1. Fish Farming
5.9 explain the methods which are used to farm large numbers of fish to provide a source of protein, including maintenance of water quality, control of intraspecific and interspecific predation, control of disease, removal of waste products, quality and frequency of feeding and the use of selective breeding.

2. Fish farming
This is an area of the sea where people catch fish on a large scale is known as a fishery.
Fisheries exist all over the world.
Many countries regulate the number of fish that can be caught.
There are restrictions of the size of the net that is used for fishing.
This allows smaller fish to escape and have a chance to breed.
These regulations are not easy to design or enforce.

3. Maintenance of water quality
Works best when water is flowing
Removes waste
Brings in fresh O2

4. Control of intraspecific predation
 Competition between the same species
Ensure enough food
When numbers get too high – fish can be removed to sell
Separate big and small fish

5. Control of interspecific predation
Competition from different species
Closed cage – so predators cannot get in

6. Control of Disease
Ill/ sick fish removed to prevent spread of diseases.
Chemicals to prevent disease - antibiotics   

7. Removal of waster products
 Water movement e.g. current can wash away waste products
Filter to remove nitrogenous waste

8. Quality and frequency of feeding
Feed enough for growth but not over feed as there would be waste, which would rot.

9. Selective breeding
Choose those fish with the most desirable characteristics to reproduce