After 2 1/2 hours out on the ocean, most of that 50 feet below the surface, Randy Fernley slides his small motorboat up to the dock, his multicolored catch sloshing about gently in a set of six deep plastic bins. He cups a few of his tiny charges in his hands, showing off their sleek, jewel-like beauty.

Fernley has collected tropical fish from the coastal waters of Hawai'i for more than 25 years. He keeps a list of about 400 specific collecting sites, and their Global Positioning System readings, to make sure he doesn't hit a particular site too often.

"I'm into protecting the reef because I know that's my life. And I need to have that reef around the rest of my life," said Fernley, owner of Coral Fish Hawaii in 'Aiea.

Fernley's system is intended to ensure that the waters he depends on for his livelihood are not overfished — but it's not something the state requires.

While the islands are valued the world over for their spectacular coastlines and aquamarine waters, the industry of harvesting fish and other marine creatures for home aquariums is largely unregulated here, raising concerns over damage to the environment, the tourism industry and the aquarium fishery itself.

With the notable exception of a five-year-old regulation project along the Big Island's Kona Coast, a $50 permit allows collectors across most of Hawai'i to net as many of a species as they want, wherever they want and whenever they want. That sometimes means harvesting hundreds of thousands per year of a single species from a single bay.

That doesn't sit well with a number of marine biologists, who worry that removing plant-eating fish from near-shore reefs already threatened by urban runoff could lead to an overgrowth of algae.

And Fernley said he is concerned that short-term collectors not counting on next year's catch may be to blame for damaging fragile coral colonies in Kane'ohe Bay in their search for fish.

But among the most unhappy are dive shop owners whose tourist clientele are the lifeblood of the state's economy.

"The dive tour operators make money by getting people out there to see these beautiful fish. And there's been ... a perceptible change. ... It just doesn't look as pretty any more as it used to," said Brian Tissot, a professor of environmental science at Washington State University, who has studied reef populations surrounding the Big Island for more than a decade.

Robert Wintner, owner of the dive shop Snorkel Bob's, which operates trips throughout the main islands, says Hawai'i's reefs are being strip-mined by aquarium collectors.

"There's no place else in America that has what we have. And you know the cookie jar is wide open and the bad kids are robbing it," he said.

Wintner said he and others are mobilizing locally to seek more control over the taking of tropical fish off Hawai'i's reefs.

"What are we doing selling off our reef fish for a million bucks?" Wintner said.

According to state figures, collectors brought in 557,673 marine creatures during the 2004 fiscal year with a reported value of $1.08 million. But state officials believe those figures to be three to five times below the industry's true worth in Hawai'i, which is the nation's biggest aquarium species exporter.

While aquarium fishermen have been required since the 1970s to submit monthly catch reports, many don't fill them out.

Forty-seven percent of the reports required of collectors working in the Islands' biggest collections area, along the west coast of the Big Island, went unfiled between January 1998 and July 2003, according to a 2004 state Department of Land and Natural Resources report.

Enforcement of the reporting requirement, however, is likely to soon be tightened, said Bill Walsh, an aquatic biologist with the Department of Land and Natural Resources at Kona.

Walsh oversees the West Hawaii Regional Fisheries Management Area, a project that includes the state's most aggressive rules for managing of the aquarium industry.

On the last day of 1999, a little more than 35 percent of the west coast of the Big Island became off-limits to collectors after a local coalition of residents pushed a collection control measure through the state Legislature.

In December the department told lawmakers that the number of the most collected fish species, the yellow tang, has since gone up 49 percent along the coast. Within the protected areas, populations of the brilliant lemon-colored fish about doubled, Walsh said.

At the same time collectors are catching more yellow tang with less effort and the fishery is worth more than ever before, he said.

"Even though everybody said, 'Aw, you know, if you ban these areas to us, you're going to ruin the fishery, we'll be out of business, there'll be all these unemployed people' ... it didn't happen," he said.

While local collector Paul Masterjohn of Ocean View objects to how the protected areas were selected, "it sure seems like they are working," he said.