By Nick Thorpe
BBC News, Romania
Danube fishermen try to make a living from catching fish other than sturgeon
Catching a sturgeon could once have changed a Danube fisherman's life but modern dams and over-fishing mean they are rapidly dying out.
"The beauty of the sturgeon," explains Radu Suciu, "is that this is an armoured fish."
And he takes down from his shelf his visitor's box, which rattles.
Inside is a mixture not of fish bones - the thin things which get stuck in your throat and you have to eat bread to dislodge - but chunks of sturgeon skeletons.
The complete one looks like a fossil, with its distinctive, long, sharp nose.
The sturgeon has been around for a lot longer than humans - at least 200 million years. It is such a perfect design that it has hardly changed.
Restrictions on fishing wild sturgeon have forced up caviar prices
"The sturgeon is not a good swimmer," continues Radu, "but it is a good climber."
He fishes out two long, yellow pectoral bones that the fish uses to anchor itself on the bed of fast-flowing rivers like the Danube, which it goes up every few years to spawn.
At the famous underwater cataracts at the Iron Gates, between Romania and Serbia, the river climbs steeply.
Navigation for ships in medieval times was impossible, but migrating sturgeon used to anchor themselves behind rocks to rest, then they swam and anchored, swam and anchored, slowly climbing their own stairway to heaven - hundreds of miles upstream in the spawning grounds of the Szigetkoz region in Hungary.
Before, that is, the Iron Gates hydro-electric dam blocked their path. Then the Gabcikovo dam in Slovakia caused the Szigetkoz to dry out.
A combination of dams, pollution and over-fishing have driven this most ancient of fish to the brink of extinction.
Radu tells the tale of a poor Danube fisherman in Isaccea in 1999, who caught a 800lb (360kg) female, nearly 12 feet (3.5 metres) long, with 180lb (82kg) of black caviar inside.
A pound in weight (0.5kg) currently sells for £2,800 ($4,500). The top price in New York last year was £4,200 ($6,800).
The fish changed his life but it was a disaster for sturgeon stocks because there are so few mature, female Beluga sturgeon left. This is the most valuable variety for caviar.
Since 2006, Romania has banned sturgeon fishing both in the Danube and in the Black Sea, their usual habitat.
In February, Bulgaria did the same and there are similar promises from Serbia and Ukraine.
From 2009, Romanian and Norwegian scientists have collaborated in a special project to find out more about sturgeon.
Satellite transmitters were attached to five adult fish in the river, which were then released, and headed back out to sea.
The transmitters only send their information to the satellite when the fish surface, which is extremely rare.
One of them, a 12-year-old male, they named Harald after the king of Norway.
Nikita Ivan did not manage to make his fortune from fishing for sturgeon
He headed down to the Turkish coast of the Black Sea for a while - who can blame him - then up to the northern shore, to a shallow ledge off the Crimean peninsula, where the water is not so cold, for the winter.
Then disaster struck, 300 days after he was released.
The satellite image showed him moving slowly for several hours, perhaps in a rowing boat.
Harald had been caught.
Then the satellite showed him moving inland at a steady pace for six days, probably on a train. Then he disappeared.
One wonders what the person who bought him thought of the transmitter. Perhaps he swallowed it.
The Danube abounds with sturgeon tales.
Nikita - a 70-year-old fisherman I met at Ghindaresti in Romania, nearly 200 miles (300 km) up the river - told me how a big sturgeon he caught in the 1980s hit his rowing boat so hard with its tail that it knocked his fishing companion into the water.
"I had to decide which of them to save - the fish or my friend," he laughs.
Eventually, after several hours thrashing around in the water, he got them both into the boat.
"And we sang all the way back to the harbour," he told me.
Would he sing me that song? "We cannot sing during Lent," he exclaimed.
Like nearly everyone in Ghindaresti, Nikita is a Russian, an old believer, whose ancestors took refuge here from religious reforms in Russia centuries ago.
Did the fish make him rich?
"We had to sell it to the fishing cooperative - for peanuts," he laments. "In my house, money is like the Danube. It rises one day and goes down the next."
In a restaurant in Sulina, where the river flows out into the Black Sea, I order grilled sturgeon.
It tastes delicious, like wild salmon. But catching sturgeon is banned.
"They say they buy it in the supermarket," Radu explains.
But in a fishing community, that is a little hard to believe.
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