Three 17-year-olds from Newport Beach could face charges for the crime of fishing just a few miles from their homes.

That is how seriously state officials and local environmentalists regard a 3-year-old no-fishing zone in effect off Laguna Beach.

The no-fishing area off the Laguna Beach coast is the only such marine reserve in Orange County and part of a network of zones in California waters that form the nation’s most expansive marine reserve.

The long-range goal is to restore fishing, in part by letting animals return to depleted areas without interference from anglers. But the no-fishing zone has sparked conflicts with dozens of people, including some who fished in the area without knowing the rules and others who were poaching for profit.

Laguna Beach once was known as a great spot for fishing, with an abundance of abalone and rocky, fish-filled caverns and places such as Totuava Cove, which was named for a 600-pound fish that was found near Thousand Steps beach. Sport fishermen roamed the coasts and commercial fishermen dropped nets near the region’s many reefs.

But decades of fishing depleted the ocean off Laguna, prompting environmentalists and others to push lawmakers to turn that stretch of ocean into a marine reserve, an underwater park of sorts that would make it illegal to take anything from the protected waters. Three years ago, state and federal lawmakers declared the area a no-fish zone.

Ocean activists like Mike Beanan, a member of Laguna Bluebelt, which was instrumental in pushing for protected beaches in his hometown, said the unique topography of the ocean floor off the 7.2-mile Laguna Beach coast – the same features that made it a great spot for fishing – make it a prime spot to rebound.

“We have a rocky bottom,” he said. “Because of that, you have tide pools and hundreds of caves that function as nurseries for fish and shellfish. Offshore, we have kelp forests equivalent to underwater redwood forests. They can grow to 120 feet high and grow at a rate of two feet a day. …

“Rather than a ‘no fish’ zone, we have a ‘grow fish’ zone,” Beanan said.

But the incident with the three Newport Beach teens, which took place earlier this month, is part of a broader pattern in which a few anglers and poachers still sometimes try to take fish from the reserve.

In the case of the three teens, state Fish & Wildlife officials say they were repeat offenders and were blatant in their disregard for the no-fishing rules.

The three were spotted by residents and others as they fished from a Boston Whaler, about 200 yards off Cress Street Beach.

Fish & Wildlife Warden Nick Molsberry said they told him they knew they were fishing in a restricted area and had caught and released at least a dozen bass. Molsberry cited them for fishing in a marine reserve and confiscated their fishing gear.

Before the Cress Street incident, Laguna Beach lifeguards contacted the three via radio twice, when they anchored a few hundred yards just south of Main Beach. And before that, they’d been contacted by a Marine Protection Officer who had issued them a warning from a stand-up paddleboard.

If charges are filed, the three teens could face misdemeanors, and possible fines could range in the hundreds to thousands of dollars, Molsberry said.

“The biggest problem was their disregard and that they were repeat violators,” said State Fish and Wildlife Warden Ryan Cordero, who has patrolled Orange County’s coastline five years.

“We like to educate as much as we can by giving warnings, but this was blatant. This is probably one of the most significant violations I’ve encountered there.”

Despite the awareness efforts, dozens of people have been cited. Most came from inland communities, had fished the areas before and were unfamiliar with the law.

Typical violations are those in which people say they did not know about the state protection and apologize for their mistake. Most violations are infractions.

Other violations are intentional. In May 2012, a fisherman was cited for poaching 47 California spiny lobster at Heisler Park. State Fish and Wildlife submitted their report for prosecution. The man was fined more than $20,000 and spent a week in jail.

In 2013, state wardens contacted thousands of people but issued only 10 violations. This year, Cordero estimates he’s issued about five violations.

Enforcement is done along Laguna’s coastline on foot, by truck and by boat day and night. Laguna – once the go-to for spear fishing – has gone quiet.

Laguna Beach lifeguards, the city’s marine protection officer and tidepool docents spoke with more than 25,000 people this year about appropriate conduct in the protected areas. In 2014, warm weather drew an estimated 5 million people to Laguna’s beaches.

“There is always a small band of poachers in every community, and that is the same for our marine reserve,” said Ray Hiemstra, associate director of OC Coastkeeper, an environmental group. “These criminals commit their crime for a variety of reasons, stealing lobsters or abalone to sell for profit for instance, or for the thrill of challenging the rules and testing the authorities’ willingness to enforce them.”

It’s not yet clear if the project is working – Hiemstra said hard data on the topic will be made public next year – but anecdotal information suggests the no-fishing zone is reviving the fish population off Laguna.

“Word from the regular divers and swimmers … is that they are seeing more and bigger fish than they have in a long time,” Hiemstra said. “Even with the effects of poaching, 95 percent of the take of marine life in the Laguna Beach Reserve has ceased and the entire ecosystem is rebounding, not just fish populations.”

A year after state protection was put in place in Laguna, Rick Erkeneff, chairman of the Surfrider Foundation in south Orange County, witnessed a poaching incident that he said is indicative of a healthier ecosystem.

Erkeneff saw a fisherman attempt to load his truck with 125 pounds of black sea bass he’d just speared off Salt Creek Beach in Dana Point, just south of the Laguna reserve. The incident would have been a violation in any location, because the black sea bass is an endangered species and federally protected.

But the existence of such a fish, Erkeneff said, was a sign of improving ocean health.

“These are indicator species that live 200 years,” Erkeneff said.

Contact the writer: 714-796-2254 or eritchie@ocregister.com or twitter: @lagunaini