Infauna refers to the organisms that live within the sediment of ocean floors, riverbeds, and other aquatic environments. These creatures, which include species like clams, worms, and crustaceans, play a crucial role in the ecosystem by contributing to nutrient cycling and sediment turnover. They help aerate the sediment and break down organic matter, which supports the overall health of the marine environment. Infauna can be found at various depths and in different types of sediments, from sandy beaches to muddy estuaries. Their presence is essential for maintaining biodiversity and providing habitat for other marine life. Understanding infauna is important for assessing the health of aquatic ecosystems and the impacts of human activities, such as pollution and fishing.