10-acre artificial reef proposed for Hawaii

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The barren seafloor off the coast of ‘Ewa could become home to coral and other marine life if an artificial reef project is approved.

The proposed 108-acre artificial reef is a massive expansion of the 1.1-acre reef replacement required for developer Haseko’s permit to build the Ocean Pointe Marina.

Haseko instead will spend $150,000 to work with the Department of Land and Natural Resources to build an artificial reef that should provide more protection for the fish.

“We need more artificial reefs. That is an excellent idea,” said Joseph “Mac” McNichols, owner of the Ho-nolulu Scuba Company.

McNichols, who lives in Ocean Pointe, said that right now, there’s really only one area off the ‘Ewa coast that has abundant marine life. “It’s kind of devoid of reef down there. There’s ‘Ewa Pinnacles, but other than that, there’s really not too much going on there.”

Elsewhere off O’ahu, boats and planes that have been sunk to create artificial reefs have become some of the best diving sites.

“They attract lots of life because the fish have somewhere to hide,” McNichols said, adding that it’s not uncommon to see turtles or spotted rays when he’s scuba diving near the wrecks.

The artificial reef proposed by Haseko and DLNR would use concrete Z-shaped blocks to attract coral in an area that now is barren limestone with a thin sand veneer.

Paul Murakawa, an aquatic biologist for DLNR’s Division of Aquatic Resources, said that if the permits are approved, the area could become a thriving coral reef with damsel fish, goatfish and surgeon fish, along with predators like papio, ulua and uku.

Some sort of artificial reef is required for a permit from the Army Corps of Engineers because Haseko plans to dredge a channel for their marina and will destroy 1.1 acres of habitat.

However, the Aquatic Resources Division thought that was too small to have much benefit. “We asked that the artificial reef would be harder to exploit and the fish would be protected more,” Murakawa said.

In a small reef, “people could go in with nets and take a whole school of fish very easily,” he said. “If it’s a larger area, fish could run to other parts of the reef and seek shelter.”

If approved, the Kalaeloa artificial reef would be the sixth in the state. Four have been created off O’ahu and one off Maui.

Sam Kahng, an associate professor of oceanography for Hawai’i Pacific University, said many people see benefits to artificial reefs, although some will argue that it’s not real or that it’s replacing a sand environment that is already there.

There also is an argument over whether the artificial reefs just attract the existing fish population or if they support growth of a larger fish population.

“In general, if you’re adding additional habitat, you’re adding to the productivity and the biomass of the habitat,” he said.

At the very least, the reefs have recreational value, since tourists can visit them and see a wide variety of fish.

Kahng said it’s likely that a reef community will follow if the state stacks the concrete blocks high enough so they won’t be scoured by sand.

The blocks will attract coral, and fish gravitate toward physical structures they can hide next to, hunt or eat algae and hunt invertebrates.

“That’s, to some extent, considered a good thing,” he said.

Recreational boaters are somewhat ambivalent. The nearest harbor is at Ko Olina Marina, which doesn’t anticipate any significant impact.

However, commercial fishers worry that it might interfere with their fishing.

Joe Soares, who operates Hawai’i Offshore Fishing Charter, said he doesn’t see much point in an artificial reef in that area.

“I think it’s doing pretty good by itself. The fishing is pretty decent,” he said. “The only reason that nobody dives out there is because it’s murky.”

Soares said the reef could help commercial fishing in the area if it’s in shallow enough water. “Otherwise it’s not going to help us,” he said.