NMFS is publishing its final List of Fisheries (LOF) for 1999 as required by the Marine Mammal Protection Act (MMPA). In addition, NMFS is amending the regulations implementing section 118 of the MMPA by clarifying and updating existing regulations. The final LOF for 1999 reflects new information on interactions between commercial fisheries and marine mammals. Under the MMPA, NMFS must place a commercial fishery on the LOF into one of three categories based upon the level of serious injury and mortality of marine mammals that occurs incidental to that fishery. The categorization of a fishery in the LOF determines whether participants in that fishery are subject to certain provisions of the MMPA, such as registration, observer coverage, and take reduction plan requirements.