Colloquially called the “king of the rivers,” the white sturgeon (Acipenser transmontanus) is a formidably armored inhabitant of both fresh and saltwater. Spending most of its life in slow moving, brackish waters, the white sturgeon swims upstream to spawn, much like salmon or striped bass. This massive fish moves up and down the West Coast ranging from Central California north to the Aleutian Islands, and sometimes stops over in San Francisco Bay—and when it does, it is extremely exciting. If you are ever fortunate enough to catch a glimpse of a sturgeon in our Bay, you will be amazed at how its dinosaur-like appearance calls another era to mind.
The white sturgeon evolved over 260 million years ago, and its exoskeleton-like frame makes it wildly unique and hard to ignore. Possibly because of this “protective armor,” the sturgeon grows at a much slower rate than most fish, typically reaching 6 feet by 25 years of age. Marine biologists also believe that the rate at which a sturgeon grows is based on the temperature of the water where it is living. (What might this mean with global climate change?) With its record-setting size of 1,500 pounds and 13 feet long, the white sturgeon is considered the world’s largest freshwater fish. On top of that, the white sturgeon has taste buds on the outside of its mouth that allow it to judge whether or not food is edible before it consumes it. Imagine tasting everything that passed by your face! After it determines if the item is delectable or not, the white sturgeon suctions its food through its proboscis-like, toothless mouth.
Sadly, the white sturgeon has lost access to many of its natural spawning rivers due to dams and drought, leaving populations landlocked or stuck at sea. The lack of freshwater flowing into San Francisco Bay also changes the composition of the water in the estuary and makes it difficult for sturgeon to survive. On top of all that, commercial and recreational fishing have been detrimental to dwindling populations of sturgeon already facing hardship. But there is hope! Conservation efforts are underway to keep fresh water rivers open for sturgeon to spawn and move freely. The California Department of Fish and Wildlife has also imposed size restrictions on recreational fishing and new management practices have been undertaken to keep waterways accessible to fish and humans. Let’s not let this dinosaur become extinct.