As our climate changes, there will be more frequent and intense rainfall events in SE Australia, resulting in repeated low salinity events and increased turbidity in estuaries. Whist seagrasses are relatively resilient to short pulses of reduced salinity and light, laboratory experiments have found that Zostera in NSW may not be able to withstand repeated stressful events. It remains unclear whether other species, such as the threatened seagrass Posidonia australis, show similar responses or have similar thresholds. Here we describe some of the observed reductions in density of P. australis after a recent flood and the gradual recovery. We will outline experiments designed to understand the species’ thresholds and ability to recover from pulses of low salinity and light. Genetic studies will also be used to identify whether certain populations of P. australis are naturally more tolerant of these stressful conditions, meaning that they could be used as sources of propagules for restoration projects to help future-proof this threatened seagrass.