OIL SPILL CASE STUDY - Sea Empress

Shoreline

The map below shows the approximate extent of coastline that was affected by heavy oil pollution during February and March of 1996. The heaviest and most persistent oiling affected shores to the south and east of the point of grounding. The degree of oil pollution within this area was very variable. Although some shores were badly affected by bulk oil pollution, others experienced only light oiling. All types of shore were affected by slicks, from wave-exposed rocky cliffs to sheltered muddy creeks. Substantial quantities of oil were stranded on certain sandy shores. Over 100km of coastline of outstanding beauty became seriously polluted by oil.

Marine organisms

The bulk oil affected seaweeds and invertebrates were killed in large quantities. Seaweeds and shore invertebrates were smothered by oil along the rocky shores, as were shellfish on sandy beaches and rock pool fishes. Some resistant shore species survived the oil and its residues, and these species were supplemented by plant and animal colonisers soon after the spill.

The species which live within the sediments appeared to be relatively unaffected by the spill apart from amphipods (small crustaceans which are important in the food chain). The removal of these organisms may have been due to the impact of the chemical dispersants within the water column. The most exposed shore recovered most quickly due to the dispersive ability of the tide and the waves. The more sheltered shores suffered from persistent residues, which although buried within the sand and mud were remobilised during autumnal storms. However these storms did accelerate the natural cleansing of the coast and by spring 1997 (just over a year after the spill) only a few shores showed any visible evidence of oiling. Therefore although the initial impact of the spill was severe, the oil naturally dispersed and had very little lasting effect on the local environment.

Birds

The plight of the birds that use the seas around South-West Wales was one of the most visible of the tragedies caused by the Sea Empress oil disaster. The birds at sea were hit hard during the early weeks of the spill resulting in thousands of casualties. More than 2,200 birds were reported to have been killed in the three weeks after the incident. The seabird most affected by the spill was the Scoter, a small duck with occurred in large groups on the sea surface. The programme to clean the seabirds had only limited success. To find out more infromation on the Scoter, click on the following link