Apo Island Marine Sanctuary, Philippines
Latest updates from the impressive ProtectPlanetOcean web site provide convincing support for Greenpeace's long-held contention that marine reserves provide the best long-term solution to the problems of overfishing and pollution which threaten the world's marine ecosystems. In case you've forgotten marine reserves are protected areas, national parks at sea where no fishing or other extractive industries (such as oil, gas or gravel extraction) are permitted.
The site has pulled together studies of 124 marine reserves around the world - scientific peer-reviewed research published in academic journals - to provide a clear picture of what has happened where reserves have been established.
"Some fished species had more than 1000 per cent higher biomass or density inside marine reserves"
And the news is good: the studies documented a wide range of changes inside the reserves, nearly all of them positive. The big picture which unfolded when all the data was analysed revealed that fish, invertebrates, and seaweeds living inside marine reserves had the following average increases:
- Biomass, or the mass of animals and plants, increased an average of 446 per cent.
- Density, or the number of plants or animals in a given area, increased an average of 166 per cent.
- Body size of animals increased an average of 28 per cent.
- Species density, or the number of species, increased an average of 21 per cent in the sample area.
These increases were similar between tropical and temperate reserves, indicating that marine reserves are effective regardless of their latitude.
Crucially, both fish and invertebrates grow bigger in marine reserves than in unprotected areas. This effect is extremely important because large animals contribute much more to the next generation. They produce substantially more offspring than smaller individuals. For example, a 60-centimeter (24 inch) coral trout produces 10 times more young than when it was 40 centimeters (16 inches) long. This increased reproduction can play a vital role in replenishing heavily fished areas close to a reserve's boundaries.
Interestingly, heavily fished species often experienced the most dramatic turn about in their fortunes, with some showing more than 1000 per cent higher biomass or density levels inside marine reserves. Additionally, research from Florida, USA and Kenya showed that reserves produced greater increases than Marine Protected Areas (MPAs), which are watered-down versions of reserves that allow some fishing to take place.
The bad news? Well, the sad fact is that that most existing marine reserves are tiny (half the sample studied were under 1.5 square miles) and badly protected (only 12 out of 255 were routinely patrolled to prevent poaching in 2005). Worst of all, the total area they currently protect is a paltry 0.1 per cent of the ocean world-wide. In 40 studies examining how much sea should be protected, the majority indicated a range between 20 and 50 per cent would be needed for our over-exploited oceans to have a realistic chance of recovery in the longer term. In the UK the Royal Commission on Environmental Pollution recommended a figure of 30 per cent. Greenpeace accepts the science, which is why we're calling on politicians and administrators the world over to embrace a prudent figure and make 40 per cent of the oceans into marine reserves.
The alternative is unthinkable - a continued drastic decline in the ocean's capacity to provide food, to sustain livelihoods and protect biodiversity.
