R. Goldberg *, J. Pereira, and P. Clark (2000)
Strategies for enhancement of natural bay scallop,
Argopecten irradians irradians, populations;
A case study in the Niantic River estuary, Connecticut, USA.
Aquaculture
International 8: 139 - 158
Abstract
We investigated strategies to enhance populations of bay scallops, Argopecten irradians irradians (Lamarck, 1819), in a presumably recruitment-limited natural habitat. At present, the Niantic River estuary supports only a minor bay scallop population that is harvested recreationally. Three enhancement strategies were evaluated; 1) collection and redistribution of natural spatfall, 2) introduction and over-wintering of hatchery-reared stock into natural habitat to provide new spawning stock, and 3) over-wintering of hatchery-reared stock in suspension culture for creation of mobile spawner sanctuaries. An assessment of natural bay scallop recruitment in the Niantic River conducted in 1997 indicated that few spat were found, they were widely dispersed within the river, and peak spawning occurred in late July 1997. Direct re-seeding was evaluated as an enhancement measure by planting hatchery-reared scallops (@ 38 mm shell height) in small-scale, 100-m 2 plots at different times and densities. Time of planting and the inferred predation intensity were major factors affecting survival; whereas, planting density had no significant effect. Approximately 9,000 scallops (35 - 45 mm shell height), broadcast within an eelgrass bed in November 1997, had high over-winter survival and underwent gametogenesis and spawning during 1998. Over-winter survival of hatchery-reared scallops and use of mobile spawner sanctuaries were also investigated. Of 26,000 bay scallops (@ 45mm shell height) over-wintered in suspension culture from 1998 – 1999, approximately 60 - 80% survived, and these scallops spawned during the summer of 1999. There is good potential for using aquacultural methods for enhancement of bay scallop populations when natural recruitment is poor and habitat and environmental conditions are not limiting.
* contact: (email) ronald.goldberg@noaa.gov (voice) (203) 882-6564