The Influence of Anadromous Alewife on Maine Lakes and Streams: Using Nutrient Limitation Assays and Stable Isotopes to Track Marine-Derived Nutrients

摘要: Anadromous fish can act as nutrient subsidies to freshwater ecosystems when they return there spawn. However, relatively few studies have quantified the role of alewife (Alosa pseudoharengus) an ecologically important source marine-derived nutrients (MDN) lakes and streams. Primary producers in streams are often limited by nutrients, such nitrogen phosphorus. If bring streams, then limitation primary those systems should be alleviated. Nutrient assays stable isotopes were used examine effects MDN on Maine their outlet run prior to, during, after runs again lake turnover. Alewife increased water concentrations slightly, but not lakes. There was also no coherent shift or alleviation compared non-alewife systems. enrichment δ 13 C 15 N zooplankton resident one comparison a lake. Additionally, white perch Fields Pond, which access restored dam removal, more enriched re-introduction 2011. less effect than expected, current densities low historical counts other areas northeastern U.S. Results from isotope data suggest that some incorporated into food webs. This study has relevance given proposed removals diadromous restoration, will restore habitat for native anadromous alewife.