SGER: Linking Marine-dDerived Nutrients To Stream Ecosystem Function Using a 15N Tracer Addition Combined with an Experimental Salmon Carcass Addition.

University Of Notre Dame, Notre Dame IN

Investigators

Abstract

Abstract Tank 0120845 Anadromous salmon are the life-blood of the Pacific Northwest, on which are based considerable economic, social, and cultural values. Normally, a massive quantity of organic material is transported from the ocean to streams annually via salmon migration. Presently, salmon stocks have declined, and lawmakers, resource managers, and the scientific community are beginning to ask what role salmon carcasses play in stream ecosystems. The PIs will address this critical knowledge gap by tracing the flow of the heavy isotope of nitrogen (15N) added to an Alaskan stream before, during, and after a salmon carcass addition. This will quantify how the pulse of marine derived nutrients (MDN) alters rates of stream N cycling from both a food web and whole-stream perspective. This research builds on the insight gained from an ongoing USDA-funded study by using the 15N tracer technique in a novel way and will help to clarify the role MDN plays in stream ecosystems.