GRANT
NUMBER:
NA66FD0023
NMFS NUMBER: 95-NER-113
REPORT
TITLE:
A New Harvest: Sea Scallop Enhancement and Culture in
New England
AUTHOR:
Susan Kuenstner
PUBLISH
DATE:
June 1998
AVAILABLE
FROM:
National Marine Fisheries Service, Northeast Region, One
Blackburn Drive, Gloucester, MA 01930. TELEPHONE:
(508) 281-9267
ABSTRACT

The overall
objective of this project was to demonstrate a viable
fishery based on harvesting scallop spat, and the subsequent
grow-out of juvenile scallops to harvest size.
Spat collection gear was deployed during two settlement
periods, at four sites, including Georges Bank, Portsmouth,
Truro, and Wellfleet. Very few scallop spat were harvested
in 1966, and it appears that spat settlement was particularly
bad throughout New England that year. In 1997, small
numbers of scallops were captured in Truro (avg. II spat/bag),
however, growth rate of spat was very high (avg. 2.58
mm/month). A greater quantity of spat were collected from
Georges Bank (avg. 240 spat/bag). However, none
of the Georges Bank spat contained tissue, indicating
that the animals had died before the bags were retrieved,
possibly through predation. Studies in Portsmouth to test
the hypotheses that spat collection activities enhance
the natural set were inconclusive since no spat were found,
either directly beneath bags or in an area devoid of bags.
A devise to quickly separate spat by size and/or form
other organisms was designed and built. Juvenile scallops
(initial size approx. 25 mm) were transplanted to three
grow-out areas; Portsmouth (pearl nets and benthic cages),
Truro (benthic cages), and Chatman (upwellers). Average
growth rates ranged from 5.53 mm/month in Truro, to 2.0
mm/month in Portsmouth. No statistical difference in growth
or mortality was observed between the Portsmouth scallops
in suspension and those in benthic cages. On a cost per
scallop basis, Truro was the least expensive grow-out
site to manage ($0.19/scallop). The upwellers in Chatman
were the most expensive ($1.27/scallop) due to the cost
of electricity to run the pumps. The break even point
for spat collection was also calculated and found to be
76 spat/bag.