Wood waste assessment, characterization, and remediation in Esquimalt Harbour

Log booming and wood processing operations in BC’s Esquimalt Harbour since the 1800s have resulted in the accumulation of wood waste deposits throughout the subtidal zone. Wood waste can adversely affect sediment quality and benthic and infaunal communities, prompting the Department of National Defence to prioritize the assessment of effects of wood waste on the ecological health of the nearshore marine environment in Esquimalt Harbour. In alignment with the overall Esquimalt Harbour Remediation Project, The Esquimalt Harbour Wood Waste Assessment and Characterization Project was initiated in 2016 and continues into 2018, with Hemmera supporting the assessment, determination of impacts and proposed remediation. To determine the spatial distribution, volume, and composition of wood waste and habitat conditions in Esquimalt Harbour, Hemmera reviewed historical wood processing activities and their duration; information on contaminants and previous assessments; and completed an in-depth biophysical site characterization including SCUBA visual assessments and wood waste stratification through both hand and sonic drill cores. Sediment chemistry analysis (e.g., total organic composition, pore water sulphides, ammonia) was used to assess the effect of wood waste on sediment quality and define levels of impact. To determine impacts to infauna, laboratory analysis of sediment grab samples across a continuum of wood waste impacted sediments was performed and a community analysis conducted. This presentation will showcase results from the Project’s spatial characterization of wood waste and impact assessment investigating the effects of wood waste on sediment quality and benthic and infauna communities. In addition, the proposed pilot remediation project will be discussed, including novel restoration options and techniques. Initial results, including anoxic sediment quality, reduced benthic organism populations and the presence of white bacterial mats at known booming and processing operation locations indicate an effect of wood waste on sediment quality and the benthic community