Butterfly effect

That the flap of a butterfly’s wing might lead to a storm or other event halfway around the globe is a popular image used to introduce chaos theory. But two small lepidopterans appear to have played a major part in the scrapping of plans to build a new nuclear power station on a shingle bank in the south-east of England, which is becoming an increasing focus in the International Year of Biodiversity. Two charities, Butterfly Conservation and Buglife, had highlighted the biodiversity on this shingle bank in Dungeness, the largest in Europe. Scarce and threatened species include the only known British population of the Sussex Emerald moth (Thalera fimbrialis) and the largest population of the White Spot moth (Hadena albimacula) in the country. The UK’s energy and climate change secretary, Ed Miliband, cited biodiversity and habitat considerations as part of the decision not to go ahead with plans for a new nuclear plant at the site. Britain has an electricity generation problem looming as several nuclear power stations are due for decommissioning in the next few years. Because coal, once a major source of electricity for the country, is now out of favour because of the greenhouse gas emissions, the government plans to build a new nuclear plant at the site of most of the current plants. But in the early stages of the lengthy consultation and planning process, the proposals for Dungeness have already been abandoned. The Dungeness site is extraordinary — five kilometres of shingle stretch inland from the sea. Apart from the power station, a few fishermens’ houses and huts and fenced areas for the Ministry of Defence mark the area. And a nature reserve is also squeezed in. The film-maker Derek Jarman famously created a driftwood garden around his house here. But the Sussex Emerald moth shuns the conservation areas and is almost wholly found behind the fence of the power plant. Surveys have found the caterpillars on wild carrot plants growing on disturbed land around the plant and not elsewhere. While humans appear to have created the environment these moths prefer, it would take little further activity to wipe them out. Researchers have studied several other sites in southern England that might be suitable for the moths, but the combination of the right vegetation and stony, partly disturbed land has not been found. Humans have created an