The Stellwagen Bank National Marine Sanctuary (SBNMS) was designated in 1993. North Atlantic Right whales, an endangered species, spend time in Cape Cod Bay and the Stellwagen Bank region in the spring.  The USGS, in cooperation with NOAA, the Canadian Hydrographic Service and the University of New Brunswick (Valentine and Butman, 1998; see library 3) has systematically mapped the sea floor using a multibeam echosounder. These surveys provide a detailed view of the topography and surficial geology of the sea floor.  A major concern has been that the effluent from the new MWRA ocean outfall in western Massachusetts Bay will impact endangered species in the Sanctuary.  Effluent dilution estimates, based on a three dimensional hydrodynamic model (Signell, 1997; Signell and others, 1996), show that the concentration of effluent in the Stellwagen Bank National Marine Sanctuary (and most of Massachusetts Bay) from the new outfall will not significantly differ from present concentrations.   This reflects the fact that much of the effluent presently discharged in Boston Harbor is transported to western Massachusetts Bay, and that the Sanctuary is far enough from the effluent source so that the change in the location of the initial release is masked by the mixing processes in Massachusetts Bay.

This Chapter/view includes relevant boundaries, topography and shaded relief images from the multibeam echosounder surveys, sediment texture, selected sediment chemistry,  fisheries abundance data for selected species (juveniles and adults), critical habitats, and the effluent dilution estimates for winter and summer.

Coverages provided in Chapter 4:   (Sumary metadta for files in the Chapter 2D view are listed alphabetically in the table below. For complete metadata, go to the directory "9_biblio" on this CD-ROM and open the file metadata.mdb using Microsoft Access or the file Gismeta.htm using your browser.)