in the 1900s. Despite these deliberate attempts to establish this species on the Pacific coast; no established populations have been reported. In 2007, 1,433,708 tonnes of Atlantic salmon were harvested worldwide with a value of $7.58 billion. Ten years later, in 2017, over 2 million tonnes of farmed Atlantic salmon were harvested. Steelhead In 1989, steelhead were reclassified into the Pacific trout as Oncorhynchus mykiss from the former binominals of Salmo gairdneri (Columbia River redband trout) and S. irideus (coastal rainbow trout). Steelhead are an anadromous form of rainbow trout that migrate between lakes and rivers and the ocean, and are also known as steelhead salmon or ocean trout. Steelhead are raised in many countries throughout the world. Since the 1950s, production has grown exponentially, particularly in Europe and recently in Chile. Worldwide, in 2007, 604,695 tonnes of farmed steelhead were harvested, with a value of $2.59 billion. The largest producer is Chile. In Chile and Norway, the ocean-cage production of steelhead has expanded to supply export markets. Inland production of rainbow trout to supply domestic markets has increased strongly in countries such as Italy, France, Germany, Denmark, and Spain. Other significant producing countries include the United States, Iran, Germany, and the UK. Rainbow trout, including juvenile steelhead in fresh water, routinely feed on larval, pupal, and adult forms of aquatic insects (typically caddisflies, stoneflies, mayflies, and aquatic dipterana). They also eat fish eggs and adult forms of terrestrial insects (typically ants, beetles, grasshoppers, and crickets) that fall into the water. Other prey include small fish up to one-third of their length, crayfish, shrimp, and other crustaceans. As rainbow trout grow, the proportion of fish consumed increases in most populations. Some lake-dwelling forms may become planktonic feeders. In rivers and streams populated with other salmonid species, rainbow trout eat varied fish eggs, including those of salmon, brown and cutthroat trout, mountain whitefish, and the eggs of other rainbow trout. Rainbows also consume decomposing flesh from carcasses of other fish. Adult steelhead in the ocean feed primarily on other fish, squid, and amphipods. Cultured steelhead are fed a diet formulated to closely resemble their natural diet that includes fish meal, fish oil, vitamins and minerals, and the carotenoid asthaxanthin for pigmentation. The steelhead is especially susceptible to enteric redmouth disease. Considerable research has been conducted on redmouth disease, as its implications for steelhead farmers are significant. The disease does not affect