BELLA BELLA, B.C. - A containment boom has been placed around a tug boat that began leaking diesel fuel after it ran aground and sank on Thursday near British Columbia's Great Bear Rainforest, says the coast guard.

The leaking fuel is expected to dissipate and divers were on the scene to examine the vessel and attempt to plug leaks, said a coast guard statement.

Photos from above the site show a slick of fuel around the barge, which remains attached to the sunken tug.

The 30-metre Nathan E. Stewart, which is registered in the United States, and an empty fuel barge it was pushing ran aground early Thursday morning in Seaforth Channel on the central coast, said the coast guard.

The coast guard was co-ordinating the environmental response, with its vessels Bartlett and John P. Tully and other ships on the scene.

“At 1:13 a.m. (Thursday), the Canadian coast guard received a report that a U.S. registered tug, the Nathan E. Stewart, and the empty fuel barge DBL 55 that it was pushing, ran aground on Edge Reef, in Seaforth Channel near Athlone Island,” said the statement. “The tug was southbound from Alaska.”

A team from the Western Canada Marine Response Corp. was helping to contain and clean up the leaking fuel.

Kirby Offshore Marine, the owner of the tug and barge unit, said no one was hurt and all seven crew members aboard got off the tug safely.

The tug had a load of about 50,000 gallons, or almost 190,000 litres, at the start of the voyage, said Jim Guidry, Kirby's incident commander, in the statement.

“Resources to meet a worst possible discharge have been activated and are either on scene or on route,” he said. “A priority for the response will be developing a plan to remove all diesel aboard the tug and to safety salvage the vessel.”

The company said 760 metres of boom surrounds the boat and a skimming vessel was operating around the site.

Kirby said it regrets the incident and it is working to mitigate the impact of the sinking.

Heiltsuk Nation Chief Marilyn Slett said in a statement that Heiltsuk vessels were on scene at first light to monitor the situation, assess environmental impacts and assist with spill response.

She said the spill threatens an area where 25 important species are harvested, including manila clam beds that provide an income to the community of approximately $150,000 per year.

“Though we are thankful that the barge was empty, we are gravely concerned about the potential ramifications of the fuel spill from the tug,” said Slett's statement. “This spill area is in one of our primary bread baskets, and we know that diesel is extremely difficult to recover.”