Tuna fishing has been good in recent years off P.E.I. (CBC)

Canadian scientists are reviewing whether to list Atlantic bluefin tuna as an endangered fish, concerned the BP oil spill could tip the scales for the giant fish.

Scientists in the U.S. are also considering whether the tuna should be declared endangered. The odds against that happening in Canada are long. Canada has never listed a commercially fished saltwater species, not even cod.

Fishing for tuna off Prince Edward Island has been good in recent years, but there are signs of serious trouble. An assessment released two years ago shows stocks of bluefin tuna on this side of the Atlantic have declined 80 per cent since 1970.

"The bluefin tuna population has been at a fairly low level for a number of years," Alan Sinclair, co-chair for saltwater fish for the Committee on the Status of Endangered Wildlife in Canada, and a research scientist with Fisheries and Oceans, told CBC News last week.

"It was thought at the time that it was low enough to warrant closer consideration."

Even if the committee agrees tuna should be listed as endangered or threatened, that doesn't mean fishing will necessarily end. It's up to the federal government to make the final decision.

Sinclair said economic considerations are written into the legislation.

"The listing under the Species-at-Risk Act of a commercially exploited fishery would generate undue economic hardship on the people that are involved in the fisheries," he said.

Sinclair said DFO has brought in stringent measures to reduce fishing when the committee suggested a species be listed, which can help. Sinclair admitted those measures didn't work with cod.

This spring, scientists will try again to have several populations of Atlantic cod listed as endangered.