An international research team, including biologists from NOAA Fisheries Service, has reported in an online scientific journal that it had failed to find a single Yangtze River dolphin, or baiji, during a six-week survey in China. The scientists fear the marine mammal is now extinct due to fishing and commercial development, which would make it the first cetacean to vanish as result of human activity.
The research paper, published last month in the online journal Biology Letters, reports that an intensive acoustical and visual survey of the main Yangtze River where the baiji live failed to find what was already considered to be one of the worlds most endangered species.
The last time these animals were surveyed was in the 1990s when only 13 were found, said Barbara Taylor, a marine biologist at NOAAs Southwest Fisheries Science Center in La Jolla, Calif., and one of the researchers on the scientific team that was working with local scientists at the invitation of the Chinese government. This time, we detected no baiji, either visually or acoustically. This would be the first human-caused extinction of a dolphin or whale and it is particularly sad for the last member of a family of a species that is over 20 million years old.
The baiji is one of only a few dolphin species that is known to have adapted from the ocean to a freshwater environment. The likely cause of the baijis decline is from the use of fishing nets with hooks that snag and drown the dolphins as bycatch. Other causes may include habitat degradation.
Scientists are also concerned that this could just be the first of many human-caused extinctions of marine mammals that are under stress around the world.
We are concerned about several vulnerable species of dolphin and porpoise around the world, including the vaquita," said Nicole Le Boeuf, international fisheries biologist for NOAA Fisheries. The vaquita is a critically endangered porpoise found only i
|Contact: Jim Milbury|
NOAA National Marine Fisheries Service