Acipenser medirsotris (Fishes)

Species Description

Sturgeons are modern relicts of an ancient group of bony fishes, and have remained relatively unchanged from when they first appeared in the fossil record, approximately 200 million years ago. They are anadromous fish, which means that like salmon they migrate up rivers from the ocean to spawn in fresh water. Sturgeons tend to be long-lived and slow-growing, reaching sexual maturity relatively late in life. These biological attributes make them vulnerable to intensive fishing pressure or other agents of elevated adult mortality.

Many species of sturgeon have experienced severe population declines worldwide because of both habitat destruction and excessive take for international trade. Indeed, in the United States, there are six sturgeon species listed under the Endangered Species Act, one of which is found here in the Bay Area. This North American Green Sturgeon, Acipenser medirostris, is classified into two distinct populations segments ("DPS"), one of which is currently protected under the Endangered Species Act: the Southern DPS, found in the San Francisco Bay Area and open ocean outside the Golden Gate.

The North American Green Sturgeon is the most marine oriented of all sturgeons. Juveniles spend one to three years in freshwater before they enter the ocean, where they disperse in a northerly migration before returning to their natal streams to spawn. The species spends much of its year migrating in the Ocean from Mexico to the Bering Sea, and hanging out in large numbers in the Columbia River.

Today the species has only three known spawning locations: the Klamath and Sacramento Rivers in Northern California, and the Rogue River in Oregon. The deep pools and turbulent, cold water in these rivers provides excellent habitat for the species to spawn, and individual sturgeon will return to these rivers once every three to five years to do so. Similar to us, green sturgeon reach sexual maturity in their teen years, with males reaching maturity around 15 years of age and females reaching maturity at 17 years of age. But in any year most of the spawning males will range from 17 and 18 years old, while most spawning females are between 27-28 years of age. When the Southern DPS Green Sturgeon are ready to spawn, it returns to the San Francisco Bay Delta and the Sacramento River. As the fish passes through the Golden Gate, it enters waters that are a part of the Golden Gate National Parks: but it is nearly impossible for visitors to see them.

The Southern DPS of the North American Green Sturgeon may only have 50 spawning-age individuals left in the wild, and has been protected under the Endangered Species Act since 2005. Threatened by pesticide use, poaching, water diversions & dams, and the lingering demographic effects of unregulated commercial fishing during the early 1900s, this ancient & long-lived fish may not make it into the next century unless we take concrete actions to help the species recover.

Conservation Action Item

Reduce household & yard toxins:
replace toxins with earth-friendly products

Biologists have published several studies showing pesticide impacts on long-lived fish like the North American Green Sturgeon. You can help reduce the number of toxic chemicals and pesticides released into our environment by replacing household and garden pesticides and cleaners with earth-friendly products.

Ideas for Reducing Toxins from the Environmental Working Group

Big Year Competitors have reported 0 sightings and taken 1 action to help this species recover so far this year.

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