SAN FRANCISCO — Two years after imposing a controversial ban on the sale of shark fins, California lawmakers are shifting their activism from the ocean to the jungle with a new effort to slow the alarming killing of African elephants by shutting down the market for ivory.

A bill moving through the Legislature — championed by zoos, museums and environmentalists, while opposed by the National Rifle Association and other hunting groups — would effectively ban the sale of nearly all ivory in California, from antique guns to chess sets, not only in San Francisco and Los Angeles Chinatowns but also among private collectors.

“It is a moral issue. When you see some of the devastation with these animals, to see baby animals standing beside the dead bodies of their mothers, it can’t help but have an emotional impact on us,” said Assembly Speaker Toni Atkins, D-San Diego, a co-author of the bill.

The nation’s most populous state drew international attention — and the ire of some Asian-Americans — in 2013 with its effort to reduce the killing of millions of sharks in the Pacific Ocean by banning the sale of their fins, a popular delicacy in Chinese restaurants.

Supporters of the new measure, Assembly Bill 96, note that scientific studies show poachers are killing 35,000 African elephants a year, or 96 every day, for their tusks, causing the African elephant population of about 500,000 to shrink at alarming rates. The poachers, often connected to terrorist groups, smuggle much of the ivory out of Sudan, Uganda, the Democratic Republic of the Congo and other African nations in violation of international law to China, where it is carved and exported to the United States, Europe and other markets.

“When we tell people about this they can’t believe it. They are moved by it,” said Gina Kinzley, one of two elephant managers at the Oakland Zoo, which is co-sponsoring the bill and has collected 10,000 signatures of support from zoo visitors.

It has been illegal to sell ivory or any elephant parts in California since 1977 — and nationwide since 1990. But federal and state laws still allow the sale of older ivory imported before those dates. As a result, supporters of the bill say, some store owners are illegally labeling new ivory as old, or falsely claiming it came from the fossils of woolly mammoths that went extinct thousands of years ago.

Banning virtually all ivory sales in California, America’s biggest market, would reduce demand and help bring back dwindling elephant populations, they say.

Opponents, however, say the bill will unfairly punish anyone who owns antiques containing ivory, particularly old firearms and other collectibles, which can be worth thousands of dollars.

“There are hundreds of thousands of pieces of ivory in California, and now they want to make it worthless,” said Sam Paredes, executive director of Gun Owners of California. “That’s just wrong. They are going after the legal owners instead of the illegal poachers.”

In June, the bill passed the Assembly by a 62-14 vote. A final vote in the state Senate is expected this week. If it passes, it will go to Gov. Jerry Brown’s desk.

Under the bill, owners of ivory would be given until July 1, 2016, to sell it. After that, sales would be a misdemeanor with fines of up to $50,000 and a year in jail.

Small exemptions would allow people to continue to sell any object more than 100 years old if it contained only 5 percent ivory by volume, and musical instruments such as pianos and violin bows if they contained less than 20 percent ivory and were built before 1975.

The bill — backed by the Humane Society of the United States, California Academy of Sciences and the California District Attorneys Association — also would ban the sale, purchase or importation of any tooth or tusk from an elephant, hippopotamus, mammoth, walrus, warthog, whale or narwhal, along with rhino horns.

Merchants selling ivory are wary of the measure, but reluctant to speak out.

At Wai Hing Chinese Crafts Imports on Grant Avenue in San Francisco’s Chinatown last week, the shelves were lined with ivory objects, including a tusk carved into an Asian village scene labeled “scenery tusk, $55,000, from the 1970s” and another featuring nine dragons for sale for $36,000 and labeled “from the 1960s.”

“I have years of collection,” said the owner, who didn’t provide his name. “What do they want me to do?”

Calling the proposed measure “unfair,” he said state officials should pay him for the merchandise if they are going to ban it.

“Because of something that happens in Africa, why are they picking on us?” he said. “If you want to protest animals being killed, why don’t you protest at the African businesses?”

Nearby at Man Hing Ivory and Imports, ivory chess pieces were for sale in the window. The owner, who also did not want to provide her name, said they came from mammoths.

“I’m getting old. I don’t care,” she said. “They are banning everything — mammoth, bone, hippo, even alabaster. It’s ridiculous. I don’t have the money to fight back.”

Similar bans passed last year in New York and New Jersey but failed this year in Oregon and Washington state over the opposition of gun groups. In Washington, Microsoft co-founder Paul Allen has funded a measure on the November ballot, Initiative 1401, to ban the purchase and sale of nearly all products from elephants, rhinos, lions, tigers, cheetahs, leopards, sea turtles and sharks.

“These are intelligent creatures,” Atkins said. “We shouldn’t just get to see them in a zoo. They should be protected in the wild.”

Paul Rogers covers resources and environmental issues. Contact him at 408-920-5045. Follow him at Twitter.com/PaulRogersSJMN