Arctic challenge FF Fish Farmer FISH FARMER VOLUME 42 NUMBER 03 MARCH 2019 Serving worldwide aquaculture since 1977 www.fishfarmer-magazine.com THE COOKE REPORT BOAT YARDSTICK SPOTLIGHT ON SALMON First look at Scotland’s most exposed farm site CREATING A BUZZ How aquaculture is driving Scottish builders Holyrood separates fact from fiction Plenty to digest in insects for feed forum £12.99pa SUBSCRIBE ONLINE ONLY For more information visit: pocketmags.com/fish-farmer-magazine March 19 Cover.indd 1 53 www.fishfarmermagazine.com since 1987, and part of Leroy since 2005. When they complete the next post-smolt sec on the will have invested a out million since 1987. akse ord, which lies on degrees northern la tude, is a com ined ow through and A facilit , with independent A s stems, and a total tank volume of , cu m, producing , tonnes a ear eing as far north as we are, we have trou le with the coldest water source in the world,’ said ,ovrud or seven months of the ear we have less than degrees elsius in the water ’ ut the compan has had almost exponen al growth since the first harvest in , and today has permits for 15.2 million smolt. Kriginall , akse ord relied on ow through, producing a one ear smolt in months from eggs, with partl natural temperature and partl natural light ut five ears ago the changed their produc on plan drama call , installing their first A and inves ng heavil in hea ng pumps in the old ow through sec ons dhe result was a s stem where ever thing can e controlled, where temperature in the hatcher is a constant degrees all ear long and etween to degrees in ever other part of the farm. dhere is no natural light the first me the fish sees light is when the go into the cages,’ said ,ovrud t meant an end to seasonal produc on and the eginning of standard atches, taking months from when the eggs hatch to when the fish are transferred to sea pens dhe freshwater part is divided into five sec ons and the spend two months in each sec on o in theor we produce six atches a year. ’m not a A nerd ut reall elieve that a well managed A , and especiall using fixed ed filters , o ers extreme sta ilit and control over water ualit , which com ined with control over the rest of the farming environment and standard atches makes it possi le to produce a high and even ualit of the fish o our sea sites can rel on getting the same ualit on each atch and that is important ’ ,ovrud said there are two almost religions in A , one is fixed ed and the other is moving the old school and the new school am a solutel in the old school’ dhe freshwater A is standard illund with fixed ed and moving ed filter ut the moving ed, ou can sell it We have learned the hard wa that start up iofilters take me and ro ust filters take much more me,’ he said, adding that well managed fixed ed filters give extremel clear water, and that rackish or seawa ter filters must e matured with rackish water akse ord has had to develop oth technolog and hus andr inno va ons to address the huge challenge’ of farming in the northern part of Eorwa zou can have a maximum iomass at sea, it’s like a ank account, ut if ou are going to have interest from that which is growth in this case it’s important to keep it as full as possi le n Eorwa , it’s not legal to transfer smolt to the sea when the tem perature is lower than degrees o from the middle of Eovem er to the middle of Darch it’s not legal to transfer smolt in inmark t’s too risk , so in northern Eorwa we have a out onl six months when we can transfer smolt to sea, which makes it ver di cult to keep the max iomass dhe o vious solu on to this is seawater rackish A We can’t have this huge produc on in ow through on our temperatures, it’s not possi le t has to e A We take the smolt to the sea when it’s small salmon and then we can move it whenever we want t’s not illegal to move small salmon alread in the sea ’ ,ovrud said this s stem means the can transfer fish all ear long, with di erent si es availa le all ear n another development, akse ord has used the spare capacit in the A to produce four post smolt test atches in the last four ears ach atch of one million smolts was transferred to rackish A in late Kcto er each ear at g and grown to g in two months dhe specific growth rate was two per cent on average, said ,ovrud Accumulated mortalit over the two months ranged from to per cent for the di erent tanks zou could name all the dead fish,’ he said, ecause there were so few of them dransfer from tanks to sea cages took place in the last da s of ecem er first da s of anuar when the sea temperature in the well oat was a out deg dhe average accumulated mortalit from cage transfer to slaughter was per cent akse ord produces tonnes in ow through and , tonnes in A , , tonnes in freshwater and , tonnes in rackish water ,ovrud said the compan has adapted to its condi ons, making its own research sta on and coming up with its own design rackish water A with old school fixed ed filters’ “ n northern Eorwa we have a out onl six sea” months when we can transfer smolt to
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