One of Canada’s top marine biologists is comparing the harm wrought by the accumulation of plastics in the world’s oceans to the warnings about the pesticide DDT in the famous 1962 book “Silent Spring.”
“What scares me about this is it is just accumulating. It is not going away. Plastic doesn’t go away. It takes decades to centuries to actually break down. That means whatever we produce now is released into the environment,” professor Boris Worm, a biologist at Dalhousie University, said in an interview.
Worm is the author of an editorial titled “Silent Spring in the Ocean” published in the Proceedings of the National Academy of Sciences, an American scientific journal.
Rachel Carson’s book, “Silent Spring,” warned of the environmental impacts of DDT on a variety of species, particularly birds. The book is often credited with altering agricultural practices, the banning of DDT, and the creation of the environmental movement.
“Carson specifically highlighted how DDT was a persistent pollutant that accumulated in the environment and threatened the survival of many bird species by interfering with their breeding cycle,” Worm wrote.
“This time a “silent spring” may be looming in the oceans.”
Scientists have estimated that concentrations of plastic in the oceans have reach 580,000 pieces per km2 and have warned those levels are increasing. The plastics are entering the oceans from a variety of sources, including plastic microbeads, plastic bags that blow away from dumpsites, and plastic debris that has found its way into rivers.
“There was no plastic around in the environment 50 years ago and these industrial microbeads are a relatively new phenomenon,” said Worm.
“The extent of the problem and the rapid acceleration in the ocean in particular has caught a lot of us by surprise. The main problem is the increasing use of disposable plastics in industrializing countries where the waste disposal systems haven’t grown at the same pace.”
Worm cites a study published earlier this year as particularly troubling. Consisting of a review of studies from 1962 to 2012, the study found that 9 out of 10 seabirds such as seagulls are likely to have plastic in their stomachs. The scientists who conducted the study warn that figure will reach 99 percent by 2050.
Other research has shown the plastic is being found throughout the water systems of the world.
Whole plastics have been found to pose multiple problems for wildlife. Birds and fish eat the plastic mistaking it as food, causing an accumulation in their stomachs and depriving them of food and nutrients. On a smaller micro-scale, as the plastic breaks down it attaches to bacteria and toxins in the environment creating a lethal dose for animals if enough is ingested.
“Imagine the food you eat is laced with plastic, and it looks just like the food you eat. There isn’t an easy way to tell it apart, and every year there would be more until the majority of what you eat is plastic,” said Worm. “That is the situation these birds are in.”
“It’s not just sea birds,” adds Worm, referring to a dead pygmy sperm whale that washed up in Halifax Harbour in March. The whale’s throat was filled with plastic bags, which is what likely caused its death.
Kaven Baker-Voakes is a freelance reporter based in Ottawa.