Troubles Bubble under the Sea Pollution and Overfishing Bring Calls for Marine Preserves, Tougher Controls

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Five hundred years ago, explorer John Cabot landed hereabouts and reported that "the seas are covered in fishes." So many, in fact, that England and France soon set up year-round fishing posts along the Atlantic Coast and in doing so began the European settlement of New England and Atlantic Canada.

Today the seas are no longer "covered in fishes." In a single generation, overfishing and poor management have devastated fish stocks in the northwest Atlantic and other regions around the world. Thirteen of the world's 15 major fishing regions have seen a decline in total catch, putting an estimated 100,000 fishers out of work and threatening the food supply of millions in developing countries.

But the deterioration of the world's fisheries is just the tip of the iceberg. There is growing concern about general declines in marine life worldwide, as many ecosystems and entire seas falter under the combined effects of a wide range of human activities. "There is no question that there is a deterioration in the oceans' capacity to regulate planetary processes and to produce the resources we depend on," says Tundi Agardy, senior director of marine programs at Conservation International in Washington. Overfishing, habitat destruction, climate change, and the indiscriminate dumping of sewage, fertilizers, oil, and other wastes into rivers and seas are exacting a terrible toll on marine life worldwide. Vast "dead zones" of oxygenless water have spread across highly polluted estuaries and seas. Fish stocks have deteriorated or collapsed around the world. Important habitats like wetlands and coral reefs are rapidly disappearing. Changes in sea temperatures are altering ocean currents that drive world weather patterns, possibly due to global warming. "Scientists who are most knowledgeable about the marine environment are looking at their study sites and their data and are getting really scared," says Elliot Norse, president of the Marine Conservation Biology Institute in Redmond, Wash. "The general public is unaware of the seriousness of these problems." Damaged seas The cumulative damage to marine life is most clearly seen in the world's semi-enclosed seas. Such seas typically have dense human populations ashore and a low rate of seawater "flushing" to the open ocean. Pollution, coastal development pressures, and fishing demands are concentrated with increasingly dramatic effects. The Black Sea is a sobering example. For millennia its bountiful fish and shellfish nurtured the human civilizations that populated its shores - from ancient Greece to contemporary Turkey. But over the past two decades, large-scale commercial fishing and agriculture have rendered the sea virtually lifeless. Twenty of 26 commercial fish species have vanished since 1970, while the anchovy harvest fell by more than 95 percent. In their place are monstrous algae blooms (which feed on human wastes) and the North American jellyfish that prey on them. Romania and Bulgaria have already sold their entire state-owned fishing fleets, and tourism is faltering as raw sewage washes onto the beach resorts that ring the sea. The principal culprit in the decline of the Black Sea is eutrophication, an explosive growth of algae and other tiny plants triggered by an excess of sewage and other nutrients; the plants quickly consume most oxygen available in the water, suffocating animal life en masse. This phenomenon affects lakes and coastal waters worldwide and has reached catastrophic proportions in the Black Sea. Algae blooms became so dense that they blocked light from reaching bottom-dwelling plants. Pastures of seagrass vanished, along with the mollusks, crustaceans, and flatfish that lived there. Other fish lost their breeding grounds, and the ecosystem began to collapse. The coup de grace came in the form of a North American Mnemiopsis jellyfish - one of thousands of so-called "alien" species that are transported across the world every day in the ballast water of cargo ships. …

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