Nicholas Birch in Van, eastern Turkey -

Locals call it Bend-i Mahi, Fish River. It is an apt name. Fish are everywhere. The pools are seething with them. Under the rapids, they burst out in a constant stream, bright little fireworks against the black basalt rocks. Put your hands in and you'll come out with half a dozen.

It is spawning season for the pearl mullet, a fish found only in Van, the vast, highly alkaline salt lake nestled in Turkey's southeastern corner. For a month in May, roughly 2bn fish congregate at the mouths of six rivers, adjusting to the fresh water. Then they swim upstream.

Without Mustafa Sari, the migration could easily have become a distant memory. A biologist at the university in the city of Van, Sari began warning in 1993 that fish stocks were decreasing dangerously fast. "The problem was overfishing, and fishing during the spawning season", he says. "Locals used to string nets across the river mouths. They were killing the goose that laid the golden egg."

His requests for help rebuffed by the Ministry of Agriculture, Sari single-handedly set about saving his fish. Over a decade, he persuaded 14 out of 15 fishing villages to fish only in winter. Back when he started, even Van's mayor didn't know about the May migrations. Now, the city streets are festooned with huge banners showing the slender, 20-centimetre fish, and the protection scheme Sari set up has UN financial backing. Illegal fishing is down by 60%.

"Everybody hated me at first", Sari remembers, who was adjudged Turkey's social entrepreneur of the year last year by accountants Ernst & Young. "Within five years, the scheme should be able to go on without my pushing."

Messy markets

At Dereagzi, one of six villages on the lake's 70-mile long southern edge that survives by fishing, Mirza Teran has nothing but praise for the professor. A decade ago, he says, the members of his 45-boat cooperative were lucky if they brought in 200 kilos of fish a day; these days there's nothing out of the ordinary about catching a tonne, and individual fish are on average twice as heavy.

The Dereagzi fisherman are now building a small filleting factory that will employ eight locals. Yet, while the only thing now threatening the source of their livelihood is the lake's increasing dirtiness, they are still nervous about their future. "The prices have gone down", Teran says. "In the past, we sold a kilo of fish for TRY1 ($0.80). Now, it's down to 30 kurus ($0.24)."

Increasing supply is only a small part of the problem, according to Teran. Much more serious is the end of a quasi-monopolistic system that held prices up for over two decades. "The fishermen got greedy and started trying to market and sell the fish themselves", he says.

Umit Demir agrees the market is in a mess. Head of the Oz Lake Van Fishing Cooperative in the city of Van, he began as a 14-year-old selling pearl mullet off a handcart. Within five years, he had expanded to control 80% of sales, with a fleet of 20 lorries transporting the catch across eastern and central Turkey. The secret of his success, he claims, was openness. "I'd bring the fishermen and the buyers together face to face to discuss prices. That way both sides knew they weren't being cheated, that I wasn't taking a huge cut."

But the system depended on the cooperation of fishermen, and that began to fall off after 2000. The final straw for Demir came in 2004, when he got a call from a buyer who had just bought 10 tonnes off him at TRY1 per kilo. "He told me a fisherman had just offered him another batch at 40% of the price", Demir says.

He promptly abandoned the pearl mullet to concentrate on importing fish from the Mediterranean. "Fishing is an art and selling is an art, and mixing the two gets you nowhere", he says.

Back in Dereagzi, Mirza Teran thinks the time has come to rebuild an efficient sales system. "By saving the fish, Mustafa Sari offered a future to the 1,500 people who survive thanks to this little port", he says, gesturing behind him to the 20-odd boats crammed into the narrow harbour. "The very least we can do is get our part of the act together."

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