Efficacy of carcass analogs for restoring the productivity of salmonid bearing watersheds U.S. Department of the Interior U.S. Geological Survey Columbia River Research Laboratory Photo by Gilbert W. Arias Lower Columbia Fish Enhancement Group

Photo by G. Ruggerrone

Why analogs? Pathogen free Nutrient characteristics of carcasses Easy transport and handling Similar rate of decay as carcasses Stable availability

Project Goal Demonstrate the effectiveness of carcass analogs for nutrient enhancement

Influence of analogs on: Water chemistry Water quality Periphyton Aquatic insects Fish

The Wind River watershed

Phase I: water chemistry (2003) Phase II: biological productivity (2004) Phase III: analog additions ( ) Project background

Analogs produced… Minor increases in N and P Minor decreases in DO Increases in algae production Increased numbers of aquatic insects Increases in fish growth

Analogs significantly increased growth in juvenile steelhead Apr-AugAug-Oct Creek Sectio n N Fork Length (mm) Mass (g)N Fork Length (mm) Mass (g) CedarControl Treat * 1.49* MarthaControl Treat * TrapTreat

Significant biological effects No degradation of water quality Demonstrated the “proof-of-principle” Summary

Two loading densities (What is a proper density? How do you determine it?) 500-m of stream (Effects at the watershed scale? How would you do it?) Applied analogs in the fall (Other times of year? Effects?) Other issues: contaminants, source material, nutrient pathways, long-term studies Using analogs on a programmatic basis? Caveats and questions… Photo by Graham Osborne