Marine protected areas

 Marine protected area (MPA) is a fluid term with a range of possible meanings.  For the most part, it is an area of the marine environment where human activity is regulated for the purpose of conserving and managing natural and cultural marine resources.  Fishery conservation zones would constitute one of the earliest examples of an MPA.  Marine sanctuaries, such as the Stellwagen Bank National Marine Sanctuary off Massachusetts, constitute a more recent example.  The Papahānaumokuākea Marine National Monument in the northwestern Hawaiian Islands is a large and more recent MPA (established in 2006).  In April 2009, the United States established a National System of Marine Protected Areas. Currently, 225 MPAs participate in the national system. National system sites agree to work together toward common national and regional conservation goals and priorities. The national system works to enhance the natural and cultural heritage of US coastal waters and promote sustainable production of its marine resources. To support the National System of MPAs, the National Oceanic and Atmospheric Administration (NOAA) maintains a comprehensive inventory of all MPAs, federal, state, and local, within the US Exclusive Economic Zone (EEZ) and coastal waters.  The U.S. has over 1,600 MPAs, ranging from typically small fully protected marine reserves where extractive uses are prohibited to large, multiple use areas where fishing, diving and other uses are permitted. Less than 1% of US waters are fully protected marine reserves.  MPAs are not just a domestic concept.  Numerous coastal nations have established MPAs, with a wide variety of size and management concepts.  Australia has managed activity within the Great Barrier Reef for many years.  The Republic of Kiribati in the central Pacific recently established the Phoenix Islands Marine Sanctuary, at 410,000 square kilometers the largest MPA in the world.  Due to the relative novelty of MPAs and the wide variety of management schemes utilized, there appears to be some disparity regarding whether the MPAs are effective conservation tools.