Since so many are looking to add fish to their diet, large amounts of fish are being taken from the sea and adopted to farmed fish instead. It is estimated that the sea will not be able to provide us with commercial fish by 2050. Those who are proponents of farmed fish will tell you that this method can sustain our eating habits and that the more we farm fish, that much less we have to worry about our supplies.
The most popular farmed fish are carp, sea bass, cod, catfish, tilapia and salmon. These farmed fish are confined to cages full of thousands of others, which is a perfect breeding ground for parasites and nasty diseases. One of the most common parasites found in farmed fish is sea lice. These sea lice travel out of the farms and pollute our ecosystems as well, which is especially detrimental when the farm is located at the mouth of a river. In order to combat these sea lice, farmers are known to use pesticides in the fish feed, which the salmon (and later, we) ingest.
Another nasty aspect of farmed fish is the fact that plenty of excrement is circulating amongst these small living spaces for the fish. This affects our ecosystem by causing destructive algal blooms. Research has found that more farmed salmon can have up to seven times the amount of PCBs (Polychlorinated Biphenyls) than its wild relatives. These fish consume a large number of toxins through fish food, which can be made from ingredients such as feces and genetically altered produce. In case you are wondering about PCBs, they are industrial chemicals that were manufactured from for around fifty years until 1979, when they were banned. PCBs have been shown to cause adverse health effects, including potential cancers, and negative effects on the immune, nervous and endocrine systems.
And to top all this, farmed fish also tend to have much less omega-3 than we expect from the wild due to their inability to eat right.