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Ocean Wise Recommended

Ocean Wise

Variety

Rainbow trout, steelhead

Oncorhynchus mykiss

Method

Farmed

Open net pen

Location

United States

Overall Rating

6.71 / 10

Summary

Rainbow trout are native throughout many freshwater systems of North America and have also been introduced as sport fish. The US produces 15,000 mt of rainbow trout and is the 10th largest producer in the world. The majority of the aquaculture operation occurs in raceways, but 3,600mt is produced in net pens from a single farm in the Columbia River, Washington.

The nature of open net pens allows for effluent containing excess feed and fish waste to flow directly into the environment. However, the habitat surrounding the farm is strictly monitored, and has not been observed to have been significantly affected. Cumulative impacts of numerous farms in one area are minimized due to strict regulation which limits the size of the industry. Although few chemicals are used, the open net pens allow the chemicals to be discharged into the surrounding water.

Rainbow trout are sourced from domesticated broodstock. This relieves fishing pressure on wild populations of rainbow trout. However, rainbow trout aquaculture uses wild fish resources in the form of feed. Rainbow trout are carnivorous fish which require about 1.5lbs of fish in the form of feed for every 1lb which they produce. They are raised with a net loss of protein.

The risk of escapes in open net pen systems is high. However, since the farmed rainbow trout are sterile, they cannot breed and genetically compromise wild populations. Furthermore, hatchery-raised rainbow trout are intentionally stocked in the wild for sports fishing. Therefore any escapes would not significantly change the present ecosystem. Open net pens can cause transfer of disease from farmed fish to wild populations. In the case of rainbow trout in the US, vaccines and effective husbandry and management greatly reduce this risk.

Data quality and understanding of rainbow trout operations in the US is high. Scientific literature, industry data and government information is also readily available. Management limits the size of the industry in order to minimize cumulative environmental impacts of numerous farms.

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Ocean Wise Recommended

Ocean Wise

Variety

Brook trout, speckled trout

Salvelinus fontinali

Method

Farmed

Recirculating Aquaculture Systems (RAS)

Location

Worldwide

Overall Rating

6.7 / 10

Summary

Recirculating aquaculture systems (RAS) are similar for various farmed species. This recommendation applies to all species grown in RAS except for those where a separate species-specific RAS recommendation is available. Closed containment has recently emerged in the farming industry as an alternative to net pens in order to reduce the environmental impacts of an aquaculture system that is open to the environment.

Source of stock is domesticated broodstock for the vast majority of RAS farms. Therefore wild populations are not depleted to source the aquaculture operations. Impacts of feed use vary amongst RAS farms and the species being cultured.

The contained nature of RAS allows for close control and prevention of potential disease or parasite outbreaks. Risk of pathogens and their transfer to wild populations is low. Predator and wildlife mortalities are virtually eliminated when RAS systems are located indoors, and risk of escapes is low as the systems are not in direct contact with natural water bodies.

About 90-99% of water is typically recirculated after filtration and waste treatment. As such, little to no effluent is discharged to the environment and there is the opportunity to treat waste before discharge. The closed design of RAS and the application of biosecurity protocols reduce the risk of disease and parasites, and consequently require low use of chemicals. When chemicals are used, they cannot flow into the environment directly, and have the opportunity to be treated and sterilized before discharge. RAS farms are typically not built in sensitive habitats, and the closed system of the farms minimizes ecosystem impacts.

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Ocean Wise Recommended

Ocean Wise

Variety

Lake trout

Salvelinus namaycush

Method

Wild

Gillnet, Trap net

Location

Canada (Lake Huron), US (Lake Huron, Lake Superior - Michigan and Minnesota, Lake Michigan)

Overall Rating

2.8 - 2.9 / 5

Summary

Although once an abundant species, lake trout population levels decreased steeply in the mid 20th century due to overfishing and predation by exotic sea lamprey. By 1960, lake trout were almost extirpated from the Great Lakes except for Lake Superior. Populations in Lake Huron have increased over the past 30yrs due to re-stocking efforts. Lake trout fisheries are small and restricted in the Great Lakes. In 2012, 200.9 tonnes of lake trout were landed in Canada which represented 62% of the lake trout quota.

Management of the Great Lakes fisheries is shared between several organizational bodies, which collaborate under Lake Committees. Management is moderately effective; the various regulatory measures concern research, enforcement, stocking, quotas, water quality monitoring, stock assessments, and other issues. Rehabilitation efforts of lake trout in Lake Huron are actively managed with specific strategies that are developed and applied in order to restore the stocks. Stock status of lake trout has recently been improving as a result of these measures. Lake trout have life history characteristics that make them vulnerable to fishing pressure. They are the largest trout species as well as the top native predators in the Great Lakes. Stock status in Lake Huron is poor although efforts to rehabilitate the population are underway. The population in Lake Michigan is recovering, and the population in Lake Superior is stable and healthy.

Bottom gillnets and trapnets cause minimal habitat impacts. Although these fishing methods make contact with the substrate, they are immobile and do not cause physical destruction of the lake bottom. Little bycatch occurs. Most non-target fish are retained and sold portside as they have commercial value.

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Ocean Wise Recommended

Ocean Wise

Variety

Rainbow trout

Oncorhynchus mykiss

Method

Farmed

Recirculating Aquaculture Systems (RAS)

Location

Worldwide

Overall Rating

6.7 / 10

Summary

Recirculating aquaculture systems (RAS) are similar for various farmed species. This recommendation applies to all species grown in RAS except for those where a separate species-specific RAS recommendation is available. Closed containment has recently emerged in the farming industry as an alternative to net pens in order to reduce the environmental impacts of an aquaculture system that is open to the environment.

Source of stock is domesticated broodstock for the vast majority of RAS farms. Therefore wild populations are not depleted to source the aquaculture operations. Impacts of feed use vary amongst RAS farms and the species being cultured.

The contained nature of RAS allows for close control and prevention of potential disease or parasite outbreaks. Risk of pathogens and their transfer to wild populations is low. Predator and wildlife mortalities are virtually eliminated when RAS systems are located indoors, and risk of escapes is low as the systems are not in direct contact with natural water bodies.

About 90-99% of water is typically recirculated after filtration and waste treatment. As such, little to no effluent is discharged to the environment and there is the opportunity to treat waste before discharge. The closed design of RAS and the application of biosecurity protocols reduce the risk of disease and parasites, and consequently require low use of chemicals. When chemicals are used, they cannot flow into the environment directly, and have the opportunity to be treated and sterilized before discharge. RAS farms are typically not built in sensitive habitats, and the closed system of the farms minimizes ecosystem impacts.

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Ocean Wise Recommended

Ocean Wise

Variety

Rainbow trout, steelhead

Oncorhynchus mykiss

Method

Wild

Midwater gillnet

Location

US Washington Quillayute River

Overall Rating

2.937 / 5

Summary

Steelhead are rainbow trout that spend part of their life in the ocean. Ocean Wise does not recommend US wild steelhead except for those coming from the Quillayute River. While the Chehalis, Hoh, Queets, Quinault, and Humptulips rivers catch bycatch species of concern including threatened bull trout or green sturgeon, the Quillayute River fishery’s bycatch is primarily Chinook and coho salmon. These two salmon species are not species of concern. All commercial fishing for steelhead in Washington is conducted by First Nations Indian tribes. The fishery is relatively well-managed. Regulations include habitat restoration, and the improvement of hatcheries to minimize their impacts on wild fish. Catches in the Quillayute River have varied between 3,988 and 11,546 steelhead per year between 2000 and 2013. Wild steelhead is consumed locally within the US.

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Ocean Wise Recommended

Ocean Wise

Variety

Rainbow trout, steelhead

Oncorhynchus mykiss

Method

Farmed

Pond, Raceway

Location

US

Overall Rating

6.72 / 10

Summary

Rainbow trout are native to North America and have been introduced in many countries for the purpose of sport fishing. The US produces over 20,000 mt of rainbow trout annually, and imported 12,000 mt of rainbow trout in 2015. Although trouts farmed in flow-through systems has the potential to cause much waste water and some habitat damage, well-regulated and enforced management schemes have resulted in low effluent concerns and minimal habitat impacts. While chemicals such as antibiotics are used, the quantities have decreased significantly over the past five years. Additionally new regulations require that any medicated feed be administered under veterinary prescription and oversight. The feed used to raise farmed trout requires fish meal and fish oil. Every 1lb of farmed trout requires 1.25lbs of wild fish in the form of feed. As rainbow trout have been intentionally stocked in North America via hatcheries, escaped rainbow trout would not have significant effects on the wild population, unless they happened to interact with genetically pure native fish. There is little evidence to show transmission of disease from farmed to wild populations.  As farmed trout is sourced from domestic broodstock, wild populations are not depleted by the farming operations.

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Variety

Lake trout

Salvelinus namaycush

Method

Wild

Gillnet, Trap net

Location

Canada (Lake Superior), US (Lake Superior - Wisconsin)

Overall Rating

2.4 - 2.7 / 5

Summary

Although once an abundant species, lake trout population levels decreased steeply in the mid 20th century due to overfishing and predation by exotic sea lamprey. By 1960, lake trout were almost extirpated from the Great Lakes except for Lake Superior. Populations in Lake Huron have increased over the past 30yrs due to re-stocking efforts. Lake trout fisheries are small and restricted in the Great Lakes. In 2011, 21,962kg of lake trout were harvested from Canada Lake Superior which represents 18.4% of the quota.

Management of the Great Lakes fisheries is shared between several organizational bodies, which collaborate under Lake Committees. Management is moderately effective; the various regulatory measures concern research, enforcement, stocking, quotas, water quality monitoring, stock assessments, and other issues. Rehabilitation efforts of lake trout in Lake Huron are actively managed with specific strategies that are developed and applied in order to restore the stocks. Stock status of lake trout has recently been improving as a result of these measures. Lake trout have life history characteristics that make them vulnerable to fishing pressure. They are the largest trout species as well as the top native predators in the Great Lakes. Stock status in Lake Huron is poor although efforts to rehabilitate the population are underway. The population in Lake Superior is recovering. Unlicensed overfishing of lake trout occurs in Canadian Lake Superior.

Bottom gillnets and trapnets cause minimal habitat impacts. Although these fishing methods make contact with the substrate, they are immobile and do not cause physical destruction of the lake bottom. Little bycatch occurs. Most non-target fish are retained and sold portside as they have commercial value.

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Variety

Rainbow trout, steelhead

Oncorhynchus mykiss

Method

Wild

Midwater gillnet

Location

US Washington: Chehalis River, Hoh River, Queets River, Quinault River, Humptulis River

Overall Rating

2.18 - 2.508 / 5

Summary

Steelhead are rainbow trout that spend part of their life in the ocean. Ocean Wise does not recommend US wild steelhead except for those coming from the Quillayute River. While the Chehalis, Hoh, Queets, Quinault, and Humptulips rivers catch bycatch species of concern including threatened bull trout or green sturgeon, the Quillayute River fishery’s bycatch is primarily Chinook and coho salmon. These two salmon species are not species of concern. All commercial fishing for steelhead in Washington is conducted by First Nations Indian tribes. The fishery is relatively well-managed. Regulations include habitat restoration, and the improvement of hatcheries to minimize their impacts on wild fish. Catches in the Quillayute River have varied between 3,988 and 11,546 steelhead per year between 2000 and 2013. Wild steelhead is consumed locally or sold within the US.

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Variety

Rainbow trout

Oncorhynchus mykiss

Method

Open net pen

Location

Chile

Overall Rating

3.8 / 10

Summary

Chile produces approximately 71,000 mt of rainbow trout annually, exporting roughly two-thirds of this, valuing 350 million USD. Due to the open nature of net pen production systems, all waste discharged from a facility directly enters the surrounding environment. There is growing concern of the potential cumulative impacts of nutrient effluent in the surrounding environment. Moreover, the is evidence of developed resistance to florfenicol, the most commonly used antibiotic in Chile, also considered a “highly important” treatment for human medicine by the World Health Organization (WHO). There is also a high degree of overlap between sites designated as ecologically important and the sites of farm operations.  Approximately 1.73 t of wild fish is used to produced 1 ton of farmed trout.  In terms of protein loss, this translate to a net loss of  -54.2%.

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