<p>Aquatic macrophytes can alter ecological interactions in freshwater environments by modifying resource availability and habitat structure, driven by their rapid reproduction and lack of natural predators. This study evaluates the relationships between the area occupied by the invasive macrophytes, the physical and chemical conditions of the water, and the fish community in a hypertrophic reservoir (Porce II, Antioquia, Colombia). We used eleven years of continuous fish community monitoring data and a time series of LANDSAT remote-sensing imagery to assess floating plant coverage and spatial changes over time. A multiple regression model was applied to analyze the relationship between macrophyte cover and water quality variables, while linear models were used to examine the association between macrophyte area and the fish community, considering different feeding strategies. We found a positive association between macrophyte cover and pH, with pH values decreasing as plant cover declined. Although no significant relationships were detected between floating plant cover and species richness or dominance, we observed a positive relationship with fish biomass and abundance—particularly among omnivorous species. These findings suggest that macrophyte cover influences the abundance and biomass of certain fish species by providing critical resources such as food and shelter.</p>