This report is a summary of a workshop on the problem of shellfish closures due to microbial contamination in Massachusetts. The workshop, sponsored by the Woods Hole Oceanographic Institution Sea Grant Program, was held on March 22, 1989, at the Woods Hole Oceanographic Institution. Its principal aim was to keep the shellfishing community informed about the status of shellfish closures throughout Massachusetts, the results of recent research on microbial contamination of shellfish, and options for shellfisheries in the region in the face of increasing closures of shellfish areas. Topics addressed by invited speakers included 1) the history of shellfish closures in the state, 2) the fecal-coliform standard and why it needs to be mod...