Four weeks after an oil spill washed blobs of crude onto Southern California’s coast, surfers have returned to the waves and people play in the surf.

But fishermen still can’t drop lines in the same waters.

California has prohibited fishing in an area that ranges about 6 to 12 miles (9.7 to 19.3 kilometers) off the shores of Orange County since an undersea pipeline leaked at least about 25,000 gallons (94,635 liters) of crude oil into the Pacific Ocean.

State environmental health experts are conducting studies to determine whether shellfish and fish are safe for human consumption — a process expected to take weeks or longer.

Scott Breneman, owner of West Caught Fish, said he still fishes for tuna and black cod well beyond the prohibited area. He said he’s been able to keep selling his catch to restaurants but customers aren’t buying like they usually do at a popular Newport Beach fish market because of concerns about the state fishing ban.

“People assume that local fish is contaminated, and we’re fishing like 90 miles (145 kilometers) off the beach here, a long ways away,” Breneman said, adding that he’s heading out fishing about half as much as usual. “I don’t want to take the resource when I can’t sell it.”

While life along the coast is returning to normal, commercial fishermen and charter operators have been hit especially hard by the closures. Some have joined lawsuits against pipeline owner Amplify Energy of Houston and say their biggest fear is that the spill’s stigma will drive away tourists even after the oily tar that washed up on the beaches is long gone.

Eric Zelien, owner of EZ Sportfishing in Huntington Beach, said clients have cancelled fishing trips even though there are plenty of areas where fishing is allowed. Instead of running daily trips, he’s now taking out groups once or twice a week.

“Most of our out-of-towners are rescheduling their trips. It’s kind of like when COVID first hit,” he said.

“When you hear oil spill, everyone thinks Exxon Valdez,” Zelien said, referring to the tanker that ran aground in 1989 in Prince William Sound, Alaska and spilled millions of gallons. “They panic that the entire ocean is covered with oil and everything is in a state of disrepair.”

Environmental advocates initially feared the worst when they learned about the spill on Oct. 2. The initial estimate was that the spill might have been five times as large as the amount that officials later announced. The Coast Guard said much of the miles-long plume of oil appeared to break up at sea, limiting the impact on sensitive wetland areas and wildlife along the coast.

Beaches in Huntington Beach, known as “Surf City USA,” were closed for swimming and surfing for a week. But surfers there and in nearby Newport Beach quickly returned to the waves after workers cleaned up the sand and local officials tested the water, deeming it safe to enter.

But authorities say eating fish from the water isn’t the same as swimming in it. Fish in oil spill zones can ingest oil, which contains polycyclic aromatic hydrocarbons that can cause cancer if eaten in certain amounts, said Susan Klasing, chief of the fish, ecotoxicology and water section at California’s Office of Environmental Health Hazard Assessment.

She said hydrocarbons break down over time, so there’s no question fishing will resume, it’s just a matter of when.

State officials are collecting samples of shellfish from along the shore and fish off the coast and sending them to a lab for analysis. After the testing is completed, state officials will assess whether the fishing grounds closure can be lifted, she said.

That process took about six weeks after a 2015 oil spill in Santa Barbara County, northwest of Los Angeles.

The spill off Orange County’s coast was caused by a leak in the pipeline that ferried crude oil from three offshore platforms. The cause is under investigation, but federal officials have said the pipeline was likely initially damaged by a ship’s anchor.

Closing fisheries hasn’t only walloped those who make their living that way. It’s taken away a recreational activity for many who live close to the water. Signs are posted at area beaches warning that fishing is off limits, though a handful of people still drop lines off local piers.

Ted Reckas of Laguna Beach said he’s been back to swim and surf at the beach, but since the spill has put on hold lobster diving, which he usually does when the season opens in October.

“The whole thing is upsetting to me — not just the lobster fishing,” said Reckas, who for years has walked from his home to the beach to dive and bring back his catch for friends and family.

He added: “Obviously, that was disappointing, but there’s a whole ecosystem of sea life that is impacted by this. How many oil spills do we need to have before we figure out a better way?”