Influence of Seasonal Water Level Fluctuations on Food Web Structure of a Large Floodplain Lake in China

Seasonal shifts in hydrology are known to alter the abundance and diversity of basal production resources habitats hence strongly influence structure function river ecosystems. However, equivalent knowledge natural lake ecosystems floodplain regions is lacking. Here, we used stable isotope ratios carbon nitrogen assess available primary sources consumer taxa during dry wet seasons a large connected Yangtze River. Fish species showed distinct δ13C values between two hydrological periods but only small changes δ15N values. Most fish had higher estimated trophic levels season, likely indicating greater carnivory. Results Bayesian mixing models revealed that benthic algae organic matter (BOM), combined with C3 vegetation, were principal food supporting biomass most low-water period, whereas seston important flood period. Overall, these findings demonstrate seasonal changes, such as water-level fluctuations, can affect ecosystem functioning webs subtropical zone.