Freshwater reconditioning and ranching of Atlantic salmon,Salmo salar L., kelts: growth and reproductive performance

Abstract Artificial reconditioning of Atlantic salmon in fresh water over two successive years produced kelt survival rates of 28% and 55% in years one and two, respectively. Eye damage and failure to identify non-feeders were important factors contributing to high mortalities. Average fecundities of kelts reconditioned for the first (1220 ova kg^-1) and second (1093 ova kg^-1) year were lower than obtained for virgin control fish (1590 and 1728 ova kg^-1 respectively). Average survival to swim-up for progeny of first-year (64.5%) and second-year (71.4%) reconditioned fish were similar to survival of virgin control fish progeny (72.3% and 68.9% respectively). Ranched kelts showed better growth parameters than for freshwater reconditioning but had lower average fecundities (1310 ova kg^-1 compared with 1820 ova kg^-1) and lower average progeny survival to swim-up (60.8% compared with 88.6%) than their control group.