Water samples await analysis for microplastic threads at the Vancouver Aquarium Marine Science Centre. (Photo: Steven Hargreaves)
Marie Noël, 33, an ecotoxicologist who is research manager of Ross’s lab, is hauling water into the boat underneath Vancouver’s Lions Gate Bridge. She hoists up two shiny steel pails full, 30 litres in all, then she and Ross carefully pour it through two filters. The first, with a mesh of 4.75 millimetres, screens out anything too big to be considered a microplastic. The second, at 0.063 millimetres, a little more than half a hair’s width, gets the really tiny bits. Then they rinse what’s caught in the finer mesh into a small glass Mason jar. Tomorrow, they’ll analyze the water in their lab to see what’s in it.
The water looks clear, apart from some miniscule plankton. But Ross bets the sample contains microplastics. A study he published in 2014 found roughly three plastic particles for every litre of water in British Columbia’s Strait of Georgia, and he expects something similar here.
This is no random test site. It’s near the 1961-era Lions Gate wastewater treatment plant, which processes waste from about 180,000 citizens and pumps the effluent here. The regional government, Metro Vancouver, plans to replace this plant with another one a couple of kilometres further east. As its representatives plan it, they’ve been pondering some uncomfortable new findings.
Studies from the United Kingdom, Finland and California, including one commissioned by the outdoor-garment giant Patagonia, show that clothes such as fleeces and athletic wear made from synthetic fabrics are shedding microscopic threads of plastic into the water every time they’re washed.
The first study, published in the U.K. in 2011, found that each garment releases more than 1,900 fibres every time it hits the washing machine, and many of those end up in waterways because wastewater treatment doesn’t capture them all. The regional government has asked Ross to look into what microplastics are getting through the old plant, and help figure out if that can be reduced.
Those tiny plastic threads matter. In 2015, Ross published another trail-blazing study establishing that two types of zooplankton in the open ocean off the coast of British Columbia were eating microplastics rather than food. Ross hypothesized that baby salmon eating the plankton would in turn be consuming between two and seven of the threads every day, and that adult salmon would ingest about 91 a day. The team’s next big study will be to see how much plastic baby salmon bodies contain.
“Salmon are on the edge to start with. If we put plastics into the mix …” He shrugs, as if to say, “Who knows what will happen?”
It’s not only zooplankton that are consuming microplastics, but also mussels, herring, cod, haddock and sharks, among others. In other words, the plastics reach from one end of the marine food web to the other. Researchers estimate that more than half of sea turtles and nine in 10 seabirds have eaten plastic. Recent necropsies of sperm whales stranded in Germany found plastic car engine covers and massive wads of plastic fishing net in their stomachs.
While plastics absorb chemical pollutants from the surrounding water, making them in some cases a million times more toxic than the ocean itself, that’s not Ross’s primary concern. Instead, he’s worried about structural injury to the body. Plastics lacerate cells and organs, move from the digestive tract to other tissues and prevent animals from eating.
But they do far more than that. Ross and Esther Gies, 32, who heads the aquarium’s microplastics program, point to a shocking study published in December 2015 on oysters exposed to microplastics in the lab. Not only did the bivalves gobble them up, but the plastics also severely impaired the oysters’ ability to produce viable eggs and sperm, shutting down some of the genes they needed for reproduction.
Some of those plastics end up on your plate. Another study on oysters farmed for human consumption in the northeast Atlantic Ocean showed that people eating a dozen or so would be consuming about 100 microplastic threads. What does that do to you? Unknown.