Types of Global Marine Protection
There are numerous definitions and ideas for what constitutes a marine protected area. As defined by the IUCN:
'a clearly defined geographical space, recognised, dedicated and managed, through legal or other effective means, to achieve the long-term conservation of nature with associated ecosystem services and cultural values’.
This definition, used in establishing the World Database on Protected Areas, provides flexibility to governments to define activities and levels of activity that are permissible to achieve long-term conservation. However, it also leads to a large over-estimate of areas that are 'protected' based on other MPA definitions that may restrict some damaging activities such as fishing, oil and gas development and extraction, as well as other activities. MPAtlas is designed to better reflect the actual protection level intended through designation of MPAs.
Many MPAs are multiple-use areas, where a variety of activities are allowed. These MPAs may provide partial protections for marine life through a single or a few protected species, gear restrictions, seasonal closures, catch limits, or other restrictions on use or extraction. For example, there are many different kinds of MPAs in US waters including: national parks, wildlife refuges, monuments and marine sanctuaries, fisheries closures, critical habitat areas, habitat areas of particular concern, state parks, conservation areas, estuarine reserves and preserves, and numerous others. Globally, while some sites exist as no-take marine reserves, the vast majority of MPAs, both in terms of numbers established and area covered, are open for fishing, diving, boating, and other recreational and commercial uses.
Currently only about 2% of the world’s oceans are in MPAs; far less than on land (roughly 15%). Many marine ecosystems are currently not protected and others are vastly underrepresented in existing MPAs.
Marine reserves are ocean areas that are fully protected from activities that remove animals or plants or alter habitats, except as needed for scientific monitoring. Most marine reserves are established with the goal of increasing the abundance and diversity of marine life inside the reserve. Scientific research shows that reserves consistently accomplish this goal, which can be a boon to not only the marine inhabitants but also to the human communities that surround reserves. In contrast to many MPAs that allow a number of human activities, marine reserves set a higher standard and provide a greater level of protection. Marine reserves are also often described as "no-take" marine protected areas. Of the 11,000+ MPAs worldwide, only a small fraction are areas designated as no-take marine reserves. The vast majority of the ocean area that is protected by no-take MPAs exists in a few very large areas, which tend to be far from coasts and therefore not necessarily representative of the oceans’ biodiversity.
Between 1975 and 2006, the largest MPA was Australia’s 345,400 sq km Great Barrier Reef Marine Park. Designed as a zoned mosaic, it was not a full no-take MPA, with only 5% of its area in no-take reserves by the mid-‘80s. By 2004, it was clear that this level of protection was not sufficient to ensure the health of the marine ecosystem, so much more of the Park (33%) was designated in no-take areas. The U.S. Pacific Remote Islands Marine National Monument is currently the world's largest fully no-take marine reserve at 1,270,000 sq km, although it should be noted that the monument is composed of five discrete, non-contiguous areas. The recently expanded Papahānaumokuākea Marine National Monument has become the world's largest no-take marine reserve.
There is accelerating momentum and opportunity for designating very large marine protected areas. A very large percentage of MPAs are tiny - nearly 50% are smaller than 10 sq km. Both small and large MPAs can export adult or larvae marine species and be useful for human fisheries (by supplementing populations in surrounding areas), but MPAs are less useful for biodiversity if the animals they export suffer significant fishing mortality. MPAs that can reduce mortality and protect critical life history phases where they occur are much more effective than those that do not.
Research suggests large MPAs are much more cost-effective to implement and manage compared to smaller MPAs (McCrea-Stroub et al 2010), and in general larger areas will provide better protection from activities that occur outside the MPA. However, it is important to note that small and well managed MPAs can still achieve important conservation benefits. A growing number of large MPAs cover the oceans of many countries and high seas areas protecting diverse pelagic ecosystems, offshore seamounts, and ocean trenches, including the recently designated St Helena Marine Protected Zone in the UK and Easter Island Marine Park (see Table).
* Officially designated, but not yet implemented
**Establishment of the MPA was ruled illegal by a UN tribunal in March 2015. Status uncertain.
Some of the most effective closed areas result from no access zones set aside for reasons such as the safety, security or regulation of shipping or military activities. One of the most notable areas is the US Island of Kaho’olawe, Hawai'i which served as a bombing practice range for the U.S. Navy for almost fifty years after the end of World War II. Today it provides thriving shallow water coral habitat as an inadvertent result of heavily restricted human use for all this time. Baseline surveys are still being conducted in order to assess the effects of the island’s converted protection as a reserve.
Although not often managed at the site level with area specific management or permanent, fishery closures are an important tool for conserving marine life. Regulations can restrict all fishing, or just some, and are frequently specific to a particular species or group of species. Often closures are put in place for limited periods of time to help a specific fishery management objective such as helping to rebuild an overfished population, or reducing bycatch of a vulnerable population. In the United States Essential Fish Habitat Designations are an important type of MPA.