Over the past few decades, Skomer Island off the south coast of Wales has witnessed a remarkable resurgence in its guillemot population. Before 1930, Skomer was home to over 100,000 common guillemots. But by the end of the second world war, this number had plummeted by about 95% and continued to decline for the next few decades.
This population decline was probably caused by chronic oil pollution during the second world war and several major oil tanker incidents in the subsequent years. In 1967, for example, the supertanker SS Torrey Canyon spilled over 100,000 tonnes of crude oil into the English channel.
