More than a quarter of the world's wildlife has been lost in the last 35 years according to a WWF (Worldwide Fund for Nature) report, compiled by the ZSL (Zoological Society London) and launched today.
The Living Planet Index monitors more than 1,400 species. From 1970 to 2005 the report shows an overall fall in population trends of 27%.
The declines are due to human activity such as habitat destruction, pollution, overexploitation such as fishing, the spread of invasive species and climate change.
Today's report highlighted 1,477 of the world's species. However, there is an amazing estimated 1.8 million species on Earth, and some scientists say even this is only 20% of the total as most are undiscovered.
Of the marine species covered in the report, 320 were monitored. The oceans are home to around 230,000 known species of organisms and the majority are tiny creatures called invertebrates, like crabs, squid, starfish and sea squirts.
Experts say that to get a truer picture of the world's biodiversity, we need to monitor a larger number of species and we still need to describe and name what is likely to be thousands more undiscovered ones.
Natural History Museum zoology expert, Geoff Boxshall, says that of the 230,000 known marine species, there are more than 52,000 species of molluscs (snails, clams, squid and relatives), 45,000 species of crustaceans (crabs, shrimps and their relatives), 12,000 species of worms, and even 5,000 species of sea squirts, and none of these are covered by today's report.
'In addition there are huge numbers of species still to be described,' Boxshall explains. 'This vast diversity of invertebrates is largely unmonitored and we have no real indication what is happening to them. The trends may well be towards biodiversity loss in the oceans but we simply don't know.'
The natural world faces unprecedented challenges and species are disappearing at an alarming rate.
Concerning marine biodiversity, Boxshall concludes, 'We need more and better data on invertebrates that dominate marine ecosystems, before we can assess the true state of the oceans. But we should adopt a precautionary approach and designate sufficient marine protected areas before it is too late.'
The WWF calls on governments to develop more biodiversity protection plans and urgently implement the Convention on Biodiversity Programme of Work on Protected Areas.