"There continues to be congressional interest in limiting human activity in certain areas of the marine environment, as one response to mounting evidence of declining environmental quality and populations of living resources. The purposes of proposed additional limits would be both to stem declines and to permit the rehabilitation of these environments and populations. One method of implementing this concept is for Congress to designate areas where activities would be limited, often referred to as marine protected areas (MPAs). Translating the MPA approach into a national program, however, would require that Congress resolve many economic, ecological, and social dilemmas. The complexity of creating a program is compounded by controversy over the uses that would be allowed, curtailed, or prohibited in MPAs; the purposes of a system of MPAs; and the location, size, and distribution of MPA units. One possible way to get past some of these complexities is to think of MPA designations as a form of zoning in the ocean. Experiences related to designating MPAs in other countries also may be instructive. However, questions have arisen about the effectiveness of administration and enforcement, the benefits and costs of MPAs, and the evaluation of outcomes at some sites."
CRS Report for Congress, RL32154