Canada exports farmed seafood products to more than 22 countries and is the main seafood supplier to the U.S. market. Finfish, primarily salmon, production is strong and shellfish production is growing, but diversification will be imperative to maintain competitiveness.
Controlling total ammonia-nitrogen (TAN) concentrations is the primary concern when sizing a biofilter for use in a recirculating aquaculture system. Sizing decisions are best based on previous experience with a given biofilter media in a specific biofilter configuration.
Fenneropenaeus chinensis was the most important farmed shrimp species in China until 1995. Lessons learned from its development made China a pioneer, especially in shrimp larval production. Shrimp farmers must enhance their understanding of the interactions of farming activities with their ecosystems.
The water quality in recirculating aquaculture systems is generally a function of the tank size, biomass, feed inputs and waste treatment efficiency. Adequate biofiltration can control the build-up of ammonia-nitrogen and nitrate-nitrogen in the systems.
The aquaculture industry in Brazil is moving toward further expansion with the support of the federal government. A key strategy of the More Fishing and Aquaculture plan is the development of aquaculture in federal waters. The plan promotes sustainable development of fisheries and aquaculture by linking those involved and consolidating state policies addressing social inclusion, security and food sovereignty. Tilapia is the main farmed fish, although tambaqui and others have potential for large-scale production due to their wide acceptance by consumers.
To start a biofilter together with a source of nitrifying bacteria, you must provide the conditions that will encourage the growth of the bacteria. The basic process requires initial preparation of water chemistry, adjustment of alkalinity to support bacterial growth and the addition of ammonia.
Biological filtration is one of the critical required unit processes in recirculating aquaculture systems. Non-corrosive filter media with large amounts of surface provides area for nitrifying bacteria cells to colonize.
A collaboration among the Center for Aquaculture Research in Colombia, Center for Research, Education and Recreation, and University of Miami is working to adapt the latest aquaculture technology available worldwide to local conditions and create opportunities for farming new commercial species in Colombia.
Controlling the speed of a pump motor with a variable-frequency drive to maintain output is more efficient than controlling the pump’s flow with a valve.
A study to evaluated operating practices and system designs that could potentially enhance depuration of off-flavors from Atlantic salmon cultured in a semi-commercial-scale freshwater recirculating aquaculture system.
Following earlier work in southwestern Norway that achieved semi-commercial production of European lobsters, a project has received grant support to develop commercialized land-based recirculating aquaculture of lobsters utilizing geothermal water sources in Iceland.
For most effective use, water should have low turbidity and high U.V. transmittance, with ultraviolet dosage tuned to the target organisms. Low-pressure/high-output amalgam U.V. lamps are often used in RAS systems.
In combination with the availability of coastal areas with favorable environmental and labor conditions, Brazil’s affluent market for seafood could support expansion of a niche aquaculture sector: boutique farming.
The development of submersible fish cage technologies may be necessary to avoid the operational challenges of surface-based aquaculture, which can include extreme temperature and weather conditions, jellyfish infestation, oil spills and many types of biofouling.
Typical electric immersion heaters used in aquaculture use resistance wire as the source of heat. When the “hot zone” of a resistance heater operates in air or becomes covered with deposits, the rapidly rising temperature can potentially damage plastic tanks and liners.
In carp and other freshwater fish, the adhesive substance that covers their eggs can be a barrier to fertilization. In field studies, the author discovered that some soils from Bengal, India, proved effective in removing the adhesive component from eggs.