According to the World Conservation Union a Marine Protected Area is defined as any area of intertidal or subtidal terrain together with their overlying waters and associated flora, fauna, historical and cultural features, which has been reserved by law or other effective means to protect part or all of the enclosed environment (Kelleher, 1995 & IUCN, 1988). According to Agardy ‘the ultimate goal of any marine protected area is marine conservation – that is, the protection of critical ecological processes that maintain the ecosystem and allow for the production of goods and services beneficial to humankind, while allowing for utilisation of ocean space and resources that is 1 International Legal Framework for MPAs, focused on Belgian Situation M. Rabaut Introduction sustainable in an ecological sense’ (Agardy, 1997). There are many formal definitions of marine protected areas, but the most broadly used definition is the IUCN definition: 

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

Types of Marine Protected Areas (MPA's) 

There are many kinds of marine protected areas that meet this broad definition, and which can have a wide range of conservation objectives. Such objectives can include: 

• To ensure the long-term viability and maintaining the genetic diversity of marine species and systems.
• To protect depleted, threatened, rare or endangered species and populations.
• To preserve habitats considered critical for the survival and/or life-cycles of species, including economically important species.
• To prevent outside activities from detrimentally affecting the marine protected areas.

Human objectives

• To provide for the continued welfare of people affected by the creation of marine protected areas. 
• To preserve, protect, and manage historical and cultural sites and natural aesthetic values of marine and estuarine areas, for present and future generations.
• To facilitate the interpretation of marine and estuarine systems for the purposes of conservation, education and tourism.
• To accommodate with appropriate management systems a broad spectrum of human activities compatible with the primary goal in marine and estuarine settings.
• To provide for research and training, and for monitoring the environmental effect of human activities, including the direct and indirect effects of development and adjacent land-use practices. 

Some people confuse marine reserves, where extraction of any resources is prohibited (no-take), as the only type of MPA. MPAs may include marine reserves, as well as other zones in which partial protection is afforded (seasonal closures, catch limits, etc.). Many MPAs are multiple-use areas, where a variety of uses are allowed. For example, there are many different kinds of MPAs in U.S. waters including national parks, wildlife refuges, monuments and marine sanctuaries, fisheries closures, critical habitat, habitat areas of particular concern, state parks, conservation areas, estuarine reserves and preserves, and numerous others. While a few sites exist as no-take marine reserves, the vast majority of MPAs, both in terms of numbers and area, are open for fishing, diving, boating, and other recreational and commercial uses.

Individual Site Selection Criteria 

• MPA's and reserves are selected using natural, cultural, logistical, and/or socioeconomic criteria that may vary with different nations and programs. Some of the most common criteria include: 
• Relative naturalness – selecting areas are still in good or nearly pristine condition. 
• Representativeness – selecting areas that represent particular habitats or include important ecological functions such as spawning, nursery or feeding areas.
• Biodiversity – selecting areas with high diversity of species and/or areas with high rates of endemism (i.e., having species that are unique to a particular area or region).
• Vulnerability – selecting areas with biodiversity that is relatively susceptible to disturbance or destruction.
• Fisheries value – selecting areas that are strategic for enhancing fisheries, such as areas of high productivity or spawning grounds for targeted fish species.
• Tourism value – selecting areas that could, if protected, enhance appropriate recreational uses and tourism revenues.
• Social acceptance – selecting areas that are acceptable to all stakeholders to be set aside for protection.
• Practicality of management – selecting areas that allow for relative ease of management due to a range of factors, such as nearness to shore.