Repeated Hyposalinity Pulses Immediately and Persistently Impair the Sea Urchin Adhesive System.

This article investigates the effects of repeated pulses of hyposalinity—reduced salinity levels caused by extreme climatic events—on the locomotor and adhesive performance, as well as the tensile behavior of tube feet, in the green sea urchin (Strongylocentrotus droebachiensis). The study found that both moderate (22‰) and severe (16‰) hyposalinity significantly impair sea urchin movement, adhesion, and tube foot mechanical strength during exposure, with some negative effects persisting even 20 hours after returning to normal salinity (32‰). Importantly, no evidence of acclimation to repeated hyposalinity pulses was observed over the two-month experimental period. These findings suggest that increasing frequency and intensity of hyposalinity events due to climate change may elevate sea urchin dislodgment risk and alter their ecological roles in nearshore marine communities.