Yakama Nation Food Web Study
The Yakama Nation was funded by Bonneville Power Administration and the Salmon Recovery Board to design, implement and assess a stream habitat restoration project in the headwaters of White Salmon Creek in Washington State. Prior to restoration, the stream channel was incised 4-6 feet. Restoration was accomplished by raising the creek bed (adding fill), particularly in riffle areas, to promote overbank flows in springtime, hold more water, and extend seasonal flow to increase the period that young-of-year steelhead could rear and migrate out of the system. The Tribe investigated potential changes to the food web by sampling riparian invertebrates, benthic invertebrate community, and fish diet to determine if there were any changes attributable to the restoration project.
The Yakama Nation contracted with EcoAnalysts to provide taxonomic identifications and length-mass regressions by taxon on over 1,100 invertebrate samples from this project. Sample types included benthic macroinvertebrates, fish diet analysis, and riparian pan traps and sticky traps. EcoAnalysts sorted and identified invertebrates to the lowest practical taxonomic group, which was often family for riparian samples, and genus/species for aquatic samples. We measured total invertebrate lengths to the nearest 0.05 mm for every sample to allow for calculation of biomass using length-weight regression curves.