MercoPress. South Atlantic News Agency

Toothfish and Antarctic fish research.

RESEARCH which could have help combat toothfish poaching is being carried out by a team of scientists who visited the Falkland Islands last week.

Thirty-one scientists are on board the Nathaniel B Palmer, working on around twenty different projects. Bill Dietrich, professor of biochemistry and marine biology at North Eastern University in Boston, is interested in the, "adaptation biology of cold living organisms," in particular Antarctic fish. He has been working in Antarctic waters since 1981 and says the purpose of this latest voyage is, "...to study the sub-Antarctic species that are closely related to the species of what we call the high latitude Antarctic. "I have worked for some twenty years studying fish at Palmer Station and McMurdoch station, very far south, but I have not had the opportunity to study the fish which would represent essentially the ancestors of the Antarctic fishes." Professor Dietrich says research into the Patagonian toothfish may help to combat poaching. He said, "It's very interesting in terms of managing fisheries in the southern oceans. This toothfish is basically found in sub-Antarctic waters around the world. "One of the things we're interested in is the population genetics of the toothfish and developing molecular markers that would allow you to distinguish where various fish populations originated. "That would be useful for detecting piracy and illegal harvesting of these fish. "If we could tell an Indian Ocean toothfish from a Falklands toothfish (upon arrival in ports) then they could be detected and the fishery could be controlled." Professor Dietrich says it is known that Antarctic fish derive from a group of fish that lived at warmer temperatures and many of these are found around the Falkland Islands. He explained, "These represent, if you will, the ancestors of the high Antarctic species which evolved to live in the cold as the Southern Ocean cooled, beginning about 25 million years ago." He says there are a variety of things the scientists are hoping to learn: "One is the mechanism of evolution: how is it that the high Antarctic species evolved and what was the genetic starting point for evolution to cold living conditions. " According to Professor Dietrich there are a number of adaptations that Antarctic fish have that are unique and the type that interest him most is the ice fish. He explains, "They don't make red blood cells; in the absence of red blood cells they have evolved a bigger heart, their vasculature is much more extensive and what they are doing is pumping a fluid that has physically dissolved oxygen in it. There is no oxygen carrier. "We have demonstrated in my lab that the globin genes have been basically deleted from the genome. We call them white blooded fish instead of red blooded. "It just so happens that one of the species lives in your waters, and we're trying to capture specimens of that because this is a fish that lives at a higher temperature range than the ice fishes in the Antarctic." Professor Dietrich says the research could have implications for the medical world: "In my laboratory we have been comparing the genes that are expressed by a red blood species and the genes that are expressed by a white blooded species and, using certain techniques, you can find out what genes the red blooded fish are expressing that the white blooded fish are not. These would be genes presumably involved in red cell development. "We've isolated one of these genes which we've named ?blood thirsty'. We've shown in the zebra fish, if you prevent the expression of ?blood thirsty' you don't get red blood cells. "This is allowing us to discover the genes involved in making red blood cells and then the products of those genes would be potentially therapeutic targets for treatment of anaemias and so on." From the Falklands, the Nathaniel B Palmer heads to South Georgia and the South Sandwich Islands where the team will attempt to put down a trawl to 7,000 metres. Professor Dietrich says they are likely to find new species, "...if we can get the net on the bottom - previously non-described species."

Source: Penguin News