Multi-scale variation in salinity: a driver of population size and structure in the muricid gastropod Nucella lamellosa
This study explores how salinity operates across spatial and temporal scales to affect the population structure of the dogwhelk Nucella lamellose in the Strait of Georgia, British Columbia, Canada. The Fraser River heavily influences surface salinity in the Strait, which varies with season, depth, and distance to the river mouth. Low salinity was linked with delayed embryonic development, elevated juvenile mortality, and decreased population size. However, a daily 3-hour high salinity exposure, as can occur in a stratified tidal estuary, mitigated the negative impacts of long periods of low salinity. Our results suggest that seasonal and interannual variation in salinity have a profound influence on N. lamellose populations, and that shorter-scale fluctuations can moderate seasonal and interannual effects.