9% of the turtles" -- and "plastics" dominated the debris found (Katsanevakis, p. 75). The list of plastic trash found in those turtles is too long to include in this research. Seabirds (especially pelicans, gannets and gulls) often fall prey to "monofilament line"; albatrosses, petrels, penguins and grebes are not found entangled in plastic fishing line or other plastic debris as often as pelicans and gulls (Katsanevakis, 2008, p. 69). What is particularly insidious about plastic is when it is ingested by marine animals is releases "toxic chemicals" due to the chemical additives that are added to the plastic during the manufacturing process. Once in the abdomen of the animal the toxic materials can block the digestive tract and block "gastric enzyme ingestion, diminished feeding stimulus, nutrient dilution, reduced growth rates, lowered steroid hormone levels, delayed ovulation and reproductive failure," Katsanevakis asserts (p. 71).

There is lethal danger for small marine organisms as well, when it comes to "microscopic plastic particles" that lodge in sediments and surface waters of oceans, Katsanevakis explains (p. 71). After these microscopic particles are ingested by small marine organisms (lugworms, bivalves, barnacles and amphipods), and these organisms are in turn consumed by larger species, the poisons move up the food chain, the author goes on (p. 71).

What are the sources of these massive quantities of plastic in the oceans?

Professor Katsanevakis teaches in the Zoology / Marine Biology departments at the University of Athens, Greece; his lengthy, scholarly essay in the 2008 book Marine Pollution: New Research offers an invaluable wealth of information on ocean pollution with specific reference to plastics. The main sources of marine litter are "…merchant shipping, ferries and cruise liners, fishing vessels, military fleets and research vessels, pleasure craft, offshore oil and gas platforms, and aquaculture installations," Katsanevakis explains (p. 56). The main sources of land-based plastic pollution are waste dumps (landfills) near the coast, storm water discharges, "unregulated disposal of litter due to absence of waste services or landfills in urban or rural areas, the plastic industry and other industrial facilities," and tourism / beachgoers (Katsanevakis, 2008, p. 56).

What international

Moreover, Article 145 demands the "prevention, reduction and control of pollution and other hazards to the marine environment… and of interference with the ecological balance of the marine environment… [including] the disposal of waste" (UN, Article 145). Katsanevakis references the "1973 International Convention for the Preventions of Pollution from Ships," as modified by the protocol of 1978 (MARPOL)" (p. 56). In that protocol, Annex V, emphasizes a prohibition against "…the disposal into the sea of all plastics, including but not limited to synthetic ropes, synthetic fishing nets and plastic garbage bags" (Katsanevakis, p. 56).
Conclusion

The problem of plastic pollution in the world's oceans is clearly a man-made issue, and indeed it is up to governments, shipping industries, pleasure craft operators and citizens to come to terms with this issue. Respect for the integrity of all the creatures that live in the sea must be reinforced, and laws must be beefed up so there are severe penalties for those caught polluting the oceans with plastic (and other pollutants). But most important is information that must be broadcast world wide and emphasized by influential groups and persons, before the world's oceans obtain a legacy of massive die-offs of marine creatures.

Works Cited

Hill, Marquita K., 2010, Understanding Environmental Pollution, Cambridge University

Press, New York City, 585

Katsanevakis, Stelios, 2008, Marine Debris, A Growing Problem: Sources, Distribution, Composition, and Impacts, in Hofer, T.N., ed., Marine Pollution: New Research, Nova Publishers, Hauppauge, New York, p. 54-75.

Moore, Charles, 2003, Trashed: Across the Pacific Ocean, Plastics, Plastics, Everywhere,

Natural History, v. 112, p. 3.

United Nations, 1973, Part VII, High Seas,…