Circulation and Contaminant Transport in Massachusetts Coastal Waters

U.S. Geological Survey studies show that the concentrations of metals
in surface sediments of Boston Harbor are decreasing with time. This conclusion
is supported by analysis of (1) surface sediments collected at monitoring
stations in the outer harbor between 1977 and 1993, (2) sediment cores from
depositional areas of the harbor, and (3) historical data from a
contaminated-sediment data base, which includes information on metal and
organic contaminants and sediment texture. During the 16 years of the
continuing study, chromium, lead, mercury, silver, and zinc concentrations in
surface sediments have decreased by about 50 percent. Although these trends are
indeed encouraging, concentrations of some metals in harbor sediments are still
above levels considered toxic to certain bottom-dwelling organisms.

Type: Bay

Waterbody or Watershed Names: Boston Harbor