Norwegian scientists say the extent of summer ice in the Barents Sea has fallen by half in a decade.
The Norwegian Polar Institute also found that average temperatures have risen by a degree during the same period, Aftenposten reported.
"We had been afraid of this, because we'd had signals through other reports that this was the situation," Environmental Minister Helen Bjornoy said. "But all reports that document the seriousness of the situation are always a wake-up call."
The Barents Sea lies north of Norway and western Russia, bordered by Svalbard and Franz Josef Land on the north and Novaya Zemlya on the east.
Scientists are unsure how much impact the warmer temperatures have had on the sharp drop in cod stocks in the past five years, since over fishing is also a major factor.
Bjornoy said a similar study needs to be done of the Norwegian Sea and the entire coastline.
Copyright 2007 by United Press International
Explore further: Thousands of dead fish again wash up in Rio Olympic bay