Marine debris refers to any human-made objects that end up in oceans, rivers, and other waterways. This debris can include items like plastic bottles, fishing nets, and metal scraps. It poses a significant threat to marine life, as animals can ingest or become entangled in these materials. The sources of marine debris are varied, including littering, improper waste disposal, and stormwater runoff. Efforts to reduce marine debris involve community clean-up initiatives and policies aimed at reducing plastic use. Organizations like Ocean Conservancy work to raise awareness and promote solutions to this growing environmental issue.