increasing demand to know (1) the distribution of geologic materials and processes

that are the framework of habitats (fig. 1),

(2) the location and character of EFH’s,

(3) the impact of habitat disturbance by

fishing gear, and (4) the processes and

time periods required for the recovery of

disturbed habitats.

Large areas on and near Georges

Bank have been closed to fishing since

December 1994 to conserve groundfish

stocks (fig. 2). Sea scallops had been

depleted in these areas, but they have

recovered locally since 1994. Parts of the

closed areas recently have been opened for

a limited time to allow scallop dredging,

thus raising questions regarding the disturbance of EFH’s and the bycatch of protected groundfish species.

USGS Research Results

Geologists and biologists of the U.S.

Geological Survey (USGS), the National

Marine Fisheries Service (NMFS) and

National Marine Sanctuaries System

(NMSS) of the National Oceanic and

Atmospheric Administration (NOAA), the

University of Rhode Island, and the University of Connecticut have been conducting joint studies of the seabed geology

allowed depleted sea scallop popula

tions to increase markedly in 4–6 years

• Some sand-dwelling flounder species

possibly prefer moving sand (strong

bottom currents), but others prefer

nonmoving sand habitats

These results are being used by the

New England Fishery Management Council (NEFMC) and the NMFS in deciding

where fishing may occur and where the

seabed must be closed to fishing to protect

fish stocks and habitats.

Seabed Mapping

The absence of maps showing the

geology and habitat character of the seabed is the greatest single obstacle to the

gathering of information required for the

informed and successful management of

the region’s seabed habitats. The USGS

has used multibeam sonar technology to

map part of Closed Area I in the Great

South Channel region (figs. 2, 3). The

habitat information provided by these

multibeam sonar images of the seabed has

been used by the NEFMC to make management decisions that opened some parts

of Closed Area I to scallop dredging and

protected other parts that are valued as

groundfish habitat.

U.S. Department of the Interior

U.S. Geological Survey

USGS Fact Sh

Figure 1. Photographs of the seab

some typical Georges Bank habita

ure 2 for locations. A, Undisturbed 

habitat with epifauna of tube worm

attached species. B, Gravel habita

by scallop dredges and lacking ep

C, Moving sand habitat (strong bott

with sand dollars in ripple troughs. 

moving sand habitat (weak current

scallops.
closed to fishing since December 1994 (CAI, CAII, NLSCA), parts of

closed areas that were opened seasonally to scallop dredging (pink),

part of Great South Channel mapped by USGS multibeam sonar (orange;

see fig. 3), gravel habitat on the northern edge of the bank (red outlines),

Figure 3. Part of Great South Channel (fig. 2) showing b

intensity draped over shaded-relief imagery of the seab

of backscatter data derived from multibeam sonar map

cate the wide variety of habitats in this important fishin

orange indicates high-backscatter material (coarse sa

gravel); green indicates moderate-backscatter materia

and blue indicates low-backscatter material (fine sand

Area I (CAI) boundary is white dashed line. Area shown 

kilometers.

nile cod, boundary (green line, dashed where inferred) betwe

sand habitat (strong bottom currents) and nonmoving sand 

(weak currents), and locations of habitats shown in figure 1 

and D). Base map from NOAA’s National Ocean Survey Cha

For more information, please contact:

Page C. Valentine

U.S. Geological Survey

384 Woods Hole Road

Woods Hole, MA 02543–1598

Telephone: (508) 457–2239

E-mail: pvalentine@usgs.gov