SACRAMENTO — Handing a victory to wildlife and conservation groups and a defeat to Chinatown shopkeepers in San Francisco and Los Angeles, Gov. Jerry Brown on Sunday signed legislation banning the sales of virtually all elephant ivory.

Assembly Bill 96, by Assembly Speaker Toni Atkins, D-San Diego, will make it illegal after July 1 for anyone to sell nearly any kind of elephant ivory or rhino horn in California, including that in antique guns and chess sets, whether at a store or from a private collection.

Co-sponsored by the Oakland Zoo, which collected 10,000 signatures from visitors, the bill is similar to a law Brown signed in 2011 banning the sale of shark fin soup, in that it aims to use California’s economy to slow the decline of an iconic species.

Scientists estimate that poachers are killing 35,000 African elephants a year — or 96 every day — for their tusks, causing the 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.

It has been illegal to sell ivory or any elephant parts in California since 1977 — and nationwide since 1990. But federal and state laws 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, will reduce demand, they say.

“By signing AB 96, Gov. Brown has closed a loophole in a law he signed three decades ago and confirms California’s commitment to joining the global momentum to save these iconic species,” said Jennifer Fearing, a lobbyist for the Humane Society of the United States.

Unlike the bill banning shark fin soup, the ivory bill did not have widespread opposition, although several gun groups opposed it, saying it would ban gun collectors from selling antique firearms with ivory handles.

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

The bill, supported by the California Academy of Sciences and the California District Attorneys Association, passed the Assembly 62-14 and Senate 26-13.

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

In Washington, Microsoft co-founder Paul Allen has funded a similar 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.

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