The main function of aquatic plants in freshwater ecosystems is to produce oxygen through photosynthesis, which is essential for the survival of aquatic organisms. They also play a key role in providing habitat and shelter for various fish and invertebrate species. Additionally, aquatic plants help stabilize sediments and manage nutrient levels within the water body, contributing to the overall health of the ecosystem. By controlling algal blooms and promoting clarity, these plants ensure a balanced and thriving aquatic environment, supporting diverse food webs.