We arrive in Vodňany, at the Faculty of Fisheries and Water Conservation of the University of South Bohemia (FROV JU), and head to the Velký Ústavní pond, where a catch is underway. "In the evening, we stretched the mat net, and in the morning, we gathered the carp into the net, lifted it up and drove it to the pond. With the help of smaller, hand-held nets, we pulled the fish into the tubs, and from there loaded them onto a truck in crates. Only on the next haul will we use a seine net, a traditional fishing net," Josef Příborský, a fish farmer, brings us up to speed on the action. He estimates this year's catch will be 85 metric tons of fish – more precisely, carp. And not just any carp

Carp with a licence

Every spring, an eight-hectare pond is populated and in the autumn, the so-called “omega3carp” is fished out. The FROV JU, along with Blatenská Fish Company and the Institute of Clinical and Experimental Medicine (IKEM) are behind the eponymous project, having decided years ago to breed carp using a special method.

"It's about the technology of rearing. The carp are fed a special feed mixture based on rapeseed pomace and extruded flax, from which they obtain a higher content of omega-3 fatty acids. These also serve as precursors for the synthesis of highly unsaturated omega-3 fatty acids, specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are the most important for humans," explains Josef.

The specifically-declared omega 3 content is one of the conditions of the licence for omega3carp, which is now solely farmed here in Vodňany, the only pond in the Czech Republic. "We have also offered the licence for omega carp to other fishermen. At first there was interest, but breeding is quite expensive and for most it is not economically worthwhile," our other guide Vladimír Nedopil from FROV JU joins the conversation.

The innovative approach draws on the wisdom of the past, when both rapeseed and flax were processed in the region, and the leftover pulp was used as feed in the carp ponds. "Marine fish are naturally higher in omega-3 fatty acids, just like fish living in colder waters. Our colleague Pavel Kozák, the current dean of the faculty, has found that this can be achieved in Czech carp, too – if you increase the omega-3 in their diet, the fat goes into the muscle and is well dispersed," Vladimír explains.

People and plankton

We watch pond fishermen moving through the water in waders and high fishing boots. A satisfied smile on their lips, the legacy of an ancient guild in their hands. Josef is carefully counting the carp in the next tub. As he works, he manages to explain that breeding omega3carp isn’t just about feeding them. "The overall management is important. We stock the pond so that the carp are left with enough usable zooplankton and benthos, or natural food for the entire season, which we combine with feed," he says, explaining why the fish stock at Velké Ústavní is relatively low, around 500 kg per hectare.

"In a transplanted pond, the plankton disappears quickly, as it cannot continuously renew itself. Where this happens, the carp have to be fed heavily, mostly with cereals. In our case, we’re not talking about conventional feeding, but rather about supplementing the fish with the fatty acids mentioned above. The plankton in the pond itself is a source of omega-3 fatty acids and gives the carp everything they need."

Tartar and segedin

It is clear from the fishermens' stories that differences in breeding significantly affect the quality of the fish meat. That is why Pavel Brichzin, chef at Čestr, is also here asking questions. Today's excursion was arranged by him – because before the carp comes to the kitchen, the chef should always go to the carp. "There are fishermen who keep only 200 kg per hectare and leave the fish purely on a natural diet. The carp from these extensive farms have first-class meat, whether it be in terms of taste, smell or texture," Josef tells us.

The sensory properties of omega3carp are investigated in the university laboratory by trained assessors. "The meat of omega3carp is beautifully reddish and forms a rainbow on the cut – you’ll see this for yourself in the kitchen. Before that, the fish is sent to the ponds to cure, and get rid of the muddy aftertaste caused by the algae. Although freshly caught carp should never smell bad, even if they live on a muddy pond floor," Vladimír takes over and continues the lesson on the art of fish: "The meat should be firm yet flexible, and must not fall in on itself. Carp like this is suitable for any kind of recipe – personally, I like tartare, but wouldn't say no to over carp svíčkova or goulash."

The catch is coming to an end, and a team of pond fishermen is slowly gathering on the dam, among them students from FROV JU. Next to us, an order is already being planned – at Čestr they’ll take 100kg of carp. We’re visiting just before Christmas, and that means the unique composition of carp meat is guaranteed to be at its best. "We can only guarantee a higher proportion of omega 3 during the autumn harvest, before Christmas, or when the fish is frozen. Over the winter, the carp burn fat reserves and thus digest the fatty acids," Vladimír points out, and on the way back to the car he hints at the next part of our itinerary of our visit. Experimentation? We can’t wait.

Research first

Ten minutes later, we're looking at the specialist facilities. "We are one of the largest farms of this type in Europe. What we save from our catches we invest in repairing the experimental ponds, of which we have fifty in total," Vladimir welcomes us to the place where the main part of the research takes place – and where omega3carp was born. "For about a year, we focussed on testing only granule processing. They contain a lot of fat, so they dissolved on contact with the water before the carp ate them," Vladimir recalls, leading us inside, past aquariums of invasive crayfish species.

"Our main work is research and project work at the faculty, where we preserve the living gene pool and focus on recirculation systems. We see fish production and processing as complementary activities – everything is connected to everything else," says Vladimír, explaining the mission of the pond keepers, who take care of the water quality in the ponds and try to manage the region in the best possible way.

Gradually, we are realising what it means Čestru's decision to take carp from Vodňany. Every portion on the plate indirectly supports research, education and, in fact, the future of the Czech carp. "It's been a few years since my colleagues, after seventeen years of crossbreeding, managed to to breed a new breed - Amur Lynx. It has good performance and progeny, but at the same time it is healthy and resistant to disease. We are returning to our rootsas is happening in other sectors," concludes Vladimir, shaking our hands in farewell. And here's to a collaboration that goes beyond the Čestr menu.

Gradually, we are realising the underlying value of Čestr's decision to source carp from Vodňany. Every portion on the plate indirectly supports research, education and, in fact, the future of Czech carp. "It's been a few years since my colleagues, after seventeen years of crossbreeding, managed to breed a new variety – the Amur Lynx. It has good performance and offspring, but at the same time it is healthy and resistant to disease. We are returning to our roots, much like is happening in other sectors," concludes Vladimír, shaking our hands in farewell.

Here's to a collaboration that goes far beyond the Čestr menu.

Source: FROV, Margit Slimáková