S9: Fish Farming Flashcards
Use of Biological Resources
What are the five main factors which are controlled in fish farming?
Pathogens and so disease,
Water Quality
Competition
Feeding volume and frequency
Selective breeding
Why are certain factors controlled when fish farming?
To improve the yield of the fish, and so the profit of the farmer
and to prevent eutrophication from occurring in the pond/ water body
How is water quality maintained on a fish farm?
Keeping a good flow of water, and filtering and aerating it.
Controlling oxygen levels so that the fish continue aerobically respiring
Removing waste material like feces and dead fish and excess food, to prevent decomposers breaking this down and releasing nitrates
which all prevents eutrophication.
How is disease controlled in a fish farm?
Antibiotics are regularly provided to the water to kill of bacteria that could cause disease.
Nets are put over the tanks, to stop wild fish from entering the system which may contain pathogens or parasites.
The population is controlled to prevent overcrowding
Waste material is regularly removed to prevent the build up of bacteria.
How is competition reduced on a fish farm?
Nets are used over the tank to prevent fish being eaten by bird or seals.
Predators are sometimes shot/killed on sight if they attempt to eat the fish.
Keep separate fish species apart
Controlling the numbers within the tank
Keeping fish of different ages and sexes in different enclosures.
How is feeding frequency and volume controlled on a fish farm?
Fish are fed at regular intervals and only with a little food each time
This ensures all the food is eaten and none is wasted
The food is high in protein to encourage the growth of the fish
Waste food can decompose and lead to the build up of bacteria, and so algae, and so eutrophication
How is selective breeding done at a fish farm?
Fish with desired characteristics such as a greater proteins content or a faster growth rate are selected and bred at large numbers.
What are the advantages of fish farming?
water quality can be monitored
Diet of fish is controlled
protection against predators
Pesticides can kill parasites
quality and yield of fish can be improved
What are the disadvantages of fish farming?
Potential spread of disease as animals are close together
Antibiotics may not have been broken down before human consumption
Can lead to eutrophication
Pesticides can be toxic to non-harmful species
Could be antibiotic resistance if overused.
