Marine protected areas not sufficient to protect global biodiversity

Only 2% of the world's tropical coral reefs are being safeguarded by Marine Protected Areas; places where some restriction is placed on human activities within the area. However, less than 0.01% of the world's coral reefs are protected from over-harvesting, poaching, siltation, nutrient enrichment and pollution. No global region currently protects more than 10% of its coral reefs adequately, with reefs in the Indo-Pacific and Caribbean remaining particularly vulnerable.

New Zealand is world-leading in protecting marine life, with over 50 Marine Protected Areas including 30 “no-take” marine reserves. The first marine reserve in New Zealand was created beside the University of Auckland's Leigh Marine Laboratory, where the new study took place.

The new research shows that 40% of marine protected areas are smaller than 1-2km2, an insufficient size to protect large fish and other animals. These animals, which are of particular interest to fishermen, tend to move large distances, spending significant time beyond the protected borders and therefore can be lost to harvesting.

The study recommends that each Marine Protected Area be 10-20 km in diameter to protect species that need large areas of habitat, and similarly spaced to ensure genetic exchange between areas. This would require the protection of only 25 590 km2, or about 5% of the world's coral reefs.

“Coral reefs are treasures of global diversity but are in jeopardy because of human threats” says Dr Camilo Mora, the Census of Marine Life scientist who led the study. “Unfortunately, actions to reverse such a crisis were very inadequate in most countries. We found that although about 19% of the world's coral reefs were within designated protected areas, only 0.01 to 2% of the world's reefs were really protected.”

“Marine protected areas are the prime strategy for the conservation of coral reefs and other marine habitats worldwide” says Dr Mark Costello of the University's Leigh Marine Laboratory. “For instance, we know that when Marine Protected Areas are managed as no-take reserves, the result is more natural species abundances and food webs – evident as larger population and body sizes of fish and crayfish, and higher production of their young.”