Grizzle et al.: Effects of a large fishing closure on benthic communities in the western Gulf of Maine 
309 
stocks. Recent analyses of commercial 
trawl data (Murawski et al., 2004, 2005) 
have shown no appreciable effect of the 
closure on stock rebuilding in the region, 
although there has been substantial re- 
covery of some groundfish stocks since the 
closure was implemented. From studies of 
MPAs in other areas, for example, New 
England (e.g., Collie et al., 2005), it seems 
reasonable to expect that a closure of the 
magnitude of the WGOM area would have 
a measurable effect on habitat recovery 
and fish stock rebounds. Its role in these 
respects, however, remains to be demon- 
strated. 
In this article, we present data from grab 
and box core samples of sediments and in- 
fauna, underwater video surveys of benthic 
fauna, and general seafloor conditions four 
to six years after the closure of WGOM, 
all of which indicate that the closure has 
resulted in substantial recovery of some 
bottom habitat types. We offer hypothetical 
causes for the recovery in the context of 
gear removal, and we discuss the implica- 
tions for ecosystem-level management of 
the closure. 
Materials and methods 
Study area 
The study was restricted to a 515-km 2 area 
that comprised a section of the central 
western WGOM closed area and a sec- 
tion outside the closed area (Fig. 1). The 
overall closure area, which covers much 
of Jeffreys Ledge, is about 30 km wide 
(east-west) and 110 km long (north-south) 
and is located off the southern Maine, New 
Hampshire, and northern Massachusetts coasts. The 
location of the study area was chosen mainly because 
it has similar environmental characteristics both inside 
the closure and outside the closure. 
A 5-m pixel resolution bathymetric map covering 
about 85% of the area and produced from multibeam 
sonar data collected between December 2002 and Janu- 
ary 2003 (Malik and Mayer, 2007) was used as a gen- 
eral base map for the present study. It functioned as a 
guide for the final selection of sampling-site locations 
and for the interpretation of data related to potential 
gear impacts on bottom habitats. 
An important feature of the study area for our re- 
search was the level of fishing activity, historically as 
well as after implementation of the closure. Data on 
date, location, and gear type (acquired by the National 
Marine Fisheries Service from federally permitted 
commercial fishing vessels) were acquired and plotted. 
For map production, the raw data (which were submit- 
Figure 1 
Location of the 515 km 2 University of New Hampshire study 
area (UNH Study Area) in relation to the western Gulf of Maine 
closure area. The map has a resolution of 90-m to one pixel and 
indicates bathymetric contours with light gray (shallow water) 
and dark gray (deep water). 
ted at 1-min intervals of longitude and latitude) were 
plotted. All locations with fewer than five trip records 
were deleted from our analysis to eliminate poten- 
tially spurious data arising from reporting mistakes 
or for other reasons. Vessel trip report data from 4.5- 
yr preclosure (1994-98) and postclosure (1998-2002) 
were obtained for all reported gear types. Bottom 
gillnets and otter trawls were represented in >95% of 
the data records, and therefore other gear types were 
not analyzed. 
Study design 
The study was a control-impact assessment (Osenberg 
et al., 1994) for which there was systematic sampling 
of the seafloor at approximately equal numbers of sites 
distributed inside and outside the closed area (Fig. 2). 
Sampling sites were located on a grid with sampling 
points at approximately 1.3-km intervals (0.75 min of 
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