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 waster products, quality and frequency of feeding and the use of selective breeding

Fish farming is a possible solution to the problem of overfishing. It is controlled and designed in a way to produce as many fish as possible.

NOTE: Everything specifically to do with fish farming in cages in the sea is in blue, everything specifically to do with fish farming in tanks is in green.

Maintenance of water quality
There is a current in the sea so water is naturally kept 'clean'.
The water can be removed, filtered and cleaned. Water can be monitored to ensure temperature, [H and oxygen level is at the best potential.

Control of intraspecific and interspecific predation

Firstly, interspecific predation is being eaten by other animals, intraspecific predation is cannibalism, basically.

Fish farming in cages stops interspecific predation as it means no animals/fish can eat the farmed fish. Big fish and baby fish are kept separate to keep intraspecific predation low.

Control of disease

Fish in cages are prone to diseases such as lice . Biological pest controls are used to control the lice as chemical pesticides can harm the fish.

Removal of waste products

The water can be removed and filtered, getting rid of waste.

Quality and frequency of feeding

A diet of food pellets is carefully controlled to maximize the amount of energy the fish get as more energy = more growth = bigger fish. Furthermore, the better the quality of food, the bigger the fish will grow.

It is easy to control how much food is given, as it doesn't wash away in the current of the sea.

Selective breeding

The fish can be selectively bred to produce fast growing, less aggressive fish, for example.