Bbc Inside Science

Invasive alien species from the cursed Signal Crayfish to the scourge of gardeners, the Japanese Knotweed, are considered some of the biggest threats to biodiversity. This year the EU has launched new legislation that attempts to limit their spread. But how big a threat are they to ecosystems? Science writer Fred Pearce author of The New Wild argues that ecologists are committed to protecting pristine environments from alien invaders, when we should be embracing the changing ecology that invasive species enable. Adam Rutherford discusses the conflicting approaches to invasive species with Fred Pearce and Dr Helen Roy - a scientist at the Centre for Ecology and Hydrology.Corals make up only 0.1% of the ocean floors, but account for up to a quarter of all marine life. A new exhibition at The Natural History Museum is showcasing some of the work of the Catlin Seaview Survey, which is compiling a huge pictorial health check of various reefs to act as a snapshot against which all future reef changes can be compare