Distribution, density and abundance of Antarctic ice seals off Queen Maud Land and the eastern Weddell Sea

The Antarctic Pack Ice Seal (APIS) Program was initiated in 1994 to estimate the abundance of four species of Antarctic phocids: the crabeater seal Lobodon carcinophaga, Weddell seal Leptonychotes weddellii, Ross seal Ommatophoca rossii and leopard seal Hydrurga leptonyx and to identify ecological r...

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Bibliographic Details
Main Authors: Gurarie, Eliezer, Bengtson, John L, Bester, Marthán Nieuwoudt, Blix, Arnoldus Schytte, Cameron, Michael, Bornemann, Horst, Nordøy, Erling Sverre, Plötz, Joachim, Steinhage, Daniel, Boveng, Peter
Format: Dataset
Language:English
Published: PANGAEA 2016
Subjects:
Marine Mammal Tracking
MMT
Antarctic
Southern Ocean
The Antarctic
Weddell Sea
Austral
Pacific
Norway
Indian
Weddell
Queen Maud Land
Hydrurga
Antarc*
Crabeater Seal
Crabeater Seals
Hydrurga leptonyx
Leopard Seal
Leopard Seals
Polar Biology
Ross Seal
Weddell Seal
Weddell Seals
Online Access:https://doi.pangaea.de/10.1594/PANGAEA.864582
https://doi.org/10.1594/PANGAEA.864582
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Summary:The Antarctic Pack Ice Seal (APIS) Program was initiated in 1994 to estimate the abundance of four species of Antarctic phocids: the crabeater seal Lobodon carcinophaga, Weddell seal Leptonychotes weddellii, Ross seal Ommatophoca rossii and leopard seal Hydrurga leptonyx and to identify ecological relationships and habitat use patterns. The Atlantic sector of the Southern Ocean (the eastern sector of the Weddell Sea) was surveyed by research teams from Germany, Norway and South Africa using a range of aerial methods over five austral summers between 1996-1997 and 2000-2001. We used these observations to model densities of seals in the area, taking into account haul-out probabilities, survey-specific sighting probabilities and covariates derived from satellite-based ice concentrations and bathymetry. These models predicted the total abundance over the area bounded by the surveys (30°W and 10°E). In this sector of the coast, we estimated seal abundances of: 514 (95 % CI 337-886) x 10**3 crabeater seals, 60.0 (43.2-94.4) x 10**3 Weddell seals and 13.2 (5.50-39.7) x 10**3 leopard seals. The crabeater seal densities, approximately 14,000 seals per degree longitude, are similar to estimates obtained by surveys in the Pacific and Indian sectors by other APIS researchers. Very few Ross seals were observed (24 total), leading to a conservative estimate of 830 (119-2894) individuals over the study area. These results provide an important baseline against which to compare future changes in seal distribution and abundance.

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