria in a deep-diving mammal. J Exp Biol 2024; 227:jeb246990. [PMID: 38495024 PMCID: PMC11058691 DOI: 10.1242/jeb.246990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 03/11/2024] [Indexed: 03/19/2024]
Abstract
Regulation of mitochondrial oxidative phosphorylation is essential to match energy supply to changing cellular energy demands, and to cope with periods of hypoxia. Recent work implicates the circadian molecular clock in control of mitochondrial function and hypoxia sensing. Because diving mammals experience intermittent episodes of severe hypoxia, with diel patterning in dive depth and duration, it is interesting to consider circadian-mitochondrial interaction in this group. Here, we demonstrate that the hooded seal (Cystophora cristata), a deep-diving Arctic pinniped, shows strong daily patterning of diving behaviour in the wild. Cultures of hooded seal skin fibroblasts exhibit robust circadian oscillation of the core clock genes per2 and arntl. In liver tissue collected from captive hooded seals, expression of arntl was some 4-fold higher in the middle of the night than in the middle of the day. To explore the clock-mitochondria relationship, we measured the mitochondrial oxygen consumption in synchronized hooded seal skin fibroblasts and found a circadian variation in mitochondrial activity, with higher coupling efficiency of complex I coinciding with the trough of arntl expression. These results open the way for further studies of circadian-hypoxia interactions in pinnipeds during diving.
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Affiliation(s)
- Chiara Ciccone
- Arctic Seasonal Timekeeping Initiative (ASTI), Arctic Chronobiology and Physiology Research Group, Department of Arctic and Marine Biology, UiT – The Arctic University of Norway, Tromsø NO-9037, Norway
| | - Fayiri Kante
- Arctic Seasonal Timekeeping Initiative (ASTI), Arctic Chronobiology and Physiology Research Group, Department of Arctic and Marine Biology, UiT – The Arctic University of Norway, Tromsø NO-9037, Norway
| | - Lars P. Folkow
- Arctic Seasonal Timekeeping Initiative (ASTI), Arctic Chronobiology and Physiology Research Group, Department of Arctic and Marine Biology, UiT – The Arctic University of Norway, Tromsø NO-9037, Norway
| | - David G. Hazlerigg
- Arctic Seasonal Timekeeping Initiative (ASTI), Arctic Chronobiology and Physiology Research Group, Department of Arctic and Marine Biology, UiT – The Arctic University of Norway, Tromsø NO-9037, Norway
| | - Alexander C. West
- Arctic Seasonal Timekeeping Initiative (ASTI), Arctic Chronobiology and Physiology Research Group, Department of Arctic and Marine Biology, UiT – The Arctic University of Norway, Tromsø NO-9037, Norway
| | - Shona H. Wood
- Arctic Seasonal Timekeeping Initiative (ASTI), Arctic Chronobiology and Physiology Research Group, Department of Arctic and Marine Biology, UiT – The Arctic University of Norway, Tromsø NO-9037, Norway
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Wege M, Salas L, LaRue M. Ice matters: Life-history strategies of two Antarctic seals dictate climate change eventualities in the Weddell Sea. GLOBAL CHANGE BIOLOGY 2021; 27:6252-6262. [PMID: 34491603 PMCID: PMC9293148 DOI: 10.1111/gcb.15828] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 06/30/2021] [Accepted: 07/29/2021] [Indexed: 06/13/2023]
Abstract
The impacts of climate change in Antarctica and the Southern Ocean are not uniform and ice-obligate species with dissimilar life-history characteristics will likely respond differently to their changing ecosystems. We use a unique data set of Weddell Leptonychotes weddellii and crabeater seals' (CESs) Lobodon carcinophaga breeding season distribution in the Weddell Sea, determined from satellite imagery. We contrast the theoretical climate impacts on both ice-obligate predators who differ in life-history characteristics: CESs are highly specialized Antarctic krill Euphausia superba predators and breed in the seasonal pack ice; Weddell seals (WESs) are generalist predators and breed on comparatively stable fast ice. We used presence-absence data and a suite of remotely sensed environmental variables to build habitat models. Each of the environmental predictors is multiplied by a 'climate change score' based on known responses to climate change to create a 'change importance product'. Results show CESs are more sensitive to climate change than WESs. Crabeater seals prefer to breed close to krill, and the compounding effects of changing sea ice concentrations and sea surface temperatures, the proximity to krill and abundance of stable breeding ice, can influence their post-breeding foraging success and ultimately their future breeding success. But in contrast to the Ross Sea, here WESs prefer to breed closer to larger colonies of emperor penguins (Aptenodytes forsteri). This suggests that the Weddell Sea may currently be prey-abundant, allowing the only two air-breathing Antarctic silverfish predators (Pleuragramma antarctica) (WESs and emperor penguins) to breed closer to each other. This is the first basin-scale, region-specific comparison of breeding season habitat in these two key Antarctic predators based on real-world data to compare climate change responses. This work shows that broad-brush, basin-scale approaches to understanding species-specific responses to climate change are not always appropriate, and regional models are needed-especially when designing marine protected areas.
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Affiliation(s)
- Mia Wege
- Gateway AntarcticaSchool of Earth and EnvironmentUniversity of CanterburyChristchurchNew Zealand
- Department of Zoology & EntomologyUniversity of PretoriaHatfieldPretoriaSouth Africa
| | - Leo Salas
- Point Blue Conservation SciencesPetalumaCAUSA
| | - Michelle LaRue
- Gateway AntarcticaSchool of Earth and EnvironmentUniversity of CanterburyChristchurchNew Zealand
- Department of Earth and Environmental SciencesUniversity of MinnesotaMinneapolisMNUSA
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Riaz J, Bestley S, Wotherspoon S, Emmerson L. Horizontal-vertical movement relationships: Adélie penguins forage continuously throughout provisioning trips. MOVEMENT ECOLOGY 2021; 9:43. [PMID: 34446104 PMCID: PMC8393751 DOI: 10.1186/s40462-021-00280-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2021] [Accepted: 08/17/2021] [Indexed: 06/08/2023]
Abstract
BACKGROUND Diving marine predators forage in a three-dimensional environment, adjusting their horizontal and vertical movement behaviour in response to environmental conditions and the spatial distribution of prey. Expectations regarding horizontal-vertical movements are derived from optimal foraging theories, however, inconsistent empirical findings across a range of taxa suggests these behavioural assumptions are not universally applicable. METHODS Here, we examined how changes in horizontal movement trajectories corresponded with diving behaviour and marine environmental conditions for a ubiquitous Southern Ocean predator, the Adélie penguin. Integrating extensive telemetry-based movement and environmental datasets for chick-rearing Adélie penguins at Béchervaise Island, we tested the relationships between horizontal move persistence (continuous scale indicating low ['resident'] to high ['directed'] movement autocorrelation), vertical dive effort and environmental variables. RESULTS Penguins dived continuously over the course of their foraging trips and lower horizontal move persistence corresponded with less intense foraging activity, likely indicative of resting behaviour. This challenges the traditional interpretation of horizontal-vertical movement relationships based on optimal foraging models, which assumes increased residency within an area translates to increased foraging activity. Movement was also influenced by different environmental conditions during the two stages of chick-rearing: guard and crèche. These differences highlight the strong seasonality of foraging habitat for chick-rearing Adélie penguins at Béchervaise Island. CONCLUSIONS Our findings advance our understanding of the foraging behaviour for this marine predator and demonstrates the importance of integrating spatial location and behavioural data before inferring habitat use.
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Affiliation(s)
- Javed Riaz
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, TAS, 7001, Australia.
- Australian Antarctic Division, 203 Channel Highway, Kingston, TAS, 7050, Australia.
| | - Sophie Bestley
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, TAS, 7001, Australia
| | - Simon Wotherspoon
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, TAS, 7001, Australia
- Australian Antarctic Division, 203 Channel Highway, Kingston, TAS, 7050, Australia
| | - Louise Emmerson
- Australian Antarctic Division, 203 Channel Highway, Kingston, TAS, 7050, Australia
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Nagel R, Mews S, Adam T, Stainfield C, Fox-Clarke C, Toscani C, Langrock R, Forcada J, Hoffman JI. Movement patterns and activity levels are shaped by the neonatal environment in Antarctic fur seal pups. Sci Rep 2021; 11:14323. [PMID: 34253749 PMCID: PMC8275608 DOI: 10.1038/s41598-021-93253-1] [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: 03/24/2021] [Accepted: 06/04/2021] [Indexed: 02/06/2023] Open
Abstract
Tracking studies of juveniles are rare compared to those of adults, and consequently little is known about the influence of intrinsic and extrinsic factors on activity during this critical life stage. We used hourly GPS data, collected from 66 Antarctic fur seal pups from birth until moulting, to investigate the explanatory power of multiple individual-based and environmental variables on activity levels. Pups were sampled from two nearby breeding colonies of contrasting density during two subsequent years, and a two-state hidden Markov model was used to identify modalities in their movement behaviour, specifically 'active' and 'inactive' states. We found that movement was typified by central place exploration, with active movement away from and subsequent return to a location of inactivity. The probability of such directed exploration was unaffected by several factors known to influence marine mammal movement including sex, body condition, and temperature. Compared to pups born at the high-density colony, pups at low-density were more active, increased their activity with age, and transitioned earlier into the tussock grass, which offers protection from predators and extreme weather. Our study illustrates the importance of extrinsic factors, such as colony of birth, to early-life activity patterns and highlights the adaptive potential of movement.
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Affiliation(s)
- Rebecca Nagel
- grid.7491.b0000 0001 0944 9128Department of Animal Behaviour, Bielefeld University, 33501 Bielefeld, Germany
| | - Sina Mews
- grid.7491.b0000 0001 0944 9128Department of Business Administration and Economics, Bielefeld University, 33501 Bielefeld, Germany
| | - Timo Adam
- grid.7491.b0000 0001 0944 9128Department of Business Administration and Economics, Bielefeld University, 33501 Bielefeld, Germany ,grid.11914.3c0000 0001 0721 1626Centre for Research into Ecological and Environmental Modelling, School of Mathematics and Statistics, The Observatory, Buchanan Gardens, University of St Andrews, St Andrews, KY16 9LZ UK
| | - Claire Stainfield
- grid.478592.50000 0004 0598 3800British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 OET UK
| | - Cameron Fox-Clarke
- grid.478592.50000 0004 0598 3800British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 OET UK
| | - Camille Toscani
- grid.478592.50000 0004 0598 3800British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 OET UK
| | - Roland Langrock
- grid.7491.b0000 0001 0944 9128Department of Business Administration and Economics, Bielefeld University, 33501 Bielefeld, Germany
| | - Jaume Forcada
- grid.478592.50000 0004 0598 3800British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 OET UK
| | - Joseph I. Hoffman
- grid.7491.b0000 0001 0944 9128Department of Animal Behaviour, Bielefeld University, 33501 Bielefeld, Germany ,grid.478592.50000 0004 0598 3800British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 OET UK
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