A ground- breaking study by five Japanese researchers at Tokyo University produced the first real proof, not mere evidence, that plastic floaters in near-shore waters were adsorbing ( being coated by) wayward toxic chemicals. In their multifaceted and cleverly designed study (“Plastic Resin Pellets as a Transport Medium for Toxic Chemicals in the Marine Environment”, Environmental Science & Technology, 2001), the researchers focused on polypropylene (PP) nurdles, the preproduction pellets that are the raw material for most plastic products. As such, they’re a major international commodity, shipped everywhere. PP –aka #5 – is a strong plastic used to make bottle caps, food and sauce containers, stain resistant carpeting, floating ropes, all-weather gear, and the like. Using sterilized stainless-steel tweezers, the research team collected nurdles from both industrial shorelines and recreational beaches in Japan. These were ‘feral” nurdles, coming from shipping spillage and escaped from processing facilities, inhabitants of the marine environment before washing ashore. A separate nurdle group consisted of “virgin” pellets secured from Grand Plastics in Japan. These were divided among several submersible baskets and secured to a wharf in industrial – that is- polluted Tokyo Harbor. Each week a basket was removed until all had been collected, so that direction of exposure and rates of contamination could be gauged.
In their lab, pollutants were extracted from the pellets with hexane, a powerful solvent, and measured using advanced instruments. The basic results were this: the longer the nurdles remained in the pollutant bath – Tokyo Harbor- the more contaminated they became. They were pollutant sponges. But even the most contaminated of the once virgin nurdles weren’t nearly as toxic as the shore-harvested nurdles. Those taken from industrial shorelines had toxic loads a million times stronger than toxic levels in nearby coastal water. Nurdles from the cleaner beach sites were less contaminated but still dangerously polluted.
One of the special problems with nurdles is their strong resemblance to fish eggs – seabird caviar. Wildlife biologists like Peter Ryan had already established that preproduction plastic pellets were virtual staples in the diets of several seabird populations. A toxified nurdle hanging out for several months in a seabird’s gut would not be a good thing. The Japanese researchers also discovered that as the nurdles decayed, they released a toxic chemical identified as nonylphenol, a common additive that slows oxidation and has been proved a potent disruptor of cell function in lab experiments.
The author discovered that minute plastic particles have penetrated into marine environment at the lowest levels of the food chain, among myctophids, commonly known as lantern fish because they are bioluminescent. Lurking in the oceans’ “twilight” zone by day – the mesopelagic zone, 650 – 3,000- feet deep – they rise at night to feast on zooplankton. Many and small, these fish are rarely longer than several inches but they make up about 65 percent of deep-sea fisg biomass. They populate every marine ecosystem as 254 distinct species. At night they literally rise and shine in a vertical migration which is the largest daily biomass shift on the planet. Lanternfish are food for creatures we eat – tuna, cod, salmon, and shark as well as whales, dolphins, pinnipeds , and penguins.
The author’s study found that 35% of the lanternfish they collected in the middle of the Pacific Ocean contained plastic bits. The larger specimens contained more plastic. Cumulatively, the 670 fish they collected yielded a total of 1,375 plastic flecks, averaging one millimeter in size. A single fish contained 83 fragments. The larger fish contained on average 7 pieces. The vast majority were fragments, with film and bits of line and rope together adding up to less than 6 percent.
Now we know, as if there’d been any doubt, that lots of different creatures accidentally eat plastics. We also know incalculable quantities of plastic litter – two hundred thousand homes and their contents were swept out to sea, for starters- by the March 2011 tsunami in Japan. Ocean currents and winds will widely disperse this debris throughout the ocean and much of it will be mistaken for food and consumed. Tons of plastic litter are washed into the sea from rivers every year. We are beginning to have a sense of the mechanical harm plastic litter can cause in the guts of living things. It’s time to consider whether the world and its inhabitants, including people, are also being poisoned by plastics.
http://www.youtube.com/watch?v=sV0dpZVpaVc
Sustainability Lecture with Captain Charles Moore Discussing his book "Plastic Ocean", Boston University, 2011
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