| |
| Scientific Name | Acipenser medirostris |
|---|---|
| Conservation Status | Near Threatened |
| Family | Chordata |
| Habitat | Northern Pacific Ocean |
| Food | Crustaceans and bottom-living mollusks |
The Green Sturgeon (Acipenser medirostris) is a species of sturgeon native to the Pacific Ocean, from China and Russia, over into Canada and the United States.
On April 7, 2006, the National Marine Fisheries Service (NMFS) issued a final rule listing the Southern distinct population segment (DPS) of North American green sturgeon (Acipenser medirostris)(green sturgeon) as a threatened species under the United States Endangered Species Act.
Sturgeons have adopted a temporal strategy to controlling risks. Sturgeons live a long time, delay maturation to large sizes, and spawn multiple times over their lifespan. The sturgeon’s long life span and repeat spawning in multiple years allows them to outlast periodic droughts and environmental catastrophes.
Little is known about green sturgeon feeding at sea, but it is clear they behave quite differently than white sturgeon (CDFG 2005a). Green sturgeons are probably found in all open Oregon estuaries, with a lot of movement in and out of estuaries and up and down the coast (ODFW 2005a). Adults feed in estuaries during the summer (ODFW 2005a). Stomachs of green sturgeons caught in Suisun Bay contained Corophium sp. (amphipod), Crago franciscorum (bay shrimp), Neomysis awatchensis (Opossum shrimp) and annelid worms (Ganssle 1966). Stomachs of green sturgeon caught in San Pablo Bay contained Crago franciscorum (bay shrimp), Macoma sp. (clam), Photis californica (amphipod), Corophium sp. (amphipod), Synidotea laticauda (isopod), and unidentified crab and fish (Ganssle 1966). Stomachs of green sturgeons caught in Delta contained Corophium sp. (amphipod), Neomysis awatchensis (Opossum shrimp) (Radtke 1966). Radtke 1966 also reported that while the Asiatic clam (Corbicula fluminea) was abundant throughout the Delta, Suisun Bay and San Pablo Bay, it was not utilized as a food source by green sturgeons.
Threats to the green sturgeon include being taken as bycatch in salmon gillnet and other fisheries, water development projects that affect migration or decrease habitat quality, and other land use stressors that affect habitat quality. Exotic species negatively affect the southern DPS. Commercial fisheries have been prohibited in the Columbia River and Willapa Bay since 2001.