Tilapia

Nile tilapia, Mozambique tilapia, Blue tilapia, St. Peter’s fish

Tilapia is the common name for many cichlid species within three genera: Oreochromis, Sarotherodon, and Tilapia. The species of greatest importance to aquaculture are the Nile tilapia (Oreochromis niloticus), Mozambique tilapia (O. mossambicus), and Blue tilapia (O. aureus) and their hybrids. According to the United Nations Food and Agriculture Organization in 2003, 82% of cultured tilapia are Nile tilapia.
Tilapia are easily cultured because they are omnivorous and can adapt their eating habits to available food. In addition, they can tolerate low oxygen levels and a wide range of salinities and can be farmed within a wide range of densities. They also have high reproductive capacity
and readily establish self-reproducing populations. Tilapia occur mainly in freshwater but also in brackish water and seawater in tropical and subtropical climates. They occupy a wide variety of habitats like rivers, lakes, sewage canals and irrigation channels. Tilapia feed mainly on phytoplankton or benthic algae but readily accept compound feed (with plant or animal protein).
Males grow faster than females, mainly because females begin reproducing early and thus divert their energy to reproduction instead of growth. There are several methods used to avoid loss of marketable biomass through excess
reproduction. Farming in cages does not allow females to pick up eggs for oral incubation,which eliminates reproduction. Culture populations that are exclusively male are also often desirable to control reproduction and maximize biomass production.

Various estimates of the amount of fish protein in to fish protein out for farmed Tilapia range from substantially less than 1.00 to 1.41. In nearly all cases, this ratio is less than 1:1, indicating that tilapia culture results in a net gain of edible fish protein. There is therefore a “low” conservation concern regarding the current use of marine resources in most culture practices. However, some caution is warranted, especially in China where over-formulation of feeds may result in the overconsumption of wild fish for optimal tilapia growth.

Tilapia are native to Africa and the Middle East, however, their adaptability to a wide range of environmental conditions have allowed them to invade a range of non-native habitats. Tilapia are now one of the most widely distributed exotic fish in the world, second only to common carp, their introduced range now stretches every continent. Therefore, the risk for escape in tilapia aquaculture productions with nets, cages, and raceways and unenclosed ponds and tanks is ranked “high”. The conservation concern is “moderate” for enclosed ponds and tanks, and “low” where cultured tilapia have no access to natural waters.

US EPA regulations are comprehensive for effluent treatment for US tilapia aquaculture farms meriting “low” conservation concern regarding pollution and habitat effects.
Though there are few reports of disease and parasite transfer from tilapia introductions, stocked tilapia can become infected from wild stocks prompting a “moderate” ranking for tilapia culture in nets, cages and raceways for unenclosed ponds and tanks. Whereas, organically certified tilapia farms are required to focus on preventing outbreaks by maintaining natural environments and behaviours, and infections are treated promptly Organic, enclosed ponds and tanks receive a “low” rating for conservation concern.

Integrated farms also rank as “low” conservation concern, as effluent is used for agriculture rather than being released into natural water bodies. Risk for organic product internationally may be low as well, but lack of demonstrated effectiveness warrants caution and a rating of “moderate” risk for organic tilapia. The risk of pollution is likewise moderate for semi-intense and intensive operations that are closed to the environment (ponds, tanks), but higher for semi-intense and intensively stocked, open systems (nets, pens, raceways). There is also a moderate but growing concern for pollution in China and Central America where rapid development of intensive cage culture continues prompting a “high” conservation concern ranking.

The management in China appears to be “ineffective”. The US has recently implemented national effluent limitation guidelines and Best Management Practise plans for aquaculture, and the US management regime is effectively enforced; thus US management, as well as organic management, is deemed “effective”. Most other countries appear to have underdeveloped management plans that merit “moderate” levels of concern.

Where was this fish farmed?

Contaminant levels do not warrant a consumption advisory.