Consumption of fish has remained a staple in the diets of nations across the world for millennia. However while populations experience continued growth, per capita demand for fish and seafood has continued to grow unabated with fish consumption increasing by 7% to 9% annually. A significant proportion of fish continues to come from wild harvest fisheries, which places stress on both salt and fresh water ecosystems. The growing practice of aquatic fish farming as an alternative to wild harvesting has reduced this stress while helping meet seafood demand. While most aquaculture practices are land-based, lake-based cage and net pen aquaculture (using cages and pens to harvest fish) is a relatively new and highly underdeveloped alternative, which has future potential as a sustainable source of fish harvesting.
. Ontario, Canada has led the way in the expansion of fresh water net pen aquaculture development in North America. This is due to the high quality of water, correct climate conditions, and complimenting infrastructure found in the southern portion of the province. This has made Ontario the natural choice to become Canada’s premiere source and innovator of freshwater net pen and cage aquaculture. Current cage culture operations in the North Channel of Lake Huron harvest approximately 320 tons of fish per year, most of which consists of rainbow trout. Net pen aquaculture is highly lucrative, with 2005 production generating approximately $1.29 million CAN ($1.03 million US).
Multiple sources are discussing the development of commercial aquaculture net pens in the Michigan waters of the Great Lakes off the Upper Peninsula and northern Lower Michigan. This has never been attempted in the state. Consequently there is a very high potential opportunity for the development of this particular Michigan food production. However, the implementation of these net pens is essentially guaranteed to generate controversy.
Garnering and maintaining public trust is already proving to be a delicate process for those attempting to implement net pen aquaculture in Michigan’s Great Lakes. A primary concern for the public is that through the process of building aquaculture net pens, public trust waters are effectively being reserved for private purposes. As the Great Lakes are widely considered to be the most important of Michigan’s heritages, it is reasonable to believe that members of the public will feel uncomfortable with sections of its shoreline being given over to private industries, however small they may be. Certain stakeholders such as private and commercial fisherman may be particularly uncomfortable with the development of net pen aquaculture in the Great Lakes, as this can be perceived as an encroachment upon their recreational and harvest areas. In Ontario there were also issues concerning the application of tribal law and land claims by Aboriginal peoples in the areas where net pens were first being constructed.
The Quality of Life (QOL) organizations of Michigan (Department of Environmental Quality, Department of Natural Resources and Department of Agriculture & Rural Development) are assisting with the implementation of aquaculture net pens must also take into consideration the needs of Native Americans, so that legal issues are avoided in the future and tribal rights concerns may be more effectively addressed.
Despite issues concerning public trust, the primary obstacle for the implementation of these pens from the perspective of the QOL agencies is that there is a scarcity of research data concerning net pen aquaculture. Many questions concerning the environmental impacts of net pen aquaculture remain unanswered. Efforts by the QOL agencies are going to be made to ensure that all risks and other scientific concerns are accurately assessed before net pen implementation is allowed to begin in earnest. One concern is how to diminish escapement risk from net pens. Research from Ontario has shown that species of fish behave differently from one another upon escapement. This has an influence in the decision for which species are chosen for harvesting. However, literature shows that native species do not survive and grow well in net pens, causing the industry to choose more appropriate species for this type of aquaculture. Another risk being assessed is how to properly manage a net pen fish population so that the risk of the spread of disease can be minimized.
Finally, the effect net pens will have on water quality will need to be determined. Chemical outputs from fish farms such as nutrients, heavy metals, and ammonia may have negative effects on lake sediment pH and thus its toxicity. Nutrient-rich waste will also have the potential to lead to algal blooms and other ecological phenomena. Both changes in water nutrient content and sediment toxicity will lead to a reduction in bio-available oxygen, which could result in additional nutrients being released from the sediments, and increased eutrophication.
Beyond environmental concerns, evaluation of net pen applications and permit allocation are also being considered based on economic aspects such as determining market demands and assessing the value and growth potential net pen aquaculture will have for Michigan agri-business. The DEQ is conducting an independent analysis to determine how the markets are likely to respond and the potential value of this proposed new industry. Supporters claim that the introduction of net pen aquaculture will be a great boon for the state of Michigan. The hope is that the expansion of this agri-business can be a critical catalyst of growth in Michigan’s agricultural sector, which will help improve our economy, provide new jobs, and see the implementation of new technology. Another potential benefit for consumers will be the reduction in the cost of fish, which will make lean, quality protein more available for people in Michigan and potentially other Midwestern states. Finally, if implemented correctly, net pen aquaculture will be able to increasingly serve as a responsible, environmentally sustainable alternative to wild harvesting. This will reduce the stress currently being placed on wild fish and their habitats, which will increase the health of our Great Lakes.
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