Tisbury selectmen this week set dates for the bay scalloping season in town. Recreational scalloping opens Oct. 17 outside ponds and in the Vineyard Haven harbor; the commercial season begins in those areas on Oct. 19. Lagoon Pond opens on Oct. 31 for family scalloping and on Nov. 2 for commercial fishermen. Lake Tashmoo opens Dec. 5 for recreational scalloping and Dec. 7 for commercial scalloping.