MPA National System

The National System of Marine Protected Areas of the United States (est. in April 2009) is a national initiative designed to strengthen the protection of U.S. ocean, coastal, and Great Lakes resources through the coordination of existing marine protected areas.

MPAs protect ecosystems such as coral reefs, kelp forests, shipwrecks, and those areas frequented by whales and other marine life. They also can provide protection to economically valuable coastal and marine resources including commercial and recreational fisheries.

Levels of MPA’s

The national system of MPAs are established and managed by the following governments:

  • Federal 
  • State 
  • Territorial
  • Tribal
  • Local 

These collections of MPA’s work together to collectively enhance conservation of the nation’s marine heritage and important natural and cultural resources.

Improvements Provided by the National System

The national system of MPAs provides the first comprehensive mechanism for coordinating MPAs to work toward national conservation objectives. Examples of some of these benefits include:

  • Enhanced stewardship through better coordination, public awareness and enhanced site management capacity
  • Building partnerships for MPAs to work together toward common conservation objectives
  • Increased support for marine conservation through the recognition provided by the national system
  • Protecting representative ecosystems and resources from all the nation’s ecosystem and habitat types
  • Identifying gaps in current protection of ocean resources to help inform future MPA planning

MPA Diversity

The U.S. has more than 1700 MPAs covering more than 41% of U.S. marine waters, and vary widely in purpose, legal authorities, managing agencies, management approaches, level of protection, and restrictions on human uses.

Some highlights:

  • State and territorial governments manage approximately 75% of the nation’s MPAs, but most MPA areas are managed by federal agencies
  • The majority of U.S. MPAs are located within the Virginian Atlantic marine ecoregion, which extends along Cape Hatteras northward to Cape Cod
  • Nearly all (86%) of U.S. MPAs are multiple use

What kind of MPA’s are there?

The National Marine Protected Areas Center has developed a Classification System that describes MPAs in functional terms using five characteristics common to most MPAs: 

  1. Conservation focus
  2. Level of protection 
  3. Permanence of protection
  4. Constancy of protection
  5. Ecological scale of protection

Marine Reserves:

Marine reserves are rare in the United States, with about 3% of U.S. waters in no-take areas. Reserves protect whole ecosystems, allowing them to return toward a more natural and balanced state. 

Nearly 94 percent of marine reserve area in the U.S. is located in the Papahānaumokuākea Marine National Monument in Hawaii. 

The remaining 6 percent is located in small reserves around the country. Marine reserves are established through the existing authorities of federal agencies, states or territories.

Where are they located?

The West Coast (California, Oregon, and Washington) has the highest number of MPAs; however, the region with the largest area of MPAs is the Pacific Islands. This is because of the Papahānaumokuākea Marine National Monument, which is the largest marine conservation area in the world.  

Most of the Great Lakes MPAs were created to protect cultural resources, like shipwrecks and historical artifacts. One example of a Great Lakes MPA is the Thunder Bay National Marine Sanctuary, which protects more than over 150 shipwrecks.

Ex: The Papahānaumokuākea Marine National Monument

The Papahānaumokuākea Marine National Monument is not only the largest conservation area in the U.S., it’s one of the largest marine conservation areas in the world. It’s larger than all of America’s national parks combined! This vast region preserves many of Hawaii’s Northwestern Islands and is made up of 582,578 square miles of reefs, atolls, shallow waters, and deep seas.

The monument contains a wide variety of critically important habitats that harbor over 7,000 marine species, several of which are only found in this region. It is also home to many rare and endangered species such as the green sea turtle and the Hawaiian monk seal.

MPA Science

Scientific understanding of MPAs is growing rapidly. Research has shown that MPAs are effective at increasing the abundance and diversity of marine life within their boundaries. In order to gain support from and build trust with MPA stakeholders, MPA managers and planners rely on natural and social science for the design and management of these special areas.


  • MPAs assisted in rebuilding the Georges Bank sea scallop fishery west of Cape Cod (MA) and the rotational reopening of these areas contributed to the high scallop landings during the past decade or more” (Hart and Jacobson). 
  • “Underwater visual surveys for a no-take MPA north of Oahu, Hawai’i found that fish abundance and biomass were correlated with distance from the MPA boundary, showing a decreasing gradient from inside to outside, indicating a spillover of adult fish” (Tissot et al.)                   
  • “MPAs in the Bering Sea reduced red king crab bycatch but increased bycatch of halibut in adjacent waters from displaced fishermen, thus creating a situation where a closure intended to protect one vulnerable species (e.g., red king crab) may increase unintended fishing pressure on another (e.g., halibut)” (Abbott and Haynie)