Southern Elephant Seal Foraging in the Southern OceanEntry ID: ASAC_468
Abstract: Twenty three juvenile (8-14 months of age) southern elephant seals (Mirounga leonina L.) from Macquarie Island were tracked during 1993 and 1995. Migratory tracks and ocean areas with concentrated activity, presumed to be foraging grounds, were established from location data gathered by attached geolocation time depth recorders. The seals ranged widely (811-3258 km) and foraging activity centred ... on oceanographic frontal systems, especially the Antarctic Polar Front and bathymetric features such as the Campbell Plateau region. The seals spent 58.6% of their sea time within managed fishery areas while the remainder was spent on the high seas, an area of unregulated fishing. The Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) areas 58.4.1, 88.2 and especially 88.1 were important and distant foraging areas for these juvenile elephant seals. From fisheries records, diet and the foraging ecology studies of the seals there appears to be little, if any, overlap or conflict between the seals and commercial fishing operations within the regulated commercial areas. However, attention is drawn to the possibility of future interactions if Southern Ocean fisheries expand or new ones commence.
The dive duration of 16 underyearling (6-12 months old) southern elephant seals Mirounga leonina during their second trip to sea was investigated using geolocating time depth recorders. Underyearling seals had a lesser diving ability, with respect to duration and depth, than adult southern elephant seals. Individual underyearlings dived for average durations of up to 20.3 minutes and depths up to 416m compared to durations and depths of 36.9 minutes and 589m, respectively for adults. Dive duration was positively related to their body mass at departure, indicating that smaller seals were limited to shorter dive durations, perhaps as a result of their lesser aerobic capacity. All seals often exceeded their theoretical aerobic dive limit (average of 22.1 plus/minus 18.1%). The number of dives exceeding the theoretical aerobic dive limit was not related to mass, suggesting that factors other than mass, such as foraging location or prey availability, may have been responsible for the differences in diving effort. Foraging ability, indicated by the ability of the seals to follow vertically moving prey, was positively related to seal mass, indicating that small mass restricted foraging ability. The shorter dive durations of the smaller seals inferred that they had shallower dive depths in which to search for prey, thus restricting foraging ability. Although foraging ability was restricted by size, foraging success was found to be inversely related to mass, the smaller seals gaining a higher proportion of blubber than larger seals during their foraging trips. Thus, despite smaller seals being restricted to shallower depths and shorter durations, their foraging success was not affected.
The fields in this dataset are:
Days at Sea
Sea Surface Temperatures (degrees C)
Departure Mass (kg)
At sea mass gain (kg)
Rate of mass gain (kg)
Divers per hour
Total Time Diving
% trip diving
Theoretical Aerobic Dive Limit
Data Set Citation
Dataset Originator/Creator: Burton, H. and van den Hoff, J.
Dataset Title: Southern Elephant Seal Foraging in the Southern Ocean
Dataset Series Name: CAASM Metadata
Dataset Release Date: 2003-03-06
Dataset Publisher: Australian Antarctic Data Centre
Dataset DOI: doi:10.4225/15/5812a9f77700dOnline Resource: https://data.aad.gov.au/aadc/metadata/metadata_redirect.cfm?md=/AMD...
Start Date: 1991-09-30Stop Date: 1992-03-31
BIOLOGICAL CLASSIFICATION > ANIMALS/VERTEBRATES
BIOLOGICAL CLASSIFICATION > ANIMALS/VERTEBRATES > MAMMALS
BIOSPHERE > ECOLOGICAL DYNAMICS > SPECIES/POPULATION INTERACTIONS > MIGRATORY RATES/ROUTES
BIOSPHERE > ECOLOGICAL DYNAMICS > SPECIES/POPULATION INTERACTIONS > USE/FEEDING HABITATS
BIOLOGICAL CLASSIFICATION > ANIMALS/VERTEBRATES > MAMMALS > CARNIVORES > SEALS/SEA LIONS/WALRUSES
Quality Values provided in temporal coverage are approximate only.
Access Constraints These data are publicly available for download from the provided URL.
Use Constraints This data set conforms to the PICCCBY Attribution License
Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_468 when using these data.
Data Set Progress
Distribution Media: HTTP
Distribution Size: 75 kb
Distribution Format: Excel
Role: TECHNICAL CONTACT
Phone: +61 3 6232 3447
Fax: +61 3 6232 3351
Email: john_van at aad.gov.au
Australian Antarctic Division 203 Channel Highway
Province or State: Tasmania
Postal Code: 7050
van den Hoff, J., Burton, H.R., Hindell, M.A., Sumner, M.D., McMahon, C.R. (2002), Migrations and foraging of juvenile southern elephant seals from Macquarie Island within CCAMLR managed areas., Antarctic Science, 14, 2, 134-145
Irvine, L.G., Hindell, M.A., van den Hoff, J., Burton, H.R. (2000), The influence of body size on dive duration of underyearling southern elephant seals (Mirounga leonina ), Journal of Zoology (London), 251, 463-471
Extended Metadata Properties
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Creation and Review Dates
DIF Creation Date: 2000-07-28
Last DIF Revision Date: 2016-12-02