3/27/08 CMOP Seminar Series: Tiffany Gregg
03/27/2008 - 3:00pm
03/27/2008 - 4:00pm
Tiffany Gregg on the R/V Barnes
Tiffany Gregg, M.S. Candidate, Oregon State University
ABSTRACT: Hydrophobic contaminants, such as PCBs, PAHs, and DDT, have recently been detected in the whole bodies and stomach contents of Columbia River basin outmigrant juvenile salmon. Some of these contaminants were measured at concentrations that approach or exceed threshold levels found to cause sublethal impacts in fish. Currently, it is not clear how and where juvenile salmon are exposed to toxics in the Columbia system.
My study aims to improve knowledge of the spatial distribution and transport pathway for contaminants within suspended particulate matter (SPM) in Columbia River waters, using polycyclic aromatic hydrocarbons (PAHs) as model compounds. Water samples were collected during the CMOP (Center for Coastal Margin Observation and Protection) sponsored cruise in August 2007. Columbia river sampling sites extended from just below the port of Vancouver downstream to river mile 53 and in the north and south channels of the Columbia estuary during neap and spring tide ETM (Estuarine Turbidity Maximum) events.
Preliminary results indicate that SPM carries PAHs, which appear to be derived from three primary sources: high temperature combustion, wood processing, and natural production. During spring and neap ETM events in the estuary, combustion and wood derived PAHs are slightly concentrated (_g PAH/g sediment) over those detected at Columbia upriver sights and perylene, a PAH of natural yet enigmatic origin, is highly concentrated. The concentration of six PAHs known to cause sublethal impacts in organisms were compared to sediment quality guidelines for these PAHs, specifically, the probable effects level (PEL), which is the concentration at which sublethal impacts areexpected to occur frequently. At river mile 53, three out of six PELs are exceeded and one PEL is exceeded at all other Columbia upriver sites. In the estuary, five out of six PELs are either exceeded by or approximately equal to PAH concentrations measured on SPM.
Location:
Paul Clayton Building—Room 401
OGI School of Science & Engineering
Oregon Health & Science University (West Campus)
20000 NW Walker Road
Beaverton, OR 97006
Alternatives:
The seminar may be also available by two-way videoconference and by webcast (non-interactive). Contact Ethan van Matre for more information.
To meet with Ms. Gregg during her visit, contact Sergey Frolov.
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