What is it for?The Hydrolab is the name of the sonde we will be using.It is a scientific instrument used to measure biological and physical properties in water.It can be used “in the field”
AdvantagesIt can store data in memory and communicate with computers.Some sondes can be programmed and left in water to gather data over a period of time.
Questions Think of a place a scientist might want to place a sonde and leave it for a week? What about a year? What is an advantage to having an electronic monitor like the Hydrolab instead of pH paper and a hand held thermometer?
Sonde DataThe Sonde here has measured several parametersover time
This sonde measured DO over timein several rivers
Hand heldSurveyor Hydrolab
pHDissolved OxygenTemperatureChlorophyll a
pH pH is a measure of the acidic or basic (alkaline) nature of a solution
pH – A scale from 0-14 A pH range of 6.0 to 9.0 provides protection for the life of freshwater fish. Min Max Effects 3.8 10.0 Fish eggs could be hatched, but deformed young 5.0 9.0 Tolerable range for most fish 4.1 9.5 Range tolerated by trout 6.0 7.2 Optimum (best) range for fish eggs 4.0 10.1 Limits for the most resistant fish species 4.6 9.5 Limits for perch 5.4 11.4 Fish avoid waters beyond these limits 3.3 4.7 Mosquito larvae live within this range 7.5 8.4 Best range for the growth of algae
Dissolved Oxygen Dissolved oxygen – the amount of oxygen dissolved in water. This is dependent on the water temperature. Cold water can hold more of any gas, in this case oxygen, than warmer water. Oxygen gets into water by diffusion from the surrounding air, by aeration (rapid movement), and as a waste product of photosynthesis.
Dissolved Oxygen - DO We will measure the saturation level of the oxygen, the DO - % saturation. Rivers that have a dissolved oxygen value of 90 percent or higher are considered healthy Rivers below 90 percent saturation may have large amounts of oxygen-demanding materials, like organic waste from sewage systems, urban or agricultural run-off, and some industrial waste.
Questions What does it mean to have a higher number on the pH scale? Turn to your neighbor and explain dissolved oxygen to them in one sentence.
Temperature Aquatic life needs specific temperatures Temperature also is important because it influences water chemistry (remember how DO is effected by temperature?)
Fish and Temperature Species Lower Optimum Upper Avoidance Avoidance Bluegill 58° F 69° F 75° F Trout, Brook 44° F 58° F 70° F Trout, Brown 44° F 56-65° F 75° F Carp 75° F 84° F 88° F Bass, 60° F 80° F 60° F Largemouth Muskellunge 55° F 63° F 72° F Pike, Northern 56 63° F 74° F
Chlorophyll a Chlorophyll is the green part of plants that helps them change light to food. Measuring the concentration of chlorophyll a provides an estimate of algal biomass This is important to know because it tells us about the health of a stream or lake.
Chlorophyll a Too much algal growth, or too much of a certain type of algae (such as blue-green algae), can cause problems in the lake ecosystem. When there is a rapid growth of a certain type of algae it is called an algal bloom As the algae die off they sink to the bottom of the lake and decompose. Decomposition uses up oxygen that organisms need to live.
Algal bloom in Lake Erie 2011
Questions How can stream temperature effect a fish? How do you think they Hydrolab can measure the chlorophyll a of a stream or Lake? Chlorophyll a levels change because of land use. Why?
Land Use that Increases Chlorophyll a Agricultural run-off Water from sewage treatment plants Storm water runoff from developed land Nitrogen from burning fossil fuels Lawn and garden fertilizers Faulty septic systems Dumping or burning leaves in or near a lake
Proper Use Hold the Hydrolab by the metal bale. Deploy with the colored cord. Bale
Keep the Surveyor and Computerdry
Other Terms Calibration: To standardize or correct sensors after determining, by measurement or comparison with a standard, the correct value. Conductivity: A measure of the ability of water to pass an electrical current. This parameter indicates the amount of dissolved substances (salts) present in the water. Turbidity: a measure of the extent to which the intensity of light passing through water is reduced by the suspended matter.