This document discusses various types of marine pollution including land-based sources, oil spills, sewage, heavy metals, plastics, and noise. It outlines impacts such as damage to marine life from ingesting oil or becoming entangled in plastic. Specific examples of polluted areas are given like the New River in California. Sources of pollution include direct discharge, surface runoff, atmospheric deposition, shipping, and deep sea mining. Mitigation requires efforts to reduce pollution at the source, better waste management, and protection of sensitive coastal and marine habitats.