Page 244 - NS-2 Textbook

OCEANOGRAPHY 239

One of the ten most serious pollution accidents in the past fifty years was the breakup of the American tanker Torry Canyon after going
aground off Land's End, England, in 1967. The 61,263-ton ship spilled more than 120,000 tons of oil on the sea and beaches of southwestern
England.

chemical and synthetic fuels, solvents, and pesticides; (5) Oil slicks on the high seas can kill plankton in the
litter; (6) domestic sewage; and (7) biological pollutants. surface zone, but in general it will dissipate over a period
Petroleum. The ,vorld-wide Uenergy crunch" Canl€ of time. Often it gathers in tarlike balls that eventually
into focus in the 1970s and will continue for the foresee- sink to the bottom. While such "oil litter" can do no
able future. Since the early 1970s, millions of tons of good, it probably does not do much permanent harm ei-
crude oil, gasoline, and other petroleum products have ther. On the other hand, when such an oil slick reaches
crossed the oceans in thousands of tankers. Each yea,; it shore or collects in harbors, coves, or bays, the results are
is estimated that more than 6 million tons of this petro- disastrous for the seabirds, mollusks, and other shallow-
leum enters the oceans. Much of it is oil washed out of water life. Also, an oil spill will devastate the economy of
fuel tanks and bilges when they are pmnped, but some of a beach resort area.
it is the result of ship collisions and groundings. Oily The Navy's major pollution problem in harbors,
waste from land areas can run off into the sea. Addition- ports, channels, and U.S. waters is the discharge of oils
ally, there have been terrible spills from lmdersea oil rigs and oily wastes. TIle Navy has an active program to
in the North Sea, the Gulf of Mexico, the California coast, eliminate all such pollution and works closely with the
and elsewhere. During Operation Desert Storm in early Enviromnental Protection Agency and the Coast Guard
1991 crude oil was intentionally dlunped into the Persian in this effort.
Gulf by Iraqi forces in Kuwait. These catastrophes Heavy Metals. The sea's main heavy metal pollutants
dumped thousands of tons of oil per day into the water, are mercury and, to a lesser extent, bariwn. These metals
creating oil slicks that covered thousands of square are discharged in the effluent from memical plants, cement
miles. works, and other manufacturing processes, doubling their