<<--  August 31, 2007  -->>
Pseudo-nitzschia totals are subdivided into the following species groups identified by light microscopy - a/f/h (P. australis/fraudulenta/heimii), p/m (P. pungens/multiseries), pd/d/c (P. pseudodelicatissima/delicatissima/cuspidata). Threshold levels of each group at which toxin testing is done are shown as a colored horizontal bar in the Pseudo-nitzschia species graph

Twice-weekly phytoplankton sampling (scroll over ORHAB beach sites to magnify data at each site) indicates that numbers of a/f/h at Copalis and Quinault beaches exceeded the threshold level of 50,000 cells/L on 8/16/07. Toxin testing of seawater and shellfish by ELISA showed no dangerous levels of domoic acid on that date. Pseudo-nitzschia numbers decreased since 8/16/07 and there is no further need for toxin testing.

Currents at the present time (both modeled and measured) indicate a well developed upwelling system. Cold water is evident all along the coast, indicating upwelling, in the model results. Drifter plots indicate that the Juan de Fuca eddy was well developed (i.e., drifters circled around the eddy). Satellite-derived chlorophyll (a proxy for phytoplankton) at the sea surface indicates extensive chlorophyll blooms along the coast and on the perimeter of the Juan de Fuca eddy. Surface currents are flowing generally southward at speeds of 30-50 km per day, as seen in the surface drifters deployed in the Juan de Fuca eddy. Drifters transit the entire Washington shelf in less than a week. As shown by the drifters, surface currents would generally be moving phytoplankton slightly offshore, away from the coast as they move southward along the coast, so that a HAB event from the Juan ed Fuca source region is unlikely on the Washington coast as long as the winds continue to be from the north. The winds are expected to continue this way for at least a week. Consistent with this pattern, the modeled Columbia plume is tending southwest off Oregon; no remnant plume is seen off the Washington coast at this time.