IUU stands for Illegal, Unreported, and Unregulated fishing. It refers to fishing activities that violate national or international laws, including catching fish without permission, not reporting catches, or fishing in protected areas. IUU fishing poses a significant threat to marine ecosystems and fish populations, leading to overfishing and depletion of resources. Efforts to combat IUU fishing involve cooperation among governments, organizations, and communities. Initiatives include stricter regulations, better monitoring of fishing activities, and increased enforcement. Organizations like the Food and Agriculture Organization (FAO) work to promote sustainable fishing practices and protect marine biodiversity from the impacts of IUU fishing.