Sakhalin Sturgeon (Acipenser mikadoi)
Did You Know?
· Sakhalin sturgeon are closely related to green sturgeon.
|Weight:||up to 330 pounds (150 kg)|
|Length:||up to 8 feet (2.5 m)|
|Appearance:||olive-dark green backs, with an olive-green stripe on their sides, and a yellowish green-white belly; they have 5 major rows of "scutes"|
|Lifespan:||at least 20 years|
|Diet:||invertebrates (mainly on shrimp, crabs, worms, amphipods, and isopods), sand lances, and other fishes|
|Behavior:||they migrate upriver in spring in spawn|
Sakhalin sturgeon are are thought to live at least 20 years, growing to about 8 feet (2.5 m) long and weighing up to 330 pounds (150 kg). They have olive to dark green backs, an olive-green stripe between the scutes on their side, and a yellowish green-white belly. They have five major rows of scutes in all.
Sakhalin sturgeon are "benthic" feeders and typically forage on benthic invertebrates (mainly shrimp, crabs, worms, amphipods, and isopods), sand lances, and other fishes.
They have a lower lip that is split down the middle and four barbels that are nearer to the mouth than the tip of its snout. They are closely related to green sturgeon.
Sakhalin sturgeon are "anadromous" fish that spend most of their life in the ocean, but return to freshwater to spawn. Sakhalin sturgeon live in higher salinity waters than other sturgeon within their range. Adults spawn in freshwater in the late spring or summer, and the young juveniles then migrate back out to the sea in the fall.
- Tumnin River, the only known persistent spawning population
- Sea of Okhotsk
- Bering Strait
- Sea of Japan
- North Korea
- Sea of Japan
Historically, Sakhalin sturgeon were native to the northwest Pacific Ocean in Japan and Russia, with an uncertain presence in China, South Korea, and North Korea. During spawning migration, they historically swam up coastal rivers in eastern Russia and in northern Japan.
The population size of Sakhalin sturgeon has been declining for over 100 years. Anecdotal reports note that the Sakhalin sturgeon was common in Japanese fish markets in the 1950s. Now, only a few are found each year.
Seine fish surveys in the Tumnin River in Russia caught:
- 0 in 2013
- 0 in 2011
- 2 in 2008
- 3 in 2005
- overfishing led to widespread declines in Sakhalin sturgeon abundance
- commercial and recreational fishing occurred for hundreds of years but is now generally banned
Current threats include:
- "bycatch" of sturgeon in fisheries targeting other species and poaching
- habitat degradation and loss from various human activities such as dredging, dams, water withdrawals, and other development
- pollution and poor water quality
- small population size
Sakhalin sturgeon are listed in Appendix II of CITES, which regulates international trade.
Russia banned fishing for Sakhalin sturgeon. An artificial propagation program has reintroduced 60 sturgeon from 2005-2009 into Lake Tunaicha in the southeast of Sakhalin, Russia.
In 2012, WildEarth Guardians and Friends of Animals petitioned [pdf] us to list 15 foreign sturgeon species under the ESA. We proposed to list 5 species as endangered under the ESA. (The other 10 species were determined to be under the jurisdiction of the U.S. Fish and Wildlife Service, and USFWS is reviewing their status.)
|Final Endangered Listing of Five Sturgeon Species||79 FR 31222||06/02/2014|
Proposed Endangered Listing of Five Species of Sturgeons under the ESA
|78 FR 65249||10/31/2013|
|90-day Finding on a Petition To List Five Species of Sturgeon as Threatened or Endangered under the ESA||77 FR 51767||08/27/2012|
|Petition to List 15 Sturgeon Species as Threatened or Endangered||n/a||various|
- Endangered and Threatened (ESA-listed) Sturgeon:
- Endangered and Threatened (ESA-listed) Fish
Updated: June 2, 2014