NMFS issues final specifications for the 2001 fishing year for Atlantic mackerel, squid, and butterfish (MSB). This action also allocates the domestic annual harvest for Loligo squid into quarterly periods. The intent of this final rule is to conserve and manage the MSB resource in compliance with the Fishery Management Plan for the Atlantic Mackerel, Squid, and Butterfish Fisheries (FMP); the regulations; and the Magnuson-Stevens Fishery Conservation and Management Act (Magnuson-Stevens Act).