Manufactured aquafeeds, if improperly managed, can result in undesirable oxygen demand that can reduce dissolved oxygen levels and pollution through effluents, and stress cultured animals.
Acid rain typically does not heavily affect aquaculture operations, and application of agricultural limestone can buffer water against the impacts of acid rain at facilities that use stream water.
With the market volatility of fishmeal, as well as rising sustainability concerns, the aquaculture industry is seeking sources of protein, such as animal byproduct concentrates, to substitute for fishmeal.
Excessive concentrations of trace metals, especially copper, are toxic to phytoplankton and other aquatic plants. The ionic forms of trace metals are toxic to fish and other aquatic animals, but soluble, chelated trace metals are relatively non-toxic.
In general, lower-intensity pond and cage farming tends to discharge higher overall pollution loads in farm effluents than closed aquaculture systems.