Figure 6.3 Comparison of historic and recent PO 4 during the dry season in a) Zone 1 and 
b) Zone 2.47 
3 - 
Figure 6.4 Comparison of historic and recent PO 4 during the wet season in a) Zone 1 and 
b) Zone 2.47 
Figure 7.1. Box plot of monthly chlorophyll a data from the Yaquina Estuary (all stations from 
1973-2006). 51 
Figure 7.2 Comparison of historic and recent dry season chlorophyll a for a) Zone 1 and 
b) Zone 2 in the Yaquina Estuary.51 
Figure 8.1 Seasonal pattern in dissolved oxygen at all locations and all years in the Yaquina 
Estuary and River with squares and triangles representing samples from Zones 1 and 2, 
respectively.54 
Figure 8.2 Interannual trend in residual dissolved oxygen values during 1960 to 1986 for a) 
Zone 1 and b) Zone 2.55 
Figure 8.3 a) Time-series of dissolved oxygen and salinity and b) salinity versus dissolved 
oxygen showing import of hypoxic ocean water at a station 3.7 km from mouth of 
estuary.57 
Figure 9.1. Spatial variation in turbidity during wet and dry seasons (1998-2006).60 
Figure 9.2 Light attenuation coefficients (kj) versus distance from the mouth of the estuary from 
cruise data (years 1998 to 2006), with filled and open symbols representing dry and wet 
seasons, respectively.*..61 
Figure 9.3. Median monthly light attenuation coefficients from the continuous data set at 
5 locations in Yaquina Estuary (1999-2003).62 
Figure 10.1 Photomap of intertidal vegetation in Yaquina Estuary from aerial surveys of 
July 23, 1997 and August 10, 1998.67 
Figure 10.2 Average percent cover and biomass values (+ 1 std. err.) of benthic green 
macroalgae in the Yaquina Estuary between June 1999 and May 2000. 68 
Figure 11.1 Spatial distribution of Yaquina Estuary eelgrass.72 
Figure 11.2 Z. marina depth distribution in the marine dominated portion (Zone 1) of 
Yaquina Estuary. 74 
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