Update on Summer 2009 Oakland Bay Water Quality

 Joe in UOB

State and Tribal scientists use fecal bacteria (FC) as an indicator of water pollution in Oakland Bay.  In 2006 during the summer months, the bacteria concentration in the water column at the head of Oakland Bay skyrocketed and restricted commercial harvest in some shellfish beds.  In in the first half of the summer of 2009, the concentrations are much lower, in spite of the hot weather we have had and a massive die-off of clams earlier in the year.  That’s good news for the Tribe, the shellfish industry and the greater community.

WC FC

The low fecal bacteria concentrations in the water column are not matched by lower concentrations in or on the intertidal sediment.  Sediment bacteria concentrations are running higher this year than in 2007 or 2008.  But for some reason, the bacteria are not being resuspended into the water column.  This resuspension often occurs when wind speed exceeds 5 mph from the southwest creating extensive wave action in the upper bay that stirs up the bacteria-laden sediment. 

SED FC

At the end of the summer, we will analyze more data including wind speed and direction to try and explain this year’s fecal bacteria counts.

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