What would happen if there were no underwater plants like hydrilla?

If there were no underwater plants like hydrilla, aquatic ecosystems would suffer significantly. These plants provide essential habitats and food sources for various aquatic organisms, including fish and invertebrates. The absence of such vegetation would lead to decreased biodiversity, disrupted food chains, and increased water pollution due to the lack of natural filtration and oxygen production. Overall, the health of aquatic environments and the species that depend on them would be severely compromised.