Experts reject Palin's claim over decline of beluga whales in Alaska

The ruling that the whales in Cook Inlet are endangered and require additional protection to survive, was her second environmental slap from Washington this year.

She has asked federal courts to overturn an Interior Department decision declaring polar bears threatened under the Endangered Species Act.

The government has put a portion of the whales on the endangered list, rejecting an argument by Palin – governor of Alaska – that it lacked scientific evidence to do so. The National Oceanic and Atmospheric Administration (NOAA) said that a decade-long recovery programme had failed to ensure the whales' survival.

"In spite of protections already in place, Cook Inlet beluga whales are not recovering," said James Balsiger, NOAA acting assistant administrator.

The decision means that before federal agencies can issue a variety of commercial permits, they must consult with the National Marine Fisheries Service to determine if there are potential harmful effects on the whales. That has the potential to affect major Alaska projects, including an expansion of the Port of Anchorage, additional offshore oil and gas drilling, a proposed $600m bridge connecting Anchorage to Palin's hometown of Wasilla, and a massive coal mine 45 miles south of Anchorage.

The state has long held serious concerns about the low population of beluga whales in Cook Inlet, Palin said in a statement.

"However, we believe that this endangered listing is premature," she said. In April, Palin successfully lobbied for a six-month delay in a listing decision until a count of the whales this summer could be included in deliberations.

That count showed no increase over 2007 numbers – 375 whales, compared with a high of 653 in 1995.

Federal regulators and conservation groups said further delay would be harmful.

NOAA said the Cook Inlet population declined by 50% between 1994 and 1998 and "is still not recovering" despite restrictions on the number of whales that Alaskans can kill for subsistence. It said recovery has been hindered by development and a range of economic and industrial activities, including oil and gas exploration.

The National Marine Fisheries Service "will identify habitat essential for the conservation of the Cook Inlet belugas in a separate rule-making within a year", the agency said.

The federal decision pleased environmentalists. "We can finally focus now not on whether the belugas are endangered, but what we can do to protect them," said Brendan Cummings, a lawyer for the Center for Biological Diversity, which petitioned for the listing.

Cook Inlet stretches 180 miles from the Gulf of Alaska to Anchorage. It is named after British explorer Captain James Cook, who sailed into the inlet in 1778 on a quest to find the Northwest Passage.

Beluga whales feed on salmon and smaller fish. They can also eat crab, shrimp, squid and clams. In summer the whales, which reach a length of up to 15 feet, can often be spotted from the roads leading away from Anchorage, gathered at river mouths, chasing fish.