This story is taken from Correspondent's Europe series

Neal Ascherson reports on the decline of a once great sea

Seven years ago the Black Sea was the most damaged piece of salt water on the planet. It was horribly polluted; overfishing was wiping out the life in it. Now, Neal Ascherson goes back to the sea he wrote a book about to find out what has happened.

In modern Turkey the fishing fleets of the Black Sea are still chasing several species of fish virtually to extinction. The good news is that pollution up in the north end of the Black Sea, on the borders of Ukraine, is down. But this is because industry and agribusiness collapsed after the end of Communism and the waste expunged into the sea has since declined.

Ukraine sinks trawler

The bad news is that Turkey is still chasing ever-fewer and ever-smaller fish. Now this quest for fish has claimed a life. Last month, Ukrainian gunboats opened fire on Turkish boats netting turbot in what the Ukrainians claim is their water. One man was killed. One boat was sunk by canon fire and two were boarded and seized.

The captain of the sunken trawler is still awaiting trial in the Ukraine. In the village caf�, other fishermen watch a video of the attack, apparently shocked. But some suspect they are secretly please. Competition in this village has become cut-throat.

Everyone at the small fishing village of Fenarkoy knows what is wrong. But nobody does anything - not even the Turkish government. As the fish get fewer the gear needed to find them grows more expensive. But as the sonar gets more high-tech, it abolishes the shoals even faster, ruining the livelihood of the small, as well the large, fisherman. A vicious down-spiral. At its end, bankrupt, divided, fishermen and a lifeless Black Sea.

More and more fish caught are under the legally agreed size

Bigger boats chase fewer fish in a cycle of decline

Once vast shoals of anchovy and bonito swarmed in the Black Sea. Now the few fish which come up in the net are mostly tiddlers - too small to be legally caught. And the net brings up filth brought up by cargo ships and tankers, a carpet of pollution across the sea floor.

There are supposed to be bans on catching undersize fish, and on nets with small meshes. Closed seasons have been decreed for some endangered species, but nobody pays any attention.

In the fish market at Istanbul, most of the fish coming off the trawlers is illegal - undersized. It is economic suicide: if these fish were allowed to grow up they would be worth twenty as much times a kilo. But the Turkish fishermen are desperate. They are like starving farmers eating their own seed corn.

Decent fish are still available in Ukraine waters and a black market trade has started in Ukrainian Turbot - with some Turkish fishermen acting as middlemen.

At the end of the road - death. Many species are already extinct. Others are in danger. Once the fish of the Black Sea fed the city states of Greece, the Roman empire, the Byzantines and the Ottomans. Now the over-fishing free-for-all is turning the Black Sea into a Dead Sea.

This story was shown on Correspondent 'Our Poison' on May 20th on BBC2 at 18:50

Producer, Jane Gabriel; Reporter, Neal Ascherson