SAN FRANCISCO — In the largest bust since a ban went into effect in July, more than two thousand pounds of shark fin were seized from a San Francisco fish vendor.

Michael Kwong, owner of Kwong Yip Inc. at 1220 Howard Street in San Francisco, was cited Jan. 29 after investigators from the California Department of Fish and Wildlife discovered 2,138 pounds of shark fin for sale inside his business, said CDFW Lt. Patrick Foy.

The discovery was the largest seizure to date “by a literal ton,” a volume of product Foy said “thousands” of sharks were killed to produce. Kwong has been one of the leading critics of the ban.

The bust marked the CDFW’s most significant citation since the shark fin ban went into effect July 1, two years after Gov. Jerry Brown signed a law making it illegal to “possess, sell, offer for sale, trade, or distribute” the cultural delicacy. Foy said only a handful of citations have been written among the 66,000 fish vendors under the CDFW’s supervision and never for anything more than about 10 pounds of shark fin.

Officials found their way to Kwong after catching Emeryville restaurant Hong Kong East Ocean Seafood at 3199 Powell Street selling shark fin soup Jan. 27, Foy said. Investigators cited the restaurant and tracked the origin of its inventory to Kwong Yip, whose 2,138 pound supply is currently undergoing further analysis to verify that all of it is shark fin.

Despite the massive quantity of shark fins found in Kwong’s warehouse, the 42-year-old man was cited and released and no arrests were made. While typical violators of the ban receive a citation and fine of about $1000 for possessing restaurant-level quantities of the product, Kwong will receive his penalty from a judge at a later date.

“A lot of people are wondering why we didn’t take him to jail,” Foy said. “But it’s still a misdemeanor level offense — he just had an extremely large quantity, like nothing we had ever seen before.”

Officials estimate that between 26 and 73 million sharks are killed worldwide every year to meet the high demand for fins and say populations will continue to decline rapidly so long as unsustainable practices persist. The ban has been lauded by conservation groups as a way to boost ocean health but shunned by the Asian community culture with its centuries-old tradition of serving shark fin soup at weddings, banquets and other ceremonial events.

“California’s shark fin ban is critical to ending the cruel practice of shark finning, and to protecting sharks and ocean ecosystems for future generations,’ said Jennifer Fearing, California senior state director for the Humane Society of the United States. “But the law only helps sharks if it is strongly enforced. This important bust by California’s ‘thin green line’ sends a strong message that breaking California’s animal protection laws has consequences.”

According to Fearing, Kwong is part of an association, the Asian American Rights Committee of California, whose members recently sued to challenge of the constitutionality of the ban. The group dropped its lawsuit in light of Kwong’s citation, Fearing said.

The lawsuit’s dismissal comes less than a week after the National Marine Fisheries Service announced its support for the ban and concluded that several state laws prohibiting the sale of shark fins are not pre-empted by federal law. A second lawsuit, filed by a separate group of shark fin merchants, is still pending in federal court.

Neither Kwong nor representatives for the Asian American Rights Committee of California could be reached for comment Friday.

Staff writer Paul Rogers contributed to this report. Contact Erin Ivie at eivie@bayareanewsgroup.com.