Most scampi in the Clyde are polluted by plastic

from Sunday Herald, 24 April 2011

More than four out of five of the scampi in the Clyde Sea have been polluted by plastic waste posing a threat to human health and a £100 million fishery, a new scientific study has found.

Fibres of fishing nets and ropes, along with tiny pieces of polythene bags, have been detected in the stomachs of 83% of scampi, also known as langoustines, sampled from around the Isles of Cumbrae off Largs.

The plastic can make it difficult for the little orange-pink lobsters to feed properly, as it can bunch up into balls and cause blockages. It can also be contaminated by toxic chemicals which scientists say are ”a potential health concern” for humans.

The langoustine fishery is the most valuable in the UK, landing 42,000 tonnes worth £96 million in 2009. There are some 40 langoustine trawlers operating out of Clyde ports, plus 30-40 from other Scottish and Irish ports.

The study was carried out by scientists from the University of London, based at a marine biological station at Millport on the Isle of Cumbrae, and from the University of Aberdeen. It is being published in the Marine Pollution Bulletin, a peer-reviewed scientific journal.

The scientists detected plastic strands inside 100 of the 120 langoustines they fished out of the sea in May and June 2009. Analysis showed that the strands were from the ropes and nets used by langoustine fishing vessels and possibly yachts, as well as plastic bags.

In 62% of the samples studied, the plastic had formed into “tightly tangled balls” which can clog up the animals’ guts. Plastic waste has also been found to contain pesticides and industrial wastes like DDT and PCBs.

The scientists warn that the high prevalence of plastic in nephrops, the scientific name for langoustines, “may have implications for the health of the stock.” But they point out that their guts are not usually eaten by humans.

“So the risk of direct human consumption of plastics is low. However, the potential presence of mobilised chemicals in nephrops tail flesh, which is eaten, is a potential health concern,” they say.

“The results of this study clearly show that nephrops in the Clyde are consuming plastics and that one of the sources of this plastic is that used by the nephrops fishery itself.”

One problem is the use by trawlers of “chafers”, bundles of hard polypropylene rope attached to the bottom of fishing nets to protect them from rocks. They fray and discard fibres as they are dragged across the seabed.

The study recommends the development of alternatives to plastic chafers. “Plastic pollution is a growing problem, the consequences of which are poorly understood for most marine species,” it concludes.

The invertebrate conservation group, Buglife, is calling for a review of langoustine fishing practices. “Yet again it’s a case of out of sight, out of mind,” the group’s Scottish officer, Craig Macadam, told the Sunday Herald.

“Invertebrates such as nephrops are a key component of marine food webs, however these plastics threaten to disrupt these webs and jeopardise an internationally important fishery.”

He added: “We urgently need research on the effects of these plastics on nephrops and other marine life, and a review of the use of chafers on fishing nets.”

Representatives of the Clyde fishing industry could not be contacted on Friday. According to the website of the Clyde Fishermen’s Association, “the nephrops fishery is now the major source of income for Clyde fishermen.”

Plastic wastes, which decay extremely slowly, are a major polluter of the world’s oceans. Ships are estimated to discard 6.5 million tonnes every year.

Other studies show that 267 marine species have either eaten or been entangled by plastic rubbish. These include 86% of all turtle species, 44% of all seabird species and 43% of all marine mammal species as well as numerous fish and crustaceans.

This story was followed up by Deadline News, The Times and the Daily Mail.