While salvage and clean-up experts assess a sunken tug off British Columbia's central coast near the Great Bear Rainforest, the Transportation Safety Board announced Monday it will look into what happened.
The board said it will gather information and conduct interviews with crew members for its assessment of what went wrong with the 30-metre Nathan E. Stewart.
A situation report on the cleanup said officials were still making plans to remove more than 200,000 litres of diesel fuel still aboard the tug. The report was issued by the federal and provincial governments, the local First Nation and the tug's owner, Texas-based Kirby Corp.
The tug was pushing an empty barge when it ran onto some rocks last Tuesday at the mouth of Seaforth Channel, about 20 kilometres west of Bella Bella.
It was submerged under about nine metres of water and continued to seep fuel from its damaged starboard and central diesel tanks. The situation report says leaking fuel was being contained by a boom. The amount of diesel that spilled has not been confirmed.
The report says there is also almost 2,500 litres of lube oil and thousands more litres of hydraulic oil, gear oil and dirty bilge water onboard the tug.
It also says an oily sheen is escaping containment.
Fisheries and Oceans Canada closed nearby shellfish harvesting on Friday. The closure near Athlone Island in Seaforth Channel affects recreational, aboriginal and commercial fisheries for clam, geoduck, horseclam, oyster and scallops.
The Fisheries and Oceans notice said there was already a closure in the area because of red tide, or paralytic shellfish poison, that is caused by toxins.
In Ottawa on Monday, Fisheries Minister Dominic LeBlanc said he thought the coast guard did a "terrific job" in saving and ensuring there was no loss of life during the sinking. Seven crew members were safely taken off the vessel.
A day after the spill, B.C. Premier Christy Clark criticized the federal government's commitment to disaster response on the West Coast, saying it has spent more money on the East Coast.
LeBlanc said he takes the premier's comments seriously and he and Transport Minister Marc Garneau have consulted with many in the industry.
"We have some specific ideas of things that we can do to improve, particularly around environmental response on all of the Canadian coasts, but certainly we understand the concern of British Columbians and we're working diligently to ensure that we have an absolutely world-class response system."
The Heiltsuk Nation called the situation an unfolding environmental disaster because it threatens clam beds vital to the community's culture and economy.
"We don't know how many years or decades it will be before we are able to harvest in these waters again," Chief Councillor Marilyn Slett said in a news release.
Federal, provincial and Heiltsuk Nation representatives are working with Kirby to plug the leaking vessel, and expect to begin night operations in hopes of speeding up the process.
This came as weather reports show an approaching storm with winds of up to 90 kilometres per hour is due to reach the area late Wednesday.
It's hoped the tug can be lifted from the water by crane and barged out of the area once its fuel tanks have been pumped out.