Of the 8 North American species of sturgeon, green sturgeon are the widest ranging. They also spend more time in marine environments than the other sturgeon species, and only move into the rivers to spawn. They range from the west coast of Mexico, the U.S., and Canada, and have been found in estuaries and bays all along the west coast.
Green sturgeon that spawn and live in the Sacramento River, Sacramento-San Joaquin Delta, and the San Francisco Bay Estuary were listed as a threatened species (ESA) in 2006. Populations specific to that region have deteriorated as a result of dams, overfishing, loss of habitat, pollution, and other anthropogenic effects.
Green sturgeon are an ancestral species that predate the dinosaurs. They have remained relatively unchanged to this day. Their color ranges from olive green, to gray or golden brown. They are a long-lived, late maturing species that spawn periodically which makes them susceptible to overfishing.