Advancements and Opportunities in Aquaculture
Advancements & Opportunities
|Advancements in Aquaculture As a result of the large number of risks associated with aquaculture, the applicability of federal clean water and environmental protection acts to aquaculture, and growing political and public pressure to manage aquaculture more safely, the practices and equipment employed have advanced over the years. A few are described below.|
Methods to Reduce Eutrophication and Bacterial Mat Buildup: Rotation, Feed Reduction, Water Recirculation and Improved Monitoring Similar to with agricultural crops, rotating pens and allowing some to lie fallow improves the productivity of the pen and allows time for the reduction of pollutants and nutrient buildup. Aquaculture systems are also more closely monitored to reduce excess feeding and reduce eutrophication. Various water-recirculation systems and equipment are being employed in tanks, ponds and pens to improve the purity of water.
A Method to Reduce Soil and Ground Water Pollution: Pond Liners Liners like the one shown to the right are designed to prevent the flow of nutrients, wastes and toxins into the underlying soil and groundwater. They are available for multiple purposes including aquaculture, golf course ponds, waste water treatment, sewage lagoons, reservoirs and canals.
Permitting and Planning Permitting and planning methods are being, or will be used, by the EPA to maintain and monitor aquaculture in the US. Permits, environmental impact statements, restoration plans, and best management practices are critical components for sustainable aquaculture operations. For more information governing aquaculture operations in the US, visit the NOAA Fisheries aquaculture website.
|Methods to Control Sea Lice: Pesticide Use Reduction and control of salmon lice depends upon the use of chemicals like Neguvon, Nuvan and hydrogen peroxide. If used properly, this method can be highly effective without inflicting harm on the environment or organisms. The timing of treatment is critical to control louse numbers effectively. Peroxide only kills the mobile adult stages of lice and is ineffective against the fixed juvenile stages. Therefore the louse populations must be constantly monitored and treatments should only take place when there are few juveniles and lots of adults. Another key factor in controlling the number of lice is to have simultaneous treatments in large areas.|
|Opportunities in Aquaculture While the above advances have helped to update aquaculture into compliance with federal laws, there is much more that can be done to improve the practice of aquaculture to be more environmentally and socially beneficial. For these methods to become widely used, however, the technologies and techniques will also need to be econmically feasible.|
|Organic Aquaculture A farmer that produces organic agricultural or aquacultural products does so without the use of any drugs, hormones, or synthetic chemicals. Sustainable farming is at its root, focusing on the reduction of inputs and outputs into the system. With aquaculture, the major system used are indoor, recirculating systems that are highly efficient for water conservation and environmental protection. Waste water is reused after processing through a series of screens and biological filters that house beneficial nitrifying bacteria. Generally only 5-10% of the water is replaced per day and this is due mostly to loss from evaporation and the removal of settled solids. Fish are packed at lower density to reduce the risk of disease, water is cleaned and reused to reduce input, and often waste is reused as described below.|
|Aquaculture Teams up with Agriculture A number of scientists and ecological designers are experimenting with more inclusive and holistic agriculture-aquaculture systems in which the waste of one half of the system is recycled and used as the resource for the other half of the system. Through waste recycling, integrated aquaculture/agriculture systems can be used to treat aquaculture effluents, increase farm productivity through efficient resource utilization, spread financial risk through diversification and reduce system nutrient losses in a closed-loop system that is inherently more sustainable than either aquaculture or agriculture is alone. For example, Dr. John Todd, Vermont-based scientists, author and entrepreneur, has designed and manufactured a series of "living technologies," ecologically-based inventions that are aimed at the purification of water, sewage, lakes, rivers, etc., including aquaculture tanks that are self-sustaining and do not rely on the input of fishfeed. (12) Integrated system models are also being developed to determine the size and structure of agriculture and agriculture components that can be used to balance the input and output of the components for a sustainable system. Hopefully, such models will provide guidance for policy makers and farmers that desire more sustainable resource utilization. (13, 14)|
Sustainable Ocean Aquaculture Researchers at the
University of New Hampshire began the Open Ocean Aquaculture Project
that aquaculture could safely and economically expand. Seeing a limited
supply of coastal waters, the team focused on utilizing open ocean
area, and developed submerged and partially-submerged galvanized pens capable
of sustaining the more unpredictable and harsh conditions 5km off-shore.
Risk of contamination by
chemical and biological agents is greater in freshwater and coastal ecosystems than in open seas; stationed in deep water with strong currents, the ocean farm's wastes and other pollutants are unable to reach harmful concentrations, as they do farther inland. The sturdy cages are thought to be relatively escape-proof (since implementation in 1997, no fish are thought to have escaped). Furthermore, the cages are tended and monitored by automated feed buoys, such that they appear to be cost-effective. These reasons suggest that the research may lead to an environmentally, economically and socially preferred aquaculture system in 5-10 years. For more information, check out the OOA website