Seed dispersal by fish (ichthyochory) plays a crucial role in river ecosystems, influencing plant community dynamics, species distribution, and ecosystem connectivity. This study evaluated the potential for ichthyochory in the highly developed, temperate Flint River system (Flint, Michigan). This study focused on seed ingestion by fish and examined how fish feeding guilds and environmental factors such as riparian width, canopy cover, urbanization, and connectivity of a site could impact seed ingestion by fish. This study also evaluated germination success following simulated gut passage (acid bath) and exposure to varying durations of water submersion. Key findings included: 1) significant differences in seed ingestion by fish across feeding guilds and environmental factors (urban/non-urban, impeded/connected); 2) high efficiency (80–100%) of gastric lavage, confirming its reliability for non-lethal dietary analysis in temperate river fish; 3) a negative correlation between riparian width and seed presence in fish diets, indicating higher seed ingestion in narrower riparian zones; and 4) plant species-specific germination responses to water submersion, with minimal effects from simulated gut passage. These findings support other research that shows that fish may serve as seed dispersers in temperate river systems.