Cultural eutrophication is reflected in the stable isotopic composition of the eastern mudsnail, Nassarius obsoletus
Citation:
Watson, E., K. Szura, E. Powell, N. Maher, AND C. Wigand. Cultural eutrophication is reflected in the stable isotopic composition of the eastern mudsnail, Nassarius obsoletus. JOURNAL OF ENVIRONMENTAL QUALITY. American Society of Agronomy, MADISON, WI, 47(1):177-184, (2018). https://doi.org/10.2134/jeq2017.05.0214
Impact/Purpose:
The stable nitrogen isotope ratio of Nassiuris obsoletus, the eastern mudsnail, was used as an indicator of eutrophication status for urbanized estuaries in coastal New York, USA. There was 15N enrichment in mudsnail tissue where watersheds had high population densities, landuse patterns were more urbanized, and when sampling sites were adjacent to wastewater treatment plant discharges. Mudsnail nitrogen isotopic composition had a high level of separation between more impacted and less developed watersheds (6.6-14.1‰), highlighting its utility as a water quality indicator. We thus propose that the stable nitrogen isotope value of the eastern mudsnail, can be used in concert with other water quality data to identify areas were improvements in water quality are needed.
Description:
In aquatic ecosystems, biological indicators are used in concert with nutrient concentration data to identify habitat impairments related to cultural eutrophication. This approach has been less commonly implemented in coastal areas due to the dominance of physical conditions in structuring biological assemblage data. Here, we describe the use of the stable isotopic composition of Nassiuris obsoletus, the eastern mudsnail, as an indicator of cultural eutrophication for estuaries in coastal New York, USA. We found 15N enrichment in mudsnail tissue where watersheds had high population densities, landuse patterns were more urbanized, and when sampling sites were adjacent to wastewater treatment plant discharges. Stable carbon isotopes were responsive to salinity and watershed forest cover, with more saline sites reflecting a predominantly C4 or algal carbon isotopic signature (-12‰) and more forested sites a lighter isotopic signature reflecting greater inputs of terrestrial detrital carbon. Mudsnail nitrogen isotopic composition had a high level of separation between more impacted and pristine and watersheds (6.6-14.1‰), highlighting its utility as an indicator. We thus propose that stable isotope values of estuarine biota, such as the eastern mudsnail, can be used in concert with water quality data to identify areas were improvements in water quality are needed and can also be used to identify sources of detrital carbon to estuarine environments.
URLs/Downloads:
DOI: Cultural eutrophication is reflected in the stable isotopic composition of the eastern mudsnail, Nassarius obsoletus