Stream monitoring for P. ramorum in WA, 2013 results

Washington Department of Natural Resources Phytophthora ramorum update – Phytophthora ramorum waterway monitoring as well as forest and nursery perimeter surveys have been conducted in Washington since 2003, with efforts since 2006 focusing on aquatic areas near previously positive nurseries.  In 2013, 11 P. ramorum stream baiting sites were established in western Washington waterways, of which two were identified as positive – one in Clallam County and one in Thurston County.  Eleven additional sites were repeatedly sampled in Clallam County as the source of the inoculum there is unknown; however, results to date have been negative or inconclusive.
In 2013, the water monitoring sampling methodology was changed from stream baiting with mesh bags to the Bottle-of-Bait method in the interest of increasing efficiency.  Since waterway sampling began in 2005, P. ramorum has been detected in seven waterways in western Washington:  two in King County and one each in Clallam, Clark, Lewis, Pierce, and Thurston Counties.  Diseased plants were found associated with one of the waterways in 2010 (Pierce County) and were destroyed.