Slovenian mussel farmers will have close to noting to offer to the market after most of this year's harvest has been devoured by gilt-head sea breams. Since they have also eaten juveniles, Slovenian Mediterranean mussels will only be available for sale in two years, if the farmers manage to save them from the fish.

"Sea breams have devoured up everything," Mitja Petrič, one of Slovenia's three major mussel farmers, told the public broadcaster RTV Slovenija.

The hungry fish ate up not just the bulk of this year's harvest, but also mid-sized mussels and juveniles that were to hit the market next year.

Five-metre long mussel framing nets, each weighing about 20 kilos, were planted three days ago. Within four months they would each produce 50 kilos of mussels ready for sale, but they are now empty.

Sea breams had affected mussel harvests in the past as well, but not to such an extent. The breams ate up to three tonnes of mussels a night.

Petrič believes his farm must have been attacked by a huge, ten-tone school of fish. Fishermen have only caught two catches of 200 kilos and a few smaller ones.

"They were all so large that the styrofoam boxes had to be broken to let the tails stick out. The smallest weighed between 3 and 3.5 kilos," he said, adding that such breams have very large mouth.

Petrič produces between 300 and 350 tonnes of Mediterranean mussels in his best years. Now, he will only have 60 tonnes to offer to the market this year and nothing next year.

He sees no point in investing in mussel farms in the Bay of Piran, Strunjan or Debeli Rtič any longer. The breams got so accustomed to the food there he says the only solution is to move the farms to another location, about a mile off the coast.

New locations have been considered in a new spatial plan for two years, but permitting takes too long, he said.

Prosub, the company that grows Mediterranean mussels in Strunjan, Sečovlje and Debeli Rtič, says sea breams have been causing problems for a long time.

It will be clear just how much of the harvest they have eaten in October, the company told the Slovenian Press Agency.