Summary
Aquatic and pulmonate snails were evaluated for their suitability as biomonitors of habitat recovery following an experimental oil spill in a freshwater marshland. The mystery snail, Viviparus georgianus, and the mimic pondsnail, Pseudosuccinea columella, were used as sediment quality biomonitors for a controlled oil-spill experiment at a wetland site along the St. Lawrence River (Ste. Croix, Quebec) to assess the impacts of crude oil, rates of natural recovery, and the efficacy of bioremediation treatments to enhance the bacterial degradation of residual oil in the sediments. Sediments from control sites and oiled sites with or without the application of fertilizers as bioremediation strategies, were evaluated both in situ and under controlled laboratory conditions at various time intervals. Snail survival, growth, and histopathological changes were monitored. While V. georgianus proved to be good biomonitors, P. columellaappeared unaffected by the treatments. The differing sensitivity may depend on the gastropods' feeding habits. V. georgianus being a detritivore assimilated contaminants from the sediments, while P. columella, being an herbivore, did not directly assimilate contaminants. Nevertheless, snails show potential as important and ideal “tools” for testing environmental conditions because of their abundance, ease of collection, wide distribution, and relatively sedentary nature.
Methodology
Snails were collected from sites and experimented on in the lab