Marine protected areas work much like our national parks on land. The size and level of protection varies, but MPAs are designed to protect some or all of an ocean area’s wildlife and habitat. Unlike traditional fisheries management tools, which regulate one species at a time, MPAs focus on protecting entire ecosystems — from predators to prey. The MLPA is designed to compliment other ocean protection legislation.

Types of MPAs

There are three types of marine protected area designation. Each prevents various types of extractive uses, such as fishing or collecting, but all provide safe havens for struggling marine life to recover and thrive. The three types of MPAs include:

Marine Parks: Some recreational fishing allowed

Marine Reserves: Fish, wildlife and habitat are protected from all fishing and resource extraction

Marine Conservation Areas: some consumptive recreational and commercial activities are allowed

Why marine reserves?

While many different types of MPAs contribute to conservation, the greatest benefits are associated with marine reserves. At least 29 nations and territories have established marine reserves for various reason — to protect biodiversity, manage fisheries, or restore depleted populations of marine animals and plants. Marine reserves are the most protective type of MPA, with higher protections than National Marine Sanctuaries. They prohibit the taking or destroying of marine wildlife or its habitat within their borders. Most marine reserves still allow scientific surveys of the area, as well as recreational use such as surfing, swimming, no-take diving and boating. With all the benefits and success stories associated with marine reserves, they cover less than 0.1 percent of the ocean world wide. Currently, most marine reserves are quite small, and the average reserve size is less than 1.5 sq. miles.

Why are large populations important, you ask?

Small populations are more susceptible to drastic decline by unpredictable catastrophes, like oil spills or global warming. Large populations contain more individuals, so they are more likely to contain individuals that are capable of surviving various stresses. The drastic decline of one species can often result in the decline of another, due to the inter-connectedness of this web of life. And why does fish size matter? Bigger body size is one of the most important biological changes in marine reserves because large fish and invertebrates can produce enormous numbers of young. The relationship between body size and number of young is well known (and often exponential!). For many marine fishes and invertebrates, small increases in body size can lead to large increases in the number of eggs produced. As a particular example of this phenomenon, a 40cm bocaccio rockfish produces an average of just 200,000 eggs per year, whereas an 80cm fish at double the length produces nearly 2 million, or ten times as many eggs!

The bigger and more abundant animals living in a marine reserve can produce far more than their smaller neighbors in unprotected waters. As a result, marine reserves can produce higher growth rates. Due to the migratory nature of fish, healthy, large and abundant fish can spill over into unprotected areas.


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