MOLECULAR ANALYSIS IN THE CONSERVATION OF STURGEONS AND PADDLEFISH

Sturgeon and paddlefish populations worldwide have declined because of anthropogenic influences. The structure and magnitude of genetic dive rsity of natural populations serves to buffer these fishes against env ironmental variation and should be maintained. Modern molecular biolog ical techniques provide the ability to sensitively characterize and qu antify the extent of genetic variation in natural populations. We prov ide a summary of those problems in sturgeon population biology that ar e amenable to investigation with DNA approaches, and their application s to date. These have included genetic identification and discriminati on of taxa, identification of hybrids, stock identification, mixed-sto ck analysis, and estimation of gene flow and homing fidelity. To date, almost all studies have been restricted to North American fauna. Impr ovements to these technologies, including nondestructive sampling, sho uld permit more widespread application of molecular approaches to prob lems of acipenseriform conservation. We suggest that the use of more s ensitive molecular tools such as analyses of hypervariable repetitive and non-coding single copy nuclear DNA may assist management even in t hese taxa which exhibit overall low levels of genetic diversity.