Meeting Abstract
Individuals living in brackish habitats routinely experience dynamic abiotic conditions that include acute and chronic exposure to different salinity environments. For species living in isolated high marsh portions of estuaries, like the anemone Nematostella vectensis, salinity can have persistent local variation across a salt marsh but also vary by more than 30 ppt over a single day dependent on rainfall or tidal surge. Because adult Nematostella are relatively sessile and offspring are locally retained, these changes in the saline environment may represent a differential lethal stressor dependent on developmental stage or a sublethal stressor that impacts physiological performance. In this study we show that, despite a large tolerance to salinity (> 40 ppt), all developmental stages have a fine scale (1-2 ppt) at the extreme ends of the salinity range where individuals undergo complete mortality. Discrete developmental stages had significant variation in acute exposures suggesting stage-specific sensitivity to salinity stress. We observed sublethal stress, both in extended time for larval settlement as well as reduced growth rates in adults, in salinity conditions where individuals did survive. A long term, common garden experiment where adults were cultured under different salinity conditions additionally showed that reproductive output and offspring survival are impacted by the adult salinity environment. We compare these data with field measurements of salinity fluctuations in Nematostella’s habitat and stage-specific variation in other estuarine species.
