Outer Island Pier Water Quality (2015)
Water quality parameters were monitored by the CSU interns during the Summer 2015 from May 29th to August 7th. Water quality monitoring occurred each day at 2:00 pm from the end of the floating dock. Water quality parameters monitored included: water temperature, salinity, conductivity, specific conductance, dissolved oxygen, Secchi disk depth, turbidity, and pH. All measurements were made on water samples collected from at a depth of one meter.
Salinity showed little variability, with a range of only 28.6 ppt (7/27) to 29.1 ppt (6/3), while conductivity showed a slightly larger range from 34.86 mS (5/29) to 43.26 mS (8/2) (Figure 1a). Water temperature gradually increased from the spring to the end of the summer (Figure 1b). Dissolved oxygen concentrations saw an early spike (10.14 mg/L) on 5/30 and decreased as temperatures increased with a low of 6.98 mg/L on 8/7. Temperature and dissolved oxygen varied inversely (Figure 1a).
Water clarity, as measured by a Secchi disk, varied from 0.70 m (6/18) to 2.0 m (5/29) during the monitoring period (Figure 2a). Greater variability was measured in water turbidity, where values ranged from 1.30 NTU (5/29) to 63.97 NTU (6/18) (Figure 2a). In general, as turbidity increases water clarity, as measured by the Secchi disk should decrease. pH ranged from a low of 8.10 (8/7) to a high of 8.29 (6/24) (Figure 2b). Similar to other parameters this season, water clarity/turbidity and pH showed less variation than previous years.