The document discusses biodiversity, defining it as the variety of life on Earth including diversity within and between species and ecosystems. It describes the different types of biodiversity as genetic, species, and ecosystem diversity. Aquatic biodiversity is specifically the variety of freshwater and marine lifeforms and ecosystems. The document outlines factors threatening biodiversity like habitat loss, pollution, and climate change and their impacts. Threats to aquatic biodiversity include overexploitation of resources, pollution, and destruction of natural habitats from urbanization.