5. Spatial and temporal patterns in water quality parameters in the Yaquina Estuary 
For the analyses in this report, we divided the year into two seasons (wet and dry) and divided 
the estuary into two zones. There are significant seasonal and spatial patterns in the water quality data 
resulting from differences in sources, transport, and losses. 
5.1 Salinity 
There are strong seasonal differences in salinity within the Yaquina Estuary driven by 
differences in freshwater inflow (Figure 5.1 and Figure 2.3). During the dry season, Zone 1 is marine 
dominated with mean salinity of 26 psu at the boundary demarking Zones 1 and 2. Salt penetrates 
about 35 km into the estuary during periods of minimal freshwater inflow. 
Zone 1 Zone 2 
Figure 5.1 Salinity versus distance from mouth of the estuary during the a) dry and b) wet seasons. 
The gray lines demark the two zones 
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