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To assess the impacts on sanctuary resources due to anthropogenic activity such as decades of commercial fishing and the installation of the Hibernia Cable it is necessary to monitor both impacted and non-impacted areas. On May 1, 1998 the Western Gulf of Maine Closed Area (WGoMCA) was closed by the New England Fisheries Management Council to all commercial fishing of groundfish (such as Atlantic cod, Gadus morhua) and has remained closed since that date. The southwest corner of the closed area, which overlaps the Stellwagen Bank National Marine Sanctuary (SBNMS) for a total of 132 nm2, or 22% of the Sanctuary, presented the opportunity to study seafloor habitat recovery following anthropogenic disturbance by bottom-contact mobile fishing gear (such as trawls and dredges). It is important to note that the closed area does not exclude all fishing activities, with commercial shrimp trawling, recreational fishing and other activities continuing to occur within the WGoMCA. As such, the WGoMCA represents an area of "reduced impact" to compare to actively fished areas, rather than a true un-impacted reference area.

The Seafloor Habitat Recovery Monitoring Project (SHRMP) was initiated in April 1998, one week prior to the closure of the WGoMCA, to investigate the recovery rates of seafloor habitat (physical and biogenic) and associated taxa (such as fishes) in the SBNMS following impacts from fishing. A total of eight stations were identified in four major habitat types-piled boulder, gravel, sand, unconsolidated mud-on either side of the WGoMCA boundary. Annual sampling is conducted using remotely operated vehicles, video drift camera systems, side scan sonar, seafloor-mounted current profilers, and bottom grabs.

Analysis of hard-bottom epifaunal invertebrate data from still photographs in 2001 showed invertebrate species richness and species diversity to be greatest at the piled boulder station inside the (WGoMCA). Richness and diversity was higher at Boulder IN than at Boulder OUT, and was also higher relative to both of the gravel stations. There were no differences in either species richness or diversity between the two gravel stations. In fact, the transects conducted at the Gravel OUT station had absolutely greater richness than the Gravel IN station. This may be attributable to high concentrations of fixed gear at the Gravel OUT station which effectively exclude mobile fishing gear from the area.

Invertebrate organisms in unconsolidated mud and sand habitats from bottom grab samples in 1998, 2001 and 2002 were counted and identified to the lowest possible taxonomic level. The total number of species counted was 234, with 22,099 organisms for all samples. Infaunal data were analyzed at both the family and species level. Cluster analyses of invertebrates in both unconsolidated mud and sand habitats showed a clear separation based on substrate type. This separation was expected because of the difference in substrate type alone. The cluster analyses for both invertebrate families and species levels for 2001 indicated a separation between stations inside and outside of the WGoMCA for both mud and sand habitats.

In September 2000, the Hibernia fiber optic cable was laid from Boston, Massachusetts to Halifax, Nova Scotia, crossing the Sanctuary for 19.8 km along its northern boundary. The cable was laid by a SEAPLOW into a trench measuring approximately 3 m across, with a targeted burial depth of 1.5 m into the seafloor. The actual depth of burial into the seafloor was between 0.5 and 0.75 m along the route within the Sanctuary. In August 2001, several sites along the cable route and in adjacent areas were added to the existing SHRMP stations to investigate the recovery of seafloor habitats following the laying of the cable by plow. Sampling at the 8 gear impact stations and at locations along the fiber optic cable route is conducted annually.

The SHRMP is a collaborative effort between the SBNMS and scientists at the Pfleger Institute of Environmental Research (PIER), the National Undersea Research Center at the University of Connecticut (NURC-UCONN), the US Geological Survey in Woods Hole, Massachusetts, the University of Maine, and Brown University (Brown participated from 2001-2003). Financial support has been provided by SHRMP for scientists, undergraduates and graduate students (both Masters and Doctoral), post-doctoral fellows, and research technicians at each of these institutions. Technical support for the operation and maintenance of the equipment associated with the project is provided by NURC-UCONN. The project's relational database was designed by, and is supported by, Perot Systems through a contract with SBNMS. These data include, but are not limited to; the identification and relative abundance of epifaunal organisms from video transects and still photographs; and infaunal organisms from bottom grabs and box cores.

This on-going collaboration is scheduled to continue through 2007 (dependent on funding).

James Lindholm, Ph.D.
Pfleger Institute of Environmental Research
901-B Pier View Way
Oceanside, CA 92054
Phone: 760-721-1441


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