One aspect of our scallop research program is examining
the effects of scallop harvesting on the marine benthic habitat. The
of mobile fishing
gear in United States coastal waters is hotly debated with opinions ranging
from the gear having little effect, to the gear devastating the marine
benthic community. We have conducted a series of experiments examining
impact of scallop harvesting on Georges Bank. We address the issues by:
- mapping the sea floor,
- conducting a Before-After-Control-Impact (BACI)
study of the scallop resource,
- conducting a comparison study with more than 125
stations within and outside the HAPC,
- publishing our observations.
Mapping the sea floor. Scallops have evolved
to live on a dynamic sand-gravel substrate, which does not support
sessile and encrusting
invertebrates very well. By defining the gravel areas into their subgroups
and showing where the substrates and sessile invertebrates do and don’t
exist some of the conflict over the effects of fishing on habitat may
We have successfully collected the information for one of the
Before-After-Control-Impact (BACI) studies
ever conducted on a scallop resource. We surveyed the historic
scallop fishing grounds of Georges Bank that have been closed to
mobile gear since 1994. Our survey design was a BACI with a 1-year
observations, 2 experimental areas (NLSA and North of 43660 in CAI)
that were exposed to intense fishing pressure, two control areas (the northern
portion of CAII, and South of 43660 in CAI) with no fishing, and
one control with constant fishing (South Channel).
We have a comparison study with >125 stations within and
outside the HAPC which had been closed for 8 years at the time of
the study. This
is one of our best data sets with both the large (2.8 m2) and small
(0.6 m2) images.
Actual data on these topics are so
lacking that all of our observations can be published. Even
things such as what fish we observed and what substrate the fish
were associated with will be of use.
We are presently organizing, analyzing and preparing several manuscripts
on these data. Preliminary data have been presented to the New England
Fisheries Management Council, Habitat Oversight Committee (12 Sept 02),
and Habitat Technician Team (25 Nov 02). We have also presented the preliminary
results from our BACI experiment at the Benthic meeting in Florida:
Stokesbury, K.D.E. and B. Harris. A Before-After-Control-Impact
Study of the Sea Scallop Fishing Grounds of Georges Bank. Symposium on
Effects of Fishing activities on benthic habitats. USGS, NOAA, AFS, ESA.
Tampa Florida, 12-14 November 2002.
Photograph: Boulders, cobble, gravel and sand with
several species of sponge and one scallop.