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Recent estimates put the upper Columbia River basin population at approximately 1,000 adult white sturgeon. The biology and life history of these fish is similar to other white sturgeon populations. However, there are small differences in timing and temperature for adult spawning, juvenile rearing and years of maturation.
Loucas Raptis artistic image of an adult white sturgeon
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Adult white sturgeon can grow up to 6 metres (19 feet) in length and weigh up to 800 kilograms (1,800 pounds). In the upper Columbia, females likely mature at about 30 years of age whereas males will mature earlier, from their mid teens to early 20's. The sturgeon is noted for its armour-like skin, which covers a cartilaginous skeleton. Its five rows of bony plates, called "scutes", run the length of his body. Adults eat live and dead fish, invertebrates, plants and are truly opportunistic feeders. - (UCWSRI photo)
Initiative team members holding a radio-tagged adult white sturgeon prior to its release
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Adult sturgeon begin spawning during the spring and early summer months and when water temperatures range between 14 to 15ºC (58-60ºF). They prefer sites based on substrate, water velocity, depth and turbidity. One or more male sturgeon releases sperm as one female sturgeon broadcasts her eggs in the water. Females spawn every 4 to 5 years, and only when the conditions are favorable. If the temperature is not right, she will reabsorb her eggs and misses spawning for that year. - (UCWSRI photo)
Border Eddy
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Females may deposit anywhere from 100,000 to 1 million eggs during a spawning season. The eggs are brown in colour and sticky to touch. Once broadcast and fertilized by the male sturgeon, they sink and adhere to the river bottom. The fertile eggs will remain on the river bottom for about a week to ten days before they hatch. Hatching time depends on water temperatures. - (Idaho Dept. of Fish and Game photo)
Enlarged image of white sturgeon eggs
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The young larval sturgeon, once hatched, are typically 1/2 inch in length and are somewhat 'tadpole-like' in appearance. They are now buoyant, which enables the larvae to rise from the river bottom and drift downstream to settle and hide in rearing habitats that protect them from predators. The larvae will remain hidden for up to 25 days while its yolk sac is absorbed. - (UCWSRI photo)
Young white sturgeon larvae
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Juvenile white sturgeon prefer a variety of habitats for their early growth years. Approximately a before hatching, these young sturgeon will have a full set of fins, rays and scutes. They prefer to feed near the river bottom, eating amphipods, mysids (a type of freshwater shrimp), small fish, and a wide range of other organisms. - (David R. Gluns/UCWSRI photo)
Juvenile white sturgeon
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Did you know that the white sturgeon has changed little from its ancestors that first appeared in the available fossil records 175 million years ago? That white sturgeon can live to be over 100 years old? That the white sturgeon Acipenser transmontanus gets its name from the white colouring along its sides and belly? That white sturgeon have four barbels, or "whisker-like sensors" to detect their food? - (UCWSRI photo)
Adult white sturgeon under water
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