Thursday, October 14, 2010

Plastic Debris Contaminates Marine Environments

Joshua Paetkau
Plastic is a synthetic organic polymer and is a specific product, which is used throughout industries across the globe. Its popularity is the result of its versatility, durability and low costs. These characteristics make it irresistible for industries to avoid plastic packaging and therefore millions of products are wrapped and stocked on store shelves encased in plastic. Beyond its packaging advantages, plastic presents devastating issues to the marine environment. Derraik claims, “a large number of marine species are known to be harmed or killed by plastic debris, which could jeopardize their survival, especially since many are already endangered.”

Its unfortunate to learn that “combined human impacts could have accelerated present extinction rates to 10 000 times the natural rate” says Derraik. Marine species are faced with countless hazards in their own habitats, some of these hazards are natural, however the major threat to their survival is the pollution of plastic debris. The application of plastic packaging has “rapidly moved into all aspects of life” sates Derraik, and currently the United States alone produces 30 million tons of plastic annually, and the harmful effects of eradicating the plastic is sadly overlooked due to the “perceived abundance of marine life and the vastness of oceans have lead to the dismissal of the proliferation of plastic debris as a potential hazard” declares Derraik. The abundance of this pollution often originates from land-based sources, however it is common for “spillage during transport and handling” says Derraik, as well as mishandling of equipment aboard fishing vessels. This problem stretches across the world and continues to increase its destructive effects.

Intake of plastic debris and entanglement in packaging, lines, or drift nets are some of the many threats that exist as a result of the excessive pollution of plastic. As the use of plastic within industries increases as does the pollution of plastic and as a result “marine debris is affecting a significant number of species” Derraik states. The build up of debris not only affects animals but also has the ability to alter the natural ecosystem functioning and modify the sea floor and its make up. Derraik also concludes that “other harmful effects from the ingestion of plastic includes blockage of gastric enzyme secretion, diminished feeding stimulus, lowered steroid hormone levels, delayed ovulation and reproductive failure.” The ingestion of plastic can eventually lead to reduced food intake, decrease in fitness and adjust migrating patterns for birds due to their poor health conditions. Moreover the destructive work of the synthetic debris is not isolated to the smaller animals, as there have been cases of various whales and manatees dying as a result of ingesting plastic. As a result of the affects of debris certain populations of species are in a way regulated, as the pollution causes the overall death toll but more importantly has fatal consequences for the young animals that are responsible for reproducing and breeding.

Above is a image of a sea turtle in the process of ingesting some plastic debris.

In addition PCBs (polychlorinated biphenyl) is a chemical, which has increasingly contaminated marine life. Plastic debris has presented itself as a route for PCBs to enter the marine food web, and unfortunately it posses’ harmful affects on the marine life. This terrible ongoing situation throughout oceans and seas has not been ignored entirely as here have been attempts to promote improvement of the environment through international legislation. An example of this is the Annex V, which was established in 1988, and “restricts a sea discharge of garbage and bans at sea disposal of plastic and other synthetic materials such as ropes, fishing nets, and plastic garbage bags” says Derraik. Although these forms of law are greatly ignored, Annex V and many other forms of legislation are steps closer to improving this situation.

Though the seas cover a mass majority of the earth’s surface the accumulation of plastic debris in our aquatic environment has grown exponentially and has had serious negative affects on the marine life ad ecosystem. Due to the carelessness and lack of initiative, Derraik concludes, “it is imperative that severe measures are taken to address the problem at both international and national level, since even if the production and disposal of plastics suddenly stopped, the existing debris would continue to harm marine life for many decades.”

Resource

Derraik, G.B. Jose. (2002). The pollution of the marine environment by plastic debris. Marin Pollution Bulletin, 44(9), 842-852.


http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V6N-46MD4CM-1&_user=1067211&_coverDate=09%2F30%2F2002&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000051237&_version=1&_urlVersion=0&_userid=1067211&md5=48760baf201425fb1ddd743d478c99c4&searchtype=a

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