Tuesday, July 10, 2012

Sockeye Salmon

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Sockeye salmon

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For other uses, see Sockeye (disambiguation).
Sockeye salmon
Male freshwater phase sockeye
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Subclass: Neopterygii
Infraclass: Teleostei
Order: Salmoniformes
Family: Salmonidae
Genus: Oncorhynchus
Species: O. nerka
Binomial name
Oncorhynchus nerka
(Walbaum, 1792)
Sockeye salmon (Oncorhynchus nerka), also called red salmon or blueback salmon in the USA, is an anadromous species of salmon found in the Northern Pacific Ocean and rivers discharging into it.
There are also completely landlocked populations of the same species, which are known as kokanee or "silver trout".[2] Sockeye salmon is the third most common Pacific salmon species, after pink and chum salmon.[3] The name "sockeye" is an anglicization of suk-kegh (sθə́qəy̓), its name in Halkomelem, the language of the indigenous people along the lower reaches of the Fraser River (one of British Columbia's many native Coast Salish languages). Suk-kegh means red fish.[4][5]
Male ocean phase sockeye
Sockeye salmon caught on an Alaskan stream
Spawning Kokanee salmon in the Sawtooth Range of Idaho

Contents

Range and habitat

Sockeye salmon ranges as far south as the Columbia River in the eastern Pacific (though individuals have been spotted as far south as the 10 Mile River on the Mendocino Coast of California) and northern Hokkaidō Island in Japan in the western Pacific, and as far north as Bathurst Inlet in the Canadian Arctic in the east and the Anadyr River in Siberia in the west.[6]

Kokanee

Some sockeye live and reproduce in lakes and are commonly called "kokanee", their name in the Okanagan language.[7] They are much smaller than the anadromous variety and are rarely over 350 millimetres (14 in) long. In Okanagan Lake and many others there are two kinds of kokanee populations - one spawns in streams and the other near lake shores. As an aside, the Kokanee Glacier gets its name from Kokanee Creek, which enters Kootenay Lake near Nelson, British Columbia (see Kokanee).
Landlocked populations occur in the Yukon Territory and British Columbia in Canada, and in Alaska, Washington, Oregon, California, New York, Utah, Idaho, Montana, Nevada, Colorado, New Mexico, and Wyoming in the United States.
Nantahala Lake is the only spot in North Carolina where kokanee salmon are found. The fish, which is native to the western United States, was stocked in Nantahala Lake in the mid-1960s by the N.C. Wildlife Resources Commission in an attempt to establish the species as a forage fish for other predator fishes in the lake. This stock has remained and become a favorite target for anglers.

Kunimasu

In Japan, a landlocked variety termed black kokanee, or "kunimasu" in Japanese, was deemed to be extinct after 1940, when a hydroelectric project made its native lake in northern Akita Prefecture more acidic. The species seems to have been saved by transferring eggs to Saiko Lake, 500 kilometers to the south, however.[8] This fish has been treated as a subspecies of sockeye Oncorhynchus nerka kawamurae, or even an independent species Oncorhynchus kawamurae

Reproduction

This section needs additional citations for verification. (October 2008)
Spawning sockeye salmon
Sockeye are blue tinged with silver in color while living in the ocean.
Sockeye spawn mostly in streams whose watersheds include a lake. The young fish, known as fry, spend up to three years in the freshwater lake before migrating to the ocean. Some stay in the lake and do not migrate. Migratory fish spend from one to four years in salt water, and thus are four to six years old when they return to spawn between July and August. Navigation to the home river is thought to be done using the characteristic smell of the stream, and possibly the sun.
Some fish spend as long as four years in fresh water lakes before migrating. In rivers without lakes, many of the young move to the ocean soon after hatching. These salmon mature after one to four years in the ocean.

Diet

Sockeye salmon, unlike other species of Pacific Salmon, feed extensively on zooplankton during both freshwater and saltwater life stages.[9] Their numerous gill rakers strain the plankton from the water. This diet may be the reason for the striking hue of their flesh, as well as their very low concentration of methylmercury. They also tend to feed on small aquatic organisms such as shrimp. Insects are part their diet at the juvenile stage.

Commerce

Smoked sockeye salmon ready for consumption
Globe icon.
 The examples and perspective in this article or section deal primarily with US/Canada and do not represent a worldwide view of the subject. Please improve this article and discuss the issue on the talk page. (November 2011)
Commercial fishermen net this species using seines and gillnets for fresh or frozen filet sales and canning, especially in Bristol Bay, Alaska site of the largest Sockeye harvest, according to the Alaska Department of Fish and Game. Canners prefer it due to its rich orange-red flesh. More than half of the catch is sold frozen.
Smoked Sockeye has a stronger flavor and firmer texture than Coho salmon.

Conservation status

United States

US Sockeye salmon populations are currently listed under the U.S. Endangered Species Act[10] by the National Marine Fisheries Service as an endangered species in the Snake River (Idaho, Oregon and Washington area) and as a threatened species in Lake Ozette, Washington. Other sockeye populations in the upper Columbia River and in Puget Sound (Washington) are not listed under the Act.
Sockeye salmon jumping over beaver dam, Aleknagik Lake, AK
Sockeye is an exception to 2010's forecast resurgence of Oregonian fish stocks. Spring Chinook, Summer Steelhead, and Coho are forecast to increase by up to 100% over 2008 populations. The sockeye population peaked at over 200,000 in 2008 and were forecast to decline to just over 100,000 in 2010. As an early indication of the unexpectedly high Sockeye run in 2010, on July 2, 2010, the United States Army Corps of Engineers reported that over 300,000 Sockeye had passed over Bonneville dam on the Columbia river. Lower temperatures in 2008 North Pacific waters brought in fatter plankton which, along with greater outflows of Columbia River water, feeding the resurgent populations.[11]
Proposed legislative efforts such as the Northern Rockies Ecosystem Protection Act are attempting to protect the headwaters of the sockeye salmon by preventing industrial development in roadless areas.

Canada

The conservation status of sockeye populations in Canada is under review by Fisheries and Oceans Canada as part of its Wild Salmon Policy strategy to standardize monitoring of wild salmon status.[12] Salmon runs of particular note are the Skeena and Nass river runs, and the most famous is the Fraser River sockeye run.
The Fraser River salmon run has experienced declines in productivity since the 1990s, mirroring a similar decline in the 1960s.[13]
The return abundance (population) of Fraser River sockeye in 2009 was estimated at a very low 1,370,000,[14] 13% of the pre-season forecast of 10,488,000.[15] That represented a decline from the recent (1993) historical cycle peak of 23,631,000 [16] and the return abundance was the lowest in over 50 years. The reasons for this (former) decline remain speculative. According to a “Think Tank” of scientists assembled to review the problem, the decline highlights the uncertainty in forecasting salmon returns. [17] After the low returns, the Government of Canada launched a formal inquiry into the decline, the Commission of Inquiry into the Decline of Sockeye Salmon in the Fraser River.[18] [19]
The Commission has been tasked with investigating all the factors which may affect Fraser River sockeye salmon throughout their life cycle. According to the terms of reference,[18] [19] the subjects of investigation are "the impact of environmental changes along the Fraser River, marine environmental conditions, aquaculture, predators, diseases, water temperature and other factors that may have affected the ability of sockeye salmon to reach traditional spawning grounds or reach the ocean."
During the commission, hundreds of thousands of documents and scientific research papers were reviewed. Twelve technical reports were published using that information, looking at the possible impacts of diseases and parasites, hatchery diseases, contaminants, marine ecology, salmon farms, fisheries, predators, climate change and government management on the productivity of Fraser River sockeye runs.[20]
The commission will submit its final report by September 30, 2012.[21]
While the commission was holding public hearings, in the late summer of 2010, the largest run of sockeye since 1913 returned to the Fraser River system. [22] Final counts show that approximately 30 million salmon returned to the Fraser River and its tributaries in 2010. In total, approximately 11,591,000 Fraser sockeye were caught by Canadian fishers and 1,974,000 Fraser sockeye were caught by American fishers. The final projected escapement (fish which were not caught) was 15,852,990 fish. [23]
Recent unpredictable fluctuations in runs are speculated to be due to changing water temperatures.[24]

Notes

  1. ^ iucnredlist.org
  2. ^ "Fish Resources - Salmon/Steelhead" (in English). USDA Forest Service. Retrieved 9 September 2011.
  3. ^ "Sockeye Salmon". NOAA Fisheries Office of Protected Resources. Retrieved 2006-11-19.
  4. ^ Bright, William (2004). Native American placenames of the United States. University of Oklahoma Press. p. 455. ISBN 978-0-8061-3598-4. Retrieved 11 April 2011.
  5. ^ nationalgeographic.com
  6. ^ "Sockeye Salmon". Alaska Department of Fish and Game. Retrieved 2006-11-17.
  7. ^ "Kokanee Lake". BC Geographical Names.
  8. ^ Scientist says he found Japan fish thought extinct Bay Ledger, December 14, 2010
  9. ^ adfg.state.ak.us
  10. ^ nmfs.noaa.gov, U.S. Endangered Species Act
  11. ^ "Fish Boom Makes Splash in Oregon". Wall Street Journal. January 21, 2010. Retrieved January 21, 2010.[dead link]
  12. ^ "Wild Salmon Policy 1".
  13. ^ "Speaking for the Salmon proceedings: Summit of Fraser River Sockeye Salmon: Understanding Stock Declines and Prospects for the Future March 30-31, 2010".
  14. ^ "NewsRelease10". Pacific Salmon Commission News Releases. Sept 11, 2009. Retrieved Sept 2009.
  15. ^ "NewsRelease01". Pacific Salmon Commission News Releases. July 10, 2009. Retrieved Jul 2009.
  16. ^ "Fraser River Annual Report to the Pacific Salmon Commission on the 2005 Fraser River sockeye and pink salmon fishing season.". Fraser River Panel reports to the Pacific Salmon Commission: 26. October 2009. Retrieved Oct 2009.
  17. ^ "Managing Fraser sockeye in the face of declining productivity and increasing uncertainty: Statement from Think Tank of Scientists.". December 2009. Retrieved Dec 2009.
  18. ^ a b "Terms of Reference for the Commission of Inquiry into Decline of Sockeye Salmon in the Fraser River.". November 2009. Retrieved Nov 2009.
  19. ^ a b "Error: no |title= specified when using {{Cite web}}". http://www.cohencommission.ca/en/.
  20. ^ "Cohen Commission technical reports".
  21. ^ "Cohen Commission to submit final report by September 30, 2012".
  22. ^ "Consumers catch a deal in record sockeye run". August 27, 2010. Retrieved Sept 07 2010.
  23. ^ "Surveillance Report British Columbia Commercial Sockeye Salmon Fisheries. November 2011".
  24. ^ "Record number of sockeye salmon return in B.C.". August 25, 2010. Retrieved Sept 07 2010.

References

Technical reports

External links

Wikimedia Commons has media related to: Oncorhynchus nerka
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