Multiple Choice, Single Answer

Marine protected areas are parts of the sea where fishing and other activities are limited or banned. Fishing communities often oppose them at first, fearing that they will lose access to valuable fishing grounds. However, studies of well-enforced reserves have found that fish inside them tend to become larger and more numerous, and that some of them move into surrounding waters, where they can be caught. This 'spillover' means that a reserve can, over time, partly make up for the fishing area that has been closed. The benefits depend heavily on enforcement: reserves that exist only on paper do little for fish or for fishermen.