Which of the following is a key factor in determining aquatic biodiversity?

Aquatic biodiversity is influenced by a multitude of factors that interact within ecosystems. Water temperature plays a vital role because it affects metabolic rates, species distribution, and reproduction among aquatic organisms. Different species have specific temperature ranges in which they thrive, thus influencing the diversity of life in a given area.

Current speed also significantly impacts biodiversity. It determines habitat structure and influences which species can inhabit certain areas. Fast currents may favor organisms adapted to withstand these conditions, while slower currents might support different kinds of species, thereby affecting overall community composition.

Light availability is another crucial factor, especially in aquatic environments where photosynthetic organisms, like phytoplankton and aquatic plants, form the base of the food web. The depth of light penetration in water affects productivity and, consequently, the types and numbers of organisms that can thrive in different regions.

Considering all these factors collectively leads to a comprehensive understanding of aquatic ecosystems. Since water temperature, current speed, and light availability all play integral roles in shaping the biodiversity of aquatic environments, recognizing that all of these factors contribute is essential for understanding aquatic life. Therefore, the answer is inclusive of the interrelated influences of these key factors on aquatic biodiversity.