Environmental groups are usually in the business of protecting marine life, not suggesting that the public eat it. Yet, the Nature Conservancy is doing just that: trying to get California groundfish on the radar of home cooks, 13 years after the group took extreme measures to protect it.

In 2006, the crash of the groundfish population — bottom-dwelling fish like petrale sole, chilipepper rockfish and sand dabs that used to be common on Bay Area tables — led the Nature Conservancy to buy up 13 fishing permits and some California fishermen’s vessels. The state worked with a handful of the state’s remaining groundfish trawlers to change how they fish and protect vulnerable habitat. Now that groundfish populations have rebounded, the Nature Conservancy wants the public to know they’re OK to eat again.

“This is such an important story for anyone who likes seafood on their menus,” said Kate Kauer, director of the California fisheries program for the Nature Conservancy, which is based in Arlington, Va. “The missing piece is ensuring that it’s economically viable, and that the fishermen who are doing all these great practices are really seeing the benefits, and that people want to buy groundfish again.”

In July, the Nature Conservancy finished transferring the remaining fishing rights — which are now managed under a quota system — to community trusts at four California fishing ports, including Half Moon Bay and Monterey Bay, which can sell the quota back to local fishermen. The only problem is that in the intervening years, restaurants and home cooks got used to buying cheaper farmed fish imported from Asia. Most people fell out of the habit of eating buttery sablefish, meaty rockfish and tender petrale sole, which are now difficult to find outside of a few seafood markets and old-school restaurants like Duarte’s Tavern and Sam’s Grill.

“Here we have this amazing resource right at our front door,” said Lisa Damrosch, executive director of the Half Moon Bay Commercial Fisheries Trust and part of a fourth-generation groundfish trawling family at Pillar Point Harbor. “Theoretically, everyone in the Bay Area wants to get it. But they’re not able to get it or to trust they’re getting it.”

Damrosch gets frustrated that so little local fish is eaten in a region that otherwise prizes fresh and local food. Eighty percent of the seafood Americans eat comes from outside the country, mostly Asia, according to the National Oceanic and Atmospheric Administration, while the majority of wild domestic seafood is exported.

In April, Damrosch, her fisherman brother Geoff Bettencourt and fellow Half Moon Bay groundfish fisherman Steve Fitz purchased the Pillar Point seafood company Morning Star Fisheries, as a place to offload their own fish and cut out the middle man.

“We had to do that to survive,” said Bettencourt.

Named for its habitat near the ocean floor, the groundfish category includes more than 90 species of fish. Trawling, the main fishing method used to catch them, is criticized because it involves pulling a net along the seafloor, which can cause habitat destruction and capture unintended bycatch.

Bettencourt and other fishermen have made adjustments to their gear for lower impact, including lightening their nets and changing the mesh so that juvenile fish can escape. In 2011, Fitz, Bettencourt and fishermen in Morro Bay and Fort Bragg partnered with the Nature Conservancy to create the California Groundfish Collective. Bettencourt acknowledges it was an unusual move in a competitive industry that doesn’t usually trust environmental groups.

The Nature Conservancy provided technology so the fishermen could share data to figure out how to target more of the fish they wanted to catch and less of the fish they should avoid, and to stay out of sensitive habitat like rocky areas in more than 23,000 square miles off of California, Kauer said.

“The Nature Conservancy influenced change,” said Bettencourt. “They incentivized guys to fish in a better way.”

In 2014, groundfish populations had rebounded and the Monterey Bay Aquarium’s Seafood Watch program gave petrale sole, sand dabs, sablefish and several types of rockfish the green light for sustainability. Still, the fishery has struggled to regain footing. When it collapsed, California ports lost a lot of infrastructure that went along with it, such as companies that offload and process fish. There are currently no industrial ice machines at the Monterey harbor that fishermen can use to fill their holds.

That will be changing next year with new infrastructure investments planned for the harbor, said Sherry Flumerfelt, executive director of the Monterey Bay Fisheries Trust, which has groundfish quota transferred from the Nature Conservancy available to local fishermen.

“It’s such an important part of the history and the culture and the identity of Monterey Bay,” said Flumerfelt.

Each year, the federal government sets quotas for the total poundage of different species of groundfish that can be fished on the entire West Coast. Commercial fishermen purchase what are called Individual Fishing Quotas that represent a percentage of that total amount. If they catch more than their quota, they must buy more, usually via an online marketplace. (They also must pay for a federal observer to come along on fishing trips to monitor what they catch and offload.)

Quotas are often bought up by larger, wealthier fishing ports in other states, like Newport, Ore., one reason the trusts were established — to make sure fishermen in smaller ports like Monterey regain access to the fishery, said Flumerfelt.

To promote groundfish, Flumerfelt’s organization helped organize a restaurant week in Santa Cruz this summer, when chefs served local fish, with menus featuring the names of the species, vessel and fishermen.

Pillar Point harbor in Half Moon Bay scheduled a seafood festival Sunday in conjunction with Half Moon Bay Commercial Fisheries Trust. Restaurants will be there to cook up local fish, along with local fishermen like Bettencourt.

The trawler still struggles to find a market for his groundfish. Last month, he spoke on the phone while heading back from a great fishing trip that he had to cut short because he had orders for only a limited amount of fish.

“We could produce more, but the market can’t stand it because they’re full of all that other (imported) fish,” he said. “That’s what seems broken to me.”

Tara Duggan is The San Francisco Chronicle’s assistant food editor. Email: tduggan@sfchronicle.com Twitter: @taraduggan