Fish Farming5.9 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.

 

Fish farmingThis 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.

Maintenance of water quality Works best when water is flowing

Removes waste

Brings in fresh O2

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

Control of interspecific predation

Competition from different species

Closed cage – so predators cannot get in

Control of Disease 

Ill/ sick fish removed to prevent spread of diseases.

Chemicals to prevent disease - antibiotics

  

Removal of waster products Water movement e.g. current can wash away

waste products

Filter to remove nitrogenous waste

 

Quality and frequency of feedingFeed enough for growth but not over feed as

there would be waste, which would rot.

 

Selective breedingChoose those fish with the most desirable

characteristics to reproduce