Strategies for enhancement of natural bay scallop, Argopecten irradians irradians, populations; A case study in the Niantic River estuary, Connecticut, USA

Citation
R. Goldberg et al., Strategies for enhancement of natural bay scallop, Argopecten irradians irradians, populations; A case study in the Niantic River estuary, Connecticut, USA, AQUACUL INT, 8(2-3), 2000, pp. 139-158
Citations number
35
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Aquatic Sciences
Journal title
AQUACULTURE INTERNATIONAL
ISSN journal
0967-6120 → ACNP
Volume
8
Issue
2-3
Year of publication
2000
Pages
139 - 158
Database
ISI
SICI code
0967-6120(2000)8:2-3<139:SFEONB>2.0.ZU;2-V
Abstract
We investigated strategies to enhance populations of bay scallops, Argopect en irradians irradians (Lamarck, 1819), in a presumably recruitment-limited natural habitat. At present, the Niantic River estuary supports only a min or bay scallop population that is harvested recreationally. Three enhanceme nt 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 h atchery-reared stock in suspension culture for creation of mobile spawner s anctuaries. An assessment of natural bay scallop recruitment in the Niantic River conducted in 1997 indicated that few spat were found, they were wide ly dispersed within the river, and peak spawning occurred in late July 1997 . Direct re-seeding was evaluated as an enhancement measure by planting hat chery-reared scallops (congruent to 38 mm shell height) in small-scale, 100 -m(2) plots at different times and densities. Time of planting and the infe rred predation intensity were major factors affecting survival; whereas, pl anting 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. Of 26,000 bay scallops (congruent to 45 mm shell height) over-wintere d in suspension culture from 1998-1999, approximately 60-80% survived, and these scallops spawned in mobile sanctuaries, during the summer of 1999. Th ere is good potential for using aquacultural methods for enhancement of bay scallop populations when natural recruitment is poor and habitat and envir onmental conditions are not limiting.