OTTAWA - The biggest fish in Canadian waters is close to disappearing from the West Coast because of a deliberate eradication program instituted by the federal government.

Fishermen used to regularly encounter the basking shark, which can reach the length of a city bus, but in the past decade there have been only six sightings.

"The population has almost certainly declined by more than 90 per cent," Jeffrey Hutchings, chairman of the Committee on the Status of Endangered Wildlife in Canada, said in an interview Monday.

The basking shark was the most notable animal on a list the government-appointed committee plans to present to the environment minister asking that certain species be declared endangered and given protections.

The shark, which has no teeth, swims through the sea with mouth wide open, ingesting vast quantities of plankton and tiny marine animals and filtering the water as it does so.

It also has a tendency to get caught in commercial salmon nets, destroying them in the process. That's the reason for the eradication program which lasted until 1970, said Hutchings.

"In retrospect it's almost unbelievable, and even at the time one would think it would have been a radical thing to do, but there were lots of eradication programs on at the time and this was one of them."

Hutchings says that the loss of a large predator upsets the ecosystem in complex ways, and the basking shark is a remarkable creature by any standard.

"Its Canada's longest fish, has the longest gestation period of any vertebrate, has an extremely slow rate of growth and it's in big trouble around the world.

"Why we took the shark out the way that we did? I can only think it was simply just as basic as taking the primacy of industry's concerns over its fishing gear over the primacy of the animals' right to exist."

Peter Ewins, director of species conservation for the World Wildlife Fund, says the federal government is just beginning to study the status of marine populations, and the list of endangered fish is likely to get much longer.

He said he believes that the basking shark is just as scarce in the Atlantic as in the Pacific but it was not possible to study populations on both coasts.

The committee also expressed alarm that aerial-feeding, insect-eating birds are disappearing. Both the common nighthawk and the chimney swift are assessed as threatened, while populations of a migratory shorebird, the red knot, have fallen by 70 per cent.

There is growing evidence from many sources that bird populations across North America are in decline, for reasons that are not fully understood. Possible factors include loss of habitat and the use of pesticides.

Also recommended for the endangered list are:

-The Eastern Pondmussel, found in the Great Lakes, which has fallen victim to the invasive zebra mussel.

-The eastern flowering dogwood, one of Canada's showiest native trees. It has fallen prey to an introduced fungus similar to one that has almost eliminated the American chestnut.

On the bright side, two once-threatened species - the sea otter and the peregrine falcon - have been removed from the endangered list because of successful recovery programs. Hutchings noted that work to protect the two species has been under way for more than 30 years.

"It underscores the point that although recovery efforts can be successful they take time. They're not going to happen overnight."

Many species subject to recovery programs have not responded in the same way, said Ewins. Bringing back endangered species from the brink is extremely difficult, and there are only a handful of success stories.

He cited the white pelican, the wood bison and the swift fox as notable success stories.

The committee's recommendations for listing and delisting species must go to Environment Minister John Baird for approval. Environmentalists continue to lobby against the requirement for ministerial approval, saying decisions should be made on scientific grounds alone.

Under the Canadian Species at Risk Act, the government must develop a recovery plan for any species listed as endangered, although critics allege that the recovery plans are frequently inadequate.