© 1997 by ICES/CIEM International Council for the Exploration of the Sea/Conseil International pour l'Exploration de la Mer
Distribution of seabirds in the northern Gulf of Mexico in relation to mesoscale features: initial observations
USGS BRD, Department of Wildlife Ecology, University of Wisconsin 226 Russell Labs, 1630 Linden Drive, Madison, Wisconsin, 53706-1598, USA
Department of Marine Biology, Texas A&M PO Box 1675, Galveston, Texas, 77553, USA
Correspondence to C. A. Ribic: tel: +6082636556; fax: 6082626099; email: caribic{at}facstaff.wisc.edu
The presence of seabirds was related to offshore surface eddies and the freshwater plume of the Mississippi River in the northern Gulf of Mexico during autumn, winter, spring, and summer 1992–1993. Skuas (Stercorarius spp.) were the most common bird seen in autumn, whereas skuas and gulls (Larus spp.) were the most common in winter. Few birds were seen in the spring, and terns (Sterna spp.) were the most common birds seen in late summer. During summer, terns were associated with the freshwater plume of the Mississippi River. In the winter, herring (Larus argentatus) and laughing gulls (L. artricilla) were associated with areas with steep thermoclines, while pomarine skuas (Stercorarius pomarinus) were found in areas of low productivity. Herring and laughing gulls in the winter, all birds in the spring, and terns in the summer were more common outside eddies. Only pomarine skuas in the winter were seen more commonly inside warm-core eddies.
Keywords: eddies, freshwater plume, Gulf of Mexico, mesoscale, productivity, seabirds