|Cetaceans in British waters|
Evans, P.G.H. (1980). Cetaceans in British waters. : 1-3
This paper summarizes the results of about two thousand sightings involving nearly 25,000 individual animals between the years 1958-1978 (but mainly from the last 10 years) and relates them to existing information collected from other sources. Difficulties of identification and potential sources of bias are discussed. Most large cetaceans are present in British waters as part of a latitudinal feeding migration whereas smaller species may be present in the N.E. Atlantic throughout the year with movements being mainly of an offshore-inshore nature. Some species are clearly very rare probably as a result of over-exploitation in the last century and early part of this century. Present evidence suggests that only the large whales exhibit definite latitudinal migrations, all other spcies being resident at high latitudes although they may show offshore-inshore or possibly small latitudinal movements. Many of the movements indicated from the present analysis can be linked to the seasonal changes in food availability and to the timing and geographical location of breeding, and these are described in detail. Many concentrations of a particular cetacean species occur regularly in the same area year after year and these may often be related to spawning concentrations of a particular fish species. Variations in herd size are noted between species and within species at different times of the year. These are related to aggregations associated with feeding, breeding, and long-distance movements which will vary according to the biology and ecology of different cetacean species.