Aberdeen – bottlenose dolphins and white-beaked dolphins

The coastal waters of Aberdeenshire are regularly inhabited by four species of cetacean; the harbour porpoise, bottlenose dolphin, white-beaked dolphin and minke whale (several further species occur on an infrequent basis). Dedicated boat- and land-based surveys to monitor the bottlenose dolphins and other cetaceans first began in April 1999, with the establishment of the South Grampian regional group of the Sea Watch Foundation. Surveys have continued on an irregular basis over the following years, according to funding and boat availability. This work has resulted in a number of scientific papers and conference presentations on the distribution, seasonality and abundance of cetaceans (primarily bottlenose and white-beaked dolphins) using the coastal waters off Aberdeen.

Bottlenose dolphins are the most frequently reported cetacean in the coastal waters off Aberdeenshire, and their occurrence appears to have increased since the early 1990s. While sighted throughout the year, bottlenose dolphins show peak occurrence during the winter and spring months, particularly between March and May. During this period bottlenose dolphins can be observed almost daily in the mouth of Aberdeen Harbour, where they spend many hours foraging and feeding on salmonids between the breakwaters.

The study of bottlenose dolphins worldwide relies predominantly on photo-identification methods, where the dorsal fins are photographed and the pattern of nicks, notches and scars is used to catalogue individuals and re-identify them in future. This process can be used to follow the movements of individual animals over space and time using a mark-recapture principle, producing information on dolphin distribution and seasonal movements, population size, site fidelity, social ecology, survival rates, and reproductive parameters such as calving intervals and length of calf dependency. Photographing individuals over time provides an indication of how frequently particular animals are using Aberdeenshire waters, which has implications for their conservation and management.

Images taken of dolphins off Aberdeen have been compiled into the Aberdeen Cetacean Catalogue (ACC). Researchers at the University of Aberdeen included the ACC in a wider comparison of bottlenose dolphin catalogues from other Scottish waters. Numerous dorsal fin matches between the areas confirmed that the bottlenose dolphins seen off Aberdeen belong to a larger north-east Scotland population that ranges widely from the inner Moray Firth south as far as Scarborough in England.