THE Rockall Trough off western Scotland, where Shell wanted to dump the Brent Spar, is âamong the richest environments in the whole worldâ, says John Lambshead of the Natural History Museum in London. The seabed dump site, which energy minister Tim Eggar claimed last week contained âjust a few wormsâ, may in fact be home to more species than the richest rainforest, even if most of them are microscopic mud-dwelling nematodes.
Speaking at the British Associationâs Annual Festival of Science in Newcastle upon Tyne this week, Lambshead contradicted another speaker, who claimed that dumping waste at sea would not damage valuable biological resources.
Research into nematodes is causing biologists to radically revise their estimates of the number of species on the planet. There may be 100 million species of nematodes, says Lambshead, who is a specialist in these worms. Most inhabit the sediments of the deep oceans. They may make up three-quarters of all the planetâs species, previously estimated to number about 30 million. And the Rockall Trough is one of the places where they congregate in greatest profusion and variety.
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In a paper to be published later this year, Lambshead and Guy Boucher of Franceâs national research agency, the CNRS, point out that the slopes that plunge from the edge of the continental shelves, known as bathyal regions, contain a greater range of species than anywhere else on land or sea. An analysis of sediment from 17 seabed sites â from European estuaries to the Great Barrier Reef in Australia and the deep Atlantic Ocean â found that the bathyal region of the Rockall Trough has more species than any other area so far measured.
Bathyal regions âhave much greater biodiversity than coral reefs, which are often said to be the rainforests of the oceanâ, says Lambshead. âCoral reefs have more vertebrates, but much less overall biodiversity.â
Gordon Patterson, also of the Natural History Museum, says that in 16 sediment cores taken from the Rockall Trough area, containing 4 cubic metres of material, he found 325 species of a single group of worms he was studying, and numerous other species he never bothered to count. âBy anybodyâs standards, that is high biodiversity,â he says.
Boucher and Lambshead argue that the conventional view that marine biodiversity declines with depth is wrong. Maximum biodiversity occurs in bathyal regions, between 1000 and 3000 metres down, they say. Nor does biodiversity in the deep ocean decrease away from the tropics, as it does on land. The Rockall Trough has significantly greater diversity than the San Diego Trough, off California, for instance.
Like other researchers with detailed knowledge of the ocean bed in the Rockall Trough, Lambshead claims he was not contacted by Shellâs consultants during their three-year environmental impact study of the Brent Spar dumping ground (This Week, 26 August). âWhen I read that Shell claimed the area where they planned to dump the Brent Spar was a quiet area, low in biodiversity, I was staggered. It was 50 years out of date,â he says.
Lambsheadâs presentation to the BA contradicts another paper, by Martin Angel of the Institute of Oceanographic Sciences in Surrey. In discussing the opportunities for waste disposal in the deep sea, Angel argued that environmentalists should not be allowed to shut off this option to deal with âlarge-bulk low-toxicity wastesâ. Angel claims that âthere are almost without exception no living resources worth exploitingâ on the deep seafloor.
âThere may not be much deep-sea fishing, but what about genetic resources?â Lambshead counters. âAfter all we donât eat much meat from the rainforest, but drug companies think the rainforests contain huge genetic resources. The same may be true of the deep ocean.â
Angel also argues in his paper that local dumping would cause âno impact on biodiversity ⊠because the distribution of species are ocean basin in scaleâ. Lambshead says there is not enough evidence to support this view, especially when it comes to the smaller animals. âWe know far too little about them,â he says.
Lambshead calls for more research into nematodes. So far, he says, their contribution to global biodiversity has gone unrecognised because there are only about twenty active marine nematode taxonomists in the world. They describe about 10 new species a year, and so far only 4000 marine species have been described.
But that doesnât mean the species arenât there. Methods routinely used to estimate the number of species on land suggest that there are many tens of millions of marine species, and up to 100 million nematodes alone, he says. Nematodes, says Lambshead, rank with insects and fungi among the most species-diverse groups of organisms on Earth.
