Ecological Juvenile farmed Chinook have been shown to have higher rates of predation due to their larger size than wild juveniles upon release into marine environments. Their size correlates with the preferred size of prey for predators like birds, seals, and fish. This may have ecological implications because of the effect on feeding. Impact on forage fish The use of forage fish for fish meal production has been almost a constant for the last 30 years and at the maximum sustainable yield, while the market for fish meal has shifted from chicken, pig, and pet food to aquaculture diets. This market shift at constant production appears an economic decision implying that the development of salmon aquaculture had no impact on forage fish harvest rates. Fish do not actually produce omega-3 fatty acids, but instead accumulate them from either consuming microalgae that produce these fatty acids, as is the case with forage fish like herring and sardines, or consuming forage fish, as is the case with fatty predatory fish like salmon. To satisfy this requirement, more than 50% of the world fish oil production is fed to farmed salmon. In addition, salmon require nutritional intakes of protein, which is often supplied in the form of fish meal as the lowest-cost alternative. Consequently, farmed salmon consume more fish than they generate as a final product, though considerably more preferred as food. Salmon Aquaculture Dialogue and ASC Salmon Standard In 2004, the World Wide Fund for Nature (WWF)-USA initiated the Salmon Aquaculture Dialogue, one of several Aquaculture Dialogues. The aim of the dialogues was to produce an environmental and social standard for farmed salmon and other species (12 species currently, as of 2018). Since 2012, the standards elaborated by the multi-stakeholder Dialogues were passed-on to the Aquaculture Stewardship Council (ASC) which was created in 2010 to administer and developed them further. The first such standard was the ASC Salmon Standard (June 2012, and revised in 2017 after comprehensive public consultation). The WWF had originally identified what they called "seven key environmental and social impacts", characterised as: Land-raised salmon Recirculating aquaculture systems make it possible to farm salmon entirely on land, which as of 2019 is an ongoing initiative in the industry. However, large farmed salmon companies such as Mowi and Cermaq were not investing in such systems. In the United States, a major investor in the effort was Atlantic Sapphire, which plans to