|Diet and fish stock availability as possible factors in the mass death of auks in the North Sea|
Blake, B.F. (1984). Diet and fish stock availability as possible factors in the mass death of auks in the North Sea. J. Exp. Mar. Biol. Ecol. 76: 89-103
In: Journal of Experimental Marine Biology and Ecology. Elsevier: Tokyo; Oxford; New York; Lausanne; Shannon; Amsterdam. ISSN 0022-0981, more
In February 1983 more than 30000 birds died on the North Sea coasts of England and Scotland.The birds were unoiled, and there was no immediately obvious cause of death. Stomach contents of aukskilled in this incident were examined to ascertain whether they provided any indication of the causal factors.Analysis of food remains showed differences between sample sites and between guillemots,Uris aalge(Pont.), and razorbills, Alca torda L. In all areas gadoid remains comprised a higher, and sandeels a lesser, proportion of the stomach contents in guillemots than in razorbills. The relative importance of clupeidremains varied with area. These differences, combined with current trends in the fisheries biology of majorprey species, provided an ecological basis for a hypothesis explaining the incident. It was concluded thatstarvation was probably a major factor in the death of the auks, and that this may have been related toa combination of adverse weather conditions and changing patterns of abundance in North Sea sprat,Sprattus sprattus (L.), populations.