White Sturgeon, Acipenser transmontanus
- White sturgeon have a slow growth rate but they are very long-lived and have the opportunity to spawn multiple times.
Sturgeon spawn in rivers, and can release anywhere from 100,000 to more than one million eggs at a time.
The largest sturgeon caught in the last forty years in San Francisco Bay weighed 468 pounds.
Sturgeon evolved over 260 million years ago.
In 1887, 1.65 million pounds of sturgeon were harvested from the Bay; in 1917, the fish had been so depleted that the commercial fishery collapsed.
Sport fishing was legalized in 1954
While the animal’s protective armor does make it “the King of the rivers” according to Biologist Melissa Schouest, their most common threat are people, both through fishing and through human-made dams on rivers, which decrease spawning habitat.
Lack of healthy water flow to San Francisco Bay has a negative impact on sturgeon. Nine out of the 10 major tributaries are currently blocked by large dams for water storage, diversion and flood control. These reductions in freshwater flow harm the overall health of the estuary and watershed ecosystems and have degraded its ability to support white sturgeon and other native fish.
Aquarium of the Bay and its partner, The Bay Institute, are working hard to heal the waters of the Bay so that sturgeon can thrive again.
At record-setting sizes of more than 1,300 pounds and 13 feet long, White Sturgeon earned their title of the largest freshwater fish in North America. Like salmon, white sturgeon are anadromous, meaning they can thrive in freshwater and salt water conditions.
Instead of having scales, white sturgeon have five rows of scutes, a sort of natural body armor of hard plates, covering their body.
White sturgeon have small, beady eyes, and limited vision. The animal relies on its barbels, which are often described as “whiskers,” on the side of its mouth to help them sense and feel out food. They use their proboscis mouth, which is akin to an elephant’s trunk, to help them suck food out of the sand.
Sturgeon skull plates and scutes have been found in Native American middens, or dumping grounds, in San Francisco Bay, the Sacramento-San Joaquin Delta and Elkhorn Slough areas.