The k2p blog

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:

A newly discovered copepod (Image: Jan Michels)

“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.

Fisher and Blomberg report their findings in the current issue of the Proceedings of the Royal Society B. These trends likely apply to other taxonomic groups, such as birds, they suspect. The study shows that most of these species turned up alive after only three or more thorough field searches. All told, 67 species once considered missing have since been rediscovered.

“It’s an encouraging number,” says conservation biologist Ana Davidson, a postdoctoral researcher at the University of New Mexico, Albuquerque, who was not involved in the study. “It provides us with incentives for future searches.”

Also a few days ago the BBC reported that:

Omaniundu reed frog

A mission aimed at rediscovering amphibian species thought to be extinct has  turned up live specimens of two West African frogs and a cave-dwelling salamander from Mexico. The cave splayfoot salamander (Chiropterotriton mosaueri)was last seen in 1941, and was rediscovered by abseiling into caves deep in the forest. The West African species – the Omaniundu reed frog (Hyperolius sankuruensis) from Democratic Republic of Congo, last seen in 1979, and the Mount Nimba reed frog (Hyperolius nimbae) from Ivory Coast, unknown since 1967 – are particularly intriguing, as both countries are subject to fairly intensive habitat loss.

There have been at least 5 “mass extinctions” in the history of the earth. Each extinction is what in fact has created the space and conditions for new species to appear. Humans probably would not have had the space or conditions to evolve if not for the extinction of the dinosaurs.

1. Cretaceous-Tertiary extinction, about 65 million years ago, probably caused or aggravated by impact of several-mile-wide asteroid that created the Chicxulub crater now hidden on the Yucatan Peninsula and beneath the Gulf of Mexico. The extinction killed 16 percent of marine families, 47 percent of marine genera (the classification above species) and 18 percent of land vertebrate families, including the dinosaurs.
2. End Triassic extinction, roughly 199 million to 214 million years ago, most likely caused by massive floods of lava erupting from the central Atlantic magmatic province — an event that triggered the opening of the Atlantic Ocean.The death toll: 22 percent of marine families, 52 percent of marine genera. Vertebrate deaths are unclear.
3. Permian-Triassic extinction, about 251 million years ago.The Permian-Triassic catastrophe was Earths worst mass extinction, killing 95 percent of all species, 53 percent of marine families, 84 percent of marine genera and an estimated 70 percent of land species such as plants, insects and vertebrate animals.
4. Late Devonian extinction, about 364 million years ago, cause unknown. It killed 22 percent of marine families and 57 percent of marine genera. Erwin said little is known about land organisms at the time.
5. Ordovician-Silurian extinction, about 439 million years ago, caused by a drop in sea levels as glaciers formed, then by rising sea levels as glaciers melted. The toll: 25 percent of marine families and 60 percent of marine genera.

So, assuming that extinction of humans is something to be avoided,  how exactly is biodiversity a problem?

Tags: Biodiversity, Census of Marine Life, lost species refound, Marine biology

This entry was posted on October 5, 2010 at 8:03 am and is filed under Biodiversity, Development, Environment, Evolution, Science, Wildlife. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.