LAST summer it was a plague of jellyfish, before that it was 50 million tonnes of mucus-like foam in the Adriatic, red tides in the Aegean, and a thousand dolphin corpses washed up on beaches from Morocco to Greece. Years of pollution, overfishing and overdevelopment have left the Mediterranean in crisis. Turtle nesting sites are under threat and monk seals are being driven to extinction. The problem is so severe that parts of the sea are devoid of life altogether (see Diagram).
But scientific understanding of what is happening to the sea that nurtured the birth of Western civilisation remains disjointed. A Mediterranean Action Plan (MAP) to clean up the sea and protect its ecosystems, agreed by the governments of the region 20 years ago this month, has failed. And a promised relaunch in June this year also seems doomed.
Case for treatment
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The problem is huge. More than 130 million people live along the 46 000 kilometres of Mediterranean coastline and their ranks are swelled each summer by 100 million tourists. Eighty per cent of their sewage 鈥� more than 500 million tonnes a year 鈥� pours into the sea without any treatment.
The sewage is a threat to tourist beaches from Cannes to Capri and from Rhodes to the Lido in Venice. Dozens of Italian beaches and 1 in 10 French beaches fail cleanliness standards laid down in the European Union鈥檚 Bathing Waters Directive. The UN Environment Programme (UNEP) says that the dirty water can cause infections of the ear, nose and throat among bathers, not to mention hepatitis, dysentery, enteritis and occasional cases of cholera. The risks may be greater than at British beaches notorious for failing to meet EU standards since the warmth of the Mediterranean waters nurtures pathogens and encourages bathers to linger in polluted waters. Seafood is tainted, too. In 1990, UNEP reported that 93 per cent of shellfish taken from the Mediterranean contained more faecal bacteria than the maximum recommended by the WHO.
Sewage is only the start. Each year, according to UNEP 120 000 tonnes of mineral oils, 60 000 tonnes of detergents, 100 tonnes of mercury, 3800 tonnes of lead and 3600 tonnes of phosphates enter the sea as a result of human activities on land. Plastic rubbish, which takes hundreds of years to disintegrate, continues to accumulate. And up to a million tonnes of crude oil are dumped from ships, often because harbours lack the facilities to collect waste oil or clean tanks.
Three-quarters of the pollution comes from France, Spain and Italy. Mercury frequently reaches dangerous concentrations in seafood collected off their coasts. France and Italy have imposed statutory limits on the concentration of heavy metals in shellfish for human consumption of 500 and 700 parts per billion. But the laws are not enforced. According to a detailed report published in 1990 on the Mediterranean marine environment by Ljubomir Jeftic, deputy coordinator of the MAP a large proportion of the French and Italian catches breach these limits.
The pollution has weakened the coastal ecosystem to the point where alien species are able to take over from native species. Monaco鈥檚 oceanographic museum boasts an impressive collection of exotic weeds in its aquaria. One of the most striking is Caulerpa taxifolia, a bright green weed found in the tropics and until recently, unknown in the Mediterranean. A decade ago, however, Caulerpa took root on the seabed outside the museum 鈥� perhaps after being flushed away accidentally when an aquarium was cleaned 鈥� and began spreading fast. Five years ago it turned up further along the French coast at Cap Martin. Now it has blanketed 1500 hectares of sea bed along a 300-kilometre stretch of the Riviera from Toulon in France to Imperia in Italy. There have been isolated finds as far west as the Balearic Islands, and as far south as Italy鈥檚 Elba and Sicily.
At the nearby University of Nice, Alexandre Meinesz, professor of marine biology and a leading expert on Caulerpa, says the weed poses a major risk to the Mediterranean. 鈥淲e could be seeing the beginning of an ecological catastrophe,鈥� he says. His research students discovered the outbreak in Monaco in 1984. The Mediterranean version seems to have mutated from its tropical cousin, he says. It grows to more than twice the size, and contains more caulerpicin, a toxin that kills algae. He claims that the mutant invader is killing the Mediterranean鈥檚 distinctive 鈥渟ea meadows鈥� of marine plants, known as posidonia beds, where hundreds of species of fish spawn and feed.
Collapsing ecosystems
The weed has only been able to take hold because the coastal ecosystems of the Riviera are profoundly sick, says John Chisholm, an Australian marine biologist based in Monaco at the European Oceanographic Laboratory. The weed, he says, is an opportunist that has spread in response to a highly polluted environment. 鈥淚t grows in sediments very rich in accumulated organic pollution 鈥� from sewage outfalls and so on. We are now seeing the long-term effects of pollution over two or three decades in the C么te d鈥橝zur.鈥� Ecosystems are being turned on their head, Chisholm says. 鈥淢icrobial populations [that support the ecosystem] can鈥檛 cope any longer. And when they crash, large stands of posidonia can disappear within a few months. It is only then that the Caulerpa invades.鈥�
Caulerpa is not the only botanical interloper. According to Charles-Fran莽ois Boudouresque of the LBMEB, a marine biology lab in Marseilles, there are more than 300 alien species in the Mediterranean, two-thirds of them discovered since 1970. Most came from the Red Sea via the Suez Canal. This biological pollution, he says, is irreversible and may prove to be one of the major ecological problems of the coming century. Certainly, the Mediterranean seems increasingly vulnerable to plagues of all sorts. And few researchers doubt that sewage and chemical pollution are at the root of the problem.
It is now 20 years since all nations bordering the sea, except Albania, adopted the MAP, one of 11 conventions on international seas organised by UNEP. They promised to 鈥渢ake all appropriate measures to prevent, abate and combat pollution in the Mediterranean Sea area and to protect and improve the marine environment in the area鈥�.
Their actions have not matched their words, however. In 1985, after a decade of research but little action, the nations met again in Genoa to set themselves 鈥渢en priority objectives to be achieved by 1995鈥�. The priorities included sewage treatment works for all cities with a population over 100 000, new efforts to cut industrial pollution, protection of endangered marine species and 50 new marine reserves (see 鈥淭ime鈥檚 up鈥�). But by the early 1990s the MAP was close to collapse, with major contributor European nations failing to pay their dues to its secretariat, and many of its research activities cancelled. At the end of April 1994, unpaid contributions amounted to $3.7 million, about seven months鈥� funds. There has been an improvement since, but 鈥渢he situation is still very unstable鈥�, says the MAP鈥檚 internal news bulletin. In November, with the 1995 deadline approaching, Jeftic told New 杏吧原创: 鈥淚 can鈥檛 tell you what progress has been made in implementing the objectives. The countries are no good at giving us information. If they are implementing, they are not saying.鈥�
Perhaps the most serious problem that the relaunched MAP will have to tackle is eutrophication 鈥� the pollution of the sea by chemicals that fertilise its waters. This leads to the explosive growth of algae, especially in summer when the sea is warm and calm, allowing pollution to build up in the surface waters. Nitrates and phosphates 鈥� derived from sewage, detergents, farm fertilisers and slurry 鈥� enter the sea both directly from drains and sewage outfall pipes and down major rivers.
Eutrophication takes two main forms in the Mediterranean. The first is 鈥渞edtides鈥�, caused by the build-up of dinoflagellates. These can release chemicals that are toxic to marine animals such as fish and anything eating fish. The French Oceanographic Institute, IFREMER, reported in 1993 that over the past 15 years dinoflagellate blooms on the Riviera had caused shellfish to accumulate so much toxin that they would be poisonous to humans if eaten in large quantities.
The second is the formation of huge quantities of mucus-like foam secreted by diatoms. The foam fouls beaches and removes oxygen from the water, killing many creatures on the seabed, such as heart urchins and shellfish. The pollution can last for several weeks and may only be cleared by autumn storms.
UNEP has records of frequent eutrophication from Juan-les Pins on the French Riviera to Castell贸n in Spain and from Split in Croatia to Alexandria on the Nile delta. During most summers, the Saronik贸s Gulf, which receives pollution from Athens, becomes eutrophic. According to Basil Katsoulis of the University of Io谩nnina, the bay around the port of Piraeus is almost dead. 鈥淭he ecosystems show severe breakdown,鈥� he says. In 1960 there were 170 species of marine fauna in the gulf. Only 30 survive today.
In the Lac de Tunis, a large shallow saltwater lagoon and bird-watchers鈥� paradise that receives the municipal waste of the Tunisian capital, a third of the lagoon is covered in algae that consume all the oxygen in the water each summer, killing any life below. Red tides also produce the foul-smelling gas hydrogen sulphide, while other algae release ammonia. Both pollutants further disrupt ecosystems.
On the Aegean coast of Turkey, half a million cubic metres of sewage and industrial waste from Izmir, a boom city which makes 15 per cent of Turkey鈥檚 exports, pours into the Izmir Bay. A study for the MAP in 1993 found that eutrophication was a serious problem throughout the year and that red tides were becoming more frequent in the bay. Pollution-related illness among local swimmers and fishermen caused an estimated 10 000 lost working days a year.
The study suggested that a $1.5 billion cleanup programme over 30 years could boost the local economy by up to $10 billion, mainly from tourism. But plans for a waste treatment plant, first drawn up in 1969, remain on the drawing board. It also predicted that pollution would 鈥渞each a critical level by 1995, leading to a collapse in the ecosystem鈥�.
The worst eutrophication occurs in the northern Adriatic. Occasional outbreaks have been occurring for many centuries, but in a 1994 study for the MAP Tarzan Legovic and Dubravko Justic of the University of Zagreb say that growths of algae are much more extensive today. They can cover up to 50 square kilometres and contain much more material than before 鈥� up to 50 million tonnes of mucus-like foam in one case. The reason, they say, is clearly pollution. The northern Adriatic鈥檚 main source of freshwater is the River Po, which drains a large, heavily populated and intensively farmed region of northern Italy. The river is heavily polluted with nutrients. Each year some 5000 tonnes of phosphorus and 100 000 tonnes of nitrate and ammonia reach the sea from the Po 鈥� about ten times as much as 50 years ago.
The effect on the enclosed bays and lagoons of the Adriatic is devastating. The city authorities in Venice now dredge up to a million tonnes of algae from their lagoon each summer in order to stop it putrefying in the heat just as the tourists arrive. In the Gulf of Trieste, says Jeftic, large numbers of fish die as a result of algal blooms. He warns that about 250 square kilometres of the northern Adriatic is becoming devoid of life, with the posidonia sea meadows 鈥渙n their way to extinction鈥� in many areas. Italian plans to clean up the Po are proceeding only slowly.
A small tidal range and calm summer waters ensure that pollution in the Mediterranean鈥檚 many bays does not disperse easily. And once out of bays it encounters a largely enclosed sea. Freshwater inputs to the Mediterranean are low, especially since virtually the entire flow of the Nile, the largest river, is now diverted onto farms. The Mediterranean exchanges water with the Black Sea, but if anything this is even more polluted: 90 per cent of it is anoxic, making the Black Sea the largest mass of water without dissolved oxygen on the planet. And renewal of water by exchange with the Atlantic, through the Strait of Gibraltar, takes around 150 years.
杏吧原创s remain remarkably ignorant about what happens to pollution away from the shore, and what impact it has on fisheries and sea mammals such as dolphins. According to Jeftic, knowledge of a limited number of coastal areas is improving, but the effect of pollution in vast areas, including the entire deep Mediterranean basin, remains poorly understood.
Dead dolphins
That is one reason nobody knows why several thousand striped dolphins, the most common cetacean in the Mediterranean, died between 1990 and 1992, struck down by a morbillivirus. First detected off Valencia in Spain, the epidemic spread east, with dead animals beached in Morocco, Algeria, France, Italy and eventually the Greek islands of the Aegean. At the height of the epidemic, schools of dolphins were only a third their normal size.
Some researchers believe that industrial chemicals had affected the dolphins鈥� immune systems making them vulnerable to disease. Compounds such as polychlorinated biphenyls (PCBs), and other organochlorine compounds which do not mix easily in water, concentrate in plankton and the fish that feed on them, and end up in the body fat of predators that eat the fish. The cause of the epidemics has not been established. But Alex Aguilar, professor of animal biology at the University of Barcelona, who monitored the results of examinations of more than a thousand dolphin carcasses, reported in 1993 that the dolphins affected were found to carry high concentrations of pollutants. He says: 鈥淪triped dolphins in the Mediterranean have carried extremely high levels of PCBs for at least the last two decades.鈥�
Viruses and pollution are not the only threats to Mediterranean cetaceans. Greenpeace claims that dolphin hunting continues on a small scale from Italian ports such as San Stefano, near Imperia. Plastic rubbish 鈥� from ropes and nets to the plastic bands from six-packs of beer cans 鈥� chokes and entangles marine mammals. This deadly flotsam concentrates along the 鈥渇ronts鈥� between bodies of water, which is also where high concentrations of nutrients are found. The nutrients support abundant supplies of plankton which, in turn, attract large numbers of fish and cetaceans. One study of cetacean carcases found that 1 in 30 had choked on plastic debris.
Several thousand dolphins and whales die each year after being accidentally caught in driftnets in the Mediterranean, says Greenpeace. Driftnets hang like vast curtains from floating lines. About a thousand fishing vessels, most of them Italian, spread driftnets in the western Mediterranean. EU legislation banned nets longer than 2.5 kilometres after the International Whaling Commission warned in 1990 that they threatened the survival of striped dolphins in the western Mediterranean. But Greenpeace claims the rules are widely flouted, especially by Italian driftnetters chasing the sea鈥檚 declining stocks of swordfish.
Fleets of trawlers with drift nets and other modern fishing gear also threaten fish stocks. More than 100 of the 500 fish species found in the Mediterranean are harvested commercially. According to the World Conservation Union (IUCN) the hake, red mullet and sole fisheries off the European coast are badly depleted. Important fish nurseries on the seafloor such as posidonia and red coral beds are also being damaged by fisherman who drag weighted nets along the bottom to catch shellfish.
The Mediterranean currently yields around 2 million tonnes of fish a year. But this cannot last, says the IUCN, which believes the sustainable yield is between 1.1 and 1.4 million tonnes. Conservationists have called for a Mediterranean fisheries convention to protect fish in international waters. Top of the list for protection would be the Atlantic bluefin tuna, the largest and most valuable fish in the North Atlantic. Every summer, ships based in the Canary Islands follow the migrating tuna into the western Mediterranean, where it spawns. Their catch is destined for Japan, where a large tuna at auction can fetch enough money to pay for a new Porsche. But increasingly, juvenile bluefin tuna are being caught. With breeding disrupted, stocks in the western Atlantic have fallen by an estimated 90 per cent since 1975.
The destruction of fisheries has knock-on effects throughout the ecosystem. Marine mammals may starve. Legovic and Justic attribute the plagues of jellyfish seen periodically over the past 20 years, including a major outbreak last summer, to overfishing of their predators.
Tourist threat
Mediterranean wildlife is also threatened by human activity on land. Large beachloving animals such as turtles and seals are especially vulnerable to tourism. The Mediterranean monk seals used to lie about on open beaches, and even sought human company, says Crassidas Zavras, secretary of the Hellenic Society for the Study and Protection of the Monk Seal. But the seal, which can grow up to 3 metres long, is one of the 12 most endangered species in the world, according to the IUCN. Once there were hundreds of seal colonies all over the Mediterranean, each containing thousands of animals. Today, estimates of the total number of animals range from 350 to 750. Most are in the Aegean, and (outside the Mediterranean itself) on the beaches of Madeira and the western Sahara. Tiny colonies of fewer than a dozen animals also persist in Morocco, Algeria, the Canaries and in the Ionian Sea.
Out on the remote islands of the Aegean Sea, between Greece and Turkey, conservationists fear that they are witnessing the demise of the monk seal. Once fish stocks began to decline in the Mediterranean, seals began to steal fish from nets. 鈥淭hey destroy the nets completely,鈥� says Zavras, 鈥渁nd fishermen have taken to destroying them, usually with guns.鈥� So now the seals live like fugitives, hiding in caves that can be entered only from the sea. The biggest colony is among the caves in the sheer cliffs of Pip茅ri, part of the northern Sporades islands in the Aegean. Even in midsummer this is a wild place, buffeted by winds and sea. In an effort to protect the seals, the islands have been declared Greece鈥檚 first marine park. Fishing and boating are illegal here. The seals鈥� only companions are falcons, wild mountain goats and automatic cameras, installed by conservationists to monitor them.
鈥淲e recorded five births last year,鈥� says Bill Johnson of the Bellerive Foundation, a Swiss-based conservation organisation that helped pay for the cameras. The foundation has also funded an emergency rescue service that has so far rehabilitated five abandoned baby seal pups. 鈥淭he population is beginning to recover inside the park,鈥� says Johnson. 鈥淭he animals are not necessarily doomed if we can preserve their last habitats.鈥�
A similar strategy is desperately needed for loggerhead turtles, which have also taken refuge in the Greek islands. An estimated 500 females lay their eggs in summer on the sandy beaches of Lagan谩 Bay on the island of Z谩kinthos. There are other, smaller nesting sites at Lara beach in northern Cyprus, the Dalyan delta in Turkey, and in Egypt and Libya.
Lagan谩 Bay has played host to loggerheads for thousands of years. Now it is also a major resort, catering for most of the planeloads of package holiday tourists that fly to the island. Last summer, for the first time, local authorities banned speedboats from the bay. This followed the deaths of nine turtles that were hit by boats the previous summer.
Futile journey
The beach itself is also dangerous. The soft sands are cluttered with sun beds and umbrellas that shade incubating eggs, preventing the embryos from developing, and puncture eggshells. Half of Lagan谩 beach is also brightly lit at night by bars, hotels and street lighting. When baby turtles hatch out in the sand, they turn to the nearest light and head for it. For millions of years that light was always the moon and stars reflected on the sea. Now it is often the Four Brothers鈥� disco or Bob and Wendy鈥檚 Bar, and many turtles expire during their futile journey or are picked off by birds the following day as they stumble through the dunes.
The Mediterranean鈥檚 crisis arises from the accumulated impact of poisons and habitat destruction in the northwest sector of the sea, and from the fast-growing populations and even faster-growing economies of the east and south. Tourists can see the truth. They are deserting the beaches of Spain, Italy, the South of France and even the Greek islands for the less spoilt shores of Turkey and north Africa. But their search for clean waters is doomed unless the nations that border the sea can act together to meet past promises.
This summer, for the third time in 20 years, these nations will again declare their intent to clean up the sea and protect its wildlife. The countries, which since 1990 have included Albania, are due to present detailed reports on their progress at a meeting in Barcelona in June, where UNEP hopes to relaunch the MAP. But Jeftic warns: 鈥淒on鈥檛 be too optimistic.鈥� When he asked nations two years ago to report on the implementation of antipollution legislation, most simply did not reply. Even if they can agree to act, the harm already done 鈥� the habitats destroyed and the pollution stored in sediments and the bodies of fish and marine mammals 鈥� will take many decades to undo. Right now, like much of the Mediterranean鈥檚 wildlife, the MAP looks dead in the water.