Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus ) fishery management in Québec, Canada, between 1994 and 2000.

Summary With fluctuating landings, Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus ) have been commercially harvested for decades in the St Lawrence River Estuary in Canada. During this period, younger fishermen replaced their senior colleagues with more active fishing methods that must be considered in order to assess the situation of the Atlantic sturgeon. The species is sought for its flesh only, not for caviar (females with ripened eggs are rarely caught). At present, better management of this fishery is limited by the lack of basic knowledge on population dynamics (e.g. mortality, recruitment, fecundity and spawning periodicity) and habitat requirements. The spawning grounds have yet to be identified and the impact of navigation channel dredging on fish habitat is unknown, but under study. The fishery is now strictly regulated and tends to protect the reproductive segment of the population. Regulatory measures have been progressively implemented to reduce mortality and limit fishing to a maximum of 60 metric tonnes. Regulatory measures include shorter seasons, a quota for each fishing zone, selected mesh size, identification and length limitations of the gill nets, a 150 cm fork length maximum size, and tagging and registration of all fish. Between 1994 and 2000, commercial fishing operations were monitored to measure the effectiveness of regulations. Length-frequencies have been evaluated and catch per unit effort calculated in addition to recording all other relevant observations possibly useful in interpreting results. Ages were assigned using the pectoral fin spine. Results show adult fish, especially males, ready for reproduction, but also an ageing sturgeon population with few recruits to sustain the future fishery, possibly a result of habitat problems and overfishing in recent years. [ABSTRACT FROM AUTHOR]