They are now seen as a nuisance, as they are one of the “most invasive species known and difficult to get rid of once established,” says Aaron Mc Nevin, a WWF biologist.
In Lake Apoyo in Nicaragua, tilapia escaped from a fish farm and their pollution and feeding reduced the lake’s quantity of an aquatic plant called charra, which was an important source of food for the lake’s native fish populations.
Like commercial farming operations on land, the density of fish in these pens necessitates certain chemicals to keep animals from getting sick and to keep things clean.
The chemicals used in marine aquaculture operations such as medicines like antibiotics and vaccines, disinfectants, and substances used to prevent corrosion of equipment (cages, etc.) can also change the composition of the surrounding aquatic ecosystem.
In fact, around 50% of the seafood we consumes comes from aquaculture.