LONG-TERM IMPACT:
Effects on marine wildlife could last for years, even decades
The fallout from Wednesday’s spill of what appears to be marine bunker oil into English Bay could last for years, even decades, a marine pollution expert from the Vancouver Aquarium said.
Peter Ross spent Thursday morning patrolling English Bay beaches with his staff where he observed “rather widespread spotting” by oil on the shoreline between Second and Third Beach.
The spill coincided with the spawning season of surf smelt, which have been in decline, and occurred in waters that are home to numerous fish species, such as the starry flounder, and rearing habitat for juvenile salmon.
“This kind of spill is troubling,” said Ross, director of the aquarium’s Ocean Pollution Research Centre. “It reminds us these types of accidents can lead to the degradation of habitat for a longer period of time of species like salmon, (which are) sensitive to a lot of different contaminants.”
The extent of damage will depend on the magnitude of the spill — the Canadian Coast Guard estimated as much as 2,800 litres, the equivalent of 13 barrels, escaped — but Ross said localized impacts could linger.
Industry material safety data sheets state that marine fuel oil contains components that will float in the water column and some that can sink, forming tar balls on the sea bottom.
Bunker oil is a cheap fuel produced from the oil left over after gasoline, jet fuel, diesel and other high-value hydrocarbons are extracted from crude oil in the refining process, said Brian Noronho, a marine engineer and instructor at BCIT.
“What is left at the bottom of the barrel is strictly residues, heavy residues after you’ve fractioned away the light components,” he said.
The fuel is listed as harmful to very toxic to fish, shellfish and aquatic plants, and when large amounts wash ashore, a Shell information sheet says it can persist and contaminate groundwater.
“It’s possible we’ll see localized impacts for years,” Ross said.
No southern resident killer whales were nearby, which is what would have been Ross’ biggest concern, so he is “hopeful the risk to them is minimal.”
Ross didn’t see any oiled birds, but was beginning to hear reports from people observing birds that appeared to be in distress. The event also coincides with the migration of numerous ducks, geese and other migratory birds, which raises another concern.
There appears to be less risk to the local spot prawn harvest. DFO spokeswoman Michelle Rainer said the waters of English Bay are closed to commercial harvesting and are not an area of high activity for recreational fishing.
English Bay, at the mouth of the once heavily-industrialized False Creek, is a water body that is still recovering, said Marvin Rosenau, a habitat biologist in BCIT’s Rivers Institute. “Is it going to cause the collapse of West Coast (salmon) stocks? Absolutely not,” Rosenau said. “More than the absolute damage, it’s kind of a wake-up call of what would happen if a bigger spill happens.”
Oil sinking to the bottom would be a bigger concern for fish, Rosenau added. On the sandier parts of the bottom, and the intertidal zones of beaches, oil could affect the eggs of just-spawned surf smelt, a small finger-like fish that Rosenau said have been in decline, as well as starry flounder, other groundfish and crabs.
Historically, spills of bunker fuel have led to surprising amounts of damage in other jurisdictions. In 2007, a spill of almost 250,000 litres of bunker oil that resulted from the collision of two cargo ships in San Francisco Bay devastated the local herring population. Researchers found that herring embryos placed in cages near the spill site died off quickly, with the fat-filled egg sacs acting like sponges, soaking up the toxic compounds for the fuel.