Strandings of striped dolphin Stenella coeruleoalba in Scottish waters (1992-2003) with notes on the diet of this species

During 1992 - 2003, 52 striped dolphin strandings were recorded in Scotland (UK). Although strandings were recorded in every month of the year, highest numbers were found in January-March and August. Striped dolphins were stranded all around the Scottish coast, but the majority were recovered from the west coast. Necropsies were carried out on 33 of these animals: 29 had live-stranded and cause of death was not established for four animals. Stomach contents were analysed for 20 animals: whiting and Trisopterus were the main prey species in the diet (both by number and by reconstructed biomass). Females had a higher average number of Trisopterus in their stomachs than did males. Trisopterus eaten in winter were larger than Trisopterus eaten in summer and both Trisopterus and whiting eaten on the east coast were bigger than those eaten on the west coast. The reproductive status was determined for six females and six males during 2001 - 2003, with the majority being immature but the sample included one pregnant female and one sexually active mature male. We calculated the length-weight relationship for this species in Scottish waters. In addition, age data were collected from samples obtained during necropsies on six striped dolphins: the oldest dolphin sampled was around 14 y old but the majority were 2-7 y old. Although the numbers are low, the regular occurrence of stranded striped dolphins in recent years around Scotland, suggests that this warm water species may now be considered resident in Scottish waters.