Mediterranean Sea. Anti-pollution plan

The Mediterranean is the planet's largest inland sea. It is very salty because evaporation is high and the freshwater influx from rivers is low. At Gibraltar its heavier, salty water flows out to the Atlantic beneath an incoming current of lighter, less-salty ocean water. It takes about eighty years for the Mediterranean's water to flush out fully. In 2000 its catchment (or basin) was home to about 210 million people in eighteen countries.

Biologically, the Mediterranean is rich, home to about ten thousand species of animals and plants. But its waters are thin in nutrients, so its total biomass and biological productivity are extremely low. This is why the water is so clear—when it is not polluted.

Marine pollution is not new. The ancient harbors of Ostia (Italy), Piraeus (Greece), and Alexandria (Egypt) were strewn with wastes. Bays, estuaries, and inlets such as Turkey's Golden Horn, the Venetian lagoons, or the Bay of Naples—were unsanitary in early modern times.

Since 1960 the main pollutants in the Mediterranean have been the same as elsewhere around the aquatic world: microbes, synthetic organic compounds such as dichlorodiphenyltrichloroethane (DDT) or polychlorinated biphenyls (PCBs), oil, and excess nutrients. The main sources are the big cities, big rivers, and a few coastal industrial enclaves.

Until 1920 microbial contamination from sewage existed in rough proportion to human population because sewage treatment scarcely existed. By 1990 about 30 percent of the raw sewage splashing into the Mediterranean received treatment, but the total quantity has tripled or quadrupled since 1900. So the risks of gastrointestinal ailments, typhoid, or hepatitis to people eating seafood or bathing have increased significantly. By the late 1980s, when the European Union developed guidelines for microbial contamination, beach closings had become routine from Spain to Greece.

Oil became a major pollutant with the emergence of Arabian oil fields after 1948. Soon about one-quarter of the world's oil shipments crossed the Mediterranean (1970-1990), leaving behind one-sixth of the world's oil pollution. One-third of that oil washed up on the beaches.

Industry did more than oil to sully the Mediterranean. Mediterranean countries accounted for about 5 percent of the world's industrial production in 1929, about 3 percent in 1950, but 14 percent in 1985. For the quarter-century after 1960, industrial production in Mediterranean countries rose by about 6-7 percent annually. This brought greater pollution. Industrial pollution concentrated where industry concentrated: in Italy, France, and Spain.

Despite the rapid growth of industry in northern Africa, by 1990 it still accounted for only 9 percent of Mediterranean industry; the several countries ranging from Israel to Croatia accounted for another 10 percent. Italy generated 66 percent of the industrial production of the Mediterranean basin; Spain (mostly Barcelona), 10 percent; France (where little industry is in the Mediterranean catchment), only 5 percent.

The greatest pollution problems therefore arose in the northwestern area of the Mediterranean basin, around the mouths of rivers with industrialized basins, such as the Ebro, Rhone, and Po, and around the centers of heavy industry, such as Barcelona, Genoa, and the northern Adriatic coast from Mestre to Trieste.

Eutrophication (the process by which a body of' water becomes enriched with nutrients) derives mainly from agricultural runoff and municipal sewage. From time to time algal blooms, also known as eutrophic blooms, occur naturally in the Mediterranean, as elsewhere in enclosed waters. (Algal blooms occur when excess nutrients allow algae populations to proliferate, sometimes covering the water surface in sheets or "algal mats.") Although algal blooms occurred in the Mediterranean prior to 1950, they happened much more often after 1950 because of urbanization and untreated sewage and because of the growing use of chemical fertilizers.

The most affected areas were France's Gulf of Lions, which suffered its most serious blooms after 1980; the Saronic Gulf around Athens, which experienced its first in 1978; and the northern Adriatic. Between 1872 and 1988, the northern Adriatic recorded fifteen eutrophic blooms. Their frequency increased after 1969, which probably reflected greater nutrient loadings but might have reflected warmer water temperatures—perhaps both. Algal blooms played havoc with fish populations, seabed life in general, and the tourist trade.

As in much of the world, explicit environmental awareness and politics around the Mediterranean date mainly from the 1970s. Most countries by 1975 had tiny bands of ecologically concerned citizens. By 1980 some countries had green parties. Mediterranean countries in 1975 launched the Mediterranean Action Plan (MAP); under the auspices of the U.N. Environment Programme (UNEP), Mediterranean countries agreed to an ongoing process of environmental management for the entire basin.

The plan supported scientific research and integrated environmental planning. It produced several protocols to limit pollution. Enforcement usually left something to be desired: About 2,000 kilometers of coastline were "sacrificed" to development through lax enforcement or special dispensations.

But the plan, together with national regulations and European Union restrictions, helped limit Mediterranean pollution after 1976. MAP helped in the construction of sewage treatment plants for Marseilles, Cairo, Alexandria, and several other cities. Although twenty-five years later the sea was more polluted than when the MAP began, it surely would have been much more so without the MAP.

Any plan involving Greece and Turkey, Syria and Israel, and other pairs of enemies (as of the 1970s) ranks as a high political achievement. In this case some credit goes to scientists who forged something of a panMediterranean community. Scientific wisdom, normally quickly ignored when hard bargaining begins in international environmental politics, carried weight because hundreds of billions of tourist dollars were at stake.

In the last quarter of the twentieth century, about one-third of international tourism involved visits to Mediterranean countries, usually to beaches. The quest for tourists, who contributed to pollution, paradoxically helped stabilize—and in some cases improve— the quality of coastal waters of the Mediterranean.