Marine reserve
[1] Benefits include increases in the diversity, density, biomass, body size and reproductive potential of fishery and other species within their boundaries.
[5] Effective reserves included habitats that support the life history of focal species (e.g. home ranges, nursery grounds, migration corridors and spawning aggregations), and were located to accommodate movement patterns among them.
[5] Movement patterns (home ranges, ontogenetic shifts and spawning migrations) vary among and within species, and are influenced by factors such as size, sex, behaviour, density, habitat characteristics, season, tide and time of day.
[2] Marine reserve whose boundaries are extensively fished benefit from compact shapes (e.g., squares or circles rather than elongated rectangles).
If the location of such special areas is unknown, or is too large to include in a reserve, management approaches such as seasonal capture and sales restrictions may provide some protection.
A location or population 20–30 km from its nearest neighbor generally qualifies as isolated in the absence of a persistent linking current.
[2] Increased fishing pressure adversely affects recovery rates (e.g., Great Barrier Reef and Papua New Guinea).
[2] Long-term protection allows species with slower recovery rates to achieve and maintain ecosystem health and associated fishery benefits.
[2] In some Coral Triangle countries (e.g., Papua New Guinea and Solomon Islands), short term protections are the most common form of traditional marine resource management.
Reopened reserves can be protected by management controls that limit the harvest to less than the increase achieved during closure, although at greatly reduced recovery rates.
[2] Local practices such as overfishing, blast fishing, trawling, coastal development and pollution threaten many marine habitats.
The size, spacing and location of reserves within a network must respect larval dispersal and movement patterns of species that are targeted for protection.
Generally this involves protecting adequate examples of each major habitat (e.g., each type of coral reef, mangrove and seagrass community).
[2] Reserves 0.5–1 km across export more adults and larvae to fished areas, potentially increasing recruitment and stock replenishment there.
[5] Most coastal fish species have a bipartite life cycle where larvae are pelagic before settling out of the plankton to live on a reef.
However, larvae can generally leave a reserve without elevated risk because of their small size and limited fishery exposure.
Greenpeace is campaigning for the "doughnut holes" of the western pacific to be declared as marine reserves[6] and for 40 percent of the world's oceans to be so protected.
