Marine reserves provide insurance against scientific uncertainty. One of the greatest challenges in fishery management is the uncertainty associated with setting safe and appropriate catch levels for individual fish stocks and trying to predict variations in natural conditions. Marine reserves can protect a portion of fish populations from potentially irreversible damage resulting from erroneous fishery management decisions. Marine reserves provide scientific research opportunities. Marine reserves can improve the scientific basis for fishery management decisionmaking by offering scientists ecological benchmarks against which fishing impacts can be measured, as well as baseline data on the age, growth, life history parameters and ecological interactions of marine communities.
Marine reserves are difficult to properly design and site.
Basic information on the ranges, life history parameters, and habitat requirements of fish species and on the ocean currents, patterns of larval dispersal, and location of critical habitat within regional marine systems is extremely scarce. This makes it difficult to determine the optimum size and location of marine reserves and to predict direct fishery benefits in advance. Many fear that the replenishment benefits provided by poorly designed reserves would not outweigh the costs of displacing fishermen. Marine reserves displace fishermen. Closing fishing grounds will displace some fishermen.