Mammals

Scotland’s seas support internationally important populations of two species of seal – grey seal and harbour (common) seal, and a great variety of whales, dolphins and porpoise (collectively known as cetaceans).

The Seals assessment relies on three datasets: grey seal pup production which until 2010 was surveyed annually and since then biennially; harbour seal moult counts based on surveys around the coast of Scotland on a 5 year cycle; and grey seal summer abundance on land surveyed at the same time as the harbour seal moult counts. The Cetaceans assessment is based on species distribution and population size estimates for the 11 main species found around Scotland plus beaked whales and killer whales. Data are derived from the SCANS-II and SCANS-III surveys of offshore cetaceans and the long-term photo-id surveys of coastal bottlenose dolphins. The two case studies Case study: PBDEs in grey seals and Case study: PCBs in grey seals highlight how monitoring the levels of persistent organic pollutants (POPs) in grey seals can give an indication of levels of these pollutants in the wider North Sea. The Case study: Scottish Marine Animal Stranding Scheme gives an overview of this scheme.