Green sea turtles are large marine reptiles known for their distinctive olive-green shells. They can weigh up to 400 pounds and are found in tropical and subtropical oceans around the world. These turtles primarily feed on seagrasses and algae, which contribute to their unique coloration. Green sea turtles are important for maintaining healthy marine ecosystems. By grazing on seagrass, they help promote the growth of these plants, which provide habitat for various marine species. They are currently classified as endangered due to threats like habitat loss, pollution, and poaching.