PLASTICS

(from: Laws, E.A. 1993)

Summary:

The industrial advantages of plastics also account for their problem as a contaminant in aquatic environments. The resistance of plastics to corrosion and degradation accounts for their persistence in the environment, and the transparency of plastics accounts for their ingestion by organisms that feed on jellyfish. Additionally, the magnitude of plastics generated (e.g., 27 million tons per year or 110 kg per person in the United States, annually) accounts for the magnitude of the problem (O'Hara et al., 1988).

While plastic doesn't seem as intimidating as exotic chemicals, such as DDT, the adverse health effects of plastics on marine life may be more extensive. Some of those effects are illustrated in these pictures of large marine organisms harmed or killed by plastics discarded in the marine environment:

(a) a turtle drowned in a scrap of fishing net

(b) seal starved by a plastic ring

(c) a fish trapped in a six pack holder.
(Photos provided by Save Our Shores.)

 

The adverse effects of plastics in the aquatic environment may be briefly categorized into the following:

aesthetics
The cover of Law's, 1993, text is a beach covered with plastic debris.

ingestion
Some marine organisms (e.g., turtles, whales, birds, and fish) mistake plastic debris for jellyfish. The ingested plastics plug their digestive tracts and the organisms starve.

entanglement
The most extensive problems of entanglement are caused by gill nets, trawl nets, and long lines. In the 1980s it was estimated that the total length of gill nets being used in the North Pacific was 170,000 km or more than four times the circumference of the globe (CEE, 1987).

ghost fishing
Some of those nets and lines are often lost or intentionally discarded at sea, where they continue to indiscriminately trap large organisms. This is referred to as ghost fishing.

damage to vessels
Plastic debris can also cause damage when they become entangled in the propellers and water intakes of marine vessels.

Corrective Actions

Web Sites:

References:

CEE (Center for Environmental Education). 1987. Plastics in the Ocean: More Than a Litter Problem. Center for Environmental Education, Washington, D.C. 127 pp.

Laws, E.A. 1993. Aquatic Pollution, 2nd edition. John Wiley & Sons, Inc., New York, NY, 611 pp.

O'Hara, K.J., S. Iudicello and R. Bierce. 1988. A Citizen's Guide to Plastics in the Ocean: More Than a Litter Problem. Center for Marine Conservation. Washington, D.C., 143 pp.

Shomura, R.S. and M.L. Godfrey (eds.). 1990. Proceedings of the Second International Conference on Marine Debris. U.S. Department of Commerce, Honolulu, HI.

Shomura, R.S. and H.O. Yoshida (eds.). 1985. Proceedings of the Workshop on the Fate and Impact of Marine Debris. U.S. Department of Commerce, Honolulu, HI.

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