PS 25-116 - Clear Creek Estuary Restoration: Monitoring Changes in Function and Diversity

Tuesday, August 8, 2017
Exhibit Hall, Oregon Convention Center
Christine E Butler-Minor, HCOP, WWU, Bellingham, WA

The Clear Creek Trail Alliance (CCTA) is working with local partners to monitor the effects of estuarine restoration on salmonid habitat in Kitsap County, Washington. As a system, the estuary displayed erosion below the artificial land bridge and undersized culvert with high levels of fine sediment deposition above. Recording observations of selected parameters aids in quantifying and qualifying an ecosystem’s ability to recover biochemical functionality and species diversity after physical modification. The Clear Creek Estuary monitoring project provides an opportunity for students and local citizens to expand their knowledge of the habitat requirements for healthy salmon life cycles, while recording changes afforded through barrier removal. Participants have gathered data related to water chemistry and flow, elevations and surface sediment composition, vegetation communities in the vicinity, and invertebrate diversity in the estuary at four sites using regionally adopted protocols.


Comparison of data collected prior to and then following construction can aid in the understanding of successful restoration practices. Less than one year since the berm and culvert removal, significant improvements have been noted in dissolved oxygen concentrations (p=0.0086) as well as macroinvertebrate diversity, particularly at the sites located nearest to the construction area (average =37.9%). Other findings indicate improving nutrient cycling and evidence of sloughing off 70 years worth of deposited fine sediments due to restored tidal exchange.