Genetic identification of Chinese shrimp Fenneropenaeus chinensis post-release in Jinzhou Bay: Implications for management of stock enhancement

Abstract

The Chinese shrimp (Fenneropenaeus chinensis), one of the important fishery resources in North China, has sharply declined. Artificial propagation and release of F. chinensis have been developed in recent decades in order to supplement wild stocks and improve economic profit. For investigation of the effects of stock enhancement in Jinzhou Bay, we traced this program by sampling 574 female shrimp after spawning and recaptured 293 individuals post-release. Among recaptured individuals, 21 were identified as being hatchery-raised via mtDNA control region and six microsatellite markers identification, accounting for 7.2%, indicating that the hatchery-released juvenile shrimps could survive in the natural environment and contribute to F. chinensis population replenishment in the wild. To address genetic impacts from stock enhancement, we compared the genetic variations between spawners used for enhancement release and local recaptured individuals. High genetic diversities were maintained in F. chinensis stocks, but local recaptured individual stock seemed to exhibit lower genetic diversity. Deviation from Hardy–Weinberg equilibrium and positive values in the inbreeding coefficient in all microsatellite loci and stocks indicated that homogenization and inbreeding may have occurred. More appropriate strategies to restore F. chinensis populations should be discussed for future fishery management.