Costa Daniel P.

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Costa
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Daniel P.
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Now showing 1 - 20 of 25
  • Article
    Temporal changes in Weddell seal dive behavior over winter: are females increasing foraging effort to support gestation?
    (John Wiley & Sons Ltd., 2018-11-23) Shero, Michelle R. ; Goetz, Kimberly T. ; Costa, Daniel P. ; Burns, Jennifer M.
    In capital‐breeding marine mammals, prey acquisition during the foraging trip coinciding with gestation must provide energy to meet the immediate needs of the growing fetus and also a store to meet the subsequent demands of lactation. Weddell seals (Leptonychotes weddellii) that give birth following the gestational (winter) foraging period gain similar proportions of mass and lipid as compared to females that fail to give birth. Therefore, any changes in foraging behavior can be attributed to gestational costs. To investigate differences in foraging effort associated with successful reproduction, twenty‐three satellite tags were deployed on post‐molt female Weddell seals in the Ross Sea. Of the 20 females that returned to the area the following year, 12 females gave birth and eight did not. Females that gave birth the following year began the winter foraging period with significantly longer and deeper dives, as compared to non‐reproductive seals. Mid‐ to late winter, reproductive females spent a significantly greater proportion of the day diving, and either depressed their diving metabolic rates (DMR), or exceeded their calculated aerobic dive limit (cADL) more frequently than females that returned without a pup. Moreover, non‐reproductive females organized their dives into 2–3 short bouts per day on average (BOUTshort; 7.06 ± 1.29 hr; mean ± 95% CI), whereas reproductive females made 1–2 BOUTshort per day (10.9 ± 2.84 hr), comprising one long daily foraging bout without rest. The magnitude of the increase in dive activity budgets and depression in calculated DMR closely matched the estimated energetic requirements of supporting a fetus. This study is one of the first to identify increases in foraging effort that are associated with successful reproduction in a top predator and indicates that reproductive females must operate closer to their physiological limits to support gestational costs.
  • Article
    Delivering sustained, coordinated, and integrated observations of the Southern Ocean for global impact
    (Frontiers Media, 2019-08-08) Newman, Louise ; Heil, Petra ; Trebilco, Rowan ; Katsumata, Katsuro ; Constable, Andrew ; van Wijk, Esmee ; Assmann, Karen ; Beja, Joana ; Bricher, Phillippa ; Coleman, Richard ; Costa, Daniel P. ; Diggs, Stephen ; Farneti, Riccardo ; Fawcett, Sarah E. ; Gille, Sarah T. ; Hendry, Katharine R. ; Henley, Sian ; Hofmann, Eileen E. ; Maksym, Ted ; Mazloff, Matthew R. ; Meijers, Andrew J. S. ; Meredith, Michael M. ; Moreau, Sebastien ; Ozsoy, Burcu ; Robertson, Robin ; Schloss, Irene ; Schofield, Oscar M. E. ; Shi, Jiuxin ; Sikes, Elisabeth L. ; Smith, Inga J. ; Swart, Sebastiaan ; Wahlin, Anna ; Williams, Guy ; Williams, Michael J. M. ; Herraiz-Borreguero, Laura ; Kern, Stefan ; Lieser, Jan ; Massom, Robert A. ; Melbourne-Thomas, Jessica ; Miloslavich, Patricia ; Spreen, Gunnar
    The Southern Ocean is disproportionately important in its effect on the Earth system, impacting climatic, biogeochemical, and ecological systems, which makes recent observed changes to this system cause for global concern. The enhanced understanding and improvements in predictive skill needed for understanding and projecting future states of the Southern Ocean require sustained observations. Over the last decade, the Southern Ocean Observing System (SOOS) has established networks for enhancing regional coordination and research community groups to advance development of observing system capabilities. These networks support delivery of the SOOS 20-year vision, which is to develop a circumpolar system that ensures time series of key variables, and delivers the greatest impact from data to all key end-users. Although the Southern Ocean remains one of the least-observed ocean regions, enhanced international coordination and advances in autonomous platforms have resulted in progress toward sustained observations of this region. Since 2009, the Southern Ocean community has deployed over 5700 observational platforms south of 40°S. Large-scale, multi-year or sustained, multidisciplinary efforts have been supported and are now delivering observations of essential variables at space and time scales that enable assessment of changes being observed in Southern Ocean systems. The improved observational coverage, however, is predominantly for the open ocean, encompasses the summer, consists of primarily physical oceanographic variables, and covers surface to 2000 m. Significant gaps remain in observations of the ice-impacted ocean, the sea ice, depths >2000 m, the air-ocean-ice interface, biogeochemical and biological variables, and for seasons other than summer. Addressing these data gaps in a sustained way requires parallel advances in coordination networks, cyberinfrastructure and data management tools, observational platform and sensor technology, two-way platform interrogation and data-transmission technologies, modeling frameworks, intercalibration experiments, and development of internationally agreed sampling standards and requirements of key variables. This paper presents a community statement on the major scientific and observational progress of the last decade, and importantly, an assessment of key priorities for the coming decade, toward achieving the SOOS vision and delivering essential data to all end-users.
  • Article
    Understanding the combined effects of multiple stressors: a new perspective on a longstanding challenge
    (Elsevier, 2022-01-29) Pirotta, Enrico ; Thomas, Len ; Costa, Daniel P. ; Hall, Ailsa J. ; Harris, Catriona M. ; Harwood, John ; Kraus, Scott D. ; Miller, Patrick J. O. ; Moore, Michael J. ; Photopoulou, Theoni ; Rolland, Rosalind M. ; Schwacke, Lori ; Simmons, Samantha E. ; Southall, Brandon L. ; Tyack, Peter L.
    Wildlife populations and their habitats are exposed to an expanding diversity and intensity of stressors caused by human activities, within the broader context of natural processes and increasing pressure from climate change. Estimating how these multiple stressors affect individuals, populations, and ecosystems is thus of growing importance. However, their combined effects often cannot be predicted reliably from the individual effects of each stressor, and we lack the mechanistic understanding and analytical tools to predict their joint outcomes. We review the science of multiple stressors and present a conceptual framework that captures and reconciles the variety of existing approaches for assessing combined effects. Specifically, we show that all approaches lie along a spectrum, reflecting increasing assumptions about the mechanisms that regulate the action of single stressors and their combined effects. An emphasis on mechanisms improves analytical precision and predictive power but could introduce bias if the underlying assumptions are incorrect. A purely empirical approach has less risk of bias but requires adequate data on the effects of the full range of anticipated combinations of stressor types and magnitudes. We illustrate how this spectrum can be formalised into specific analytical methods, using an example of North Atlantic right whales feeding on limited prey resources while simultaneously being affected by entanglement in fishing gear. In practice, case-specific management needs and data availability will guide the exploration of the stressor combinations of interest and the selection of a suitable trade-off between precision and bias. We argue that the primary goal for adaptive management should be to identify the most practical and effective ways to remove or reduce specific combinations of stressors, bringing the risk of adverse impacts on populations and ecosystems below acceptable thresholds.
  • Article
    A standardisation framework for bio-logging data to advance ecological research and conservation
    (Wiley, 2021-03-15) Sequeira, Ana M. M. ; O'Toole, Malcolm ; Keates, Theresa R. ; McDonnell, Laura H. ; Braun, Camrin D. ; Hoenner, Xavier ; Jaine, Fabrice R. A. ; Jonsen, Ian ; Newman, Peggy ; Pye, Jonathan ; Bograd, Steven ; Hays, Graeme ; Hazen, Elliott L. ; Holland, Melinda ; Tsontos, Vardis ; Blight, Clint ; Cagnacci, Francesca ; Davidson, Sarah C. ; Dettki, Holger ; Duarte, Carlos M. ; Dunn, Daniel C. ; Eguíluz, Víctor M. ; Fedak, Michael ; Gleiss, Adrian C. ; Hammerschlag, Neil ; Hindell, Mark ; Holland, Kim ; Janekovic, Ivica ; McKinzie, Megan K. ; Muelbert, Monica M. C. ; Pattiaratchi, Charitha ; Rutz, Christian ; Sims, David W. ; Simmons, Samantha E. ; Townsend, Brendal ; Whoriskey, Frederick G. ; Woodward, Bill ; Costa, Daniel P. ; Heupel, Michelle R. ; McMahon, Clive R. ; Harcourt, Robert ; Weise, Michael
    1. Bio-logging data obtained by tagging animals are key to addressing global conservation challenges. However, the many thousands of existing bio-logging datasets are not easily discoverable, universally comparable, nor readily accessible through existing repositories and across platforms, slowing down ecological research and effective management. A set of universal standards is needed to ensure discoverability, interoperability and effective translation of bio-logging data into research and management recommendations. 2. We propose a standardisation framework adhering to existing data principles (FAIR: Findable, Accessible, Interoperable and Reusable; and TRUST: Transparency, Responsibility, User focus, Sustainability and Technology) and involving the use of simple templates to create a data flow from manufacturers and researchers to compliant repositories, where automated procedures should be in place to prepare data availability into four standardised levels: (a) decoded raw data, (b) curated data, (c) interpolated data and (d) gridded data. Our framework allows for integration of simple tabular arrays (e.g. csv files) and creation of sharable and interoperable network Common Data Form (netCDF) files containing all the needed information for accuracy-of-use, rightful attribution (ensuring data providers keep ownership through the entire process) and data preservation security. 3. We show the standardisation benefits for all stakeholders involved, and illustrate the application of our framework by focusing on marine animals and by providing examples of the workflow across all data levels, including filled templates and code to process data between levels, as well as templates to prepare netCDF files ready for sharing. 4. Adoption of our framework will facilitate collection of Essential Ocean Variables (EOVs) in support of the Global Ocean Observing System (GOOS) and inter-governmental assessments (e.g. the World Ocean Assessment), and will provide a starting point for broader efforts to establish interoperable bio-logging data formats across all fields in animal ecology.
  • Dataset
    Data collected daily along the ship track in JGOFS format from ARSV Laurence M. Gould and RVIB Nathaniel B. Palmer cruises to the Southern Ocean from 2001-2003 as part of the Southern Ocean GLOBEC project.
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-03-27) Beardsley, Robert C ; Costa, Daniel P. ; Limeburner, Richard ; Torres, Joseph J. ; Wiebe, Peter H.
    Data collected daily along the ship track in JGOFS format from ARSV Laurence M. Gould and RVIB Nathaniel B. Palmer cruises to the Southern Ocean from 2001-2003 as part of the Southern Ocean GLOBEC project For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/2345
  • Dataset
    Autonomous buoy position data from Southern Ocean GLOBEC from ARSV Laurence M. Gould LMG0106 in the Southern Ocean from July 2001
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2019-01-28) Costa, Daniel P. ; Fritsen, Chris H.
    Autonomous buoy position data from Southern Ocean GLOBEC from ARSV Laurence M. Gould LMG0106 in the Southern Ocean from July 2001. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/3114
  • Dataset
    Ice thickness transect data from ARSV Laurence M. Gould LMG0106, LMG0205 in the Southern Ocean from 2001-2002 (SOGLOBEC project, Sea Ice Microbes project, Crabeater Seal Foraging project)
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-01-22) Costa, Daniel P. ; Fritsen, Chris H.
    Ice thickness transect data from ARSV Laurence M. Gould LMG0106, LMG0205 in the Southern Ocean from 2001-2002 (SOGLOBEC project, Sea Ice Microbes project, Crabeater Seal Foraging project). For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/3119
  • Dataset
    Data collected daily along the ship track in JGOFS format from ARSV Laurence M. Gould and RVIB Nathaniel B. Palmer cruises to the Southern Ocean from 2001-2003 as part of the Southern Ocean GLOBEC project.
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2019-02-28) Beardsley, Robert C ; Costa, Daniel P. ; Limeburner, Richard ; Torres, Joseph J. ; Wiebe, Peter H.
    Data collected daily along the ship track in JGOFS format from ARSV Laurence M. Gould and RVIB Nathaniel B. Palmer cruises to the Southern Ocean from 2001-2003 as part of the Southern Ocean GLOBEC project For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/2345
  • Dataset
    N isotope data for individual amino acids from modern west Antarctic seals
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2022-08-22) Hall, Brenda ; Koch, Paul L. ; Costa, Daniel P. ; Hoelzel, A. Rus
    This dataset includes N isotope data for individual amino acids from modern west Antarctic seals. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/732754
  • Dataset
    C and N isotope data for individual amino acids from fossil seals from the western Ross Sea, Antarctica
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2022-08-22) Hall, Brenda ; Koch, Paul L. ; Costa, Daniel P. ; Hoelzel, A. Rus
    This dataset contains C and N isotope data for individual amino acids from fossil seals from the western Ross Sea, Antarctica. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/732078
  • Article
    Iron mobilization during lactation reduces oxygen stores in a diving mammal
    (Nature Research, 2022-08-02) Shero, Michelle R. ; Kirkham, Amy L. ; Costa, Daniel P. ; Burns, Jennifer M.
    The profound impacts that maternal provisioning of finite energy resources has on offspring survival have been extensively studied across mammals. This study shows that in addition to calories, high hemoprotein concentrations in diving mammals necessitates exceptional female-to-pup iron transfer. Numerous indices of iron mobilization (ferritin, serum iron, total-iron-binding-capacity, transferrin saturation) were significantly elevated during lactation in adult female Weddell seals (Leptonychotes weddellii), but not in skip-breeders. Iron was mobilized from endogenous stores for incorporation into the Weddell seal’s milk at concentrations up to 100× higher than terrestrial mammals. Such high rates of iron offload to offspring drew from the female’s own heme stores and led to compromised physiologic dive capacities (hemoglobin, myoglobin, and total body oxygen stores) after weaning their pups, which was further reflected in shorter dive durations. We demonstrate that lactational iron transfer shapes physiologic dive thresholds, identifying a cost of reproduction to a marine mammal.
  • Preprint
    Convergence of marine megafauna movement patterns in coastal and open oceans
    ( 2017-09) Sequeira, Ana M. M. ; Rodríguez, Jorge P. ; Eguíluz, Víctor M. ; Harcourt, Robert ; Hindell, Mark ; Sims, David W. ; Duarte, Carlos M. ; Costa, Daniel P. ; Fernández-Gracia, Juan ; Ferreira, Luciana C. ; Hays, Graeme ; Heupel, Michelle R. ; Meekan, Mark G. ; Aven, Allen ; Bailleul, Frédéric ; Baylis, Alastair M. M. ; Berumen, Michael L. ; Braun, Camrin D. ; Burns, Jennifer ; Caley, M. Julian ; Campbell, R. ; Carmichael, Ruth H. ; Clua, Eric ; Einoder, Luke D. ; Friedlaender, Ari S. ; Goebel, Michael E. ; Goldsworthy, Simon D. ; Guinet, Christophe ; Gunn, John ; Hamer, D. ; Hammerschlag, Neil ; Hammill, Mike O. ; Hückstädt, Luis A. ; Humphries, Nicolas E. ; Lea, Mary-Anne ; Lowther, Andrew D. ; Mackay, Alice ; McHuron, Elizabeth ; McKenzie, J. ; McLeay, Lachlan ; McMahon, Cathy R. ; Mengersen, Kerrie ; Muelbert, Monica M. C. ; Pagano, Anthony M. ; Page, B. ; Queiroz, N. ; Robinson, Patrick W. ; Shaffer, Scott A. ; Shivji, Mahmood ; Skomal, Gregory B. ; Thorrold, Simon R. ; Villegas-Amtmann, Stella ; Weise, Michael ; Wells, Randall S. ; Wetherbee, Bradley M. ; Wiebkin, A. ; Wienecke, Barbara ; Thums, Michele
    The extent of increasing anthropogenic impacts on large marine vertebrates partly depends on the animals’ movement patterns. Effective conservation requires identification of the key drivers of movement including intrinsic properties and extrinsic constraints associated with the dynamic nature of the environments the animals inhabit. However, the relative importance of intrinsic versus extrinsic factors remains elusive. We analyse a global dataset of 2.8 million locations from > 2,600 tracked individuals across 50 marine vertebrates evolutionarily separated by millions of years and using different locomotion modes (fly, swim, walk/paddle). Strikingly, movement patterns show a remarkable convergence, being strongly conserved across species and independent of body length and mass, despite these traits ranging over 10 orders of magnitude among the species studied. This represents a fundamental difference between marine and terrestrial vertebrates not previously identified, likely linked to the reduced costs of locomotion in water. Movement patterns were primarily explained by the interaction between species-specific traits and the habitat(s) they move through, resulting in complex movement patterns when moving close to coasts compared to more predictable patterns when moving in open oceans. This distinct difference may be associated with greater complexity within coastal micro-habitats, highlighting a critical role of preferred habitat in shaping marine vertebrate global movements. Efforts to develop understanding of the characteristics of vertebrate movement should consider the habitat(s) through which they move to identify how movement patterns will alter with forecasted severe ocean changes, such as reduced Arctic sea ice cover, sea level rise and declining oxygen content.
  • Article
    Stroke frequency, but not swimming speed, is related to body size in free-ranging seabirds, pinnipeds and cetaceans
    (Royal Society, 2006-12-05) Sato, Katsufumi ; Watanuki, Yutaka ; Takahashi, Akinori ; Miller, Patrick J. O. ; Tanaka, Hideji ; Kawabe, Ryo ; Ponganis, Paul J. ; Handrich, Yves ; Akamatsu, Tomonari ; Watanabe, Yuuki ; Mitani, Yoko ; Costa, Daniel P. ; Bost, Charles-Andre ; Aoki, Kagari ; Amano, Masao ; Trathan, Phil N. ; Shapiro, Ari D. ; Naito, Yasuhiko
    It is obvious, at least qualitatively, that small animals move their locomotory apparatus faster than large animals: small insects move their wings invisibly fast, while large birds flap their wings slowly. However, quantitative observations have been difficult to obtain from free-ranging swimming animals. We surveyed the swimming behaviour of animals ranging from 0.5kg seabirds to 30000kg sperm whales using animal-borne accelerometers. Dominant stroke cycle frequencies of swimming specialist seabirds and marine mammals were proportional to mass−0.29 (R2=0.99, n=17 groups), while propulsive swimming speeds of 1–2ms−1 were independent of body size. This scaling relationship, obtained from breath-hold divers expected to swim optimally to conserve oxygen, does not agree with recent theoretical predictions for optimal swimming. Seabirds that use their wings for both swimming and flying stroked at a lower frequency than other swimming specialists of the same size, suggesting a morphological trade-off with wing size and stroke frequency representing a compromise. In contrast, foot-propelled diving birds such as shags had similar stroke frequencies as other swimming specialists. These results suggest that muscle characteristics may constrain swimming during cruising travel, with convergence among diving specialists in the proportions and contraction rates of propulsive muscles.
  • Article
    Deadly diving? Physiological and behavioural management of decompression stress in diving mammals
    (Royal Society, 2011-12-21) Hooker, Sascha K. ; Fahlman, Andreas ; Moore, Michael J. ; Aguilar De Soto, Natacha ; Bernaldo de Quiros, Yara ; Brubakk, A. O. ; Costa, Daniel P. ; Costidis, Alexander M. ; Dennison, Sophie ; Falke, K. J. ; Fernandez, Antonio ; Ferrigno, Massimo ; Fitz-Clarke, J. R. ; Garner, Michael M. ; Houser, Dorian S. ; Jepson, Paul D. ; Ketten, Darlene R. ; Kvadsheim, P. H. ; Madsen, Peter T. ; Pollock, N. W. ; Rotstein, David S. ; Rowles, Teresa K. ; Simmons, S. E. ; Van Bonn, William ; Weathersby, P. K. ; Weise, Michael ; Williams, Terrie M. ; Tyack, Peter L.
    Decompression sickness (DCS; ‘the bends’) is a disease associated with gas uptake at pressure. The basic pathology and cause are relatively well known to human divers. Breath-hold diving marine mammals were thought to be relatively immune to DCS owing to multiple anatomical, physiological and behavioural adaptations that reduce nitrogen gas (N2) loading during dives. However, recent observations have shown that gas bubbles may form and tissue injury may occur in marine mammals under certain circumstances. Gas kinetic models based on measured time-depth profiles further suggest the potential occurrence of high blood and tissue N2 tensions. We review evidence for gas-bubble incidence in marine mammal tissues and discuss the theory behind gas loading and bubble formation. We suggest that diving mammals vary their physiological responses according to multiple stressors, and that the perspective on marine mammal diving physiology should change from simply minimizing N2 loading to management of the N2 load. This suggests several avenues for further study, ranging from the effects of gas bubbles at molecular, cellular and organ function levels, to comparative studies relating the presence/absence of gas bubbles to diving behaviour. Technological advances in imaging and remote instrumentation are likely to advance this field in coming years.
  • Dataset
    Skeletal measurements from fossil seals from the western Ross Sea, Antarctica
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2022-08-22) Hall, Brenda ; Koch, Paul L. ; Costa, Daniel P. ; Hoelzel, A. Rus
    This dataset includes skeletal measurements from fossil seals from the western Ross Sea, Antarctica. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/732661
  • Article
    Seals map bathymetry of the Antarctic continental shelf
    (American Geophysical Union, 2010-11-03) Padman, Laurie ; Costa, Daniel P. ; Bolmer, S. Thompson ; Goebel, Michael E. ; Huckstadt, Luis A. ; Jenkins, Adrian ; McDonald, Birgitte I. ; Shoosmith, Deborah R.
    We demonstrate the first use of marine mammal dive-depth data to improve maps of bathymetry in poorly sampled regions of the continental shelf. A group of 57 instrumented elephant seals made on the order of 2 × 105 dives over and near the continental shelf on the western side of the Antarctic Peninsula during five seasons, 2005–2009. Maximum dive depth exceeded 2000 m. For dives made near existing ship tracks with measured water depths H<700 m, ∼30% of dive depths were to the seabed, consistent with expected benthic foraging behavior. By identifying the deepest of multiple dives within small areas as a dive to the seabed, we have developed a map of seal-derived bathymetry. Our map fills in several regions for which trackline data are sparse, significantly improving delineation of troughs crossing the continental shelf of the southern Bellingshausen Sea.
  • Article
    Changes in serum adipokines during natural extended fasts in female northern elephant seals
    (Elsevier, 2021-03-27) Rzucidlo, Caroline L. ; Sperou, Emily S. ; Holser, Rachel R. ; Khudyakov, Jane I. ; Costa, Daniel P. ; Crocker, Daniel E.
    Adipose tissue is essential to endotherms for thermoregulation and energy storage as well as functioning as an endocrine organ. Adipose derived hormones, or adipokines, regulate metabolism, energy expenditure, reproduction, and immune function in model systems but are less well studied in wildlife. Female northern elephant seals (NES) achieve high adiposity during foraging and then undergo natural fasts up to five weeks long during haul-outs associated with reproduction and molting, resulting in large changes in adipose reserves. We measured circulating levels of four adipokines: leptin, resistin, adiponectin, and kisspeptin-54, in 196 serum samples from female NES at the beginning and end of their breeding and molting fasts. We examined the relationships between these adipokines and life-history stage, adiposity, mass, cortisol, and an immune cytokine involved in the innate immune response interleukin 6 (IL-6). All four adipokines varied with life-history stage. Leptin concentrations were highest at the beginning of the breeding haul-out. Resistin concentrations were higher throughout the breeding haul-out compared to the molt haul-out. Adiponectin concentrations were highest at the beginning of both haul-outs. Kisspeptin-54 concentrations were highest at the end of the breeding haul-out. Leptin, resistin, and adiponectin were associated with measures of body condition, either adiposity, mass, or both. Resistin, adiponectin, and kisspeptin-54 were associated with circulating cortisol concentrations. Resistin was strongly associated with circulating IL-6, a multifunctional cytokine. Adiponectin was associated with glucose concentrations, suggesting a potential role in tissue-specific insulin sensitivity during life-history stages categorized by high adiposity. Increased cortisol concentrations late in lactation were associated with increased kisspeptin-54, suggesting a link to ovulation initiation in NES. This study suggests dramatic changes in circulating adipokines with life-history and body condition that may exert important regulatory roles in NES. The positive relationship between adiponectin and adiposity as well as the lack of a relationship between leptin and kisspeptin-54 differed from model systems. These differences from biomedical model systems suggest the potential for modifications of expression and function of adipose-derived hormones in species that undergo natural changes in adiposity as part of their life-history.
  • Article
    Seasonal habitat preference and foraging behaviour of post-moult Weddell seals in the western Ross Sea
    (The Royal Society, 2023-01-25) Goetz, Kimberly T. ; Dinniman, Michael S. ; Hückstädt, Luis A. ; Robinson, Patrick W. ; Shero, Michelle R. ; Burns, Jennifer M. ; Hofmann, Eileen E. ; Stammerjohn, Sharon E. ; Hazen, Elliott L. ; Ainley, David G. ; Costa, Daniel P.
    Weddell seals (Leptonychotes weddellii) are important predators in the Southern Ocean and are among the best-studied pinnipeds on Earth, yet much still needs to be learned about their year-round movements and foraging behaviour. Using biologgers, we tagged 62 post-moult Weddell seals in McMurdo Sound and vicinity between 2010 and 2012. Generalized additive mixed models were used to (i) explain and predict the probability of seal presence and foraging behaviour from eight environmental variables, and (ii) examine foraging behaviour in relation to dive metrics. Foraging probability was highest in winter and lowest in summer, and foraging occurred mostly in the water column or just above the bottom; across all seasons, seals preferentially exploited the shallow banks and deeper troughs of the Ross Sea, the latter providing a pathway for Circumpolar Deep Water to flow onto the shelf. In addition, the probability of Weddell seal occurrence and foraging increased with increasing bathymetric slope and where water depth was typically less than 600 m. Although the probability of occurrence was higher closer to the shelf break, foraging was higher in areas closer to shore and over banks. This study highlights the importance of overwinter foraging for recouping body mass lost during the previous summer.
  • Dataset
    Location, weathering, bulk isotope, and 14C data for fossil seals from the western Ross Sea, Antarctica from from 2013-2014
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2022-08-22) Hall, Brenda ; Koch, Paul L. ; Costa, Daniel P. ; Hoelzel, A. Rus
    This dataset includes location, weathering, bulk isotope, and 14C data for fossil seals from the western Ross Sea, Antarctica from from 2013-2014. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/732524
  • Dataset
    Thermistor data at 10 cm intervals in air, ice, water from autonomous buoys from ARSV Laurence M. Gould LMG0106 in the Southern Ocean, August to November, 2001 (SOGLOBEC project)
    (Biological and Chemical Oceanography Data Management Office (BCO-DMO). Contact: bco-dmo-data@whoi.edu, 2020-01-22) Costa, Daniel P. ; Fritsen, Chris H.
    Thermistor data at 10 cm intervals in air, ice, water from autonomous buoys from ARSV Laurence M. Gould LMG0106 in the Southern Ocean, August to November, 2001 for the Southern Ocean GLOBEC project. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/3115