RELEASE OF HATCHERY‐REARED BAY SCALLOPS (<i>Argopecten irradians</i>) ONTO A SHALLOW COASTAL BOTTOM IN WATERFORD, CONNECTICUT

Abstract

ABSTRACT Survival and growth of hatchery‐reared bay scallops ( Argopecten irradians ) transferred to a shallow coastal area in outer Jordan Cove, Connecticut, were monitored by SCUBA during the summer and fall of 1979. In all, 47,000 bay scallops were released over 4 sequential seedings. Based on slopes derived from linear regression models the time to 50% loss of bay scallops from the release areas was less than one day for juveniles ≤22 mm and ≥6 days for scallops ≥24 mm. Significant (α = 0.05) reductions in the rate of loss occurred as scallop size increased at release. Scallops released with shell heights &gt;45 mm had the lowest rates of loss. Both predation and dispersion effected these loss rates. Predation of scallops was attributed to the following benthic invertebrates: 6 species of crabs ( Cancer borealis, Cancer irroratus, Carcinus maenus, Callinectes sapidus, Pagurus pollicarpus, Pagurus longicarpus ), lobsters ( Homarus americanus ), 2 species of oyster drills ( Urosalpinx cinerea and Eupleura caudata ) and sea stars ( Asterias forbesi ). These predators contributed to most of the losses of bay scallops ≤22 mm and at least 20–50% of the losses in scallops ≥24 mm. Dispersion consisted of a northwest drift of scallops across the field study areas, which was probably enhanced by current patterns. Growth of bay scallops from October 3–24 was 0.26 mm/day and the rate of growth slowed as the water temperature dropped below 15°C.