Enhancing the Potential for Population Recovery: Restoration Options for Bay Scallop Populations,Argopecten irradians concentricus, in North Carolina

Abstract

Historically depressed bay scallop populations in North Carolina have retained some capacity to replenish themselves. However, continued abnormally high predation by cownose rays, and growing degradation of seagrass beds may limit bay scallop population recovery. We modified existing methods for protecting spawning adult scallops from cownose rays (stockades) and enhancing scallop set (spat collectors in the natural habitat and in managed shore-side ponds) to determine whether the population growth of bay scallops could be enhanced. We found, with one important exception, that spawner sanctuaries inside stockades could be used to concentrate and protect adult scallops during a time when they are susceptible to ray predation. Spat collector bags proved effective not only in gathering scallop spat but serving as nurseries for juvenile scallop grow-out. The results from our pond experiments were mixed: spat collector bags did not do well in the pond, but an alternative collector design holds promise for making shore-side ponds important sources for inexpensive scallop seed. The simple techniques examined in this study can be used to enhance the potential of bay scallop populations to recover from low abundances, and were applied successfully to enhance North Carolina bay scallops during the two years of this project.