People Eat Fish, That Eat Fish, That Eat Plastic

Photo: Scripps Institution of Oceanography researcher Rebecca Asch dissects fish and looks for traces of plastic inside of them.
Scientists at the Scripps Institution of Oceanography are surprised by the sheer amount of plastic they're uncovering in hundreds of samples they hauled back from the North Pacific Ocean last August. A team of graduate students sailed a thousand miles west of California to a rarely-traveled but much-hyped area called the North Pacific Gyre -- a continent-sized, slowly swirling stretch of water where oceanic currents have deposited tons of plastic trash. The Scripps team set out to find how much debris is really there and whether it's having a major impact on marine life.
Scripps is the first major scientific institution to study the large accumulation of plastic, dubbed the "Great Pacific Garbage Patch," in the becalmed waters of the North Pacific. The Long Beach-based Algalita Marine Research Foundation introduced it to the public a decade ago, with photos of an albatross carcass littered with bottle caps and tangles of fishing tackle, bath toys, bags and jugs. Now, with the Scripps study, the emphasis is on tiny bits of plastics, about the size of a grain of rice -- but potentially toxic to smaller organisms. While the researchers found plenty of large pieces, they're more concerned with the confetti-like shards broken down by sun and waves over many years. Chief scientist Miriam Goldstein put it this way from her UCSD lab, while holding two jars filled with jagged bits of blue, green, yellow and pink: "Scientists are floored when I show them these samples. Regular people are usually not very impressed because they're like ‘Where are our islands of trash?' This is a huge amount of plastic to get in a manta tow [net]."
In 100 years of sampling the world's oceans, previous Scripps researchers never found so much plastic. Goldstein can't quantify it yet, since they're still sorting through jars of zooplankton, crustaceans and fish.
Not only did Scripps find a lot of plastic, they've found that fish are eating it. "We did indeed find some indisputable pieces of plastic in their guts," said Pete Davison, a Scripps graduate student dissecting the fish.
Scripps researchers found tiny plastic bits in about 5 to 10 percent of the fish they opened up, mainly small swimmers common in the deep ocean, like lanternfish and hatchetfish. Davison added that some fish could have eaten plastic in their nets, although others definitely consumed it in the wild. While people don't directly dine on these species, larger commercial fish do. "If tuna is eating a lot of lanternfish, it is indirectly ingesting the plastic that might be in the lanternfishes stomach," Davison said. Plastic also absorbs toxins like PCB and DDT that could be leaching into sea life.
Scripps researcher Rebecca Asch, studying the fish with Davison, added that plastic could be getting caught in fish intestines. "If that's the case, it would be a similar thing to what happens in sea birds where they get this stomach full of plastic and they stop eating regular food," she said. "They feel full because their stomach is full of plastic and they end up starving."
The Scripps team also found juvenile yellowtail -- the kind you find at sushi bars -- and blue muscles -- again, a variety that people eat -- in the far-away gyre. Both are typically found in coastal regions, which means sea life could be hitching rides on plastic rafts to places they don't normally live. The gyre is considered a biological desert. There are rare and old species there, many smaller in size because of the lack of food. But these remote waters are becoming a graveyard for plastic discards -- which never fully break down -- from industrialized Asia and North America.
Goldstein said plastic may be supporting life forms that wouldn't normally thrive in the gyre, harming others and possibly transporting invasive species. She plans to publish her research in a science journal later this year.
For now, Goldstein confirmed Scripps found plastic in 1,700 miles of open ocean. "We definitely think there's a lot of plastic out there."

Manuel Martinez

Project GreenBag, 2200 Market St, San Francisco, CA, 94114, United States