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View Full Version : Plastics Are Poisoning the World's Seas



Willow
Thursday, December 7th, 2006, 10:52 PM
Microscopic particles of plastic could be poisoning the oceans [...] small plastic pellets called "mermaids' tears", which are the result of industry and domestic waste, have spread across the world's seas. The scientists had previously found the debris on UK beaches and in European waters; now they have replicated the finding on four continents. Scientists are worried that these fragments can get into the food chain.

Plastic rubbish, from drinks bottles and fishing nets to the ubiquitous carrier bag, ends up in the world's oceans. Sturdy and durable plastic does not bio-degrade, it only breaks down physically, and so persists in the environment for possibly hundreds of years.

Maybe in a different chemical environment, perhaps in the guts of organisms, those chemicals might be released Among clumps of seaweed or flotsam washed up on the shore it is common to find mermaids' tears, small plastic pellets resembling fish eggs. Some are the raw materials of the plastics industry spilled in transit from processing plants. Others are granules of domestic waste that have fragmented over the years. Either way, mermaids' tears remain everywhere and are almost impossible to clean up.

Dr Richard Thompson at the University of Plymouth is leading research into what happens when plastic breaks down in seawater and what effect it is having on the marine environment. He and his team set out to out to find out how small these fragments can get. So far they've identified plastic particles of around 20 microns - thinner than the diameter of a human hair. In 2004 their groundbreaking study reported finding particles on beaches around the UK. Historical records of samples taken by ships plying routes between Britain and Iceland confirmed that the incidence of the particles had been increasing over the years.

Now the team has extended its sampling elsewhere in Europe, and to the Americas, Australia, Africa and Antarctica. They found plastic particles smaller than grains of sand. Dr Thompson's findings estimate there are 300,000 items of plastic per sq km of sea surface, and 100,000 per sq km of seabed. So plastic appears to be everywhere in our seas. The next task was to try and find out what kind of sea creatures might be consuming it and with what consequences.

Thompson and his team conducted experiments on three species of filter feeders in their laboratory. They looked at the barnacle, the lugworm and the common amphipod or sand-hopper, and found that all three readily ingested plastic as they fed along the seabed. "These creatures are eaten by others along food chain," Dr Thompson explained. "It seems an inevitable consequence that it will pass along the food chain. There is the possibility that chemicals could be transferred from plastics to marine organisms."


Other contaminants

There are two ways in which this might happen. Firstly, the Plymouth scientists want to establish whether there is the potential for chemicals to leach out of degraded plastic over a larger area after the plastic has been ground down. The second aspect of this research is focusing on what happens when plastic absorbs other contaminants. So-called hydrophobic chemicals such as PCBs and other polymer additives accumulate on the surface of the sea and latch on to plastic debris. "They can become magnified in concentration," said Richard Thompson, "and maybe in a different chemical environment, perhaps in the guts of organisms, those chemicals might be released."

Whether plastics present a toxic challenge to marine life and subsequently to humans is one of the biggest challenges facing marine scientists today. The plastics industry's response is that much of the research is speculative at this stage, and that there is very little evidence that this transfer of chemicals is taking place in the wild. It says it is doing its bit by replacing toxic materials used as stabilisers and flame retardants with less harmful substances.

Whatever the findings eventually show, there is little that can be done now to deal with the vast quantities of plastic already in our oceans. It will be there for decades to come.


Source: http://news.bbc.co.uk/go/pr/fr/-/1/hi/sci/tech/6218698.stm

Gorm the Old
Thursday, December 7th, 2006, 11:53 PM
The title of this post is a classic environmentalist dictum. MAYBE these "mermaids' tears" are harmful to some organism(s), but , if so, WE DON'T KNOW IT. We don't know WHAT effects they may have on what. The statement that they are :"poisoning:" the seas is typical hysterical environmentalist rhetoric. :eek

I wish that they would have the sense and decency to confine themselves to the facts, namely that plastic debris MAY constitute an environmental problem, instead of screaming hysterically that the oceans are being poisoned !

This is why, as an old-guard conservationist, I have little respect for environmentalists. They are ignorant, and prone to gross exaggeration. Their approach to environmental problems is not scientific but polemical They are not scientists but lobbyists. "The confidence of ignorance is unabashed." :doh

We (When I say "we", I mean scientists, of which I was once one, and conservationists of which I am still one.) don't know if "mermaids' tears" are harmful to any organism , but THEY claim to. We don't know what causes global warming, but THEY claim to. We don't know what causes the hole in the Ozone Layer, but THEY claim to. :rolleyes:

The less one knows about a subject, the easier it is to speak positively about it. The learned man has doubts; the ignorant man is sure. I am sick and damned tired of the environmentalists' stridently purveying misinformation. Learn to distinguish fact from speculation. :read:

klokkwerx
Friday, December 8th, 2006, 01:19 AM
I come to see through all my travels is the 3rd and 2nd world countries that their dry/wet rivers become a dumping ground for all the people up river, and when it rains all the trash is swept to the sea. This counts for the greater % of the pollution in the sea, and it all boils down to 2 things: education and governmental interaction / enforcement. The only thing that I see that will hamper this problem besides organizational intervention is an individual being aware of what he is buying (plastics), and etc. The companies that are partly responsible are Coca-Cola, Pepsi, and others for producing mass amount of plastic and not setting up recycling centers of off set the damage.

NatRev
Saturday, December 9th, 2006, 10:54 AM
I saw the news about that on TV.

Gotta admit that seeing a seagulls stomach full of plastic bits really upset me. :(