Artificial reef could raise fish population
The state, a federal program and Haseko would collaborate on the submarine habitat
The state wants to bring more fish to Oahu, but first it has to hook the community with its plan.
The state Department of Land and Natural Resources’ fifth shallow-water artificial reef would be build off the coast of Ewa if it clears permits and receives favorable community feedback.
The administrators say the reef would encompass 224 acres and benefit commercial and recreational fishers by increasing the marine habitat where there is now only a sandy sea bottom.
Plans are to establish the reef about a mile and a half from shore, near Oneula Beach Park.
Paul Murakawa, coordinator of the Artificial Reef Program in the DLNR’s Division of Aquatic Resources, said the reef will increase the diversity of reef fish in the area and raise fish biomass – the pounds of fish.
Recreational divers could venture out and commercial fishermen could set their nets over the reef, Murakawa said. The reef will begin attracting fish immediately but will take four to five years before increasing fish biomass significantly.
Murakawa said the reef will not affect currents or prevent beach erosion.
One downside would be that recreational Kona crab net fishers would lose flat areas in the ocean to cast their nets, said William Aila, the harbormaster of Waianae Small Boat Harbor. But other than that, he supports it.
„Any time you put a structure in an area that is flat and barren and you make that structure horizontally orientated, you create a habitat for new fish to occupy,” he said, adding that artificial reefs jump-start the regeneration process for coral reefs that were damaged by Hurricanes Iniki and Iwa.
A reef high and large enough to prevent spear fishermen from getting to the middle would also create an artificial reserve that continually produces fish like the artificial reef off Waianae, Aila said.
Many popular fish at the state’s Waianae artificial reef are the red weke, mu, menpachi, aweoweo, kole, uku and papio caught by commercial and recreational fishers. Artificial reefs also attract scuba divers and snorkelers.
DLNR Director Peter Young said the artificial-reef program is something his agency would like to expand in areas where the natural habitat is not enough.
Haseko, a developer building the Ewa marina and housing community, has agreed to help the state install the reef. The company was required to build a 1-acre reef as part of its permit to dredge a marina, but state officials adopted the plan, expanding it to make it more effective, Murakawa said.
Haseko will fund the state’s reef with $150,000 for the first acre of the project, a Haseko spokeswoman said.
Previously, old cars, barges and other structures have been used to create artificial reefs, but the Ewa reef will be made of thousands of concrete blocks, 4 by 8 feet and 6 inches thick. Shaped like a Z, the blocks have concrete feet on opposite ends to create cavities beneath.
The concrete outlasts car bodies, which disintegrate over time, Murakawa said.
About 500 of the blocks will be dropped into 60- to 120-foot-deep water for the first installment, continuing at about an acre a year for the next 20 years.
The Federal Aid’s Sport Fish Restoration Program is partially funding the program with money from fishing tackle and motorboat taxes. Donated concrete helps reduce the cost of the project, while every state dollar is matched by $3 from the federal program.
Officials have spent three years developing the project, delaying it once to relocate the site in compliance with federal recommendations. Diving for an alternative location with a flat limestone bottom and where the new reef would not damage existing coral has taken some time, Murakawa said.