Yesterday The Guardian reported that
While some 230,000 marine species have been recorded there are thought to be at least 1 million species in the sea. Ian Poiner, chair of the Census of Marine Life (COML) steering committee, said: “All surface life depends on life inside and beneath the oceans. Sea life provides half of our oxygen and a lot of our food and regulates climate. We are all citizens of the sea”. To mark the end of the COML project, scientists at the British Antarctic Survey (BAS) showed off the results of the Census of Antarctic Marine Life, an inventory of more than 16,000 marine species and the culmination of more than 19 trips into Antarctic waters.
In fact the total is unknown and may be as many as 10 million. The New Scientist points out:
“There are three to four unknown species for every known,” says Paul Snelgrove of Memorial University of Newfoundland in St John’s, Canada.
The Census has so far added 1200 new species to the tally, though that is likely to rise as over 5000 more organisms that were collected have yet to be studied or named. The new species include several that were thought to have disappeared, such as the “Jurassic shrimp”, which was believed to have died out 50 million years ago.
The Census was also able to identify those regions that are richest in diversity, which include the Gulf of Mexico and the Australian coastline. The Galapagos Islands, meanwhile, turned out to have less biodiversity than the chilly South Orkney Islands, in the Southern Ocean near Antarctica.
However, plant and animal diversity looks insignificant compared to the sea’s micro-organisms, which may number 1 billion. Their diversity is “spectacular”, Snelgrove says.
Just a few days ago Science reported that
Diana Fisher and Simon Blomberg of the University of Queensland in Australia carried out a comprehensive analysis of missing and extinct mammalian species. They created a database of all 187 mammal species that have been identified as extinct or possibly extinct, then combed through the literature to find out which ones had been rediscovered. They also included what threats the species had been facing, such as habitat destruction or hunting.

