Dried totoaba bladders like these sell for thousands of dollars in China.

Mexican authorities say the leader of a drug trafficking group accused of smuggling fish was arrested in Baja California last week.

The suspected cartel associate Oscar Parra Aispuro, or “El Parra,” was captured with two bodyguards last Thursday. He’s accused of illegally trafficking in the totoaba fish. The black market for the fish is a leading threat to the nearly-extinct vaquita porpoise.

“State police captured the dangerous gang member and drug trafficker known as ‘El Parra,'” says Sergio Trochez, spokesman for Baja California’s Public Safety Ministry. “He was caught with weapons, tactical gear, radio communication equipment and drugs.”

Police say the trafficker has ties to the Sinaloa drug cartel and allegedly ran a smuggling operation selling totoaba fish bladders for thousands of dollars on the black market in China.

The nets used to catch totoaba are deadly to the endangered vaquita porpoise.

The small dolphin is considered the rarest marine mammal with as few as 15 remaining in Mexico’s Sea of Cortez.