Salem ferry announced that starting next week (week of September 19) through the end of its season (October 31st), it will reduce service to 3 days a week: Fridays through Sunday. However, ferries will run on Columbus Day and Halloween (both Mondays). The 7am commuter trip from Salem will also end. The ferry operator, Boston's Best Cruises, says that it will resume service as always next spring. They state that high fuel costs and reduced ridership are the reason for the cut-back.
Keep in mind that the commuter rail is available for travel between Boston (North Station) and Salem, and that the MBTA usually provides extra service on Halloween and sometimes the days preceding.
For more information see: