Eight leading Canadian environmental groups have joined forces to file a landmark lawsuit against the Department of Fisheries and Oceans (DFO).

The suit alleges the federal government has failed to legally protect endangered and threatened resident killer whales.

"There are the most iconic and renowned animals on the West Coast," said Lara Tessaro, a lawyer representing the groups. "They are culturally and genetically unique and they are greatly at risk."

Tessaro says the groups launched legal action after the DFO ignored a September 10 order to protect the whales under the federal government's Species at Risk Act. The DFO helps to enforce the Act, which protects species considered at risk.

"B.C.'s endangered species deserve better," says Gwen Barlee, Policy Director of the Wilderness Committee.

Biologists estimate there are only 87 southern killer whales left worldwide -- a number environmentalists say will shrink because of threats to their natural habitat and a sharp decline in salmon stocks.

The groups, including the David Suzuki Foundation, Environmental Defense, Greenpeace, International Fund for Animal Welfare, the Raincoast Conservation Society and the Wilderness Committee, want stricter protection measures for the killer whales.

Bill Wareham, a senior marine specialist from the David Suzuki Foundation, says most of the existing conservation methods DFO uses to protect whales are non-binding and non-legal, making them ineffective.

"We have tools to protect the habitat, but we're not using them," says Wareham.

"To truly protect killer whales' critical habitat, Canada needs to legally protect areas that serve the whales' basic needs for food and rest -- marine-use plans need to include new protected areas if we hope to recover populations of these magnificent whales."

Killer whale populations face numerous threats on the West Coast, including declining food stocks, increased boat and tanker traffic, and acoustic impacts from seismic and military sonar testing.

Ecojustice, a non-profit environmental law firm, estimates the southern killer whale population fell by about 20 per cent between 1993 and 2003.