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Каспинфо октябрь 2003 |
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Название: ПРОБЛЕМЫ СОХРАНЕНИЯ ОСЕТРОВЫХ (на англ. яз.) Главные Пункты: * Подборка материалов в западной прессе с критикой решения СИТЕС о повышении квот на экспорт отсетровой продукции из Каспийского региона (13.10.2003) Полный Текст ПРОБЛЕМЫ СОХРАНЕНИЯ ОСЕТРОВЫХ (на англ. яз.) ПРОБЛЕМЫ СОХРАНЕНИЯ ОСЕТРОВЫХ (на англ. яз.) *** A High Price to Pay for Caviar New Scientist, September 20, 2003 By Fred Pearce Experts can't agree on how many beluga sturgeon are left in the sea. At stake is the future of one of the world's most sought-after fish and its coveted "black gold". One of the world's most valuable fish could be driven to extinction because an international conservation body has miscalculated how many are left in the wild. So claim fisheries scientists who are warning that flawed science is behind a decision this month to allow continued fishing of beluga sturgeon, whose caviar can fetch $3000 a kilogram. Trade in beluga and the caviar they produce is governed by the Convention on International Trade in Endangered Species. CITES believes that beluga sturgeon numbers are on the increase, reaching 11.6 million last year, up from 9.3 million in 2001 and 7.6 million in 1998. Based on those estimates, it has sanctioned Russia, Iran and other nations bordering the Caspian Sea, the fish's last surviving stronghold, to harvest up to 155 tonnes of beluga sturgeon and export up to 9 tonnes of caviar. But critics say there may in fact be fewer than half a million fish left, and that raw data published by CITES itself suggests that the sturgeon population crashed by 40 per cent in 2002 alone. Continued fishing and trade in beluga caviar will only hasten the demise of the species, they say. CITES's approval also comes at a time when the US government, the world's leading importer of beluga caviar, is considering an outright ban. CITES is standing by its assessment of sturgeon stocks. Following a crackdown on poaching by the Russian mafia, "the historical decline has been arrested, and populations have increased", claims deputy director-general Jim Armstrong. Countries bordering the Caspian Sea "are truly starting to turn the situation around", he says. CITES bases its assessment of beluga sturgeon numbers on statistics produced by the Caspian Fisheries Research Institute in Astrakhan, Russia's caviar capital. Russian researchers estimate beluga populations based on small survey trawls carried out each summer. Last year's figure of 11.6 million fish is based on a total research catch of just 56 beluga. The Russian calculation assumes that for many of the trawls, either 24 fish, or 10 fish, escape the path of the trawl for every one caught in the net. The difference depends on the size of trawling net used. But Ellen Pikitch of the Wildlife Conservation Society in Washington DC, which is pushing for a ban on beluga caviar, claims that standard models used by UN and US fish researchers usually assume that at most one fish gets away for every one caught. Apply that formula and the real beluga population could be less than half a million. If so, the rate of capture sanctioned by CITES means that "virtually all mature beluga sturgeon will fall prey to either legal or illegal fishing, leaving the population at greater risk of extinction", Pikitch says. Armstrong says the validity of the demographic model used by CITES is justified by a scientific review written by Russian researchers. But a copy seen by New Scientist admits that "data on sturgeon catchability is very contradictory" and "scientists do not agree". The review also fails to cite any reference later than 1991. Pikitch says raw survey data published by CITES shows that the number of beluga caught in each survey trawl went down by 39 per cent last year, and the number of adult beluga appearing in rivers for spawning also fell. This contradicts CITES' estimates of rising numbers, she says. "CITES is using unreliable data without any review by independent experts," agrees Vadim Birstein, a Russian sturgeon geneticist based in the US. "It is expecting us to believe they have performed a miracle." CITES's optimism rests mainly on the belief that poaching, which once caught 10 times as many beluga as legal fishing, has been contained. A crackdown has "completely closed the illegal international trade", Armstrong says. But according to the Russian press, the police chief in Astrakhan has reported a 20 per cent increase in sturgeon poaching this year. Beluga are also threatened by toxins in the Caspian Sea, where 80 to 90 per cent of the world's sturgeon catch is taken. According to research published this summer, levels of DDT and PCBs in beluga are higher than in other sturgeon, and are sufficient to damage reproduction (Marine Pollution Bulletin, vol 46, p 741). Behind the disagreement lies a difficult conservation dilemma, however. Beluga, like other Caspian Sea sturgeon, are largely cut off from their natural river spawning grounds by dams. Armstrong says around 90 per cent of beluga now come from artificial hatcheries, which are very expensive to build and maintain. So perversely, a total ban in international trade would stop the money that pays for the hatcheries, and might itself lead to the species' extinction, he says. Beluga sturgeon can live for more than a hundred years. During their lives they produce roe many times, so instead of obtaining the caviar by killing the fish, the big hope is to find a sustainable way to harvest it. In July, scientists in Kazakhstan achieved this by injecting a hormone into beluga stusturgeon. The hormone prompted the fish to release its roe, which could be massaged out from the sturgeon's body within minutes. The problem is that the eggs produced by this method -- known as the Padushka massage, after the scientist who invented it -- have a poor texture and make bad caviar. But Ellen Pikitch of the Wildlife Conservation Society in Washington DC, who has seen the technique, says, "They would be immensely useful for hatcheries. It would have a huge and immediate impact." Meanwhile, Russian researchers say they can also remove caviar-grade roe through a small incision made in the sturgeon's body. They claim this "Caesarean method" does not usually kill the fish. (back to top) 6 Caviar Supplies under Threat The Daily Telegraph(London), September 18, 2003 By Robert Uhlig Supplies of caviar could be threatened because an international conservation body monitoring numbers of the beluga sturgeon could have got its sums wrong. The Convention on International Trade in Endangered Species (Cites) believed numbers of beluga sturgeon, from which top grade caviar is obtained, rose to 11.6 million last year, a rise of almost two million on 2001. Its findings allowed Russia, Iran and other countries bordering the Caspian Sea to harvest the fish and export up to 155 tons of the fish and nine tons of caviar. But the raw data, published recently by Cites, suggests the sturgeon population might have crashed by 40 per cent to fewer than half a million fish. The raw data is based on a small survey trawl of 56 beluga sturgeon and makes an assumption that up to 24 fish escape the path of the trawl for every one that is caught. Environmentalists believe only one fish evades the trawl for every fish caught. If correct, the true population could be fewer than 500,000 and continued fishing could be disastrous. Backing their case is the finding that the number of beluga caught by Cites in each trawl fell by 39 per cent last year and the number of adult beluga appearing in rivers for spawning also fell. (back to top) 7 Overfishing Could Spell the End of Caviar The Independent, September 18, 2003 By Charles Arthur Beluga caviar, which costs about pounds 2,000 a kilogram (pounds 900 a lb) could literally become priceless - because scientists think overfishing will make beluga sturgeon extinct. Russia, Iran and other states around the Caspian Sea, the beluga's stronghold, were allowed this month to harvest up to 155 tonnes of the fish a year. The decision - by Cites, the Convention on International Trade in Endangered Species - was based on sturgeon numbers growing from 7.6 million in 1998 up to 11.6 million last year. But New Scientist magazine today says critics of the decision think there could be fewer than half a million fish - and Cites' own raw data hints stocks fell 40 per cent in 2002. "Cites is using unreliable data without any review," said Vadim Birstein, a Russian sturgeon geneticist, "and expects us to believe (the fish) have performed a miracle." Scientists think sturgeon stocks have fallen about 90 per cent since the 1970s, mainly due to overfishing and an illegal trade by Russian mafia, worth about pounds 500m, that threatens the fish's survival. Cites' estimate of sturgeon numbers is made by scientists in Astrakhan, based on a trawl of the Caspian and assuming that 10 to 24 fish escape for every one caught, and multiplying that by the volume trawled. But Ellen Pikitch of the Wildlife Conservation Society in Washington DC said UN and US fisheries researchers assume at most one fish escapes for each caught - hence a far smaller estimate of 500,000. Cites said its model was justified by previous research, but agreed the data was "contradictory" and that scientists did not agree on its interpretation. (back to top) |