Rivers and lakes are populated with pike, walleye, whitefish, rainbow, speckled, brown trout, and sturgeon. In April, they netted alewife, sturgeon and salmon. Another use is a pond for growing crabs, whitefish and sturgeon for caviar. There are also many species of tree frogs, and fish such as sturgeon and paddlefish. The Nechako is home to a number of fish species, including salmon and sturgeon. The Caspian fishing industry concentrates on the dwindling stocks of sturgeon and beluga. The Caspian fishing industry is concentrated on the dwindling stocks of sturgeon and beluga. By 1908, there was widespread concern about the decline of salmon and sturgeon. The lake also supports populations of the endangered pallid sturgeon. The main production was caviar, taken from the eggs of lake sturgeon. Aquaculture facilities cultivate White Sturgeon in California and juveniles can be sold to aquarist. Gymnovaries are the primitive condition found in lungfish, sturgeon, and bowfin. The spearfishing season for lake sturgeon is in February. Kaluga hybrid, American osetra, Ossetra, Siberian sturgeon and Sevruga. Additionally, both the Yangtze sturgeon and Chinese sturgeon are considered critically endangered by the IUCN.