YOU might think the world鈥檚 green turtles face an uncertain future, especially because they have recently been confirmed on the World Conservation Union鈥檚 (IUCN) Red List of endangered species. But they are not endangered at all, according to one marine biologist. In fact, there are over 2 million green turtles alive today, and their numbers are rising.
Annette Broderick, a member of the IUCN鈥檚 marine turtle research group, says the organisation was wrong to list green turtles as endangered during a reassessment completed in 2004. It 鈥渄etracts attention from populations truly threatened with extinction鈥�, she writes this month in Global Ecology and Biogeography (vol 15, p 21). And she detects a general malaise about the Red List, saying scientists too readily interpret local population declines as evidence of a global threat.
Broderick, of the University of Exeter, UK, says that while some small turtle populations are falling, green turtles in general are undergoing a dramatic revival, particularly in the Atlantic Ocean, where six of the eight places regularly monitored for the animals are showing big increases.
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On one major site, British-run Ascension Island in the South Atlantic, Broderick has measured a tripling of numbers since 1970. 鈥淭he population is increasing exponentially,鈥� she says. There are currently more than 10,000 breeding females 鈥� close to the number that she calculates nested here before the British navy arrived on the then uninhabited island almost 200 years ago. Organised turtle hunting ended on Ascension in the 1930s.
There have been similar increases across the Atlantic in Mexico, Costa Rica and Florida, as well as Australia and Hawaii, with populations doubling in the last 30 years. Broderick puts the total world population 鈥渋n excess of 2.6 million鈥�.
The official Red List assessment makes no overall population estimate. But it describes an 鈥渆xtensive and widespread鈥� decline on many islands and estimates there are only half as many green turtles worldwide as three generations 鈥� or 130 years 鈥� ago. It rates the green turtle as 鈥渁t very high risk of extinction in the wild鈥�.
Broderick takes issue with these statistics. She told 快猫短视频 that she submitted her new data from Ascension, which has the Atlantic鈥檚 second largest population, before the assessment was completed. Nonetheless, the report includes an old assessment of a mere 39 per cent increase over the past 30 years in green turtles on the island.
While Broderick is listed as a member of the marine turtle task force, she says she had no input into the IUCN analysis. Of the claim that the green turtle is at high risk of extinction, she says flatly: 鈥淭his is not the case.鈥� Nicolas Pilcher, director of the marine research foundation in Sabah, Malaysia, who chaired the listing process, agrees that Broderick has a point. 鈥淲e are reviewing this and we think regional listings sometimes make more sense.鈥�
