Aquaculture Systems and Structures Flashcards
What are the problems with open cages?
- No barriers between fish/shellfish and environment
- Risk of Escape
- Risk of transfer of parasites/pathogens
- Increased nutrient load from environment
What are the strengths of open cages?
- Nutrient flow can be good for wild species biodiversity
- Attraction of wild fish can be +ve for local fisheries
What is ecological sustainability?
Minimizing environmental impacts
What is ethical sustainability
Sustainable feeding + good health and welfare in farms
What is economic sustainability?
Job opportunities and local and rural development
What qualities do open systems have?
- Water quality fluctuates around the optimum
- Sludge leaves but pathogen enters
What qualities do closed systems have?
- Water quality at optimum
- Sludge recycled and no pathogens can enter
You have both seabased and land-based containment systems; give their qualities
- Seabed semi-closed systems = hard and soft shelled cages
2. Land based closed recirculating systems = parital/full RAS
Give some example of set shelled seabased systems
- Nekton, Aquafuture, Flexing, Aquadome
What are soft shell sea-based systems?
Essentially closed plastic bags in the sea
Give the qualities of The sea based hard shell Neptune
- 40m in diameter
- 4 pumps (100m3 per minute)
- Sediment trap - 80% particulate matter collected
- Worlds largest hard shell
How much water is exchanged per day in partial and full RAS?
partial - >10%
Full - <10%
Are RAS land based? / Are they indoor or outdoor?
Both land based - Both can be Indoor or Outdoor
What happens in multi-trophic-aquaculture?
- Fish farming is combined with farming of extractive species which remove inorganic wastes from the water (can be land or sea based)
What does IMTA stand for?
Integrated Multi-Trophic Aquaculture
How do you decrease nutrient leakages?
- optimise feeding regimes
- camera surveillance and automatic sensores
- manual adjustments
What are the ‘fed species’ in IMTA?
Fish and or shellfish
What are the extractive species in IMTA
- muscles and oysters (filter particles)
- Suspension feeders (eat particles in sediment)
- Algae (assimilate dissolved nutrients)
What is the IMTA concept
Cultivation of several species at different trophic levels in the same system
What types of fish should be cultivated in the future?
Halibut, Turbot, Cod, Pollock, Wolf fish, Sole
What is the future of offshore farming?
- Large open systems
- Fish and wind farms combined
- Immersible farming systems
