Between a quarter and a third of the world’s wildlife has been lost since 1970, according to the Zoological Society of London. Populations of land-based species fell by 25%, marine by 28% and freshwater by 29%. Humans are wiping out about 1% of all other species every year in one of the “great extinction episodes” in Earth’s history.
http://news.bbc.co.uk/2/hi/uk_news/7403989.stm