Objectives of management In the United States, the Magnuson-Stevens Act provides a mandate to manage U.S. sheries at sustainable levels for the overall benet of the nation. This act also serves as a signpost to the world that sustainable sheries management is of paramount importance for all humankind. The exact level of sustainability is, however, a moving target. The maximum production resulting from the activities of sheries depends on many factors. The most important of these factors is the carrying capacity of our environment. Thus actions that help maintain or even increase the carrying capacity of our sheries would be of benetas long as the increase in carrying capacity does not result in the detriment of something else (e.g., destroying mangroves to accommodate more shrimp mariculture farms).