Fish farms don't have to be bad news, but generally speaking they are. Aside from the pollution problems, a person might think they are saving a wild fish and helping to preserve the oceans by eating farm raised fish instead. Unfortunately most farm-raised fish is fed fish meal which is made from other fish harvested from the ocean. And since it takes far more than a pound of ocean-caught fish to make a pound of farm-raised fish, you are not really helping to preserve the ocean at all.
Exceptions to this would be farming fish that do not require large amounts of fish meal that are raised on farms that do not pollute. A multiple crop farming system is the ideal way to go. Plants love the nutrients that fish produce and under the right set-up the "vegetable" part of the farm can completely clean the water polluted by the fish. Raising crawfish in rice paddies are one example of this. The crawfish eat the algae in the rice ponds and at the same time fertilize the rice. With the rice set-up a farmer would need to buy less fertalizer for his rice and also get a bonus crop of crawfish...
AmbergrisCaye.com 
