Outer Island Pier Water Quality (2014)
Water quality parameters were monitored by the CSU interns during the Summer 2014 from May 31st to August 3rd. 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.
Water temperature gradually increased from the spring to the end of the summer. Dissolved oxygen concentrations saw an early spike (12.36 mg/L) on 6/3 and decreased as temperatures increased with a low of 5.44 mg/L on 7/29. Temperature and dissolved oxygen varied inversely (Figure 1a). Salinity showed little variability, with a range of only 25.7 ppt (6/9) to 28.4 ppt (8/3), while conductivity showed a slightly larger range from 32.93 mS (5/31) to 41.82 mS (7/23) (Figure 1b).
Water clarity, as measured by a Secchi disk, varied from 0.5 m (7/6) to 1.3 m (7/16) during the monitoring period (Figure 2a). Greater variability was measured in water turbidity, where values ranged from 1.73 NTU (6/6) to 6.09 NTU (7/13) (Figure 2a). In general, as turbidity increases water clarity, as measured by the Secchi disk should decrease. pH ranged from a low of 7.93 (7/4; 7/5; 7/27) to a high of 8.17 (7/21) (Figure 2b). Similar to other parameters this season, water clarity/turbidity and pH showed less variation than previous years.