Fish Farming
Benefits of fish farming
- Most fish are still caught in the wild (i.e. in the open ocean or in freshwater rivers and lakes)
- However, overfishing has lead to dramatic declines in many fish populations
- Fish farms are ways of raising large numbers of fish in a small space to provide food (protein) for humans
- Fish are bred in large tanks or cages to minimise energy losses and maximise yield
Methods to maximise yield in fish farms
- Within fish farms, large numbers of fish are kept in freshwater or seawater enclosures and are carefully monitored and controlled in different ways (many of which are not possible with wild-caught fish)
- Selective breeding ensures high quality, fast-growing fish
- Interspecific predation is prevented using nets and cages
- Intraspecific predation is limited by grouping fish according to their age and size
- Water quality is carefully controlled by monitoring pH and temperature as well as removing fish waste or dead fish
- Diet is controlled by feeding high protein fish pellets regularly to ensure rapid growth
- Diseases and pests are prevented using antibiotics and pesticides or biological controls
The effect of fish farms on biodiversity
- Fish farms, whilst reducing the pressure of overfishing of wild fish, can have a negative impact on biodiversity in several ways
- Predators may be attracted to the fish farms and may get caught in nets trying to reach the fish
- Diseases can spread quickly in fish farms due to the enclosed space and number of individuals in close proximity. Diseases can also spread in the water to other species outside of the fish farm
- If any caged fish were to escape, they can cause issues with the native species nearby (i.e. those that live in the area naturally)
- Eutrophication can occur
Fish Farming Methods Table