A study by the U.S. Fish and Wildlife Service has officially confirmed sturgeon spawning in the San Joaquin River.
The study, spurred by reports of anglers fishing sturgeon in the river from the California State Department of Fish and Wildlife, verified spawning on the San Joaquin in 2011 and 2012.
The study showed that white sturgeon use the river for spawning during wet and dry years.
Anglers and state wildlife officials noted that sturgeon caught during March and April expel eggs during handling, showing that spawning was happening nearby. State fish and wildlife wardens told federal officials that poachers went after spawning sturgeon on the San Joaquin near Grayson.
The roe of spawning sturgeon can be processed into caviar, fetching $150 a pound on the black market, according to state officials.
In April 2011, federal biologists placed mats in spots where sturgeon were reported swimming. Biologists documented fertilized white sturgeon eggs on the mats in both 2011 and 2012.
"Most work with sturgeon has taken place in the San Francisco estuary and in the Sacramento system, because sturgeon have for decades been very rare in the San Joaquin system," said Marty Gingras, program manager in the state's Bay-Delta Region. "This evidence of spawning in the San Joaquin will help the two agencies protect and manage sturgeon habitat there."
California's green and white sturgeon mature late, spawn infrequently and are dependent on certain environmental conditions, according to a U.S. Fish and Wildlife press release.
Green sturgeon are federally threatened species and can't be sportfished.
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