Archive for the ‘Fact Sheet’ Category

Zebra Mussel Test Page

Friday, January 30th, 2009

Sidebar should be the zebra mussel. Atlantic Salmon now.

Zebra Mussel (Driessena polymorpha)

Thursday, January 29th, 2009
Status & Synopsis Economic Value of Potentially Affected Fisheries Geographic Distribution PSMFC Funded Projects
Publications Links Educational Materials References

Do you want to become a Zebra Mussel Monitoring Volunteer? Go to:

Volunteer Zebra Mussel Monitoring Program (Portland State University)

Zebra Mussel


Zebra mussels are listed as an injurious species under the federal Lacey Act. They are regulated in some way in all states west of the 100th meridian.


The zebra mussel (Dreissena polymorpha) is a small bivalve mollusk with two matching half shells. Its name is derived from the striped pattern on its shell. The zebra mussel originated in the Balkans, Poland, and the former Soviet Union and was introduced in 1988 into the Laurentian Great Lakes (See Figure 1) as a result of the discharge of contaminated ballast water which contained free swimming zebra mussel larvae, called veligers (Mackie et al. 1989, Griffiths 1991). They rapidly dispersed throughout the Great Lakes and major river systems from the Mississippi River east due to their: 1) high fecundity (as females can produce up to one million in a spawning season), 2) downstream drift of veligers; and 3) ability to attach themselves to boats and move overland to uninfected waters. Zebra mussels are now found in 22 states and two Canadian provinces (See Figure 2).

Map of Zebra Mussel in Lake Saint Claire

Source: Zebra Mussel Information System, USACE

Figure 1: Zebra mussels were likely first introduced into Lake St. Clair in 1988 by the release of ballast water from a transoceanic vessel (Mackie et al. 1989, Griffiths 1991)

Recreational watercraft are seen as the most likely vector to move zebra mussels from infested waters to uninfested waters in the West. In California alone, from January 2000 to January 2006, the California Department of Agriculture reported 64 cases of zebra mussels attached to watercraft intercepted at agricultural check stations. Zebra mussels, both dead and alive, have also been found attached to watercraft in Colorado, Montana, Washington, Utah, Nevada, and Arizona.

The zebra mussel is one of the most economically damaging aquatic organisms to invade the United States. Its destructive power lies in its sheer numbers and its ability to attach itself to solid objects: water intake pipes, propellers, boat hulls, dock pilings, submerged rocks, and even other aquatic animals. Zebra mussel populations can reach astonishing densities, up to 750,000 individuals per square meter in layers more than a foot thick (though lower densities are more common).

If introduced into the Columbia River basin, zebra mussels could threaten the health and survival of native salmon and steelhead stocks, many of which are protected under the Endangered Species Act. Zebra mussels would likely attach themselves to fish ladders, fish diversion screens, and other pipes and conduits that sensitive salmon species use to make their way around dams. As a result, expensive maintenance of facilities could be required and physical damage to adult and juvenile salmon ultimately reducing survival of these imperiled fish stocks.

In the event of an invasion, the economic impact to the Northwest’s power generation capacity could be significant due to costs associated with zebra mussel control. Those facilities that primarily rely on raw water as the source of water will be at greatest risk. These could include turbine cooling systems, fire suppression systems, fish passage facilities, drains and sumps, and certain monitoring facilities such as forebay/tailwater sensors, oil/water separators, and dissolved gas monitors (Athearn and Darland 2006).

The Bonneville Power Administration commissioned a study of the costs associated with zebra mussel control on hydro-power facilities in the Columbia River (Phillips et al. 2005). The study found that the one-time cost for installing zebra mussel control systems at hydroelectric projects could range from hundreds of thousands of dollars to over a million dollars per facility (click here to see the study).

In addition, zebra mussels would have significant and costly impacts on irrigated agriculture, domestic water supply, navigation, boating, swimming and other forms of recreation.

Economic Value of West Coast Fisheries Resources That Potentially Could Be Affected by Zebra Mussels

  1. For the Pacific Ocean Salmon Fishery (coho, chinook) from Cape Falcon, Oregon to the Canadian Border, (Pacific Fisheries Management Council 2005):
    • Estimates of ex-vessel value for Council-adopted 2005 non-Indian commercial troll salmon fishery: $1.798 million.
    • Coastal community income from recreational ocean fishery in 2004: $7,625,000.
  2. Idaho: In 2001 anglers spent a total of $311 million in Idaho on travel, lodging, meals, equipment, licenses, and other items related to fishing (USFWS and Bureau of Census 2003).

Geographic Distribution (USA): Zebra Mussel (Driessena polymorpha)


Figure 2: Zebra and Quagga Mussel Sightings Distribution.

PSMFC Funded Projects


Educational Materials


Meridian Initiative

Zebra Mussel Volunteer Substrate Monitoring Program, Center for Lakes and Reservoirs, Portland State University

U.S. Geological Survey Zebra Mussel Page

California Department of Water Resources Zebra Mussel Watch

US Army Research and Development Center Zebra Mussel Information System


Athearn, Jim and Tim Darland. 2006. Bonneville Project Response Plan for Zebra Mussels (Dreissena polymorpha) (Appendix); in: Heimowitz, Paul and Stephen Phillips. 2006. The Rapid Response Plan for Zebra Mussels in the Columbia River Basin (Draft). Pacific States Marine Fisheries Commission and US Fish and Wildlife Service, Portland, Oregon.

Griffiths, R.W., Schloesser, D.W., Leach, J.H., and Kovalak, W.P. 1991. “Distribution and dispersal of the zebra mussel (Dreissena polymorpha) in the Great Lakes region,

New Zealand Mudsnail (Potamopyrgus antipodarum)

Thursday, January 29th, 2009
Status & Synopsis Economic Value of Potentially Affected Fisheries Geographic Distribution (USA) PSMFC Funded Projects
Publications Links Educational Materials References


Image by: Amy Benson, USGS


The State of Washington classifies the New Zealand mudsnail (NZMS) as a “prohibited species.” In Oregon, NZMS’s are not specifically classified as “prohibited,” “controlled,” or “non-controlled.” As a result, live snails cannot be possessed, imported, purchased, sold, exchanged, or offered for sale, purchase or exchange without a state permit until they are classified. California classifies NZMS’s as “restricted.” Therefore, it is unlawful to import, transport, or possess live NZMS’s in the state except under permit issued by the California Department of Fish and Game. NZMS’s are not specifically regulated by the state of Idaho. However, under Idaho Administrative Code, “no person shall import, export, transport into or cause to be transported within, release or sell within the state of Idaho any living wildlife including wildlife eggs” without first obtaining a permit from the Idaho Department of Fish and Game. In Montana, NZMS’s are listed as a Priority Class 2 species. Priority Class 2 species are species that are present and established in Montana, have the potential to spread, and for which there are limited or no known management strategies for these species (Proctor 2004).


The New Zealand mudsnail is native to freshwater streams and lakes of New Zealand and adjacent small islands. It is naturalized in Australia and Europe. Populations are widespread in the Western United States, as well as Lake Ontario and Lake Superior. The NZMS is about ¼ inch in length.

It was discovered in 1987 in the middle-Snake River in south central Idaho (near Hagerman). The Western U.S. population of NZMS was likely introduced in a batch of rainbow trout eggs brought from New Zealand or Australia. Since then, it has spread into 10 western states and Canada. Unfortunately, the snail has spread to blue ribbon trout streams across the west in California, Montana, Colorado and Wyoming (See Figure 1).

The North American population is composed of self-cloning females (triploid parthenogenetic females) – meaning a single individual can start a new population. The NZMS can form colonies dense enough to carpet a stream bottom. In the Madison River drainage, including Yellowstone National Park, researchers at Montana State University reported between 750,000 (Hall 2001) and 800,000 mudsnails per square meter (Lucas, 1959 in Dorgelo, 1987). Research has shown mudsnails have a negative effect on mayfly (Baetis spp.) survival (Cada 2004). Mudsnails have been found to deplete the standing crop of aquatic algae and periphyton (Cada 2001, Hall 2001, Hall et al. 2003). Fish in North America sometimes ingest mudsnails. These species include mountain whitefish (Prosopium williamsoni), sculpin (Cottus sp.) and brown trout (Salmo trutta) (C. Cada and B. L. Kerans, unpublished data in Proctor, 2004). These fish gain little energy from the snails, however, because studies have shown that the snails are capable of passing through the digestive canal of trout alive and intact (Bondesen and Kaiser 1949, Haynes et al. 1985).

New Zealand mudsnails hitchhike around the country by lodging in waders and other fishing gear, closing their operculum (the trap door used to seal off their shell), and then traveling as far as the host carries them. The seriousness of this problem became apparent as mudsnails spread to popular trout streams hundreds of miles from the nearest known mudsnail infestation. In 2001, for example, the Owens River, a popular trout stream in California’s Eastern Sierra, became infested; likely caused by contaminated fishing gear. In 2004, Boulder Creek, a trout stream near Boulder, Colorado became infested. The impact to anglers was significant. Shortly after the infestation, the Colorado Wildlife Commission closed fishing on a two-and-one-half mile stretch of Boulder Creek to reduce the risk of accidentally moving exotic New Zealand mudsnails to other streams and lakes. The NZMS was also recently found in Oregon’s Deschutes River, another popular fishing destination.

New Zealand mudsnails are difficult to eradicate once in a stream. Research on potential biological control methods includes the use of a trematode (a fluke), which shows some promise (Emblidge and Dybdahl 2004). There is a concern that NZMS could negatively affect anadromous and resident fish resources in the western U.S. These fisheries provide substantial economic benefit (see below).

Scientists have only begun documenting (and publishing) impacts in the past 5-6 years; with no studies directly linking mudsnails to significant disruption of the aquatic ecosystem and adverse impacts to fish. This may explain why funding for mudsnail management activities is minimal when compared to other invasive species issues such as zebra mussel prevention and ballast water management and research. The timeline of NZMS arrival in North America mirrors that of the zebra mussel in the 1980’s. Despite arriving about the same time, there have been scores of studies documenting zebra mussel impacts.

Economic Value of Fisheries Resources That Potentially Could Be Affected by the New Zealand Mudsnail

For the Pacific Ocean Salmon Fishery (coho, chinook) from Cape Falcon, Oregon to the Canadian Border, (Pacific Fisheries Management Council 2005):

  • Estimates of ex-vessel value for Council-adopted 2005 non-Indian commercial troll salmon fishery: $1.798 million.
  • Coastal community income from recreational ocean fishery in 2004: $7,625,000.

Chinook Salmon, State of Idaho: During the 2001 salmon season, recreational fishing for salmon was responsible for $89,880,015 in expenditures in Idaho (Reading 2001).

Geographic Distribution (USA): New Zealand Mudsnail (Potamopyrgus antipodarum)


Source: Department of Ecology, Montana State University, Bozeman


PSMFC Funded Projects


Educational Materials



Montana State University
National Management and Control Plan for the New Zealand Mudsnail (Potamopyrgus antipodarum) DRAFT



Bondesen, P. and E. W. Kaiser. 1949. Hydrobia (Potamopyrgus) jenkinsi (Smith) in Denmark illustrated by its ecology. Oikos 1:252-281.

Cada, Chelsea. 2001. Effects of New Zealand mudsnails on native invertebrates in Darlington Ditch, Montana. Minutes of the First Annual Conference on New Zealand Mudsnails in the Western USA, July 9-10, 2001. Bozeman, Montana.

Cada, Chelsea. 2004. Competitive interactions between the invasive Potamopyrgus antipodarum and baetid mayflies: temporal variation and community-level consequences An Annual Report to the Montana Water Center, US Geological Survey. Montana State University-Bozeman, Bozeman, MT. 14pp

Dorgelo, J. 1987. Density fluctuations in populations (1982-1986) and biological observations of Potamopyrgus jenkinsi in two trophically differing lakes. Hydrobiological Bulletin 21:95-110.

Emblidge, Alison and Mark Dybdahl. 2004. Third Annual Potamopyrgus antipodarum Conference, 215 Cheever Hall, Montana State University, Bozeman, MT.

Hall, R.O. 2001. Estimating New Zealand mudsnail impact based on consumption rates of algae in 2 rivers in Yellowstone National Park. Montana. Minutes of the First Annual Conference on New Zealand Mudsnails in the Western USA. Bozeman, Montana.

Hall, R.O., J.L. Tank, and M.F. Dybdahl. 2003. Exotic snails dominate nitrogen and carbon cycling in a highly productive stream. Frontiers in Ecology and the Environment 1:407-411.

Haynes, Alison, B. J. R. Taylor, and M. E. Varley. 1985. The influence of the mobility of Potamopyrgus jenkinsi (Smith, E. A.) (Prosobranchia: Hydrobiidae) on its spread. Archives of Hydrobiologie 103:497-508.

Lucas, A. 1959. Les Hydrobia (Bythnellidae) de le Ouest de la France. Journal of Conchology 99:3-14.

Proctor, Tina. 2004. Management and Control Plan for the New Zealand Mudsnail (Potamopyrgus antipodarum) DRAFT Prepared by the New Zealand Mudsnail Management and Control Plan Workgroup August 2004. USFWS, Denver Co. 57 pp.

Reading, Don. 2001. The Economic Impact of the 2001 Salmon Season in Idaho. Ben Johnson Associates. 6070 Hill Road Boise, Idaho 83703.

European Green Crab (Carcinus maenas)

Thursday, January 29th, 2009
Status & Synopsis Economic Value of Potentially Affected Fisheries Geographic Distribution [intlink id=”37″ type=”page”]PSMFC Funded Projects[/intlink]
Publications Links Educational Materials References

Green Crab image


In 1998, the European green crab (Carcinus maenas) was formally recognized as an Aquatic Nuisance Species (ANS) by the Federal ANS Task Force (a national coordinating body). That same year Washington State made it illegal to possess or transport European green crabs. It is a prohibited species in Oregon and California. In Alaska, there are no fish and game laws barring importing live green or mitten crab into the state for the live food market.


Background: The European green crab was first discovered on the east coast of North America in the early 1800’s (Say 1817). They are native to Europe and northern Africa and were introduced into North America via shipping. Green crabs arrived in California prior to 1990. By 2000, the green crab had dispersed as far north as Port Eliza on the northern coast of Vancouver Island, British Columbia. The potential range of green crabs includes southeast Alaska (Behrens Behrens-Yamada 2001, Carlton 2003).

Economic Value of West Coast Fisheries Resources That Could Potentially Be Affected by Green Crabs

Dungeness crab (Cancer magister) 2005 Oregon fishery ex-vessel value (through 2/9/05): $50 Million (Oregon Dungeness Crab Commission 2005).

Annual value in sales of farmed oysters, mussels, clams, and geoducks in Washington state: $77 million (PCSGA 2003).

Scientists, managers and shellfish growers are concerned that increases in the abundance and distribution of this efficient predator and competitor could permanently alter native communities. They are also concerned that the green crab will threaten commercial species such as juvenile Dungeness crab, juvenile flatfish, and bivalves (Lafferty and Kuris 1996, Jamieson et al. 1998). Green crabs have been shown to compete with native juvenile Dungeness crabs and shore crabs (McDonald et al. 2001, Jensen et al. 2002), as well as many types of organisms, including commercially valuable bivalve mollusks (e.g., clams, oysters, and mussels), polychaetes, and small crustaceans (Cohen et al. 1995).

On the east coast of North America, green crabs have been associated with the decline in soft shell clam (Mya arenaria) landings (Glude 1955, Ropes 1968). Research and observations on the west coast have not indicated similar impacts to shellfish. However, green crabs are a relatively new arrival to the west coast, so future effects on native species have yet to be determined.

Research conducted by Dr. Ted Grosholz (University of California, Davis) in California (see [intlink id=”37″ type=”page”]PSMFC Funded Projects[/intlink]) has shown that in recent years, green crab population densities are highest in Tomales Bay and Elkhorn Slough. There is no evidence that green crabs have established populations south of Elkhorn Slough and there are no records of any green crab presence south of Point Conception. Therefore, the populations in central California continue to represent the majority of green crabs found along the west coast. These may be the key source of recruits for populations farther north, although this remains to be demonstrated.

Circumstantial evidence from research conducted by Dr. Sylvia Behrens-Yamada (see [intlink id=”37″ type=”page”]PSMFC Funded Projects[/intlink]) suggests that Coos, Yaquina, Netarts, and Tillamook estuaries in Oregon and Willapa Bay in Washington, harbor small self-sustaining populations of green crabs that do not depend on a larval source from California.

Geographic Distribution (USA and Worldwide):

European Green Crab (Carcinus maenas)


Source: U.S. Geological Survey (USGS)
Map of Green Crab distribution in the World

Source: National Introduced Marine Pest Information System (NIMPIS), Australia

PSMFC Funded Projects
Educational Materials
  • Global Invasive Species Database Green Crab Page
  • CSIRO Marine and Atmospheric Research Green Crab Page
  • USGS – Nonindigenous Aquatic Species Green Crab Page
  • Smithsonian Environmental Research Center Marine Invasions Research Lab
  • References

    Behrens Yamada, S. 2001. Global Invader: The European Green Crab. 123 pages. Oregon Sea Grant, Washington Sea Grant.

    Behrens Yamada, S., B.D. Dumbauldt, A. Kailin, C. Hunt, R. Figlar-Barnes and A. Randall. 2005. Growth and persistence of the recent invader Carcinus maenas in Pacific Northwest estuaries. Biological Invasions, 7(2): 309-321.

    Carlton, J.T. and A.N. Cohen. 2003. Episodic global dispersal in shallow water marine organisms: the case history of the European shore crabs Carcinus maenas and C. aestuarii. Journal of Biogeography, 30: 1809-1820.

    Cohen, A.N., J.T. Carlton and M.C. Fountain. 1995. Introduction, dispersal and potential impacts of the green crab Carcinus maenas in San Francisco Bay, California. Marine Biology, 122: 225-237.

    Glude, J. B. 1955. The effects of temperature and predators on the abundance of the soft- shell clam, Mya arenaria, in New England. Trans. Am. Fish. Soc., 84: 13-26.

    Oregon Dungeness Crab Commission. 2005. Oregon Dungeness Crab Landings (through 4/8/05). Coos Bay Oregon.

    Jamieson, G.S., E.D. Grosholz, D.A. Armstrong and R.W. Elner. 1998. Potential ecological implications for the introduction of the European green crab, Carcinus maenas, (Linnaeus), to British Columbia, Canada and Washington, USA. Journal of Natural History, 32: 1587-1598.

    Jensen, G.C., P.S. McDonald and D.A. Armstrong. 2002. East meets west: Competitiveinteractions between green crab, Carcinus maenas, and native and introduced shore crab Hemigrapsus spp. Marine Ecology Progress Series, 225: 251-262.

    Lafferty, K. and A. Kuris. 1996. Biological control of marine pests. Ecology, 77: 1989-2000.

    McDonald, P.S., G.C. Jensen and D.A. Armstrong. 2001. The competitive an predatory impacts of the nonindigenous crab Carcinus maenas (L.) on early benthic phase Dungeness crab Cancer magister Dana. Journal of Experimental Marine Biology and Ecology, 258(1): 38-54.

    Oregon Dungeness Crab Commission. 2005. Crab harvest off the Charts. Press release of August 15, 2005. Coos Bay, Oregon.

    PCSGA (Pacific Coast Shellfish Growers Association). 2003. Shellfish Economy: Treasure of the tidelands. Olympia, WA.

    Ropes, J. W. 1968. The feeding habits of the green crab, Carcinus maenas. Fish. Bull., 67: 183-203.

    Say, T. 1817. An account of the crustacean of the United States. Journal of the Academy of Natural Sciences of Philadelphia, 1: 57-63.

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Chinese Mitten Crab (Eriocheir spp.)

Thursday, January 29th, 2009
Status & Synopsis Economic Value of Potentially Affected Fisheries Geographic Distribution PSMFC Funded Projects
Publications Links Educational Materials References


Image by: Lee Mecum, California Fish and Game


The genus Eriocheir is listed as an injurious species under the federal Lacey Act, which bars the importation and interstate transport of live crabs. The Chinese mitten crab is on the list of 100 Most Dangerous Invaders to Keep Out of Oregon (2006). It is a prohibited species in Washington, Oregon and California.


The Chinese mitten crab is a burrowing species native to the coastal rivers and estuaries of the Yellow Sea (Asia), with a native distribution from the province of Fukien, China, northward to the Korean Peninsula (~26°N northwards to ~ 40°N). Chinese mitten crabs are established in England and most of Europe, including Russia. They also have been found in the Chesapeake Bay (Patapsco River, Maryland in 2005 and 2006), the St. Lawrence River and periodically since 1965, in the Great Lakes (O’Neill and MacNeill 2005).

The Chinese mitten crab is a catadromous species (living in fresh water but migrating to marine/estuarine waters to breed). Juveniles can migrate upstream several hundred miles. The crabs are believed to have one reproductive season and die shortly after reproduction (Panning 1939).

The Chinese mitten crab was first discovered in San Francisco Bay in the winter of 1992 (Rudnick et al. 2003). It is likely that mitten crabs arrived in the Bay, as well as in other parts of the continent, either through the discharge of contaminated ballast water or as a result of the release of live adult crabs imported for sale in local Asian markets (Cohen and Carlton 1997).

A population of mitten crabs in the Columbia River has yet to be confirmed, but there have been reported sightings. A sturgeon angler near Astoria caught a male Japanese mitten crab (E. japonica) in July 1997. In September 1999, a mitten crab was reportedly caught by a crayfish fisherman under the Sauvie Island Bridge over the Multnomah Channel, near Portland. The crayfish fisherman recognized the uniqueness of the crab when he caught it and gave it to another individual who placed it in a pond. The pond was later drained and cleaned, but the crab was no longer present. The crayfish fisherman was shown a preserved mitten crab and viewed a video about the crab. He confirmed that the crab he caught was a mitten crab (Sytsma 2000).

Economic Value of Select Fisheries Resources That Could Potentially Be Affected by Chinese Mitten Crabs

Chinook Salmon (Onchorynchus tchawytscha): California coastal community and state personal income from the 2003 ocean salmon fishery was $30.3 million from the commercial fishery, and $13.3 million from the recreational fishery (PFMC 2004).

Commercial Signal Crayfish (Pacifastacus leniusculus): The 1998 San Francisco Bay fishery retail value of catch was $750,000 (CALFED 1998).

Commercial Grass Shrimp (bait, food): The 1998 San Francisco Bay fishery retail value of catch was $1.5 million (CALFED 1998).

Mitten crabs pose ecological, economic, and human health concerns. Following their introduction into California, it was feared that the Chinese mitten crabs were a secondary host for a dangerous lung fluke that can infect humans and that has caused deaths in Asia (Dugan et al. 2002). However, results of a study conducted by researchers at the University of California, Santa Barbara, suggested that Chinese mitten crabs in the San Francisco Bay estuary were not infected with the ling fluke. Another concern about the Chinese mitten crab is its high burrowing density, which has been linked with bank and levee weakening, and even collapse in some areas where this species has been introduced (Panning 1939, Dutton and Conroy 1998).

The most severe impacts in California have been at water engineering projects where the crabs have clogged fish salvage facilities. In 1998, the Bureau of Reclamation, at its Tracy California Central Valley Project pumping plants, collected about 1 million crabs. It appears that there are still significant numbers of mitten crabs in and around San Francisco Bay and its tributaries, but the number of mitten crabs in the Sacramento-San Joaquin Rivers Delta now appears to be at a historic low (Bergendorf 2005).

Fish passage facilities, such as fish ladders, may also be impacted by the mitten crab. One study suggests (Culver 2005) the mitten crab may represent a significant threat to salmonid eggs and larvae through direct consumption. The crab’s foraging activity could also result in the indirect mortality of salmonid eggs and larvae by exposing the eggs and larvae to other predators and/or unfavorable conditions (Culver 2005).

One study has shown that few estuaries in the Pacific Northwest are likely to develop large mitten crab populations. However, Puget Sound and Coos Bay could have the proper combination of temperature, salinity and retention time for mitten crab establishment (Hanson 2005).

Geographic Distribution: Chinese Mitten Crab (Eriochier spp.)


Source: U.S. Geological Survey (USGS)

PSMFC Funded Projects


Educational Materials


Prince William Sound Regional Citizens Advisory Council NIS Species and Technology Fact Sheets

U.S. Geological Survey Chinese Mitten Crab Page

California Department of Fish and Wildlife

Global Invasive Species Database Chinese Mitten Crab Page


Bergendorf, David. 2005 Personal Communication. US Fish and Wildlife Service. Stockton, California

CALFED Ecosystem Restoration Program Plan. 1998. CALFED Bay-Delta Program.

Cohen, A and J Carlton. 1998. Accelerating invasion rate in a highly invaded estuary. Science 279: 555-558.

Dugan, Jenifer E., Mark Walter, and Carolynn Culver. 2002. Evaluating the health risk posed by the invasive Chinese mitten crab. Final Report to National Sea Grant Aquatic Nuisance Species Research and Outreach Project R/CZ-160.

Dutton, C and C Conroy. 1998. Effects of burrowing Chinese mitten crabs (Eriocheir sinensis) on the Thames tideway. Environment Agency. London, U.K.

O’Neill, Chuck and David MacNeill. 2005. NYSG Educating river residents regarding potential for invasive species new to northeast; Enlist Aid In Spotting Chinese Mitten Crab. New York Sea Grant. Brockport, NY.

Pacific Fishery Management Council. 2004. Review of 2003 Ocean Salmon Fisheries. Portland, Oregon. 317 pp.

Panning, A. 1939. The Chinese mitten crab. Smithsonian Institution annual report for 1938, Washington, D.C.

Rudnick, Deborah A., Kathryn Hieb, Karen F. Grimmer, Vincent H. Resh. 2003. Patterns and processes of biological invasion: The Chinese mitten crab in San Francisco Bay. Basic Appl. Ecol. 4, 249-262

Sytsma, Mark. 2000. Personal Communication. Center for Lakes and Reservoirs, Portland State University. Portland, Oregon

Atlantic Salmon (Salmo salar)

Thursday, January 29th, 2009
Status & Synopsis Economic Value of Potentially Affected Fisheries Geographic Distribution PSMFC Funded Projects
Publications Links Educational Materials References


Image by: unknown


Atlantic salmon (Salmo Salar) are raised in marine net pens in Washington State and British Columbia. In Oregon, however, they are listed as one of the “100 Most Dangerous Invaders to Keep Out of Oregon in 2005.” Alaska currently has a ban on finfish farming. In 2003, California passed a bill (SB 245) which prohibits spawning, incubating, or cultivating anadromous or transgenic fish species, or any exotic species of finfish in waters of the Pacific Ocean that are regulated by the state.


Atlantic salmon are native to eastern North American coastal drainages from northern Quebec to the Housatonic River, Connecticut (possibly formerly to Delaware); inland to Lake Ontario, where they are now extinct (though restoration efforts are ongoing) (see Figure 2). They also are native to Europe from the Arctic Circle to Portugal (Page and Burr 1991). Unsuccessful attempts were made in the early 20th Century by Canadian and United States federal agencies to introduce Atlantic salmon to Pacific waters. According to the Washington Department of Fish and Wildlife, the release of Atlantic salmon smolts, for the purpose of establishing runs in Washington, occurred in 1951, 1980, and 1981. These releases failed to establish Atlantic salmon in Washington State.

The value of British Columbia-farmed salmon (mostly Atlantic) was $308 million in 2003 (Canadian dollars). Washington produced 16.7 million pounds of Atlantic salmon, worth $14.7 million in 2001 (Kerwin 2003). See Figure 1 for a map of British Columbia fish farm (net pen) sites.

The growth of the farmed Atlantic salmon industry in the past 20 years has severely impacted the West Coast commercial salmon industry by driving down prices and shifting the market share. Alaska’s share of the world salmon market fell from 40 percent in 1980 to 20 percent in 2000 (Knapp 2003). The price of commercially caught Chinook salmon in Alaska fell from $2.69 a pound in 1988 to $1.30 in 2002; and the ex-vessel value for all commercially caught salmon species fell from a high of $782 million in 1988 to about $163 million in 2002 (ADFG 2005). However, more recently, wild salmon prices have rebounded.

Concerns regarding Atlantic salmon effects on wild salmon stocks include disease transfer, pollution from net pen facilities, and ecological impacts from escaped salmon. For further information, go to Environmental Impacts of Atlantic Salmon Aquaculture

A major concern in recent years has been the potential impact on wild salmon stocks of sea lice (Lepeophtheirus sp.) originating from net pens in British Columbia. It is known that marine salmon farms have contributed to the spread of sea lice to wild fish and that sea lice can kill juvenile fish, even at low infestation levels. There is suggestive evidence of impacts from sea lice to wild populations of salmon (Gallaugher et al. 2004).

Atlantic salmon that have escaped from hatcheries show up as adults in commercial and recreational catches in Washington, British Columbia, and Alaska. There is one documented instance of an Atlantic salmon caught in the Bering Sea (Brodeur and Busby 1998). Feral Atlantic salmon juveniles were found in three Vancouver Island, British Columbia, streams (Tsitika, Adam, and Amor De Cosmos) in 1998 (Volpe et al. 2000), indicating the likelihood of successful spawning of net pen-reared fish in the wild. In reviewing the scientific literature that is available through September 2006, there have been no further reports of Atlantic salmon successfully spawning on the West coast in the wild (i.e., discovery of wild juveniles) since the 2000 British Columbia sightings.

Since 2003, with funding from Pacific States Marine Fisheries Commission (PSMFC) and the National Oceanic and Atmospheric Administration, the Washington Department of Fish and Wildlife (WDFW) has been monitoring for Atlantic salmon in selected freshwater streams primarily using snorkel surveys. In 2003, an estimated 1,000 to 2,000 Atlantic salmon juveniles were found in Scatter Creek (Chehalis River Basin) and three Atlantic salmon juveniles were found in Cinnabar Creek (Cowlitz River Basin). The source of these fish was Atlantic salmon hatcheries. According to WDFW, after fish screen repair was done at the Scatter Creek hatchery in 2004, snorkelers found “a few” fish (through June 2006). No juveniles have been found in Cinnabar Creek since 2003, but scoop traps on both the Chehalis and Cowlitz Rivers have captured Atlantic salmon for a number of years. To date, there is no evidence that these fish are wild progeny. In the 1980s, the Washington Department of Fish and Wildlife also reported “a few” Atlantic salmon at the McNary juvenile fish collection facility. These fish were attributed to the net pens located in Rufus Woods Reservoir (Columbia River mainstem, north central Washington). For data on juvenile Atlantic salmon sitings, please go to the Atlantic salmon data page.

In Washington State, while Atlantic salmon escapes from marine net pens still occur, the number of reported escapes has trended downward (1996-1999: 613,000; 2000-2003: 0, 2004: 24,552, 2005: 2,500). In 2006, Atlantic salmon adults were caught in both Alaska and Washington. The Alaska fish were captured by a set net in Cook Inlet in July 2006. Based on their thermal marks (per Washington State Law), the Atlantic salmon appear to be from the Scatter Creek Hatchery in Rochester, Washington (Chehalis Basin). These fish escaped as adults during a transfer in May 2006 from a net pen to a barge in Puget Sound. Although they were apparently healthy at the time of capture, it was likely they had not fed after their escape (Piorkowski 2006).

For more information on escapes and captures in British Columbia, Washington and Alaska, go to the Atlantic salmon data page.

Economic Value of West Coast Fisheries Resources that Could Potentially be Affected by Atlantic Salmon

Pacific Salmon, Alaska: Estimated ex-vessel value (preliminary) for the 2004 Alaska salmon harvest was $235,859,000. (Alaska Department of Fish and Game, Division of Commercial Fisheries, 2005).

Pacific Salmon (coho, chinook), Cape Falcon, Oregon to Canadian Border, Ocean Fishery (Pacific Fisheries Management Council 2005):

  • Estimates of ex-vessel value for Council-adopted 2005 non-Indian commercial troll salmon fishery was $1,798,000.
  • Coastal community income from the 2004 recreational ocean fishery was $7,625,000.

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Geographic Distribution (USA): Atlantic Salmon (Salmo salar)


Source: U.S. Geological Survey

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[intlink id=”37″ type=”page”]PSMFC Funded Projects[/intlink]

[intlink id=”49″ type=”page”]Publications[/intlink]

[intlink id=”31″ type=”page”]Educational Materials[/intlink]


Prince William Sound Regional Citizens Advisory Council NIS Species and Technology Fact Sheets
Alaska Department of Fish and Game
Fisheries and Oceans Canada
Washington Department of Fish and Wildlife
U.S. Geological Survey Atlantic Salmon Fact Sheet
FAO Fisheries Global Information System Atlantic Salmon Fact Sheet

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ADFG (Alaska Department of Fish and Game, Division of Commercial Fisheries). 2005. Salmon Ex-vessel (Price per Pound) by Area and Species. Juneau, Alaska.

Brodeur, R. D. and M. S. Busby. 1998. Occurrence of an Atlantic salmon Salmo salar in the Bering Sea. Alaska Fishery Research Bulletin, 5: 64-66.

Gallaugher, P., J. Penikett, and M. Berry. 2004. Speaking for the Salmon Workshop: A Community Workshop to Review Preliminary Results of 2003 Studies on Sea Lice and Salmon in the Broughton Archipelago Area of British Columbia. Burnaby, BC, Centre for Coastal Studies, Simon Fraser University.

Kerwin, John. 2003. Presentation at the Conference on Marine Aquaculture: Effects on the West Coast and Alaska commercial fishing industry. Pacific States Marine Fisheries Commission. November 17-19, 2003. Seattle, Washington.

Knapp, Gunnar. 2003. Univ. of Alaska, Fairbanks Conference on Marine Aquaculture: Effects on the West Coast and Alaska Commercial Fishing Industry. November 17-19, 2003. Seattle, Washington.

L.M. and B. M. Burr. 1991. A field guide to freshwater fishes of North America north of Mexico. The Peterson Field Guide Series, Volume 42. Houghton Mifflin Company, Boston, MA.

Pacific Fishery Management Council. 2005. Preseason Report III. Analysis of Council Adopted Management Measures for 2005 Ocean Salmon Fisheries. Published April 2005.

Piorkowski, Robert. 2006. Personal Communication. Alaska Department of Fish and Game. Juneau, Alaska.

Volpe, J.P., E.B. Taylor, D.W. Rimmer and B.W. Glickman. 2000. Natural reproduction of aquaculture escaped Atlantic salmon (Salmo salar) in a coastal British Columbia river. Conservation Biology, 14: 899-903.

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ANS Examples



(Caulerpa Taxifolia)

Nicknamed “killer algae”, part of this species success as an invader in non-native habitats is the lack of natural predators. Predation by herbivorous fish and invertebrates is an important controlling factor in the ecology of this alga. C. taxifolia grows unchecked in environments with no natural predators.