Aquatic biodiversity refers to the variety and abundance of life forms in aquatic ecosystems, including marine, freshwater, and estuarine environments. This field of research encompasses studies of the diversity of species, populations, and habitats within aquatic systems, as well as the interactions between various organisms and their environments. Aquatic biodiversity plays a crucial role in maintaining the health and functioning of ecosystems, providing ecosystem services such as water purification, nutrient cycling, and food production. Researchers in this field work to understand the factors influencing aquatic biodiversity, monitor changes over time, and develop conservation strategies to protect and sustain these valuable ecosystems.