Author(s): Modesto, Vanessa ; Tosato, Luca ; Pilbala, Ashkan ; Benistati, Nina ; Fraccarollo, Luigi ; Termini, Donatella ; Manca, Dario ; Moramarco, Tommaso ; Sousa, Ronaldo Gomes ; Riccardi, Nicoletta
Date: 2023
Persistent ID: https://hdl.handle.net/1822/86788
Origin: RepositóriUM - Universidade do Minho
Subject(s): Unionida; Hall sensors; Water discharges; Sediment transport; Valve movements; Transition behaviour
Freshwater mussels (FMs) are useful bioindicators to detect environmental disturbances. However, studies that evaluate FMs suitability for monitoring the hydrodynamic stressors impact are lacking. Since future climatic scenarios predict an increase in frequency and intensity of extreme events, understanding how flood conditions affect freshwater organisms are crucial for their conservation. In this study, we performed experiments in an artificial flume to evaluate the eligibility for FMs behaviour for developing a tailored biological early warning system (BEWS). For this, we used the valvometric technique (Hall magnetic sensors) to measure the FMs valve gaping behaviour when subjected to increasing discharges/sediment transport mimicking the onset of floods. After analysing baseline behaviour in non-stressful conditions, we performed experiments in steady and transient conditions to verify the FMs' response and the threshold that prompted it. Under steady conditions, FMs maintained a constant gaping frequency that characterizes their normal behaviour. The FMs promptly reacted to discharge variations with sediment transport, showing a transition from their normal behaviour to higher valve gaping frequencies. We demonstrated that FM transition behaviour is a useful tool to measure hydrodynamic stressors. A future step will be the application of this BEWS on natural ecosystems to assess possible hydrodynamic changes in real-time.
