Marine researchers from Dalhousie University, Halifax, Nova Scotia Community College, Dartmouth, and the Bedford Institute of Oceanography, Dartmouth, Canada published their findings in the Marine Pollution Bulletin on November 14, 2019.
This study was the first comprehensive assessment of benthic debris using a drop camera system in Eastern Canada. Over a span of three years, the research team used underwater photography to document 281 locations in the bay – giving them enough data to extrapolate the amount of garbage present.
On average the researchers found 291 items per square kilometer (0.4 square miles) on the seafloor that included everything from plastic litter, dumped or lost fishing gear and other garbage. Plastics accounted for 51 percent of the litter, with fishing gear amounting to 28 percent of the litter. The rest of the garbage was comprised of everything from cables to metal pieces and tires.
Biologist Tony Walker, assistant professor in the school for resource and environmental studies at Dalhousie University, said the litter eliminates potential habitat by covering the bottom, reports CTV News Canada.
“A tire made of rubber or some metal is actually occupying space that would be a benthic habitat for micro-organisms and small invertebrates,” he said in an interview.
Benthic habitats cover about 70 percent of the earth’s surface. Of the marine species, 98 percent live on or in the ocean floor. The benthic zone maintains a substantial part of the world’s biodiversity.
Walker, one of six co-authors, said the garbage “is occupying a footprint on what should otherwise be a pristine, sandy ocean habitat.” Like other marine researchers, this group also is concerned about the degradation of larger pieces of plastic into microplastics that can be ingested and held in marine life, including invertebrates such as rock crab.
“There is a potential for it to have negative impacts. …. A precautionary principle should kick in, and we should do our best to avoid this pollution,” Walker said.
Researcher Alexa Goodman, the lead author of the study, suggests that the government and fishing industry establish a recycling system for fishing gear – rather than just dumping the stuff over the side of the ship. “We need to work with the industry to find better ways to manage solid waste,” she said in an interview.
The research paper also notes that Canada signed the Ocean Plastics Charter and there is “a growing sense of urgency to move forward with these commitments to improve land and ocean-based waste management.”
