Brook said that while the whale sharks enjoy protection in Ningaloo Reef waters, the sharks migrate over large distances, often traveling thousands of miles. "Artisanal fisheries via harpoons for meat, for example, off the coasts of India and Indonesia, but mostly by Taiwanese and Chinese commercial fisheries" are likely responsible for the declines, he said, adding that whale shark meat is referred to as "tofu fish" due to its texture, which is also prized in shark fin soup and Chinese medicine. Ship strikes also tend to kill larger adults, he said, though evidence for the strikes is hard to compile since resulting deaths would usually remain unknown. These latest findings counter a study late last year by Brad Norman and Jason Holmberg of ECOCEAN, a research education and conservation organization. That report, based on multiple underwater images of the sharks, concluded that Ningaloo Reef whale sharks are thriving. Norman did, however, admit to Discovery News that the species is "rare" and "vulnerable to extinction." Brook and his colleagues have authored a written response to Norman's paper, which is still under consideration by the journal, Ecological Applications. They say that while whale sharks receive some trade protection from the Convention on International Trade in Endangered Species, "it is difficult to police non-international trade or local hunting by indigenous people." The migratory habits of whale sharks, Brook said, "mean it is impossible to protect the Ningaloo population once the sharks leave Australian waters for Indonesia and the Philippines." The researchers urge officials to establish well-enforced international protection for the sharks. They also hope that collaborative tagging studies in the future will help to better identify and monitor whale shark migration routes. Related Links: |
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