Columbia River : Select Area Fishery Evaluation project : 1995-96 Annual Reports. Page: 24 of 212

                                
RESULTS

Physicochemical Monitoring
Physicochemical data are presented graphically in Figures 1-9 and in tabular form in
Tables 1-8. Each site has different physicochemical characteristics so the data has
been organized graphically by the different parameters for a visual comparison
between different net-pen rearing locations. Tabular data has been organized by site
with the arithmetic mean and standard deviation of the mean shown for all
physicochemical parameters. Tables are self- explanatory with some exceptions. The
dissolved oxygen percent concentration is an automated feature that gives an
indication of expected dissolved oxygen value for that temperature and barometric
pressure. This feature was available only after April 1995 due to a software upgrade
provided by the Hydrolab Corporation. Due to equipment malfunction all
physicochemical data for October 1995 at Wallace Slough, Clifton Channel, Blind
Slough, and Tongue Point were lost.
The Youngs Bay location had a temperature low of 5.75 degrees C during the month of
December 1994 and a high of 21.86 degrees C the month of July 1995. A pH of 6.33
was lowest during February and highest during May at 8.01. Specific conductivity
varies greatly with a low of 134.09 micro Siemens per centimeter during February 1995
and a high of 9407.37 micro Siemens per centimeter during October 1995. Salinity is a
function of specific conductivity, so the months that had the highs and lows of specific
conductivity will be the same months that contain the highs and lows in the salinity
category. Dissolved oxygen concentration fluctuates with the water temperature and
barometric pressure. The waters ability to retain oxygen is inversely proportional to the
water temperature so it would be expected that the highest dissolved oxygen
concentrations to be at the time of the lowest water temperatures. The low for
dissolved oxygen was during July 1995 at 6.64 mg/L and a high of 13.79 mg/L during
December 1994. Turbidity was lowest during October 1995 at 6.24 NTUs and highest
during January at 69.22 NTUs.
The Tongue Point location had a temperature low of 5.07 degrees C during January
1995 and a high of 20.10 degrees C during July 1995. Mean lows and highs for pH
readings were 6.73 and 7.95 during December 1995 and May 1995, respectively.
Specific conductivity lows and highs were 92.53 micro Siemens per centimeter and
2494.67 micro Siemens per centimeter during December 1995 August 1995,
respectively. Dissolved oxygen concentrations were lowest and highest during the
months of July and January 1995 with readings of 7.82 mg/I and 15.52 mg/L. Turbidity
was lowest in August at 13.27 NTUs and highest during June 1995 at 74.81 NTUs.
The Deep River location had low and high temperatures of 4.59 degrees C and 23.37
degrees C during December 1994 and July 1995, respectively. Low and high mean ph
readings were 4.98 and 6.47 during March 1995 and September 1995, respectively.
Specific conductivity measurements were lowest and highest at 41.89 micro Semens

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