Environmentalists are calling for stricter regulations for tugboats pulling barges through British Columbia's waterways, following Monday's spill of diesel fuel near the Robson Bight Ecological Reserve off Vancouver Island's northern coast.

A diesel slick 14 kilometres long and 50 metres wide is seen on Tuesday.
(CBC)

Alexandra Morton, director of the Raincoast Research Society, said there should be more rigorous inspections and safety standards.

"If you're going to be moving fuels through that inside coast there should be some very strict regulations and rules," Morton told CBC News on Tuesday. "Barges should be checked. The trucks should be lashed down. They should not be going through Robson Bight at all."

A tug tipped its load near the favourite summer habitat of northern orcas, resulting in a diesel slick of 14 kilometres long and up to 50 metres wide as of Tuesday.

Officials from the Department of Fisheries and Oceans estimate 199 litres of fuel have leaked out so far but as many as 10,000 litres of gasoline and diesel were on board the barge.

Cleanup crews are working in the area but efforts are difficult because a fuel truck and logging equipment lost in the accident lie hundreds of metres below the surface.

A Burrard Clean Operations vessel leaves Robson Bight on Tuesday after completing the cleanup operation.
(Terry Milewski/CBC)

Whale researchers said they're worried the diesel fuel spill may prove toxic to orcas.

Peter Ross, a marine mammal toxicologist at the Institute of Ocean Sciences in Sidney. B.C., said he's worried the whales may inhale the volatile fumes.

"That can lead to lung lesions," Ross said. "It can lead to pneumonia. It can lead to systemic and possibly fatal toxicity."

Ross said he's concerned the fuel spill may also be toxic to the fish on which the orcas feed.

Burrard Clean Operations of Burnaby, B.C., has been hired to clean up the oil slick by Ted Leroy Trucking, which operates the barge.

The trucking firm, based in Chemainus, B.C., will have to cover the cleanup costs.