By Marty Graham
SAN DIEGO (Reuters) - U.S. border officers in California are seizing a large number of smuggled bladders from an endangered fish that are prized for use in Chinese soups, with seven people charged since February in connection with the trade, authorities said on Wednesday.
The bladders of the totoaba macdonaldi fish are smuggled across the border from Mexico, with each organ fetching $5,000 on the U.S. black market and over $10,000 in Asia, federal prosecutors said. The fish is found in the Gulf of California between the Mexican mainland and Baja California.
The totoaba's swim bladder is a tube-shaped organ that fills with gas to help control the buoyancy of the fish, which the U.S. Attorney's Office said can grow over 6 feet long, weigh up to 220 pounds (100 kg) and live to the age of 25.
The United States listed the totoaba as an endangered species in 1979 and they are also protected in Mexico. Officials said the fish's bladder was seen in some Chinese cuisine as a prime ingredient in a type of soup and prized for its supposed ability to boost fertility and circulation.
"The Mexican fish is very similar to a Chinese species of fish that was eaten to extinction," U.S. Fish and Wildlife Special Agent in Charge Jill Birchell told reporters.
The totoaba spawn in the spring, and during that time they swim to shallow waters at the mouth of the Colorado River on the north end of the Gulf of California and fishermen begin to go after them, as the black market trade in the animal's swim bladders heats up, officials said.
"The shores are littered with carcasses because catching them (totoaba) is illegal and they don't want to move the entire fish," Birchell said.
In the latest case that led to criminal charges, a U.S. Customs and Border Protection officer inspecting a car at the Calexico-Mexicali port of entry, about 130 miles east of San Diego, found 27 totoaba bladders hidden under floor mats in the back seat of a car, U.S. prosecutors said in a statement.
Federal agents returned all but one bladder to the driver, Song Shen Zhen, 73, of Calexico, California, officials said.
"The officer thought something was fishy," said U.S. Customs officer Billy Whitford.
Federal agents followed Zhen to a rented house in Calexico. When they returned to the home with a search warrant, they found over 200 fish bladders spread out on floors and counters to dry, officials said.
They also found packing material and ledgers for other shipments that went to China and Hong Kong, said U.S. Attorney Laura Duffy. In all, the bladders taken from Zhen could have fetched more than $3.6 million in foreign markets, prosecutors said in the statement.
Zhen was charged last Friday with smuggling and unlawful importation of wildlife. If convicted, he faces up to 20 years in prison.
No attorney for Zhen was listed in court documents, and he could not be reached for comment.
Six other people have been charged since February in connection with the smuggling of the endangered fish bladders, in cases that authorities say are not related. In two of the cases, the defendants are still at large.
(Editing by Alex Dobuzinskis and Peter Cooney)