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Marine Life Conservation Districts

One of Hawai`i’s most spectacular natural treasures is the wide variety of marine fishes that occur in the nearshore waters of the state. Over 400 species of inshore and reef fishes inhabit Hawai`i’s coastal waters.

There is remarkable diversity among these fishes. For example, over fifty species of brightly colored wrasses are found among the reefs, along with nearly thirty species of angelfishes and butterflyfishes. Large predators such as jacks and sharks also inhabit the reef area. Each one of the 400-plus species has its own unique role in the nearshore environment.

The coastal waters of the islands feature a number of different habitats, each with its own characteristic marine life. Some fish are at home in sandy bottom areas, others in boulder-strewn waters off rocky shorelines. Tidepools provide “nursery” areas for young fish of many species.

The coral reef is the best known and most impressive of Hawai`i’s nearshore habitats. A healthy reef provides fish with abundant food resources and protection from predators. It is for this reason that reefs attract a great deal of marine life. 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.

Marine Life Conservation Districts (MLCDs) are designed to conserve and replenish marine resources. 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. Fishes in most MLCDs are fairly tame and often show little fear of humans. MLCDs are most popular as sites for snorkeling, diving and underwater photography.

MLCDs were introduced to Hawai`i in the fall of 1967 with Hana`uma Bay on `Oahu. The resulting increase in fish populations was phenomenal, and the bay has become world famous. At the present time there are eleven MLCDs statewide, and other sites are being considered as well.

Regulations in MLCDs

Since the purpose of MLCDs is to protect marine life to the greatest extent possible, the taking of any type of living material (fishes, eggs, shells, corals, algae, etc.) and non-living habitat material (sand, rocks, coral skeletons, etc.) is generally restricted, if it is permitted at all. This fosters non-consumptive uses of the area, such as swimming, snorkeling and diving.

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