Abstract
The breeding performance of higher predators has often been used to monitor fluctuations in the abundance of important prey stocks in marine ecosystems. The development of electronic data-loggers in recent years has also provided the opportunity of using wide-ranging marine animals to measure physical oceanographic conditions. In this study, time–depth recorders (TDRs) programmed to record temperature were deployed on female Antarctic fur seals (Arctocephalus gazella) at Bird Island, South Georgia (54°00′S; 38°02′W) during the breeding seasons 1994 to 1998. Temperature sensors had relatively slow response times, and thermal radiation errors occurred during the day when seals spent a large proportion of their time at the surface. Nevertheless, measurements provided temperature–depth profiles which were typical of the vertical stratification of the ocean. During the early stages of a foraging trip temperature increased, suggesting that fur seals travelled northwards from South Georgia towards the warmer waters of the Polar Front. In addition, higher temperatures were recorded by females that remained at sea for longer, implying that these individuals also travelled further. Mean sea-surface temperature (SST) increased from ∼1 to 4 °C from December to March and agreed with SSTs from ship, buoy and satellite. Future studies on marine mammals which combine satellite tracking with oceanographic measurements are likely to provide valuable information on biophysical aspects of the ocean.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 16 June 1998 / Accepted: 13 February 1999
Rights and permissions
About this article
Cite this article
McCafferty, D., Boyd, I., Walker, T. et al. Can marine mammals be used to monitor oceanographic conditions?. Marine Biology 134, 387–395 (1999). https://doi.org/10.1007/s002270050555
Issue Date:
DOI: https://doi.org/10.1007/s002270050555