Atlantic Salmon

Atlantic Salmon (farmed)

Salmo salar

Sometimes known as Eastern salmon or farmed salmon.

This species is farm-raised.

Summary

There are high environmental costs in farming salmon such as water pollution, disease, the high content of wild fish in feed, and overuse of antibiotics. All Atlantic Salmon sold in the U.S. is farmed.

These fish contain levels of mercury or PCBs that may pose a health risk to adults and children. Please refer to www.EnvironmentalDefense.org/seafood for more details.

Criterion Points Inherent Operational Risks 0.75 Feed 1.25 Pollution 0.75 Risk to Other Species 0.25 Ecological Effects 1.75 Final Score (average of criteria) 0.95 Color

Final Score Color 2.60 - 4.00 2.20 - 2.59 1.80 - 2.19 1.40 - 1.79 0.00 - 1.39

Last updated January 9, 2006.

Inherent Operational Risks

Core Points (only one selection allowed)

General System Design:

An aquaculture system's design is a good overall proxy measure for the likely effect of the operation on the environment. For example, open systems (e.g., net pens and net cages) are more likely to have pollution, disease, and escape issues than closed systems (e.g., recirculating tanks). With shellfish, which don’t require supplemental food input, the more important question is whether they are harvested on or off of the bottom.

1.00	This species is raised in a high risk system (e.g., net pens; net cages). Atlantic salmon are almost exclusively raised to market size in marine net pens (Naylor et al. 1998).
2.00	This species is raised in a moderate risk system (e.g., most ponds; raceways; bottom culture of mollusks).
3.00	This species is raised in a low risk system (e.g., re-circulating closed system; suspended culture of mollusks; zero-discharge ponds).

Points of Adjustment (multiple selections allowed)

-0.25	Species is raised at a high stocking density; OR there is a high density of sites in the geographic region, with evidence of environmental impact. A common maximum stocking density is 25 kg per cubic meter, which is high. In the United States and Canada, Atlantic salmon farms are clustered into two small areas at the U.S.-Canadian border on either coast. Environmental impacts such as nutrient blooms and discharge of antibiotics into the environment are frequent (Molver et al. 1988; Folke et al. 1994; Swanson 2001).
-0.25	Operations do not incorporate best-available, cost-effective technology to reduce environmental impact.
-0.25	There are no effective zoning or permitting practices for siting of facilities.
-0.25	Government programs encourage expansion of high-impact systems.

+0.25	Species is raised at a low stocking density OR there is a low density of sites in the geographic region, which results in minimal impact to the natural ecosystem.
+0.25	Operations incorporate innovative culture methods that limit environmental impacts (e.g., polyculture).
+0.25	There are effective zoning or permitting practices for siting and operation of facilities (e.g., mandatory consideration of hydrographic characteristics; requirements for site rotation).
+0.25	Government programs preferentially encourage the expansion of low-impact systems over high impact systems.

0.75	Points for Inherent Operational Risks

Feed

Core Points (only one selection allowed)

Ecological Footprint of Feed:

"Trash" fish, frequently used in developing countries, is an industry term used to refer to whole fish or fish parts fed to farmed fish without being processed into fish meal and fish oil.

Twenty percent was selected as a cut-off because carnivorous species (e.g., salmon; eel; tuna; cobia; etc.) generally consume greater than twenty percent fish products (fishmeal, fish oil, or trash fish), while omnivorous or herbivorous species (e.g., catfish; tilapia; carps; etc.) consume less than twenty percent fish products.

1.00	Typical aquaculture feed includes high levels of fishmeal, fish oil, or "trash" fish (i.e., >20% of the feed; e.g., salmonid feeds). Salmon diets consist of 45% fishmeal and 25% fish oil (Naylor et al. 1998).
2.00	Typical aquaculture feed includes moderate levels of fishmeal, fish oil, or "trash" fish (i.e., <20% of the feed; e.g., tilapia and catfish feeds).
3.00	No feed is used (e.g., mollusks and seaweeds) or typical aquaculture feed includes no fishmeal, fish oil, or "trash" fish (e.g., paddlefish; filter-feeding carps).

Points of Adjustment (multiple selections allowed)

-0.25	When fish products are used, the major sources score low on the Wild-Caught Fisheries Ranking System.
-0.25	Feed contains greater than 10% of fish products and public or private sectors are not working to reduce fish content in feed.
-0.25	Feed conversion ratio (FCR) is high (i.e., >2.0; e.g., eel).
-0.25	Government policy promotes research, development and commercialization of carnivorous or other highly fishmeal-dependent species.

+0.25	When fish products are used, the major sources score high on the Wild-Caught Fisheries Ranking System; OR the source is innovative and ecologically sound (e.g., fisheries byproducts); OR no feed is used.
+0.25	Feed contains less than 10% of fish products OR public and private sectors are working to reduce the fish content in feed; OR no feed is used.
+0.25	Feed conversion ratio (FCR) is low (i.e., <1.3; e.g., salmon); OR no feed is used. The FCR is approximately 1.3, and is lower in many instances.
+0.25	Government policy promotes research, development and commercialization of herbivorous species or other species not highly dependent on fishmeal.

1.25	Points for Feed

Pollution

Core Points (only one selection allowed)

Typical effluent treatment procedures:

1.00	Effluent is not treated before discharge (e.g., salmon net pens). Farmed Atlantic salmon are raised in net pens, which allow all effluent to flow freely into the surrounding waters (Naylor et al. 1998).
2.00	Effluent is partially treated before discharge (e.g., infrequently discharged effluent from catfish ponds).
3.00	Effluent is substantially treated before discharge (e.g., recirculating shrimp systems; settling ponds; reconstructed wetlands); OR treatment is not necessary because supplemental feed is not used (e.g., molluscs or seaweeds).

Points of Adjustment (multiple selections allowed)

-0.25	Operations have demonstrated negative impacts on water quality or sediment/benthic characteristics (e.g., elevated nutrient levels; algal blooms; altered benthic communities). Salmon feces and uneaten, decomposing feed impact water quality. These nutrient releases can cause phytoplankton growth, which can lead to hypoxia in the water column (Silvert and Sowles. 1996 ).
-0.25	Pollutants (e.g., pesticides; parasiticides; antibiotics; plastic; nets; dead fish) are frequently discharged into the environment or otherwise not appropriately discarded. The frequency and regulatory authority over antibiotic use varies on a national basis. The United States has one of the more stringent sets of regulations; however, U.S. farms only produce a minor portion of the Atlantic salmon consumed in the United States (roughly 15,000 mt). Chilean and Canadian farms each exported approximately 50,000 mt of farmed Atlantic salmon to the United States in 2000. Canadian regulations on antibiotic use are reputedly more lenient than strict U.S. controls, but not as lax as Chilean regulations. Imports from the UK, Norway, and Faroe Islands are also significant.
-0.25	Effluent regulations do not exist, are lax, or are poorly enforced, which allows for degradation of the aquatic environment.
-0.25	Available technologies and practices to reduce or recycle waste (e.g., feed sensors; low-pollution feeds) are not used.

+0.25	Operations generally improve water quality or sediment/benthic characteristics (e.g., oyster farms).
+0.25	Chemicals (e.g., pesticides; parasiticides; antibiotics) are rarely or never used.
+0.25	Robust water quality regulations exist (e.g., permits required; discharge caps; strong enforcement), and regular monitoring occurs.
+0.25	Innovative methods and practices to reduce or recycle wastes are used (e.g., integrated systems; effluent and solid wastes used as terrestrial fertilizer); OR innovative methods and practices are not needed because raising this species does not create waste. The salmon farming industry has developed technologies such as video and Doppler radar, which monitor and help reduce the amount of waste from fish feed that flows into the ocean. Experimental operations have used floating tanks or bag systems to recapture some of the solid waste. These designs do not enjoy widespread use though. Polyculture techniques are uncommon as well.

0.75	Points for Pollution

Risk to Other Species

Core Points (only one selection allowed)

Frequency and Impact of Escapes:

1.00	Farmed species regularly or intermittently escape into the wild AND escapes are non-native to the area or otherwise pose a risk to native populations or ecosystems (e.g., most non-native fish raised in outdoor facilities). There have been many incidents of farmed salmon escaping due to bad weather, boat-related accidents, or pinnipeds biting through the nets. Between 30-40% of Atlantic salmon caught in Norway and over 90% of salmon caught in the Baltic Sea originated from fish farms (Hansen et al. 1997; Naylor et al. 2001). Atlantic salmon are non-native to several areas where they are farmed including British Columbia and Chile.
2.00	Escape frequency is not known OR farmed species is native to the area where it is raised and poses minimal risk to native populations or ecosystems (e.g., channel catfish in the US; most native mollusks).
3.00	Farmed species never (or virtually never) escape to the wild (e.g., species is raised in bio-secure facilities).

Points of Adjustment (multiple selections allowed)

-0.25	This farmed species has been known to survive in the surrounding ecosystem if it escapes; OR would likely survive given its physiological requirements. Substantial catches of Atlantic salmon, which have escaped from farms, in Norway and in the Baltic Sea show that Atlantic salmon survive if they escape (Hansen et al. 1997; Naylor et al. 2001).
-0.25	This farmed species is known or is likely to compete with wild species for food or habitat if it escapes; OR this species is known or is likely to compromise the genetic integrity of the wild species (e.g., through spawning disruption, genetic introgression or establishment of feral stocks) if it escapes. According to NMFS and the US Fish and Wildlife Service, escaped Atlantic salmon in Maine pose a threat to wild stocks of Atlantic salmon in Maine through disease and interbreeding. There is also concern that escaped Atlantic salmon are reproducing in British Columbia rivers and competing with wild salmon there.
-0.25	This farmed species is known or is likely to amplify and transmit disease or parasites to wild populations (e.g., infectious salmon anemia or sea lice infestations) if it escapes. Infectious salmon anemia has been known to spread from farmed salmon to wild salmon. It was discovered in Norway and Scotland in the 1980s, and has since spead to Canada and Maine (Revkin 2001). Sea lice is spread from farmed to wild populations (IMB 1998). Another disease that regularly afflicts farmed salmon, Furunculosis, is transferable to other salmon, halibut and cod (Hjeltnes 1995).
-0.25	Regulatory authorities are not adequately addressing the risks of escape or spread of disease associated with farming this species.

+0.25	This farmed species has not been known to survive in the surrounding ecosystem if it escapes; OR would not likely survive given its physiological requirements; OR farmed species is a native mollusc.
+0.25	Operations employ management protocols and techniques to limit the ecological impacts of escaped farmed fish (e.g., triploidy; sterilization); OR it’s unlikely that escaped individuals will either compete with wild species for resources, or compromise the genetic integrity of wild species.
+0.25	Operations employ effective disease and parasite management protocols (e.g., fallowing of pens; retaining water when disease outbreak occurs); OR incidence of disease or risk of retransmitting disease is low.
+0.25	Regulatory authorities are addressing the risks of escape and spread of disease associated with farming this species.

0.25	Points for Risk to Other Species

Ecological Effects

Core Points (only one selection allowed)

Ecological sensitivity of site used for operations:

1.00	Operations are generally located in areas of high ecological sensitivity (e.g., coastal wetlands; mangroves).
2.00	Operations are generally located in areas of moderate ecological sensitivity (e.g., coastal and nearshore waters; rocky intertidal or subtidal zones; river or stream shorelines). Operations are located in coastal bays (Naylor et al. 1998).
3.00	Operations are generally located in areas of low ecological sensitivity (e.g., land that is less susceptible to degradation such as land formerly used for agriculture or land previously developed).

Points of Adjustment (multiple selections allowed)

-0.25	Farming this species causes substantial damage to surrounding habitat, ecosystem or other resources (e.g., groundwater depletion; stream diversion; saltwater intrusion; soil salinization; loss of habitat for juvenile fish; loss of flood control; dredging hard bottoms; etc.).
-0.25	Harmful or lethal predator deterrents are used (e.g., bird/seal shootings; acoustic deterrent devices); OR operation otherwise harms wildlife (e.g., dolphin/seal entanglement; disrupting migration routes; bird/animal shooting). Some salmon farms use ADDs and AHD, acoustic deterrent devices and acoustic harassment devices, to keep away mammalian predators. These devices have been shown to alter the pathways of other mammals such as killer whales.
-0.25	If seed is collected from wild sources, the intensity of collection is high enough to result in depletion of brood stock, wild juveniles, or associated non-target organisms (e.g., collection of postlarvae shrimp).
-0.25	Government policy encourages aquaculture operations to locate or expand in areas of high ecological sensitivity.

+0.25	Operations enhance habitat structure or function (e.g., constructed wetlands).
+0.25	Predator deterrents are not used OR predator deterrents are used but are not harmful or lethal (e.g., predator exclusion nets), AND operation does not otherwise harm wildlife.
+0.25	Seed comes predominantly from hatcheries or on-farm sites (e.g., seed for trout); OR if seed is collected from the wild, it does not deplete brood stock, wild juveniles, or associated non-target organisms (e.g., collection of oyster or mussel spat).
+0.25	Government policy encourages the growth of aquaculture operations in areas of low ecological sensitivity; OR protects sensitive habitats from aquaculture operations (e.g., prohibitions on cutting mangroves).

1.75	Points for Ecological Effects

References

*We would like to thank Monterey Bay Aquarium's Seafood Watch Program for their research contribution toward this Score Card.

Benbrook, C.M., Antibiotic Drug Use in U.S. Aquaculture. 2002, The Northwest Science and Environemental Policy Center.

EAO, Salmon Aquaculture Review. 1995, Environmental Assessment Office, British Columbia: British Columbia.

EPA, EPA Press Release: EPA Issues Aquaculture Permit for Maine Fish Farm. 2002, Environmental Protection Agency.

Hansen, L.P., D.G. Reddin, and R.A. Lund, Short communication: The incidence of reared Atlantic salmon (Salmo salar L.) of fish farm origin at West Greenland. ICES Journal of Marine Science, 1997. 54(1): p. 152-155.

Hewitt, R., Salmon farm receives water quality permit, in Bangor Daily News. 2002: Bangor, Maine. p. 1.

Hjeltnes, B., et al., Susceptibility of Atlantic cod Gadus morhua, halibut Hippoglossus hippoglossus and wrasse (Labridae) to Aeromonas salmonicida subsp. salmonicida and the possibility of transmission of furunculosis from farmed salmon Salmo salar to marine fish. Diseases of Aquatic Organisms, 1995. 23: p. 25-31.

IFFO, FISHMEAL INFORMATION NETWORK: SUSTAINABILITY DOSSIER. 2001, INTERNATIONAL FISHMEAL & FISH OIL ORGANISATION.

IMB, Press Release: IMB Battles sea lice. 1998, National Research Council of Canada: Institute for Marine Biosciences.

IntraFish, China is the world's biggest buyer of fishmeal. 2001, IntraFish.

Molver, J., A. Stigebrandt, and V. Bjekenes. On the excretion of nitrogen and phosphorus from salmon. in Aquaculture International Congress and Exposition. 1988. Vancouver, B.C.

Nash, C.E.e., The net-pen salmon farming industry in the Pacific Northwest (NOAA Technical Memo). 2001, U.S. Department of Commerce, NMFS.

Naylor, R.L., S.L. Williams, and D.R. Strong, Aquaculture--A Gateway for Exotic Species. Nature, 2001. 294: p. 1655-1656.

Naylor, R.L., et al., Nature's Subsidies to Shrimp and Salmon Farming. Science, 1998. 282(5390): p. 883-884.

Pike, I.H. and S.M. Barlow. FISH MEAL AND OIL TO THE YEAR 2010, SUPPLIES FOR AQUACULTURE. in WORLD AQUACULTURE 99. 2001. SYDNEY, AUSTRALIA.

Revkin, A.C., Virus Is Killing Thousands of Salmon, in New York Times. 2001: NY,NY.

Silvert, W. and J.W. Sowles, Modelling environmental impacts of marine finfish aquaculture. Journal of Applied Ichthyology, 1996. 12: p. 75-81.

Swanson, E., Personal Communication. 2001.