Seafood Results

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.

Learn more about harvest methods

• Gillnet
• Trap net

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.

Learn more about harvest methods

• Recirculating Aquaculture Systems (RAS)

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.

Learn more about harvest methods

• Recirculating Aquaculture Systems (RAS)

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.

Learn more about harvest methods

• Gillnet
• Trap net

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%.

Learn more about harvest methods

• Open net pen