Latest research shows that in the last 20 years climate change has affected ecosystems in the northern Bering Sea which may threaten the life of apex predators, such as gray whale, walrus, seal in that region.

The changes in the northern Bering Sea have coincided with a reduction in sea ice, and increases in air and ocean temperatures, said Cui Xuehua, a Chinese predoctoral student from University of Tennessee, US, who is one of the science party in the 3rd Chinese National Arctic Expedition.

According to Cui, the northern Bering Sea is one of the richest areas in the global ocean.

The ecosystem has been significant food source for many species of fish but it has been degenerating due to climate change. The food sources are decreasing and the functions are being interrupted, Cui said.

She said a 20-year-long research project by the US showed that the benthic stock, such as crustaceans and worms, at the beginning of the 21st century was only 50-70 percent of that at the end of the 1980s and the beginning of the 1990s.

"Declining prey items of apex predators, such as gray whale, walrus, seal in the northern Bering Sea cause them to relocate the primary foraging area northward, threatening their habitat and survival," Cui said.

China launched its third scientific expedition to the North Pole on July 11. The team, with 122 scientists and logistics staff, will study the polar region's distinctive maritime resources and air quality, and also do comprehensive research on geological and meteorological conditions in the 75 days of the expedition.

(Xinhua News Agency July 29, 2008)