An attempt to restrict the harvesting of 'opihi to help increase populations of the limpets in Hawai'i failed yesterday in the Legislature.

The measure, Senate Bill 6, would have established a six-month "closed season" for harvesting 'opihi, set a five-year moratorium on taking 'opihi on O'ahu, and prohibited people from harvesting 'opihi from offshore islets, marine life conservation districts and other areas.

Senate Water and Land Committee Chairman Clayton Hee, who introduced the bill, said he was disappointed and would try again next year.

"This bill would have ... restored the 'opihi population to a sustainable level for future generations," said Hee, D-23rd (Kane'ohe, Kahuku).

The measure — originally drafted as a ban on the sale of 'opihi except for jewelry purposes — resurfaced this year after stalling last session. Gov. Linda Lingle in 2006 vetoed a bill to enact a permanent ban on selling 'opihi, citing concerns that it would be difficult to enforce and that it would result in a black market.

Some of the concerns surrounding the current bill, which was held back in both houses, were that the final version included new provisions that did not receive public hearings during the legislative session. There were also concerns about establishing closed seasons for picking 'opihi on the Neighbor Islands.

"I agree certainly on (O'ahu) that there's a big problem with the depletion of the resource, but it's not necessarily the same on all the Neighbor Islands, so I think we need to look at it a little more closely and get the community involved," said Senate Majority Leader Gary Hooser, D-7th (Kaua'i, Ni'ihau).

Hee said the final bill, which would have included an exemption for Native Hawaiian gathering rights, was "more reasonable" than earlier versions and that it was the result of working with 'opihi experts and others.

Chris Bird, a marine ecologist at the Hawai'i Institute of Marine Biology who was among those who worked with Hee on the final bill and supported the measure, said none of the three 'opihi species in Hawai'i is currently at risk of becoming endangered. But he said 'opihi populations and commercial harvests have declined and that 'opihi populations on O'ahu have been "knocked down severely."

Commercial harvest numbers on 'opihi show a decline from about 16,000 pounds harvested annually in 1970 to about 8,100 pounds a year now, according to Bird. Another indicator of the decline in 'opihi numbers has been the exponential increase in the price of the limpets.

State fishing regulations permit the collecting of limpets year-round if their shell diameter is at least 1.25 inches or the diameter of the meat is a half-inch.