Protected areas are locations which receive protection because of their environmental, cultural or similar value. Countries often have extensive systems of protected areas developed over many years. These systems vary considerably country to country, depending on national needs and priorities, and on differences in legislative, institutional and financial support. Protected areas transcend different environments from the highest mountains to the deepest sea, across forests, deserts, lakes and even national boundaries (territories).
The WDPA uses the definition of a protected area (terrestrial, freshwater, and marine) as adopted by IUCN as the main criteria for a locations entry into the database.
A protected area is:
“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”.
Source: Dudley, N. (Editor) (2008). Guidelines for Applying Protected Area Management Categories. Gland, Switzerland: IUCN. x + 86pp.
Definition of a MPA:
Any area of intertidal or subtidal terrain, together with its overlying water 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.
The first key point of this definition is that the primary objective of the protected area is conservation of biological diversity. The second key point is that the protection is 'effective'. This will generally mean that the area is protected by an Act of Parliament, in the case of public land, or by a covenant or conservation agreement, in the case of privately owned, or indigenous land.
For more information on the IUCN protected area definition please see here.