Baltimore Ecosystem Study Cary Institute of Ecosystem Studies

2012 BES Annual Meeting Presentation and Poster Abstracts



 
Environmental stress in ephemeral ponds: impacts on gastropod life history traits and predator-induced defenses
 
Suski, Jamie
Co-Authors: Jamie G. Suski and Christopher J. Salice

 
Abstract: Projected climate-induced scenarios indicate increasing temperatures and unpredictable precipitation events across North America. This can have large implications to ephemeral ponds that are dependent on rain events. Increases in temperature will also lead to increased evaporation rates resulting in warmer and more saline ponds. In addition to projected climate-induced changes many ponds receive anthropogenic contributions of salts from road de-icing agents and storm and wastewater effluents. Overall, we may expect that temperature and salinity are likely to increase under future climate projections and, understanding how these factors impact aquatic communities is important for future management. We used freshwater gastropods as models to determine how salinity and temperature may alter invertebrate communities. Gastropods are model organisms for evaluating impacts to aquatic systems as they represent a functional link in the trophic chain. Additionally, mollusks tend to be one of the most sensitive taxa to salt stress. In one study, decreased survivorship and delayed reproduction was seen in Helisoma trivolvis exposed to environmentally relevant salinities and temperatures. Furthermore, the combination of increasing salinity and temperature disrupted predator- induced defenses in H. trivolvis; traits that relate directly to reducing predation risk. In a second study, toxicity of salts differed depending on the cation, which has clear implications for de-icing agents. Exposure to potassium chloride resulted in decreased hatching success, survivorship and reproduction when compared to sodium chloride and calcium chloride. These studies may be particularly relevant for urban areas where runoff and heat island effects may increase salinity and temperature in aquatic systems.