The possibilities of using of captive and domestic broodstocks for saving of natural populations. 2. Salmonidae. Atlantic salmon (Part 2)

In first review we considered the problems of creation of sturgeon broodstocks in freshwater with full exclusion of marine phase. Several species of salmonids (trouts) which easily change their life stategy (sea trout/brown trout Salmo trutta, steelhead/rainbow trout, brook trout Salvelinus fontinalis and other chars) also could be grown in fresh water up to definitive sizes and maturation. Atlantic salmon differs from above species. In present article the intraspecific structure of Atlantic salmon and its life strategies (anadromous, potamodromos and riverine/residential), development of methods of artificial propagation of salmonids and possibilities of Atlantic salmon growing in conditions of freshwater farm are considered. Three types of broodstocks could be created — sea-run (wild), captive (grown from wild smolts) and domestic (grown from eggs) ones. The creation of domestic freshwater broodstock of Atlantic salmon is more complicated in comparison with “trouts” because of precocious maturation of great percent of males and low quality of mature germinal cells in males and females. The other negative features of domestic breeders are decreased genetic variability, increased straying and reduced reproductive success. So commercial aquaculture uses traditional scheme of transfer of large smolts (near 100 g) to sea cages. Conservation aquaculture prefers wild non-resident breeders. Atlantic salmon is characterized by riverspecific broodstocks, so each river should have its own broodstock. As a result, domestic broodstock of Atlantic salmon in conservation aquaculture could be used only as last measure when all other possibilities are already exhaused.