Aquaculture |
Header Photo: Todd Marsee, Michigan Sea Grant
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Aquaculture is the controlled cultivation of aquatic animals and plants. It refers to the breeding, rearing, and harvesting of plants and animals in all types of water environments, including tanks, ponds, rivers, lakes, and the ocean. Aquaculture is used for a variety of purposes including producing seafood for human consumption; enhancing wild fish, shellfish, and plant stocks for harvest; restoring threatened and endangered aquatic species; producing sportfish and baitfish for commercial and sport fisheries; and providing fish for aquariums.
Globally, aquaculture supplies more that 50 percent of all seafood produced for human consumption Worldwide, aquaculture has been the fastest growing segment of agriculture for the last decade. There is aquaculture in some form or another in all 50 states. The largest production states for marine aquaculture are Maine, Washington, Virginia, Louisiana, and Hawaii. The largest states for freshwater aquaculture are Mississippi (catfish) and Idaho (trout). |
Brown Trout at Oden State Fish Hatchery. Photo Credit: Todd Marsee, Michigan Sea Grant
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The aquaculture industry in the Great Lakes region is not large compared to other areas in the United States. The aquaculture industry includes both private and public (state-owned) fish farms. Currently, Michigan's aquaculture industry is comprised of farms raising fish for use as bait, stocking ponds, fee fishing, and a small number growing fish for food production. As of 2015, Michigan had 43 active registered aquaculture facilities including:
- 24 pond systems
- 14 flow-through systems
- 5 recirculating systems
Types of Aquaculture
Credit: NOAA
Net-Pen (Cage) Aquaculture
Net-pen aquaculture is the practice of raising fish in an underwater net or structure that serves as a pen. Found offshore in coastal areas or in freshwater lakes, open net-pens or cages are considered a high-risk aquaculture method as they allow for free and unregulated exchange between the farm and the surrounding environment. |
Oden State Fish Hatchery, Oden, MI. Credit Todd Marsee, Michigan Sea Grant
Flow-Through Aquaculture
Flow-through systems involve the continual flow of a high-quality water source through a tank or channel called a raceway. The constant flow of water helps provide oxygen into the system while removing wastes from the system. Flow-through systems provide waste treatment as required, and then discharge the water rather than treating and recirculating it. |
Spring Valley Trout Farm in Dexter, Michigan
Pond Aquaculture Systems
Pond cultures are the most common aquaculture production system. An aquaculture project can consist of only one pond, or hundreds of specially designed ponds. The size of the pond varies depending upon its purpose. It is designed to meet the natural environmental requirements of the fish being raised and the natural growth of aquatic organisms provides a natural food for the fish and makes the pond an attractive habitat for other aquatic animals. |
Credit: Todd Marsee, Michigan Sea Grant
Recirculating Aquaculture Systems
Recirculating aquaculture systems are indoor, tank-based systems in which fish are grown at high density under controlled environmental conditions. Recirculating systems are the most expensive means of culturing fish, but also the most environmentally friendly. Advantages of recirculating systems include:
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Risks and Concern
Aquaculture, or “fish farming,” under the right conditions can be a viable part of the solution to the increasing pressure on our oceans’ resources and in meeting the demand for seafood by our growing population. The environmental impact of aquaculture depends on the species, the location of the farm, and how they are raised. When the environment is considered, strong management practices are implemented, and good practices are used, it is possible to raise sustainably farmed seafood. However, problems have already transpired and have been remediated in Michigan and throughout the U.S. and world. The following are the primary problems and concerns associated with aquaculture.
Nutrient Pollution
Nutrient pollution can be introduced into water bodies through wastewater from flow-through systems or from open water net-pen systems. Nutrient discharge from fish farming operations is organic and comes from two sources – fish excrement and uneaten fish food that drifts into the water column. Both types of discharge contain nitrogen and phosphorus.
Phosphorus is often the limiting nutrient in aquatic systems, and very small changes in the level of it can lead to significant changes to aquatic ecosystems. In flow-through systems, discharges with excessive nutrients can lead to increases and shifts in algal communities, algae blooms, filamentous algae, less of some pollution intolerant aquatic invertebrates (like stoneflies, mayflies and caddisflies) and even less of certain stream fish populations. Some research has documented brook trout density decreases with minor nutrient pollution. In open water net-pen systems, nutrients and waste would accumulate on the bottom, smothering benthic life, creating anoxic areas. It could also stimulate dangerous Microcystis algae blooms that can render water unsafe for public use, like the one that shut down Toledo's drinking water source in 2014.
Fish Health and Diseases
Crowded fish cages are breeding grounds for disease and parasites. Large and dense fish concentrations increase the probability of disease and the severity of disease outbreaks. Managing disease risks at fish farms often involves applying antibiotics and other pharmaceuticals. The addition of antibiotics and growth hormones to the fish food is similar to other large-scale meat production operations. However, because aquaculture in flow-through systems or open water net-pen systems uses public waters those antibiotics and growth hormones will be released into public waters where they can affect wild fish health and public drinking water supplies.
Escapes
Fish inevitability escape from aquaculture facilities. Fish escape from aquaculture operations for many reasons including human error, extreme weather events (e.g., ice sheet movement, storms, etc.), damage to nets, catastrophic gear failure, and even vandalism. The potential for these fish to escape exists at various stages in their life history, but tends to occur during handling or as a result of damage to infrastructure. The magnitude of escape events can vary from small releases which may go undetected for some time to large-scale releases. These escaped fish will compete with wild fish for food, disrupt their natural reproduction, and interfere with their genetic diversity. These disruptions would erode our wild fish population’s ability to adapt and survive.
In addition, escapes could lead to introductions of invasive species if nonnative species are raised in the net-pens. As we have seen with a number of invasive species, they can result in complete ecological imbalances. The perfect example is the Asian carp - a result of an insufficiently regulated aquaculture operation.
Nutrient pollution can be introduced into water bodies through wastewater from flow-through systems or from open water net-pen systems. Nutrient discharge from fish farming operations is organic and comes from two sources – fish excrement and uneaten fish food that drifts into the water column. Both types of discharge contain nitrogen and phosphorus.
Phosphorus is often the limiting nutrient in aquatic systems, and very small changes in the level of it can lead to significant changes to aquatic ecosystems. In flow-through systems, discharges with excessive nutrients can lead to increases and shifts in algal communities, algae blooms, filamentous algae, less of some pollution intolerant aquatic invertebrates (like stoneflies, mayflies and caddisflies) and even less of certain stream fish populations. Some research has documented brook trout density decreases with minor nutrient pollution. In open water net-pen systems, nutrients and waste would accumulate on the bottom, smothering benthic life, creating anoxic areas. It could also stimulate dangerous Microcystis algae blooms that can render water unsafe for public use, like the one that shut down Toledo's drinking water source in 2014.
Fish Health and Diseases
Crowded fish cages are breeding grounds for disease and parasites. Large and dense fish concentrations increase the probability of disease and the severity of disease outbreaks. Managing disease risks at fish farms often involves applying antibiotics and other pharmaceuticals. The addition of antibiotics and growth hormones to the fish food is similar to other large-scale meat production operations. However, because aquaculture in flow-through systems or open water net-pen systems uses public waters those antibiotics and growth hormones will be released into public waters where they can affect wild fish health and public drinking water supplies.
Escapes
Fish inevitability escape from aquaculture facilities. Fish escape from aquaculture operations for many reasons including human error, extreme weather events (e.g., ice sheet movement, storms, etc.), damage to nets, catastrophic gear failure, and even vandalism. The potential for these fish to escape exists at various stages in their life history, but tends to occur during handling or as a result of damage to infrastructure. The magnitude of escape events can vary from small releases which may go undetected for some time to large-scale releases. These escaped fish will compete with wild fish for food, disrupt their natural reproduction, and interfere with their genetic diversity. These disruptions would erode our wild fish population’s ability to adapt and survive.
In addition, escapes could lead to introductions of invasive species if nonnative species are raised in the net-pens. As we have seen with a number of invasive species, they can result in complete ecological imbalances. The perfect example is the Asian carp - a result of an insufficiently regulated aquaculture operation.
Net-Pen Aquaculture in Michigan
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In 2014, the State of Michigan received proposals to establish privately owned net-pen fish operations in public waters of the Great Lakes – northern Lakes Huron and Michigan. The proposals under consideration are for floating cages packed with thousands of fish to be installed at sites near Escanaba and Rogers City.
While Ontario has established net-pen operations in the North Channel and Georgian Bay in Lake Huron, there are no commercial net-pen aquaculture operations in Michigan’s open waters of the Great Lakes. Ontario has six licensed net-pen operations: one in Parry Sound and five in the North Channel off the Manitoulin Island. Three other aquaculture operations are conducted by First Nations, which are not licensed by Ontario. |
Ontario net-pen operation. Credit: NOAA
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To determine how to proceed and respond to the proposals, a scientific advisory panel was established by the Michigan departments of Natural Resources (MDNR), Environmental Quality (MDEQ) and Agriculture and Rural Development (MDARD). The panel was to look into the scientific, environmental, economic, and regulatory considerations regarding potential Great Lakes aquaculture.
The following reports were produced as part of the process:
Science-based review
Regulations-based review
Economics-based reviews
Commercial Net-pen Aquaculture in the Great Lakes Public Input and Comment
Synthesis Report Regarding Net-pen Aquaculture in the Great Lakes. March 9, 2016
As a result of this research, the Michigan Quality of Life agencies do not recommend pursuing of commercial net-pen aquaculture in the Great Lakes at this time for the following reasons:
Michigan Attorney General Opinion
In January of 2017, Michigan Attorney General Bill Schuette issued an opinion confirming that current state law does not allow for net pen operations in the Great Lakes. State law allows for fish farm operations only in private waters, meaning only a farm or facility engaging in aquaculture in privately controlled waters can be registered as an aquaculture facility. The Great Lakes are not private, rather part of the public trust. Therefore, current state law does not permit aquaculture in the Michigan waters of the Great Lakes.
“Only operations that meet the definition of an “aquaculture facility” under the Michigan Aquaculture Development Act, 1996 PA 199, MCL 286.871 et seq., may be registered to engage in aquaculture in the State of Michigan. Under the Act, an aquaculture operation in the Michigan waters of the Great Lakes could not be registered to engage in aquaculture because the operation would not meet the current definition of an “aquaculture facility” since the Michigan waters of the Great Lakes are not “privately controlled waters” as defined in the Act.”
Click to read the full Attorney General Opinion
The following reports were produced as part of the process:
Science-based review
Regulations-based review
Economics-based reviews
- Overview of Natural Resource Values Potentially at Risk from Consequences of Net-Pen Aquaculture
- Expected Economic Impact of Cage Trout Aquaculture on Michigan’s Great Lakes
- Aquaculture Industry Report from IBIS World Industry Report 11251- Fish & Seafood Aquaculture in the US
Commercial Net-pen Aquaculture in the Great Lakes Public Input and Comment
Synthesis Report Regarding Net-pen Aquaculture in the Great Lakes. March 9, 2016
As a result of this research, the Michigan Quality of Life agencies do not recommend pursuing of commercial net-pen aquaculture in the Great Lakes at this time for the following reasons:
- Given the ecological and environmental risks and uncertainties, as pointed out by the Science Panel and with further information provided through public input, commercial net-pen aquaculture would pose significant risks to fishery management and other types of recreation and tourism. Furthermore, both collaborating management interests and tribal nation interests would likely not agree to Michigan moving forward and pose a significant challenge in any attempts to do so.
- The $3.3 million to implement a commercial net-pen aquaculture program by the State to protect the public’s interest in the Great Lakes and provide the stated expected service to the industry are not provided through any conventional funding models available to the QOL agencies. There would need to be a new funding stream identified for this industry effort to support initial costs as well as the $2.33 million needed annually to monitor and maintain the program and protection of the state’s resources. This level of public investment for an estimated return of $10 million (under the modeled scenarios for two facilities) does not appear to be a prudent use of the state’s resources at this time.
- Regulatory authority does not currently exist to issue registrations for commercial aquaculture in the Great Lakes.
Michigan Attorney General Opinion
In January of 2017, Michigan Attorney General Bill Schuette issued an opinion confirming that current state law does not allow for net pen operations in the Great Lakes. State law allows for fish farm operations only in private waters, meaning only a farm or facility engaging in aquaculture in privately controlled waters can be registered as an aquaculture facility. The Great Lakes are not private, rather part of the public trust. Therefore, current state law does not permit aquaculture in the Michigan waters of the Great Lakes.
“Only operations that meet the definition of an “aquaculture facility” under the Michigan Aquaculture Development Act, 1996 PA 199, MCL 286.871 et seq., may be registered to engage in aquaculture in the State of Michigan. Under the Act, an aquaculture operation in the Michigan waters of the Great Lakes could not be registered to engage in aquaculture because the operation would not meet the current definition of an “aquaculture facility” since the Michigan waters of the Great Lakes are not “privately controlled waters” as defined in the Act.”
Click to read the full Attorney General Opinion
The Future of Aquaculture in Michigan
While the Attorney General’s Opinion confirms that aquaculture is not allowed in Michigan’s Great Lakes waters, at any time, lawmakers could introduce legislation to change state law and allow net-pen aquaculture in the Great Lakes. In fact, bills were introduced previously to do just that. That’s why we must remain vigilant. We, along with other environmental and conservation partners, will keep an eye out for any such proposal and will do everything possible to stop it.
At the same time, we need to develop a clear regulatory framework to conduct aquaculture the right way in Michigan. Sustainable, on-land aquaculture systems that fully treat their wastewater should be fostered.
While the Attorney General’s Opinion confirms that aquaculture is not allowed in Michigan’s Great Lakes waters, at any time, lawmakers could introduce legislation to change state law and allow net-pen aquaculture in the Great Lakes. In fact, bills were introduced previously to do just that. That’s why we must remain vigilant. We, along with other environmental and conservation partners, will keep an eye out for any such proposal and will do everything possible to stop it.
At the same time, we need to develop a clear regulatory framework to conduct aquaculture the right way in Michigan. Sustainable, on-land aquaculture systems that fully treat their wastewater should be fostered.
Aquaculture in the Great Lakes
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Congressman Dan Kildee (MI-05) has taken steps to not only protect Michigan’s waters, but the entire Great Lakes and certain rivers with outstanding natural, cultural, and recreational values. The Congressman introduced legislation to ban harmful aquaculture practices in both the Great Lakes and federally designated “Wild and Scenic Rivers.”
AuSable River
The Ban Aquaculture in the Great Lakes Act (HR 961), which would ban aquaculture facilities in the Great Lakes, in an effort to protect water quality and wildlife habitat. It would also end the current patchwork of state laws that attempt to regulate such commercial fishing.
The Preserving Fishing on Wild and Scenic Rivers Act (HR 962), which would ban aquaculture facilities on Wild and Scenic Rivers and its tributaries, such as the Au Sable River, unless such facilities are shown not to discharge pollutants into the river. |
Michigan's 16 designated
"Wild and Scenic Rivers" Michigan has approximately 51,438 miles of river, of which 656.4 miles are designated as wild & scenic—just a bit more than 1% of the state's river miles. |
