Environmental groups have launched legal action against the Canadian government to force it to protect endangered species along the route of Enbridge Inc's proposed Northern Gateway crude oil pipeline and in West Coast waters where oil tankers would pick up the Gateway crude.

Ecojustice, on behalf of the Sierra Club and four other green groups, alleged on Wednesday that Ottawa has failed to implement its Species at Risk Act and has delayed producing recovery strategies for threatened species for years.

The species include the southern mountain caribou, marbled murrelet, Nechako white sturgeon and Pacific humpback whale.

The lawsuit is latest bid by environmental groups to complicate matters for the government and Enbridge, which seeks to build the contentious C$6 billion ($6.1 billion) pipeline that would ship more than half a million barrels a day of oil sands-derived crude to the Pacific Coast from Alberta. The proposal is currently the subject of public hearings before a federal regulatory panel.

"By delaying the recovery strategies and therefore delaying identification of the critical habitat it must then protect, the federal government is making it easier for big projects, like the Enbridge Northern Gateway pipeline, to speed through regulatory review without a full understanding of the long-term impacts on these wildlife species and their habitat," Ecojustice said in a statement.

The other groups represented by Ecojustice in the action are Greenpeace, David Suzuki Foundation, Western Canada Wilderness Committee and Wildsight.

They want the court to force the federal Environment and Fisheries and Oceans departments to develop proposed recovery plans for the species within 30 days and final plans within 90 days.

The Conservative government of Prime Minister Stephen Harper has expressed strong support for opening up new markets in Asia for growing volumes of Canadian crude.

Northern Gateway, and Kinder Morgan Energy's proposed $4.1 billion expansion of its Trans Mountain pipeline are two projects that would bring about that market diversification, and, it is expected, higher returns for Canadian oil.

An official at Environment Canada declined to comment on the allegations. "Our government takes our responsibilities under the Species at Risk Act seriously. As the matter you raise is before the courts, it would be inappropriate to comment further," spokesman Adam Sweet said in an email.

Steve Wuori, head of Enbridge's liquids pipeline division, also declined to comment on the legal action but said such issues are being dealt with at the Northern Gateway public hearings.

"We really do believe that we've studied these things and will be vetting them through the regulatory hearing process," he told reporters after speaking at an industry event in Calgary.

The case is file numbers 1777-12, 1778-12, 1779-12 and 1780-12 in Federal Court in Vancouver.

Photo: Ecojustice's Devon Page displays filing documents at a press conference in Vancouver.