Tilapia is the third most important fish in aquaculture after carps and salmonids, with production reaching 1,505,804 metric tons in 2002. Because of their large size, rapid growth, and palatability, tilapiine cichlids are the focus of major aquaculture efforts, specifically various species of Oreochromis, Sarotherodon, and Tilapia, collectively known colloquially as tilapias. Like other large fish, they are a good source of protein and a popular target for artisanal and commercial fisheries. Most such fisheries were originally found in Africa, but outdoor aquaculture projects in tropical countries such as Papua New Guinea, the Philippines, and Indonesia are underway in freshwater lakes. In temperate zone localities, tilapiine farming operations require energy to warm the water to tropical temperatures. One method uses waste heat from factories and power stations.