Is the invasive cordgrass, Spartina anglica, becoming integrated within invertebrate food webs in north Puget Sound, WA, USA?
Hellquist, C.*,1, Nelson, S. 1, Rhodes, B. 1, Lee, R. 1, Black, R.1, 1 Washington State University, Pullman, WA ABSTRACT- Spartina anglica is an invasive estuarine cordgrass that has colonized approximately 400 ha of intertidal habitats in north Puget Sound, WA. This invasion has resulted in the extensive colonization of some mudflats while other similar mudflats may have little or no Spartina present. This distribution pattern has created opportunities to examine trophic relationships following colonization of a non-native species. We examined estuarine trophic relationships by sampling the stable isotopic composition (13C, 15N, and 34S) of phytoplankton, zooplankton, benthic invertebrates, macroalgae, and vascular plants. Initial data using 15N and 13C indicate that invertebrate isotopic ratios vary between sites and species. Macoma balthica (Bivalvia) collected within roots of S. anglica has a C signature (13C -16‰) that is relatively similar to S. anglica (13C -13‰). In bivariate i
