Intermittent rivers and ephemeral streams (IRES) in Texas are experiencing frequent and prolonged droughts due to climate change, altering flow regimes and creating environmental stress for aquatic communities. IRES rely on algal assemblages to support food webs within remnant pools that persist through dry periods. Algae use various strategies (e.g., mucilage production, filamentous growth, and resting stages) to help withstand hydric stress. Intermittent flows and associated remnant pools also shape the distribution and abundance of fish and macroinvertebrates, which can further influence the composition and abundance of algal assemblages. This collaborative project employed a fish-grazer exclusion experiment to investigate how fish grazing dynamics and intermittent hydrology influence algal functional groups in Texas riverine pools. We hypothesized that transitions between flowing and drying phases would favor assemblages dominated by cyanobacteria or diatoms with traits like mucilage production. Alternatively, lower water levels, which concentrate nutrients during transitional phases, may favor taxa tolerant of higher nutrient levels or shifts in nutrient ratios. Release from grazing pressure in the presence of invertebrate-grazing could increase algal abundance, or grazing pressure in the presence of macroinvertebrates could reduce algal abundance, especially for nutritious groups like diatoms, and increase in grazer-resistant algae (cyanobacteria). We sampled epilithic algae in remnant pools in the presence and absence of fish grazers during the wet (July) and dry (October) periods in 2024. We used light microscopy and FlowCam® imaging to characterize assemblage structure, functional groups (e.g., motile, low or high profile, filaments), and the relative abundance of major taxa (cyanobacteria, diatoms, green algae). Preliminary results indicate that mucilage-rich cyanobacterial filaments and diatoms dominated across all grazer treatments and hydrologic phases. The relative abundance of diatoms increased in the presence of fish, which may indicate reduced macroinvertebrate grazing pressure. Prolonged drying conditions showed increased surface filamentous green algae. Findings suggest that algal assemblages in Texas intermittent rivers are adapted to fluctuating hydrology but remain sensitive to shifts in grazer presence and pool connectivity. Together, this work enhances our understanding of how climate-driven changes in flow and food-web interactions influence the formation of algal functional groups and ecosystem dynamics in ephemeral waters.