Responses of seabirds, in particular prions (Pachyptila sp.), to small-scale processes in the Antarctic Polar Front
Small-scale distribution patterns of seabirds in the Antarctic Polar Front (APF) were investigated in relation to other biological, physical, and chemical features during the ANT-XIII/2 research cruise of R.V. Polarstern from December 1995 to January 1996. The APF is characterized by steep gradients...
Published in: | Deep Sea Research Part II: Topical Studies in Oceanography |
---|---|
Main Authors: | , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2002
|
Subjects: | |
Online Access: | https://hdl.handle.net/11370/3c8e3e09-5417-4b8a-971d-22625c4f186d https://research.rug.nl/en/publications/3c8e3e09-5417-4b8a-971d-22625c4f186d https://doi.org/10.1016/S0967-0645(02)00118-2 https://pure.rug.nl/ws/files/9931299/2002DeepSeaRes2vFraneker.pdf |
Summary: | Small-scale distribution patterns of seabirds in the Antarctic Polar Front (APF) were investigated in relation to other biological, physical, and chemical features during the ANT-XIII/2 research cruise of R.V. Polarstern from December 1995 to January 1996. The APF is characterized by steep gradients in sea-surface temperature and salinity. Within the APF, gradient zones were closely associated with elevated levels of primary production, chlorophyll-a (chl-a) concentrations, and zooplankton densities. Even broad-billed prions ('Pachyptila vittata-group'), which dominated the seabird community by 83% in carbon requirements, showed small-scale distributional patterns that were positively related to primary production, chl-a, and total zooplankton densities. The findings demonstrate a close, direct link between fine-scale physical processes in the APF and biological activity through several food web levels up to that of zooplankton-eating seabirds. Broad-billed prions appeared to forage on very small copepods (Oithona spp.) in close association with the front. Fish- and squid-eating predators showed poor correlations with small-scale spatial structures of the APF. However, in a wider band around the APF, most top predators did occur in elevated densities, showing gradual spatio-temporal diffusion of the impact of the APF on higher trophic levels. (C) 2002 Elsevier Science Ltd. All rights reserved. |
---|