Shrimp (farmed, U.S.)

Pacific Whiteleg Shrimp (Litopenaeus vannamei)

This species is farm-raised.

Summary

Farmed shrimp require high amounts of fishmeal and fish oil in their food compared to other farmed fish and shellfish. To reduce pollution when shrimp water is discharged, it is usually treated. Imported farmed shrimp come from areas with weaker environmental protections, and practices commonly damage ecosystems. U.S. farm-raised shrimp are a better alternative to imported farm-raised shrimp and to trawl-caught shrimp.

Criterion	Points
Inherent Operational Risks	2.00
Feed	1.25
Pollution	2.75
Risk to Other Species	2.00
Ecological Effects	3.50
Final Score (average of criteria)	2.30
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 July 18, 2005.

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).
2.00	This species is raised in a moderate risk system (e.g., most ponds; raceways; bottom culture of mollusks). Most marine shrimp are raised in coastal or inland systems with little or no discharge except at harvest (Rosenberry 2003; Samocha et al. 2002; Treece 2002). In 2002, Texas - the major shrimp farming state - had nine coastal and five inland farms (TAA 2004; Rosenberry 2003). Other states with inland farms include California, Arizona, Arkansas, Alabama, North Carolina, South Carolina, and Florida (US MSFP 2004a).
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. Shrimp are raised at medium to high stocking densities (Farnham 2003; Rosenberry 2003; Baker 1997). Generally sites are at low density, except for two adjacent farms on the South Texas coastline (Baker, pers. comm., 2004). We chose not to subtract here because shrimp are not always raised at a high stocking density in U.S. farms, and the farms are not densely packed in any one region.
-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. Government research and development programs encourage a number of good practices (Samocha et al. 2002), along with a few less desirable ones, such as the approval of antibiotics for use in U.S. shrimp production.

2.00	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). In 2002, fishmeal and fish oil comprised on average 23% and 2%, respectively, of global shrimp feeds (Tacon 2004). Some U.S. shrimp farms may use feed that contains less fishmeal. Pacific Whiteleg Shrimp - the predominant species raised in the US - feed at a lower trophic level than Tiger Shrimp - the other species that constitutes a major fraction of world farmed shrimp production. However, we are aware of no data on fishmeal and fish oil use in U.S. shrimp feeds.
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. The U.S. government is not promoting research and development for more fishmeal-dependent shrimp species, although it is promoting farming of carnivorous marine finfish 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. There is some U.S. research and development looking into ways to reduce fishmeal levels in shrimp feed (US MSFP 2004b).
+0.25	Feed conversion ratio (FCR) is low (i.e., <1.3; e.g., salmon); OR no feed is used.
+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).
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). Texas shrimp farms rarely discharge wastewater except at harvest (Farnham 2003). Effluent is generally treated with settling basins or constructed wetlands (Baker, pers. comm., 2004).

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).
-0.25	Pollutants (e.g., pesticides; parasiticides; antibiotics; plastic; nets; dead fish) are frequently discharged into the environment or otherwise not appropriately discarded.
-0.25	Effluent regulations do not exist, are lax, or are poorly enforced, which allows for degradation of the aquatic environment. The U.S.’s Environmental Protection Agency’s effluent discharge limitation guidelines for aquaculture, finalized in 2004, do not mandate discharge permits for aquaculture ponds. However, some states, including Texas, regulate effluent discharges from shrimp ponds.
-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. Some U.S. shrimp farms use innovative methods (e.g., biofilters, integrated aquaculture) to handle wastes, but others do not.

2.75	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).

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).

U.S. coastal shrimp ponds only discharge effluent during harvest (Farnham 2003). There have been documented escapes from Texas farms in the past. Farms have since implemented biosecurity measures, and no escapes have been documented in the last several years (Baker, pers. comm., 2004). Escape to marine waters from inland farms is virtually impossible.

Pacific Whiteleg Shrimp are native to the Pacific coast of the U.S., but not to the Atlantic and Gulf of Mexico coasts.

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. Shrimp from coastal ponds may survive if they escape (Baker 1997).
-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.
-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.
-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. When disease outbreaks occur at coastal U.S. shrimp farms, they retain the pond water to prevent the spread of disease to wild populations. However, the potential transfer of shrimp viruses from coastal aquaculture facilities to wild populations remains a concern (Baker 1997).
+0.25	Regulatory authorities are addressing the risks of escape and spread of disease associated with farming this species. There are now strict regulations in Texas to quarantine and otherwise prevent the spread of disease from coastal shrimp farms to wild populations (Farnham 2003). Some other states (e.g., South Carolina) also have regulations in place to reduce the likelihood of disease transmission.

2.00	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).
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). Most U.S. shrimp ponds are on former agricultural land or on land that is otherwise not of special ecological sensitivity (Baker, pers. comm., 2004).

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).
-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). U.S. shrimp farm stock comes from hatcheries.
+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). U.S. permit requirements discourage construction of shrimp farms in wetlands -- the primary type of sensitive habitat that has been lost to shrimp farms in other countries.

3.50	Points for Ecological Effects

References

**We would like to thank Environmental Defense for their U.S. farmed shrimp research and contributing this score card to our Seafood WebGuide.

Baker, P.B. 2004. Personal communication. Environmental Defense.

Baker, P.B. 1997. Coastal Shrimp Farming in Texas: A Case Study. In Murky Waters: Environmental Effects of Aquaculture in the United States. Environmental Defense, Washington D.C.

Farnham, T.T. 2003. The Texas Coastal Shrimp Farm Industry: A History and Update on Environmental Performance. Memo drafted for Environmental Defense, Nov. 2003.

Rosenberry, B. 2003. World Shrimp Farming. Shrimp News International, Number 16.

Samocha, T. M., L. Hamper, C. R. Emberson, A. D. Davis, D, McIntosh, A. L. Lawrence, P. M. Van Wyk. 2002. Review of some recent developments in sustainable shrimp farming practices in Texas, Arizona, and Florida. Journal of Applied Aquaculture 12: 1-42.

Tacon, A.G.J. 2004. Use of fish meal and fish oil in aquaculture:

a global perspective. Aquatic Resources, Culture and Development 1(1), 1–12.

Texas Aquaculture Association (TAA). 2004. Available at: http://www.texasaquaculture.org/id127.html.

Treece, G. 2002. Shrimp Farm Effluents. In: Responsible Marine Aquaculture, eds. Stickney, R. R. and J. P. McVey. CAB International, pp. 297-309.

U.S. Marine Shrimp Farming Program (US MSFP). 2004a. Newsletter. Available at: http://www.usmsfp.org/news/Newsletter/4-2004/page4-article1.htm.

US MSFP. 2004b. Newsletter. Available at: http://www.usmsfp.org/news/consort.htm.