Ribbed Mussels Continue to Feed and Biodeposit in the Presence of Injured Conspecifics and Predators

Abstract

Species interactions may mediate the ability of organisms and communities to provide valued services but are rarely considered in forecasting how service provisioning will change as restored communities mature and change in species composition. Bivalves are foundational species in many communities that contribute to services such as habitat provisioning, water filtration, and denitrification but that also may respond to predator presence by reducing activity. Filtering and biodeposition rates of ribbed mussels (Geukensia demissa) in the presence of predators (blue crabs (Callinectes sapidus), oyster drills (Urosalpinx cinerea)), injured conspecifics, or other local species (mud snails, Tritia obsoleta) were compared in laboratory experiments conducted in July–August 2019 in the Hudson River estuary (New York, USA). The effect of predator diet on ribbed mussel responses was also considered. Although mussels tended to be less active in the presence of predators and injured conspecifics, significant decreases were observed in few traits, and there was no evidence that predator diet influenced mussel responses. Variability in feeding rates and other factors such as water quality may play a larger role than predator presence in determining mussel activity. These results suggest that G. demissa will continue to provide positive impacts on water clarity and quality and increase denitrification rates via biodeposition even as restored communities attract predators.