Puget Sound Stream Benthos

Regulatory Effectiveness Project, King County - DNRP

Benthic macroinvertebrate sampling was conducted annually in August and September at 9 streams as part of a larger program studying the effectiveness of Critical Area Ordinance Regulations. Sampling began in 2008 and concluded in 2012.

Sample collection methods were based on the recommended sampling protocols outlined by Karr and Chu (1999) with some minor modifications. At each location, a Surber sampler (500 micron mesh, 1 sq ft frame) was used to collect three samples along the midline of three separate riffles or non-depositional habitats starting downstream and working upstream. All large materials (e.g., large gravel and large wood) within the sampling area were scrubbed by hand and examined before being placed downstream. A “weed tool” was used to vigorously agitate the substrate within the perimeter of the frame to a depth of approximately 10 cm, for 60 seconds. Each sample was condensed separately and transferred into three sample containers and preserved in the field with 95-100% ethanol (EtOH). Samples were then sent to a private lab for taxonomic identification. Chironomids were identified to family level, oligochaetes and Acari to subclass, and other taxa were identified to the lowest practical level (generally genus or species). Sampling was conducted annually between early August and mid September.

For more information on the project and links to presentations and the final report visit: http://www.kingcounty.gov/environment/wlr/sections-programs/science-section/critical-areas.aspx

Contact Person: Overall project coordinator: Gino Lucchetti, gino.lucchetti@kingcounty.gov, 206-477-4759 or for the bug sampling Jo Wilhelm, jo.wilhelm@kingcounty.gov, 206-477-4849