DESPITE centuries of scientific inquiry, so little is known about most of Earth's estimated 8.7million living species that even a tiny series of marine samples can result in the discovery of many new species.
This was again the experience of a team of marine biologists from UCT, who recently
found more than 10 species new to South Africa, and two new to science, all within a single subgroup of crustaceans and sampled from an area just two metres square in Sodwana Bay on the KwaZulu-Natal North Coast.
Team leader Professor Charles Griffiths, of UCT's Marine Biology Research Centre, said they had been able to determine the status of these particular species simply
because he had the experience to identify them accurately.
"There would be many more in the other groups which we cannot identify with certainty."
Griffiths was responding to the Cape Argus's request for comment on new research by scientists of the Census of Marine Life (CoML) project.
The findings, published last week, put the number of species at 8.7 million, of which
less than 15 percent have been formally described by science.
About 6.5 million of these species live on land and 2.2 million in the ocean, according to their calculation which, although an estimate, has the highest degree of certainty of any estimates yet made.
Griffiths, who was leader of the CoML group in Africa, said the researchers had made some assumptions in their new estimate – for example, that the taxonomic groupings of families, genera and species all had a similar structure.
"But the fact that most species on Earth are undescribed is certainly true and accepted by all taxonomists, and I can provide many local examples where a tiny series of marine samples has resulted in discovery of many new species.
"I absolutely agree with the comment (by Lord Robert May of Oxford, past president of Britain’s Royal Society) that it’s crazy that we can list all the books in the Library of Congress, or all the telephone subscribers or taxpayers in any country, but not all the species on Earth."
Professor Melodie McGeoch, general manager of SA National Parks' Cape Research Centre, said the new research provided "quite a bit" to think about.
"My first impression, on having given it a quick read, is that it provides numbers that seem much more reasonable than previous approaches, and which at the same time are more defensible.
“The method used is a big improvement – it's more robust – on previous methods.
"It's interesting to note that insects at the very least make up more than 12 percent of all species on the planet, and the percentage will be higher than this. The same method can be applied across marine and terrestrial environments and across all groups of species. This wasn't possible with any degree of confidence before."
Professor Gavin Maneveldt, head of the department of biodiversity and conservation biology at UWC, said it was accepted among biological scientists that most species across the planet were undiscovered and undescribed.
"Most of this biological diversity it to be found in the oceans. The oceans contain roughly 99 percent of the living space on the planet and it’s estimated that around 80 percent of all life on the planet is found under the ocean’s surface."
Environment & Science Writer
Article posted by: (31 August 2011)