3- Fish lecture 1 Flashcards
Define aquaculture
Farming aquatic organisms such as fish, molluscs, crustaceans & aquatic plants
Name the 3 water types of aquaculture production systems
Freshwater production
Marine production
Brackish water production (lowest to highest intensity)
Name 4 different natures of fish production systems
Ponds
cages
raceways
recirculating aquaculture systems
What are basic requirements of a fish production system
Water
Oxygen - natural/artificial
Food
Waste removal
What is a major source of waste in aquatic production systems?
Food waste
Describe the basic production system
Brood stock (Breeding parents)
Hatchery
Grow-out
Slaughter
What is the least intensive vs most intensive fish production system?
Least = Pond
Most = Recirculating aquatic systems (RAS)
Advantages & Disadvantages of cage production systems?
+ = Easy feeding, stocking & harvesting
- = Little environmental control = Susceptible to predators, water-borne irritants, bad weather conditions, Shared water body (Easy to spread disease)
What is a raceway production system?
Single pass system = Water flows from one end to the other- can allow transfer of disease
- follow through system
Rectangular structures = gravity flow
require large volumes of water
Describe the RAS production system
Little water is required as is cleaned via mechanical/biological filters and put back into the system- sig energy input
most intensive
2 Pain processes known in fish
Nociception & conscious recognition
What are operational welfare indicators?
Measurable parameters relating to welfare needs of fish that have practical application and value on the farm
Explain the difference between direct and indirect operational welfare indicators in fish
Direct = Outcomes such as measurable behavioural, physical or physiological changes
Indirect = Environmental parameters known to influence or effect welfare outcomes
Examples of indirect operational welfare indicators
- environment based
Lighting,
feed quality
stocking density
tank microbiome
Water quality parameters (temp, salinity, oxygenation, nitrogenous elements, water flow)
Examples of direct operational welfare indicators
Can be group/individaul basesd
Group = mortality, behaviour, appetite, growth, emaciated fish/blood/scales in water, discolouration, presence of disease
Individual animal = Gill condition, body condition, smoltification, fin/skin condition, presence of haemorrhages, deformity
