It's nice to be reminded now and then that reports about the environment can be positive sometimes, too. We grow so accustomed to hearing about the awful effects of pollution and global warming that it takes us a moment to recognize a glimmer of hope when one appears. But there was just such a glimmer last month when scientists gathering at a conference in San Francisco announced that marine reserves actually work.
A marine reserve, of course, is an area of the ocean managed specifically for scientific study and to preserve the habitat in its natural state. Perhaps the single most important feature of a marine reserve is that fishing and mining are prohibited within its bounds.
Once a reserve is established the changes can be dramatic. Studies of existing reserves have shown, for example, that population densities are almost twice as great within a reserve as compared to outside it. Species diversity, meanwhile, is almost 25 percent higher, and the size of individual animals also increases. Even better, these changes occur within the first few years of a reserve's establishment.
But there's more good news. Because tides and currents disperse most marine species, especially during the early stages of their development, the areas surrounding reserves benefit, too. Think of the reserves as natural hatcheries that service whole regions. It's a small step, then, to imagine networks of these reserves, carefully placed to take advantage of currents and dispersal patterns, covering the globe. Yes, fisherman will lose access to certain areas, but their catches will improve elsewhere. Biodiversity, meanwhile, will be protected.