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Figure 2.3 Monthly discharge statistics (Yaquina River + Big Elk Creek) calculated using data 
from 1972-2002 Chitwood gauge (corrected for Big Elk Creek using relationship from 
Brown and Ozretich, in review). In the plot, the boxes represent the 25 th and 75 th 
percentiles, the whiskers represent the 5 and 95 percentiles, and the horizontal line is 
the median. The dashed line indicates 30-year median discharge. 
Estuaries in the Pacific Northwest (PNW) are adjacent to the California Current System, 
which exhibits strong interannual, seasonal and event scale variability (Hickey and Banas, 2003). 
In this region, seasonal wind-driven upwelling advects relatively cool, nutrient rich (NO3 and 
3 - 
P0 4 ) water to the surface. The upwelling season typically commences in April and continues 
through September, approximately coinciding with the dry season. During this time period, 
upwelling favorable winds from the north dominate. The upwelling conditions are interrupted by 
brief periods of downwelling favorable conditions, which usually persist for several days. 
Previous studies have demonstrated that the oceanic inputs of nutrients and phytoplankton are 
8 
