Cultivation of Arctic charr: an update

There has been interest in farming Arctic charr, Salvelinus alpinus, since the 1970s, but expansion of the industry has not been as rapid as originally predicted due to problems experienced with obtaining supplies of viable eggs and juveniles, variable growth and flesh pigmentation during grow-out, problems with year-round culture in sea water, early maturation, and problems related to the marketing of portion-size fish. Several of these problems are probably a manifestation of a mismatch between the environmental requirements of the fish and the rearing environment. For example, variable rates of broodstock maturation and poor survival of eggs are probably the result of holding broodstock charr at temperatures that are unsuitable for optimal reproduction. Poor and heterogeneous rates of growth during grow-out may be the result of rearing the fish at sub-optimal stocking densities. Further, variable fillet pigmentation may be a manifestation of variable growth rates, rather than being a true reflection of the ability of charr to deposit carotenoids in their flesh. Provided that the fish are held under conditions that promote good rates of growth, charr appear to be able to deposit adequate amounts of pigment in their flesh when fed diets that contain 50-70 mg pigment per kg diet.