Recovery of the marine environment following the Braer spill, Shetland

Abstract

The oil tanker Braer was wrecked on the south west tip of Shetland in January 1993 spilling 84,000 tonnes of crude oil and 1500 tonnes of bunker oil into the sea. Heavy weather conditions resulted in almost all of the oil being dispersed into the surrounding water producing oil-in-water concentrations near the wreck as high as 20,000 times background. Concentrations fell rapidly with time regaining background values in 30-40 days. As surface slick formation was minimal and most seabirds were offshore at the time of the spill, seabird mortalities were relatively light and seal and otter mortalities were in single figures. Catching and marketing of fish and shellfish for human consumption from the oil contaminated area was prevented by the establishment of a Fishery Exclusion Zone. Oil concentrations in fish from this zone fell to background levels within two months of the spill. Shellfish were more severely affected; the most heavily contaminated regaining background levels within a year. An exception was the sediment dwelling Norway lobster which is still contaminated. Impact on the intertidal habitat was minimal and most shores had recovered within a year. Offshore benthic communities in contaminated sediments did not show evidence of being significantly stressed.