For the first time in Bulgaria, rainbow trout has been successfully raised in a marine environment. The pilot project was implemented near Kavarna by scientists from the Thracian University, a mussel farm and the General Fisheries Commission of the European Union. Even more unusual is that freshwater fish successfully coexist with Black Sea mussels in a common facility, Nova TV reported.
The idea for such a type of aquaculture belongs to entrepreneur Veselin Prokopiev, who has been working on it for decades. “35 years of my life! The idea is to first raise mussels, but in the facility itself the idea was to be able to raise trout as well. Not only trout, but also any type of aquaculture that can withstand seawater. And this thing worked!“, he said.
Initially, experts were skeptical about the possibility of a freshwater species adapting to a marine environment. “Studying the experience and possibilities, I came to the idea that we need to experiment – things that were considered impossible, to prove that they are possible“, explained Assoc. Prof. Galin Nikolov from Thrace University. According to him, the first proof is that freshwater fish can be grown in the Black Sea.
The Black Sea turns out to be less salty than expected, which helps the process. “We were prepared for 18 per mille salinity. When we brought the fish and measured the water, it turned out to be 20 per mille. One sleepless night, in which we expected whether they would survive“, Nikolov said.
The stocking material was delivered from Samokov. The fish were gradually adapted to the salinity during transport and after arrival.
The results surprised the scientists.“The growth of the trout is over six times faster than in standard freshwater technologies“, said Assoc. Prof. Nikolov.
“In 5 months and 20 days the fish grew from 80-120 grams to 900 grams - 1.2 kilograms. This is simply unique!“, added Prokopiev.
According to the team, the feeding of the fish does not differ from standard practices in freshwater farms and no artificial additives are used. “There is nothing artificial. We have not used hormones, antibiotics. The fish is ecological and clean“, said Assoc. Prof. Nikolov.
According to him, the results show that the Black Sea has the potential for the development of such sustainable aquaculture.
The project is already being applied in local restaurants in the area of Cape Kaliakra, where seafood is offered directly from the farm.
The team plans to expand the experiment with new species and a closed production cycle.“We will continue with brown algae, oysters, sea bream and sea bass“, said Assoc. Prof. Nikolov.