Conservation aquaculture-A sturgeon story

Sturgeon are found circumglobally throughout the northern hemisphere. Longevity, late age to sexual maturation and infrequent spawning are typical life history strategies that have supported their evolution over millennia but at the same time have made them vulnerable to extirpation or extinction when population sizes have been reduced as a result of overharvest, habitat degradation and/or pollution. As a consequence sturgeons are among the most at risk species as listed by the International Union for the Conservation of Nature. Aquaculture has been used as a conservation strategy to arrest declines or maintain current population levels for several sturgeon species. Here we describe the development of this conservation strategy in sturgeons, examining the importance of understanding genotype and environment in development of appropriate rearing strategies toward improved conservation practice for this imperiled group of fishes. Recent research indicates a significant effect of environment on phenotype, with early life history being particularly relevant; evidence suggests that repatriation should be the preferred approach where possible. We suggest that while aquaculture can be a valuable conservation and recovery tool, it is particularly effective when the impacts on phenotypic development during early life history are considered and combined with effective post-release monitoring and implementation of additional restoration efforts.