The individual coral animals which create much of the reef are sensitive to changes in water quality, as are the microorganisms which form the base of the food chain. A reef habitat that becomes degraded as a result of pollution or siltation will lose its ability to support a diversity of marine life. Protecting reef and other nearshore ecosystems is necessary and challenging. The need for MLCDs Nearshore fishes have always played important roles in the lifestyles of Hawai'i's people. Many of these fishes are commercially valuable, some as food fish and some as aquarium pets.
Recreational fishing is enjoyed by many local residents.
Hawai'i's recent history has shown that the state's growing population can have an adverse effect on nearshore fish populations. Protecting this important resource for the enjoyment of future generations is essential. Ideally, management of the resource should balance the needs of different user groups, but the welfare of the marine environment on which its inhabitants depend must be the most important consideration. MLCDs allow only limited fishing and other consumptive uses, or prohibit such uses entirely. They provide fish and other aquatic life with a protected area in which to grow and reproduce, and are home to a great variety of species.