The utility of aquatic macroinvertebrates as indicators of the ecological conditions has long been established in rivers and streams. However, useful invertebrate indicators of wetland conditions remain underdeveloped.

Recently, WU Haitao at Northeast Institute of Geography and Agroecology of Chinese Academy of Sciences together with Darold P. Batzer at University of Georgia discovered that snail assemblages and certain indicator species may provide a robust and rapid indicator of environmental impacts on wetlands in Northeast China. The finding was published online in Ecological Indicators.

The researchers sampled snail assemblages in 16 wetlands across a range of conditions, from relatively pristine “best available” reference sites to obviously human-impacted sites, to investigate the utility of snail taxa for indicating environmental variation across these wetland habitats

Besides, they sampled in 12 floodplain wetlands along Wusuli River (headwater-, mid-, and downstream-reaches) in Northeast China’s Sanjiang Plain.

Comparisons between river-connected and levee-isolated wetlands were performed at 10 sites.

The results demonstrated that it is simple and effective to a make rapid assessments of wetland condition by using snail assemblages as surrogates for overall aquatic invertebrate communities. Whether the wetlands are isolated from the river or not, snail assemblages were concurrently being impacted by human impact and river reach. Snail species were indicators of specific wetland types.

Snails are distributed widely and are generally easy to sample and identify, this overall approach should have applicability in the many wetlands worldwide where diverse snail assemblages naturally occur.

Typical snail taxa for indicating environmental variation (Image by WU Haitao)