Changes in otter numbers in Shetland between 1988 and 1993

The otter population in Shetland has increased significantly between 1988 and 1993, with more animals being found on all coastal strata and in all parts of the archipelago except South Mainland, the only area to show a decline. South Mainland is where the tanker Braer grounded in January 1993 and the subsequent oil spill might have affected the distribution of otters there. The causes of the changes are unknown and it is not known what happened to the otters in South Mainland after the spill, but it is is highly unlikely that the large increases recorded elsewhere on the archipelago were caused by the movement of animals away from South Mainland .