Temperature and DO Temperature  A measure of heat Dissolved Oxygen (DO)  The concentration of oxygen (gas) which is dissolved in water. Both are important individually and to one another

Why is Temperature Important?  Most aquatic organisms are poikilothermic (“cold-blooded”), which means they don’t internally regulate their core body temperature.  The rate of many chemical reactions increases at higher temperatures.  Oxygen solubility

Temperature - Units  Fahrenheit (°F), Celsius (°C), Kelvin (K)  Celsius (°C) used for most science (SI unit) –a.k.a. centigrade, where “centi-” = hundredth  Water Freezes at 0°C = 32°F = K  Water Boils at 100°C = 212°F = K 0°C 32°F 100°C 212°F

Temperature - Units  Conversion Factors (°F – 32) 1.8 °F = (°C x 1.8) + 32 °C =

Temperature – Q 10 Rule  General rule which predicts: Growth rates of cold-blooded aquatic organisms and many biochemical reaction rates will double for every 10°C (18°F) temperature increase within their "preferred" range.

Temp – Biological Effects Growth Rate Temperature (Celsius) Lethal Optimum

Temperature Standards Temperature All waters64°F (17.8°C) Salmon spawning, egg incubation, and fry emergence 55°F (12.8°C) Bull Trout50°F (10°C) Columbia River (to RM 309)68°F (20°C) Willamette River (to RM 50)68°F (20°C) Rolling 7-day average of maximum daily temperatures

Temperature – Deep Cr (Clack) day max AVG = 20.6°C

Temperature – Causes  Loss of riparian shading  Warm water inputs –Retention ponds –Municipal or industrial wastewater –Stormwater runoff  Groundwater inputs  Weather –Air temperature, cloud cover, day length  Turbidity

Dissolved Oxygen  O 2 gas dissolved in water  Required by nearly all aquatic life O2O2 CO 2 Atmosphere21 %0.035 % Water 0 % 20 %

DO – Solubility  Inverse, non-linear relationship to temperature  Decreases with decreasing barometric pressure –Weather, elevation  High salinity reduces solubility

DO – Solubility

DO – Units Concentration: mg/L = µg/mL = ppm (parts per million) Percent Saturation: DO % Sat. = Measured DO (mg/L) Solubility (mg/L)

DO – Sources  Photosynthesis –Influenced by sunshine, temperature, water velocity  Atmospheric Re-aeration –Turbulent mixing Water velocity and depth Oxygen deficit  Inflow of oxygenated water

DO – Sinks  Respiration –Greatest source of DO loss in summer  Biochemical Oxygen Demand (BOD) –Decomposition of organic wastes –Standard measure is 5-day BOD = BOD 5  Nitrification (NBOD) –NH 3 + O 2 = NO 3

DO – Diel Fluctuations Dissolved Oxygen Time of Day AM PM

DO – Standards Salmonid Spawning thru Fry Emergence Water Quality Standard> 11 mg/L Intergravel Standard> 6 mg/L unlessIntergravel DO > 8 mg/L> 9 mg/L orNatural conditions> 95% sat. Cold-water Aquatic Resources> 8 mg/L Natural conditions> 90% sat. Cool-water Aquatic Resources> 6.5 mg/L Warm-water Aquatic Resources> 5.5 mg/L

DO and Temp Data Quality AccuracyPrecision Temperature+ 0.5°C+ 1.0°C Dissolved Oxygen mg/L+ 0.5 mg/L

Measuring DO and Temp  Measure Immediately - In Field  Measure Both at Same Time  Recording Time is Crucial  Sample Collection –Below surface ~ 4 inches (or ½ way to bottom of shallow stream) –Cap DO bottle underwater