Pinto abalone (Haliotis kamtschatkana kamtschatkana) re-introduction strategies for population recovery: experimental hatchery and outplant techniques

Carolyn Friedman (University of Washington) and Don Rothaus (Washington Dept. of Fish & Wildlife)
$34,999

Pinto abalone (Haliotis kamtschatkana kamtschatkana) in the Puget Sound, Georgia Basin and coastal waters of British Columbia, Canada have experienced dramatic population declines. This trend has resulted in fisheries closures, followed by Federal and State listings for this species. Despite these actions, studies conducted in the San Juan Archipelago by the Washington Department of Fish and Wildlife (WDFW) indicate that continued declines through 2006 may be due to reproductive failure associated with low population density (Allee Effect). This hypothesis is supported by results of a recent juvenile recruitment study conducted by the University of Washington (UW, Bouma et al., unpublished data). If continued population declines are the result of low adult densities, natural recovery of abalone populations may not be possible without human intervention.

Following guidelines established by the American Fishery Society (AFS, Williams et al. 1988) and The World Conservation Union (IUCN, 1998) for re-introduction of endangered or threatened species, we propose to conduct pilot-scale experimental introductions and optimize hatchery rearing techniques to maintain genetic integrity in wild populations. In order to reach this goal we will: 1) conduct a temporary, pilot scale experimental outplant to better understand the survival of hatchery raised individuals relative to local native populations; and 2) extend hatchery techniques developed under previous grants to maintain high genetic diversity in hatchery raised juveniles for future supplementation. Prior to our pilot outplant trial, we will conduct intense pathology screening of a sub-sample of the hatchery reared individuals to eliminate the possibility of infecting native stocks. We will also acquire and archive tissue samples of outplanted individuals so that future evaluations of outplant success can be directly linked to genetic contribution. Although funding for this project is for one year, it is the goal of both the UW and WDFW to survey the discrete outplant sites over two years, after which introduced abalone will be collected.

Juvenile abalone in the wild, being tracked by the study team. Photos by Carolyn Fiedman study team.

Photos by Josh Bouma.