A Review of Factors Influencing Maturation of Atlantic Salmon, Salmo salar, with Focus on Water Recirculation Aquaculture System Environments

Abstract

Sexual maturation of Atlantic salmon, Salmo salar, is a complex process, with many variables having the capacity to influence the timing and prevalence of maturation and acting as promoters and/or inhibitors of sexual development. Precocious maturation has the capacity to seriously impact production in commercial aquaculture settings, and in response there has been a significant amount of research devoted to understanding this issue in order to develop remedial strategies. Very little research has been conducted specifically examining salmon maturation in land-based, closed containment water recirculation aquaculture systems, which have recently received attention as an alternative technology for the sustainable production of market-size Atlantic salmon. Unfortunately, the nascent closed containment salmon industry has thus far experienced high levels of precocious maturation, for reasons that are presently unclear. Given the economic challenges facing the closed containment industry's expansion, it is imperative that best management practices be developed to reduce economic losses from early maturation, in order to assist the sustainable growth of farmed Atlantic salmon production. This review provides a brief summary of published research on factors associated with early salmonid maturation, as well as information from research examining maturation and growout performance of Atlantic salmon in closed containment aquaculture systems.

A mobile sex-determining region, male-specific haplotypes, and rearing environment influence age at maturity in Chinook salmon

“…Hatcheries are commonly used to supplement wild salmon stocks; however, an unintended outcome of hatchery rearing practices is that hatchery-reared males often exhibit a shift towards earlier maturation. This has been observed in both Pacific and Atlantic salmon (Larsen et al 2004, Good and Davidson 2016). Water temperature and feed rations at hatcheries are often optimized for high growth, which in turn promotes early maturation (Larsen et al 2019); however, hatchery stocks vary in the proportion of males with premature maturation even when raised under identical conditions suggesting genetic differences in susceptibility to early maturation (Spangenberg et al 2015).…”

Morphological and ecophysiological adaptations of wild gilthead seabream Sparus aurata associated with tuna farms

“…Many fish species exhibit marked morphological changes during sexual maturation cycles (Good & Davidson 2016). Considering that the specimens in this study were sampled during the spawning period and that the chosen length range corresponds to the life stage when the majority of individuals start to consume somatic energy for various reproduction purposes (e.g.…”

Plasma 11‐Ketotestosterone in Individual Age‐1 Spring Chinook Salmon Males Accurately Predicts Age‐2 Maturation Status

“…The physiological mechanisms involved in these decisions are not yet clear (Mangel and Satterthwaite ; Taranger et al. ; Good and Davidson ). However, it has been demonstrated that the minijack rate increases with increased feeding and energy reserves in hatchery‐reared Chinook Salmon juveniles (Larsen et al.…”

“…Previous research has shown that a fish will mature if the rate of acquisition or attainment of a particular energy-related trait (e.g., growth rate, adiposity, or size) during a critical period exceeds a genetically determined threshold. The physiological mechanisms involved in these decisions are not yet clear (Mangel and Satterthwaite 2008;Taranger et al 2010;Good and Davidson 2016). However, it has been demonstrated that the minijack rate increases with increased feeding and energy reserves in hatchery-reared Chinook Salmon juveniles (Larsen et al 2006;Spangenberg et al 2014).…”