Hydrolab

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.

QuestionsThink 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 parameters over time

This sonde measured DO over time in several rivers

Hand heldSurveyor Hydrolab

What is our class testing ?pHDissolved OxygenTemperatureChlorophyll a

pHpH is a measure of the acidic or basic

(alkaline) nature of a solution

pH – A scale from 0-14A pH range of 6.0 to 9.0 provides protection for the

life of freshwater fish.

 Min Max Effects3.8 10.0 Fish eggs could be hatched, but deformed

young 5.0 9.0 Tolerable range for most fish4.1 9.5 Range tolerated by trout6.0 7.2 Optimum (best) range for fish eggs4.0 10.1 Limits for the most resistant fish species4.6 9.5 Limits for perch5.4 11.4 Fish avoid waters beyond these limits3.3 4.7 Mosquito larvae live within this range7.5 8.4 Best range for the growth of algae

Dissolved OxygenDissolved 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 - DOWe 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.

QuestionsWhat 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.

TemperatureAquatic life needs specific temperatures

Temperature also is important because it influences water chemistry (remember how DO is effected by temperature?)

Fish and TemperatureSpecies Lower

AvoidanceOptimum Upper

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, Largemouth

60° F 80° F 60° F

Muskellunge 55° F 63° F 72° F

Pike, Northern 56 63° F 74° F

Chlorophyll aChlorophyll 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 aToo 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

QuestionsHow 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-offWater from sewage treatment plantsStorm water runoff from developed landNitrogen from burning fossil fuelsLawn and garden fertilizersFaulty septic systemsDumping or burning leaves in or near a lake

Proper UseHold the Hydrolab by the metal bale. Deploy

with the colored cord.

Bale

Keep the Surveyor and Computer dry

Other TermsCalibration: 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.

Hydrolab in Use on the R/V Lake Guardian