Behavioural Responses of Cerastoderma edule as Indicators of Potential Survival Strategies in the Face of Flooding Events

According to climate change scenarios the incidence of extreme events, such as flooding, is expected to increase worldwide. In the current climate change context, understanding behavioural responses of marine species to such stressors is essential, especially for species of high ecological and economic interest such as bivalves, which can be quite useful for future management and conservation actions. In this study, a laboratory experiment using different salinity conditions was undertaken to assess potential behavioural responses of cockles (Cerastoderma edule), as a survival strategy facing low-salinity stress during riverine flood events. Results showed consistent patterns of burrowing/emergence of cockles facing salinity variation: with high salinities the individuals were observed buried in the sediment; when salinity decreased, organisms were observed to actively emerge, and when salinity was <10, cockles were found exposed at the sediment surface. These behavioural changes may be a strategy for the survival of this species in response to flooding: once at the sediment surface, hydrodynamics may transport organisms towards areas that are more suitable

Automated summary

In this study, cockles were found to exhibit different burrowing/emergence patterns in response to salinity variations: buried in sediment at high salinities, actively emerging as salinity decreased, and exposed at the sediment surface when salinity was <10. These behavioral changes may represent a survival strategy for this species in response to flooding events, as being at the sediment surface could enable transport towards more suitable areas.