Aquaculture problems: Fish feed
The amount of feed needed for farmed fish and shrimp is staggering. For example:
- up to 22kg of wild-caught fish is needed to produce just 1kg of farmed tuna
- 4kg of wild-caught fish is needed to produce 1kg of farmed salmon
- up to 2kg of wild-caught fish is needed to produce 1kg of farmed marine shrimp
This means that the aquaculture industry is using a large proportion of the fish caught in the world’s oceans each year.
Many of the fish stocks used as feed - mostly anchovies, pilchards, mackerel, herring, and whiting - are already fished at, or over, their safe biological limit. So instead of relieving pressure on the marine environment, aquaculture is actually contributing to the overfishing crisis that plagues the world's fisheries.
In 2004, the aquaculture industry used 87% of the world’s fish oil and 53% of the world’s fishmeal, with salmon farming alone using over half the global production of fish oil.