Mating systems and the conservation of commercially exploited marine fish

Unprecedented declines of marine fish have revealed our inability to predict the susceptibility of populations to collapse and their capacity for subsequent recovery. Lack of knowledge about the behaviour and ecology of exploited species has hindered our understanding of how exploitation influences the resistance of marine fish to catastrophic decline and their resilience thereafter. Based on available data, particularly on the Atlantic cod Gadus morhua, we argue that the breeding behaviour of marine fish is considerably more complex than was believed previously. Mate competition, mate choice and other components of mating systems can affect population growth rate deleteriously during and after periods of intense exploitation. There is a pressing need to incorporate knowledge of mating systems in population assessments, to undertake field research on spatial and temporal scales of reproduction, and to initiate laboratory manipulation experiments to test hypotheses about marine fish mating systems, Allee effects and correlates of individual reproductive success.