Chile is close to large forage fisheries which supply fish meal for salmon aquaculture. Some profitable aquaculture cooperatives promote sustainable practices. Most crops are cultivated in agriculture or aquaculture. Phytoplankton are a key food item in both aquaculture and mariculture. CEA technologies include hydroponics, aeroponics, aquaculture, and aquaponics. Sodium silicate gel is also used as a substrate for algal growth in aquaculture hatcheries. Much controversy exists about the ecological and health impacts of intensive salmonids aquaculture. There are many species of warmwater and coldwater fish that adapt well to aquaculture systems. However, there is little direct competition for aquaculture shellfish harvest. Level five is unfit for drinking, aquaculture, industrial use, or even agriculture. However, aquaculture, or fish farming, which has been practiced since about 3,500 BCE. It is also used as a feed supplement in the aquaculture, aquarium, and poultry industries. It is a popular fish food in aquaculture and aquaria. It provides research and advice relating to ecosystems and aquaculture. Other food sources include aquaculture and fishing.