Approaches for delaying sexual maturation in salmon and their possible ecological and ethical implications

Abstract

The aquaculture industry is under pressure to satisfy global demand for marine foods. Atlantic salmon has been bred for more than 40 years, and substantial progress has been made within the culturing and breeding programs. The improved growth rate of Atlantic salmon has been accompanied by an earlier onset of maturation. Among the factors controlling maturation in salmon are photoperiod, temperature, and body composition. Early sexual maturation is detrimental to fish health and quality when viewed from an aquacultural viewpoint. There are several approaches for alleviating this problem: (1) traditional selection, (2) manipulation of external factors affecting puberty (e.g., light), (3) novel biotechnological methods for improving breeding methods, (4) induction of polyploidy, and (5) genetic modification controlling maturation. This article presents the ecological and ethical issues connected to these approaches and argues the importance of acknowledging and discussing such issues in order to ensure that all stakeholder concerns are considered.