Several vessels in Cowichan Bay broke free from their moorings as a result of recent storms, with one sinking.
Michelle Inbeau, a spokeswoman with the Canadian Coast Guard, said a 35-ft vessel with a speedboat (with an outboard motor) attached to its mooring, sank in 80 feet of water and had to be raised on Dec. 17 and removed from the bay.
She said that when the vessel was brought to the surface, an extensive non-recoverable sheen could be seen on the water, and that an overflight confirmed the sheen had spread.
Inbeau said a “sheen” is a very thin layer of pollutant (less than 0.0002 inches or 0.005 mm thick) floating on the water surface and is the most common form of pollutant seen in the later stages of a spill.
“Sheens dissipate through evaporation and wind and tidal action, and they are usually diesel” she said.
“It spreads out and looks large, but it is such a thin layer that floats on the surface that it can’t be recovered.”
Lori Iannidinardo, the director for Cowichan Bay on the board of the Cowichan Valley Regional District, said there should have been a containment boom placed around the sheen to capture as much of it as possible, regardless of how thick it was.
“It’s not just the oil and diesel from this one vessel that concerns me as much as the accumulative impacts on the bay over time as several vessels sink or leak there,” she said.
“It’s a death by 1,000 cuts.”
Inbeau said the majority of the vessels that broke free during the storms were retrieved by their owners and none were at risk to pollute, therefore the Coast Guard did not receive any reports about them.
“The Coast Guard only assisted one owner with retrieving a sailboat,” she said.