The scientists studied the community of small animals living in the mud and sand of Hampyung Bay in Korea. They found different types of sediment in the bay and identified 168 species of animals, with worms and crabs being the most common. They also measured the amount of carbon in the sediment and found that some species were more abundant in certain areas of the bay. By looking at the types of sediment, they grouped the bay into five different areas based on the animals living there.