The IUCN recommends that "as an integral component of marine conservation and management, each national government should seek cooperative action between the public and all levels of government for development of a national system of marine protected areas."
The statements from these organisations reflect the importance that is being given to MPAs as essential tools in the suite of measures used by States to conserve their fishery and other marine resources. This is also reflected in the Jakarta Mandate on Marine and Coastal Biological Diversity, which is "a global consensus on the importance of marine and coastal biological diversity and is a part of the Ministerial Statement on the implementation of the Convention on Biological Diversity, as adopted by the Conference of the Parties (COP) at its second meeting held in Jakarta in November 1995. The Ministerial Statement reaffirms that there is a critical need for the Conference of the Parties to address the conservation and sustainable use of marine and coastal biological diversity, and urges Parties to initiate immediate action to implement the decisions adopted on the issue." Marine and coastal protected areas were one of the five thematic issues identified within the Jakarta Mandate.
MPAs can be developed to offer varying degrees of protection to the protected area, ranging from total exclusion of all fishing and other extractive practices (commonly known as 'no take areas') to less stringent measures which allow, for example, fishing by certain gear types or during certain times of the year while prohibiting other practices (known as 'multiple use protected areas'). The extent of protection offered in any particular MPA will normally depend on the conservation objectives for and the socio-economic context of that MPA. For example, an MPA designed to protect one particular species or group of species and established in an area already utilised by people dependent on the area for their livelihoods may prohibit only those practices considered harmful to the protected species, while allowing other uses of the area to continue in a sustainable manner. In contrast, an MPA established to protect an important and scarce habitat type may exclude any human activity that threatens that habitat.
In general, MPAs can be established to serve:
- as a tool to assist in sustaining exploited fish stocks;
- to protect critical habitat;
- to protect biodiversity.
It is important to recognise that MPAs are not the only nor an infallible tool to achieve any of these objectives. In order for an MPA to realise the conservation objectives it is designed to fulfil: those objectives need to have been carefully and precisely defined; the role of the MPA in achieving them needs to have been evaluated and tested using the best information available and found to be feasible; and the establishment of the MPA must be supported by the majority of users, residents and/or neighbours and others affected by its establishment. Such considerations have been developed in some detail in the documentation listed below.