Sidney BC; Researchers from the University of St Andrews, Raincoast Conservation Foundation, Oceans Initiative and Environment Canada teamed up to assess the presence and potential threats from floating plastics and other debris to BC’s marine animals.
The study, part of a larger effort to survey marine mammals, estimated that the inshore waters of coastal British Columbia are filled with approximately 36,000 pieces of garbage with the most common form being Styrofoam, followed by plastic bottles and plastic bags.
Marine debris poses a threat to birds and mammals that accidentally consume garbage thinking it’s food or become entangled in debris with lines or mesh. A third, but little studied area of concern, is the sub lethal effect from plastic’s toxic properties.
“ While there is evidence to suggest that the problem of marine pollution is pervasive, most animals that die from consumption or entanglement do so at sea, and their carcasses are never found or analyzed” explained the study’s lead scientist Dr. Rob Williams. “Further, there have been few attempts to quantify the scale of the marine garbage problem.”
This study was intended to further awareness and understanding of BC’s marine debris problem by first surveying floating garbage at sea, then mapping areas where marine mammals and garbage are likely to overlap, and finally identifying higher-risk areas for the animals.
“Surprisingly, marine plastic density was greatest in remote coastal waters such as those off Prince Rupert, Langara Island and Cape Scott rather than urban areas such as Vancouver” said study co author Erin Ashe. “These areas are habitat for Pacific white-sided dolphins, humpback whales and elephant seals, among others. One of the highest risk areas for BC’s endangered fin whales was off Gwaii Haanas National Park Reserve”.
The study also makes recommendations for greater evaluation of debris risks to BC’s marine mammals in order to assess the extent of the problem. “BC elephant seals have been recovered with Styrofoam in their stomachs and a grey whale recently recovered in Washington State had over 50 gallons of marine debris in its stomach” said Raincoast Researcher Misty MacDuffee, “Are animals in BC dying from ingestion or entanglement, and if so, on what scale? We need a better handle on the threat this debris is posing to our marine wildlife”.
Estimates from California suggest that 60-80% of marine debris has its origin on land. So it is far easier and cheaper to reduce input of garbage than to do clean up in the ocean. Allocating funds for volunteer groups that take on beach cleanups is one way to reduce the scale of the problem. The study will be published in Marine Pollution Bulletin and available online as of March 30.
Attached Figure: The above figure shows the density of marine garbage in the waters of coastal British Columbia. Darker areas contain higher density of debris. The waters off Prince Rupert, Langara Island, Cape Scott and Victoria show the highest concentration of garbage. Zig zag lines are the ship transects taken in the study area.
Attached Photo: Cascadia Research (credit)
Caption: In 2010, researchers performing a necropsy on a beach cast grey whale in Washington State found over 50 gallons of marine debris in the whale’s stomach. Plastic bags, a golf ball and a pair of sweat pants were among the items recovered.
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Misty MacDuffee, Raincoast Conservation Foundation