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Why forensics could be key to untangling the ocean microplastics crisis

Scientist Peter Ross uses all the high-tech tools of a crime scene investigator — except his crime scene is the open ocean

  • Sep 28, 2017
  • 2,179 words
  • 9 minutes
Peter Ross analyses water samples from various locations for microplastic threads Expand Image

It’s a sunny morning in late spring and Peter Ross, one of the world’s top marine toxicologists, is on a boat leading a plastics-finding expedition in the Pacific Ocean harbour south of Vancouver’s Stanley Park.

He doesn’t have far to go. Mere minutes into the journey, he points off in the distance and yells to the boat’s captain: “Jeremy! Emergency!”

Jeremy Heywood, a diving safety officer with the Vancouver Aquarium, abruptly shifts course and throttles the engine. Minutes later Ross reaches into the ocean and fishes out a boulder-sized piece of rotted Styrofoam, a type of plastic, smutted with algae.

“It’s gonna break down into bits, a bajillion bits,” he says, holding it up.

Within seconds, his prediction starts to come true. The Styrofoam, likely loosed long ago from a dock, is already so degraded that a slight wind snatches small flakes from it and blows them back into the water.

It’s those little bits of plastic, and the even tinier, invisible pieces they disintegrate into, that have captured Ross’s attention. And while scientists have been worried for decades about visible plastic in the ocean — the six-pack rings that garrotte sea birds, the lighters that show up in the corpses of baby albatrosses, the shopping bags that suffocate migratory turtles — they now fear those large pieces are not the most dangerous.

Instead, it’s what the big pieces degrade into: increasingly smaller pieces of themselves, immortal, spreading from pole to pole, from surface to depths, from shore to gyre. The sheer reach and volume of the stuff has shocked the world’s scientific community.

Although Canada has recently labelled plastic microbeads a toxic substance — a step toward banning beads used in products such as facial cleansers — there’s still a tremendous amount of even tinier plastic in the water. One recent study found that if trends continue, by the middle of this century there will be more plastic by weight in the ocean than fish.

Some scientists are sprinting to determine the impact of microplastics on the marine animals that consume them, but Ross has turned his attention to another piece of the puzzle. He’s using the forensic tools of a high-tech crime scene investigation to uncover precisely which of several thousand chemical fingerprints a plastic fragment carries, possibly which manufacturer made it and maybe even which product it was in before it broke down into a marine threat. His reasoning? If you can trace plastic back to its source, you can stop it from getting into the water. To him, the problem is now so severe that the focus must be on prevention.

“We can identify and turn off some of the taps,” says Ross. “But it’s going to be tough.”

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Ross, 53, still remembers the image he saw on a childhood friend’s television that triggered his lifelong fascination with toxic chemicals: a Tokyo police officer directing traffic wearing a gas mask. It was the start of realizing that the planet’s air and water are linked and that toxic chemicals in one place mean they can show up somewhere else.

He’s telling me this story at the Vancouver Aquarium Marine Science Centre, in a small meeting area overlooking outdoor tanks where researchers work with Steller sea lions and northern fur seals. Ross landed at the aquarium in 2014, nearly a year after the government of former prime minister Stephen Harper axed the marine toxicology team he led at Fisheries and Oceans Canada. Within a year, Ross set up an ocean pollution research team at the aquarium to do the work.

Ross is a scientist’s scientist, which is to say that he’s obsessed with impeccable methodology. He takes no shortcuts, brooks no spin. He is incapable of exaggeration. And while he admires good laboratory experiments, his strong bias is for research with wild animals roaming free.

His life’s work is a devastating, precise and pioneering catalogue of the many ways human-made chemicals harm sea life and the creatures that depend on it, particularly their immune and endocrine systems. His findings rarely won friends in his government department, where, he says, the emphasis was on fish rather than the toxins they contain.

“I get that, but it’s in no one’s best interest to have those chemicals in those products,” he says. “My argument is that if you don’t know about it, you can’t turn off the tap.”

At university, he worked his way through research on toxic metals poisoning dragonfly nymphs in acid-rain-drenched lakes, PCBs killing double-breasted cormorant chicks in the Great Lakes and then, just in time for his PhD, he hit upon an intriguing scientific mystery: harbour seals were dying en masse in Europe. Scientists suspected a virus.

But Ross remembered that PCBs and other long-lasting toxic pollutants can impair immune systems. So he moved to the Netherlands and set up a study catching mother and pup harbour seals in the wild and then, for 93 weeks, fed them either herring from the highly polluted Baltic Sea or from the lightly polluted Atlantic Ocean. Results, published in 1994, were both groundbreaking and clear. The chemicals were harming the seals’ ability to fight infection; the virus was killing them because they were already weakened.

Returning to Canada in 1996, Ross joined the federal government in Sidney, B.C., and began a frenzy of research on how long-lived toxins collect in the bodies of marine creatures over time and harm their health: harbour seals, killer whales, Steller sea lions, belugas, salmon, sea otters, northern elephant seals and a host of other animals. His work helped lay the groundwork for the Canadian ban on the most toxic form of the flame-retardant PBDEs in 2005.

Then in the late 1990s, he got a call from a conservation protection officer who was handling the fallout from a fishing lodge fire off the west coast of Vancouver Island. Giant blocks of Styrofoam had broken free from the site and were in the water. The lodge’s owner claimed the plastic would eventually dissolve. The officer wanted to know if that was true.

Ross started researching. He discovered that plastic, Styrofoam or otherwise, would remain in the ocean forever, only becoming smaller and harder for humans to see. With his long history of looking at persistent marine pollution, he figured that some marine species would start eating the plastic in place of food — with unknown consequences. Not only was plastic a problem, it was a big problem.

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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.

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The next afternoon, Ross is in his lab at a microscope, ready to look at the water he collected near the treatment plant. The sample has been treated with hydrogen peroxide overnight to dissolve the flesh of any living creatures. Invisible to the naked eye, but clear under 16-times magnification, there they are: tiny, wiggly threads of plastic, likely the remains of decades-old nets, shopping bags and fabrics.

Figuring out exactly what types of plastic they are is the next step. Ross and his team are still developing protocols for that. They’ve acquired a Fourier transform infrared spectrometer that uses wavelengths of light to determine what something is made of. It’s the same type of machine the Royal Canadian Mounted Police use to match a fibre found on a murder victim to a suspect’s rug.

Ross has bought a commercial library containing the unique spectrometer readings of 4,500 plastic polymers and their additives, and his team will eventually be able to scan a whole crop of plastic fibres with the machine and identify them, building up a more robust database.

The Vancouver Aquarium lab is one of the few in the world dedicated to microplastic analysis of this kind. Until now, most researchers could only say that a plastic fragment was bendy or brittle, fouled or not. Ross points over into a corner, where the grimy Styrofoam from his expedition the day before stands. It, too, will be put to use in tests to examine just how plastic degrades in the ocean.

Where will it all lead? A key is keeping plastic out of the ocean in the first place with more recycling. And Ross is in talks with two clothing companies to see if fabric manufacturing can be modified to keep plastics out of wash water. Over time, as the science becomes ever more precise about the dangers of plastics, he can envision global regulation, just as there has been on other toxic substances such as mercury, DDT and PCBs.

It’s the reason he’s so immersed in this issue: there are practical steps we can take to make things better.            

“There are so many solutions out there,” says Ross. “That’s why I’m sort of excited.”


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Ross in the Vancouver Aquarium Marine Science Centre analyzing water samples. Credit is: Steven Hargreaves


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