Making a finer point about plastic waste
The seas around Europe and beyond are awash with tiny scraps of plastic discarded by beachgoers and other careless polluters, say UK researchers who combed scores of British beaches in search of evidence. But what does this mean for the environment and fragile marine ecosystems?
Beachcombers will attest to the changing nature of jetsam found stranded on coasts around the world since plastic entered the commercial world some 40 years ago. Plastic bottle tops, buckets, milk containers and cheap toys are just some of the debris thrown overboard, washed to sea from storm-water drains or left behind by beach picnickers.
|Seems clean enough, but scientists now believe oceans and beaches are teeming with minute plastic particles|
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A team of researchers from the Universities of Plymouth and Southampton found that minute fragments of polyester, nylon and seven other types of plastic are littered across shores all over the island and in the open seas. Reporting in the latest edition of Science journal, Richard Thompson – senior lecturer at Plymouth and lead writer – and his fellow researchers say there is a high chance the British case is not an isolated one.
For years, environmental groups have warned of the ecological damage caused by ocean-borne plastic debris. Worldwide, more than a million seabirds and 100 000 mammals and sea turtles die each year from entanglement in – or ingestion of – plastics, according to the UK’s Marine Conservation Society.
Possible environmental impact
It is not yet known whether the breaking down of plastics into minute particles further endangers wildlife, says Thompson, but their study does show that smaller marine invertebrates, such as barnacles, lugworms and detritus-eating amphipods, ingested the fragments within a few days of being exposed to them.
The scientists collected and studied samples of seawater and sediment from 18 regions along Britain’s coastline. To look at the long-term trends, they also analysed plankton samples gathered over the past 40 years in shipping lanes between Iceland and Scotland. Results showed around three times more plastic in this water column in the 1990s compared with the 1960s.
“I expected to find this material, but I was surprised by how common it is,” says Thompson whose team identified the inorganic material in their samples and found that up to one third of this material was synthetic polymers used in plastics. They could only identify coloured polymer fragments larger than 20 micrometers in diameter, which means the percentage of foreign material may be even higher.
The scientists plan to investigate the environmental impacts of this finding. These include the effects these particles may have on the digestive systems of marine invertebrates, and whether there is any potentially harmful chemical transfer – such as biocides or colourings – from plastics to these organisms. Thompson is also concerned that floating plastic particles could become coated with more dangerous industrial pollutants (such as polychlorinated biphenyls or PCBs in pesticides) which, if ingested, may have a disruptive effect on animal endocrine systems – affecting reproduction and gender.
Research Contacts page
Plastic particles surf polluted waves (Nature online, 7 May 2004)Oceans awash with microscopic plastic (National Geographic, 6 May 2004)Science online (homepage)Bagging the plastic blight once and for all (Headlines, 16 September 2003)