The document discusses market control in various food industries in the United States. It shows that the top four grocery manufacturers control over 80% of the market. It also shows that Walmart controls over 50% of grocery sales in 29 markets, and is the largest purchaser of beef in the country. Additionally, the top four seafood firms control over 70% of the US seafood consumption market. The document examines concerns over lack of food labeling transparency and testing for chemicals in various aquaculture foods.