My visit to Valperca’s juve­ni­le fish rea­ring faci­li­ty in Chavornay, Vaud, star­ted ear­ly in the mor­ning. Remy Studer from Valperca sales accom­pa­nied me. Upon arri­val, Guirec Dewavrin, the chief bio­lo­gist in Chavornay, was alre­a­dy wai­ting for me. Over a cup of cof­fee, he explai­ned how it all began about ten years ago when the first perch were sourced from the sur­roun­ding lakes, Lake Neuchâtel and Lake Geneva. It took some time befo­re the fish could be suc­cessful­ly fer­ti­li­zed. For years, meti­cu­lous rese­arch and bree­ding were con­duc­ted. Guirec repea­ted­ly empha­si­zed that in Chavornay, they „talk“ to the fish, and the perch „tell“ them what they need or what bothers them. This struck me seve­ral times. It sounds plau­si­ble, much like how we listen to our own bodies – here at Valperca, they listen to the fish. Of cour­se, pre­cise tem­pe­ra­tu­re, light, and many other fac­tors play a cru­cial role. The path to today­’s posi­ti­ve results was long and arduous but ulti­m­ate­ly rewar­ding: while fish in the wild have a mor­ta­li­ty rate of 40%, in this farm, it is almost 0%. Whether it’s fer­ti­lizati­on, plank­ton cul­ti­va­ti­on (feed), or much more – ever­ything is done by hand and pre­cis­e­ly con­trol­led. This allo­ws the fish to grow slow­ly and safe­ly in various tanks with dif­fe­rent tem­pe­ra­tures and feed pre­pa­ra­ti­ons (mother’s milk, acid, plank­ton, salt). 

Daily, Guirec Dewavrin and his team inspect the juve­ni­le fish under a micro­scope to check the deve­lo­p­ment of seve­ral important cha­rac­te­ri­stics. For exam­p­le, the swim blad­der can indi­ca­te whe­ther the fish have been over­fed or under­fed. Furthermore, the mouth size deter­mi­nes which feed the fish recei­ve. With a spe­cial appa­ra­tus, through which many fle­xi­ble, water-fil­led tubes run, the juve­ni­le fish are re-sor­ted dai­ly accor­ding to their size, ensu­ring that even the smal­lest fish gets its food. Since perch are pre­da­to­ry fish, they must assert them­sel­ves against their con­spe­ci­fics here. As soon as the fish weigh appro­xi­m­ate­ly 10 g, they are trans­por­ted weekly to the rea­ring faci­li­ty in Raron, Valais. 

In the old base sta­ti­on of the „NEAT Lötschberg,“ whe­re the com­pa­ny „Valperca“ has estab­lished its­elf, the perch enjoy the exclu­si­vi­ty of the untouch­ed Lötschberg water. Because the water only sees the light of day in the fish tanks after its long jour­ney through the rock, it is abso­lut­e­ly clean and pure. The water only needs to be enri­ched with air and war­med by 2 degrees. Markus Vainer, now the chief bio­lo­gist and fish far­mer in Raron, has built a clo­sed-loop system here. The perch now swim in lar­ge tanks until they reach a slaugh­ter size of appro­xi­m­ate­ly 200 g. Only then are the ani­mals first stun­ned by an elec­tric shock, then kil­led, and final­ly trans­por­ted via other water-fil­led pipes to the next buil­ding, whe­re pro­duc­tion takes place. There, trai­ned but­cher Tobias Brehm is respon­si­ble for processing. 

In the first rooms, whe­re the fish are indi­vi­du­al­ly pla­ced on a con­vey­or belt, it is cool and bright. Subsequently, the fish, sor­ted by size, fall into a lar­ge kett­le whe­re they are des­ca­led. After that, they are mecha­ni­cal­ly gut­ted and fil­le­ted. At a long table, the fil­lets are trim­med, inspec­ted, and pla­ced into chip­ped cra­tes. Once the cra­tes are fil­led, they are weig­hed and chip­ped again. This allo­ws the system to pre­cis­e­ly iden­ti­fy the loss rate or the poten­ti­al for impro­ve­ment among the employees. 

Upon request, the fil­lets are also mecha­ni­cal­ly skin­ned, pro­ces­sed into tar­ta­re, or smo­ked. Afterwards, they under­go a final inspec­tion whe­re the fish are washed again. Then, they pro­ce­ed to stacked final pack­a­ging in crates. 

To con­clude our visit, we were invi­ted to a small meal in their own cha­let and trea­ted to perch tartare/perch meu­niè­re, boi­led pota­toes, and white wine. We also lear­ned that anti­bio­tics, medi­ca­ti­ons, or growth hor­mo­nes are com­ple­te­ly avo­ided at every sta­ti­on and in every situa­ti­on, and that the uni­que bree­ding con­di­ti­ons, as well as the pro­ces­sing and con­trol pro­ce­du­res, even gua­ran­tee sushi qua­li­ty, which repres­ents argu­ab­ly the hig­hest distinc­tion for a fish farm. 

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