Census of Marine Life

Orange roughy, at risk in New Zealand waters

Over the past ten years, more than 2,700 scientists from 82 nations involving 538 field expeditions backed by US$650 million of funding have been conducting a census of global marine life. Now the results are becoming available in final form.

In October the Census of Marine Life will publish more detailed, final results but advance estimates have recently become available. The research has so far counted over 230,000 individual species.

The Guardian Weekly sums up the Census results nicely (full article here):  

"The results show that around a fifth of the world's marine species are crustaceans such as crabs, lobsters, krill and barnacles. Add in molluscs (squid and octopus) and fish (including sharks) and that accounts for up to half of the number of species in the world's seas. The charismatic species often used in conservation campaigning – whales, sea lions, turtles and sea birds – account for less than 2% of the species in the world's oceans. 

The surveys have also highlighted major areas of concern for conservationists. "In every region, they've got the same story of a major collapse of what were usually very abundant fish stocks or crabs or crustaceans that are now only 5-10% of what they used to be," said Mark Costello of the Leigh Marine Laboratory, University of Auckland in New Zealand. "These are largely due to over-harvesting and poor management of those fisheries. That's probably the biggest and most consistent threat to marine biodiversity around the world."

The main threats to date include overfishing, degraded habitats, pollution and the arrival of invasive species. But more problems are around the corner: rising water temperatures and acidification thanks to climate change and the growth in areas of the ocean that are low in oxygen and, therefore, unable to support life."

The Guardian UK also has some very useful graphics providing more detailed information on various ecosystems and regions of the world here and a brief item on just how the census takers count marine species and how they estimate species yet to be discovered here.

 The advance results of the Census were published in the 2 August issue of the Public Library of Sciences ONE Journal available here.

Both New Zealand and Australia have huge marine resources surrounding their coastlines and have equally huge tasks ahead of them in managing those resources in more sustainable ways. Better management requires better knowledge and the Census of Marine Life is an important improvement in that knowledge base.

 Hoki, at risk in New Zealand waters