Wealth of new species found at the Great Barrier Reef
By Steve Connor, Science Editor

Hundreds of new species of marine creatures, from shrimp-like crustaceans to soft-bodied corals, have been discovered by scientists exploring the rich assortment of life inhabiting the Great Barrier Reef in Australia.

Among the discoveries were dozens of small crustaceans, a rare insect-like animal with a whip-like back leg three times the length of its body and a jellyfish that floats upside down to dangle its tentacles in the sunlight.

About half of the 300 soft corals found are thought to be new discoveries, although they will only be given names and classified formally once the scientists have compared them against existing species. Unlike their hard-bodied cousins, soft corals do not build reefs but are nevertheless considered vital for the marine environment. These colourful animals can dominate some regions of the sea, covering up to 25 per cent of the ocean floor.

The four-year project is centred on the extensive coral reefs of western and north-western Australia and is part of a larger effort to take a census of all marine life in the world, due to be finished in 2010. When complete, the census will be used as a "baseline" to try to quantify the rate at which species are becoming extinct in the marine environment.

Coral reefs are considered to be the rainforests of the sea because of their rich biodiversity. It is estimated that something between one million and nine million species of marine creatures live in and around coral reefs, but scientists have little idea of the precise numbers.

The study, on the Great Barrier Reef and a smaller reef off north-western Australia, aims to estimate this biodiversity by taking samples of corals and seawater at three sites in two ocean basins over a period of several years, said Julian Caley, principal research scientist at the Australian Institute of Marine Science.

"We were surprised and excited to find such a large variety of marine life which had never been described – most notably soft coral, isopods, tanaid crustaceans and worms – and in waters that divers access easily and regularly," he said. "Compared to what we don't know, our knowledge of marine life is a proverbial drop in the ocean. Inventorying the vast diversity and abundance of life across all ocean realms challenges both science and the imagination."

The scientists collected hundreds of specimens belonging to the isopod group of marine animals, which are known as the vultures of the sea because they feed on dead fish. About 100 specimens have not yet been described in the scientific literature, including one that lives as a parasite by burrowing into the mouth of a living fish whose tongue is eventually replaced by the invader's body.

On Lizard Island on the Great Barrier Reef, the scientists found a bustling community of bristle worms – related to terrestrial leeches and earthworms – estimating that about two-thirds of them were new to science. "Some of the worms are stunningly spectacular," said Dr Caley. "One of them burrows into the hard corals and lives by sticking its tentacles out of the end like a feather duster."

One of the phenomena the scientists hope to explain is why some areas of a reef appear to be richer in marine species than others. Ron O'Dor, chief scientist on the Census of Marine Life, said: "Hundreds of thousands of forms of life remain to be discovered. Knowledge of this ocean diversity matters on many levels, including possibly human health. One of these creatures may have properties of enormous value to humanity."

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