Fish
White Sturgeon
Acipenser transmontanus · also called Pacific sturgeon, Columbia sturgeon
The biggest fish in any North American river is a white sturgeon: an armour-plated, barbel-chinned bottom-feeder that can grow longer than a car, weigh more than a grand piano, and live past a hundred years. On the Fraser River, anglers hook them, measure them, and let them go.
Overview
Acipenser transmontanus lives along the Pacific coast and in its large rivers from Alaska to central California, with major populations in the Fraser, Columbia, and Sacramento systems. It is a bottom feeder, vacuuming up clams, crayfish, insects, and fish with a tube-like toothless mouth guided by four barbels.
Old, huge, and slow
The record is a Fraser River fish of about 6 metres and over 600 kg. White sturgeon regularly live 60 to 100 years, but females do not spawn until 15 to 30 and then only every few years, so a population recovers from losses only over decades.
Status
Globally Least Concern, carried by healthy lower Fraser and lower Columbia stocks, but the Kootenai River and upper Columbia populations are Endangered, cut off by dams and surviving mainly on hatchery-reared young because their eggs no longer survive in the wild.
White Sturgeon: common questions
How big does a white sturgeon get?
Bigger than any other fish in North American fresh water. The record is a fish from the Fraser River in British Columbia measured at just over 6 metres and estimated at more than 600 kilograms, and nineteenth-century accounts describe individuals heavier still. Fish of 3 metres and 200 to 400 kilograms are still caught and released on the lower Fraser today. Only a handful of freshwater fish worldwide, such as the beluga sturgeon, the Mekong giant catfish, and some other sturgeon and stingrays, reach a comparable size, and the largest of those live in Europe and Asia.
How old can a white sturgeon be?
Commonly 60 to 100 years, and the oldest confirmed individuals exceed a century, aged by counting growth rings in a cross-section of the leading fin ray. This means the very large fish being caught and released on the Fraser today were alive before the rivers were dammed, and some hatched in the nineteenth century. That extreme longevity comes packaged with very late maturity and infrequent spawning, so the biggest, oldest fish are irreplaceable on any human timescale, which is the main argument for strict catch-and-release rules.
Why are some white sturgeon populations endangered while the species is not?
The species overall is buoyed by two large, still-productive populations in the lower Fraser and lower Columbia rivers. But dams have cut other populations off into isolated stretches of river and changed the flow, temperature, and gravel conditions the fish need to spawn successfully. In the Kootenai River and the upper Columbia, sturgeon still spawn but almost none of the eggs or larvae survive, so the wild population is ageing with no young coming through, and it is kept from disappearing only by releasing hatchery-raised juveniles. Both of those populations are formally listed as endangered.
Can you eat white sturgeon or its caviar?
In a few tightly regulated fisheries, yes, but across most of the range the wild fish is fully protected and must be released. Historically white sturgeon were fished hard for their flesh and for caviar, and populations crashed around 1900, which is why the modern rules are so strict. Today the sturgeon meat and caviar sold legally in North America come from sturgeon farms, which raise white sturgeon in tanks and ponds specifically for that purpose and have taken the pressure off wild fish.