The Marine Mammal Protection Act (MMPA)

The Marine Mammal Protection Act (MMPA) of 1972 was enacted to maintain marine mammal stocks at their optimum sustainable population (OSP) level and to restore depleted stocks.  The law prohibits the take of  all 128 species of marine mammals, including whales, dolphins, sea otters, manatees, polar bears, seals, and walruses.  The term “take” is defined as “to harass, hunt, capture, or kill, or attempt to harass, hunt, capture or kill any marine mammal.” 

In addition to shifting the focus of conservation from species to ecosystems, the Act contains many innovative features never before established in legislation. It: 

  • Presented a single comprehensive federal program to the place of former state-run programs; 
  • Included protection for population stocks in addition to species and subspecies. A population stock is “a group of marine mammals of the same species or smaller taxa in a common spatial 
  • arrangement that interbreed when mature;” 
  • Shifted the burden from resource managers to resource users to show that proposed taking of living marine resources would not adversely affect the resource or the ecosystem; 
  • ƒEstablished the concept of “optimum sustainable populations” (OSP) to ensure healthy ecosystems. Prior to the Act, the management of marine species was aimed at producing a “maximum sustainable yield” (MSY) to ensure the species replenished itself for an adequate harvest in subsequent years; and 
  • ƒDirected federal agencies to seek changes in international agreements, such as the Whaling Convention and the North Pacific Seal Convention corresponding to the Act.

The 1994 reauthorization introduced substantial changes to the MMPA, with new requirements designed to establish a long-term strategy for managing interactions between marine mammals and commercial fishing operations.  This amendment established a program to authorize and control the take of marine mammals in commercial fishing operations. It also called for the preparation of stock assessments for all marine mammal stocks in U.S. waters.  These stock assessment reports, or SARs, provide NOAA Fisheries and the fishery management councils with the necessary scientific information to determine appropriate levels for the incidental take of marine mammals. 

NOAA Fisheries classifies each commercial fishery under one of three categories according to the incidence of marine mammal injury or death.  Category I and II fisheries have “frequent” or “occasional” incidences of marine mammal death or injury. These fisheries must also comply with Take Reduction Plans (TRPs).  TRPs are developed by Take Reduction Teams with the short-term goal of reducing, within 6 months, the incidental take of marine mammals to a level that will allow for the recovery of the stock and the long-term goal of reducing the incidental take of marine mammals to insignificant levels within 5 years.  The Council has participated in the development of four completed take reduction plans and one in-progress TRP.