A marine reserve around Kaho'olawe is feeding bottomfish into the surrounding waters of Maui County, showing the value of modern-day Hawaiian fishing restrictions, or kapu.

A new study prepared by the University of Hawai'i's Hawai'i Undersea Research Laboratory and Oceanic Institute tracked the movements of the prized pink snapper, or 'opakapaka, from reserve waters, where the fish were fitted with radio tags, into open fishing zones outside the reserve.

Previous studies had shown that bottomfish were more abundant inside the reserve than out.

"When the population grows to the point that fish begin leaving reserve waters to feed in surrounding areas, it indicates the reserve is helping to restore the marine ecosystem inside and outside of the reserve boundary," said Sol Kaho'ohalahala, executive director of the Kaho'olawe Island Reserve Commission, which manages the island and its marine protected area.

The protected waters around Kaho'olawe are well-suited for providing a boost to the Maui County fisheries and prove the value of no-fishing zones in protecting fish stocks and neighboring fisheries, said Chris Kelley, marine biologist with the Hawai'i Undersea Research Laboratory.

"The Kaho'olawe Island reserve is probably one of the best bottomfish reservoirs in the main Hawaiian Islands," Kelley said.

Researchers are finding increasing evidence for the benefits of no-fishing zones. Five years after setting aside 37 percent of the Big Island's Kona coast in a series of reserves, a survey found there are more fish being caught in the remaining areas than were being collected in the entire coastline before.

"Collectors are collecting more fish and making more money. Dive companies say they are seeing more fish. Everybody's happy," said Rick Gaffney, a representative of recreational fishers and a new member of the Western Pacific Regional Fishery Management Council.

"The Kaho'olawe study merely supports the results of other studies that show the value of marine protected areas," Gaffney said.

The Kaho'olawe reserve has two zones. Entry without a permit is prohibited in Zone A, from the island's shore to water 180 feet deep. Zone B goes from that point to two miles from Kaho'olawe's shore, and here bottomfishing is prohibited and trolling is allowed two weekends a month.

Oceanic Institute biological oceanographer David Ziemann said for the study, a research crew caught 'opakapaka in the reserve and performed minor surgery, implanting a radio transmitter into each animal's abdomen. The fish were anesthetized before the operation and their incisions were closed with a single stitch. They were kept in a tub of water until they recovered from the anesthesia and could be released.

Researchers deployed underwater listening sites outside the reserve, which tracked those fish that swam into the free-fishing zone. They were tracked for two months. Eighteen fish were fitted with acoustic tags, and the listening devices eventually heard 12 of them.

The results showed that fish swam out of the reserve waters, and some also swam back in.

"Overall we can say that at least 25 percent of the tagged 'opakapaka population were in the open fishing area with sufficient frequency that they could be collected by fishermen," Ziemann said.

The animals appeared to employ a typical day-night feeding pattern, moving into waters roughly 600 feet deep by day and coming upslope to shelves 350 to 400 feet deep at night.

"One of the purposes of the reserve is to replenish the depleted resources outside the reserve, and from what this initial survey has shown, it is working. The reserve is doing its job, and the waters of Kaho'olawe are an oasis inside a desert," said Dean Tokishi, an ocean resources specialist with the Kaho'olawe Island Reserve Commission.

Kaho'ohalahala said the reserve staff is thrilled with the results, although the protection of fish stocks are only one justification for the marine reserve.

"The submerged lands and waters surrounding Kaho'olawe also contain unknown quantities of unexploded ordnance that present a public health and safety hazard," he said.

There is little dispute that bottomfish resources in the main Hawaiian Islands are depleted. The average 'opakapaka caught in the main Hawaiian Islands is just 4 pounds, according to data from the National Marine Fisheries Service, while the species in the less heavily fished Northwestern Hawaiian Islands averages 10 pounds.

Kelley said that while other tagging studies suggest the mature bottomfish may roam far and wide within the Hawaiian archipelago, the fishery could benefit from additional closed zones.

"My personal feeling is that there should be a reserve for every bank," he said. Kaho'olawe takes care of Maui County, but he believes there should be a significant reserve for the Big Island, for O'ahu, for Kaua'i, and for Ni'ihau and Ka'ula Rock.