Short-term impact
Birds and mammals
The impact of the Sea Empress oil spill on birds and mammals was relatively slight as compared with the quantities spilled by the tanker. The statistics supplied by the RSPCA (Royal Society for the Prevention of Cruelty to Animals) revealed that 2,961 dead birds and 6,900 oiled birds were reported.
Three thousand five hundred oiled birds were cleaned and three quarters of them survived. The main species hit by the spill were the common scoter (Melanitta nigra), guillemots (Uria aalge), cormorants (Phalacrocorax carbo) and penguins (Alca torda).
Bird colonies on the islands of Skomer and Skokholm were not unduly affected by the spill. Note in passing that the ban on overflights of these islands/bird sanctuaries by JRC certainly avoided scaring the birds that were nesting there and avoided forcing them to flee towards the slicks where they would only have been coates with oil when diving and thus causing much higher mortality rates.
However, WWF considers that only 10% of the dead birds were ever collected which implies that bird deaths were far higher than those reported.
Two hundred and sixty seals were oiled but no deaths were reported.
Fishing
On the 1st March, fishing was banned from Saint David’s Head to the Gower peninsula near Swansea.
The ban was extended to the estuaries and rivers that cateer to migratory species such as salmon and sea trout. Fish tend to start spawning in the rivers round about the month of April and line fishing starts in the area on the 20th March. The ban on river fishing was lifted on 20th May.
Overal assessment of the pollution
• 60,000 tonnes were pumped off the vessel and shipped to the Texaco refinery;
• 73,000 tonnes were spilled :
- 35 to 40 % evaporated (according to OSIS)
- 10 to 20 % dispersed naturally (according to OSIS)
- 6 % were collected at sea
- 3 to 5 % were collected ashore
- 13 % were chemically dispersed
- 20 % could be buried or trapped.