REDUCING OUR FOOTPRINT REDUCING OUR FOOTPRINT Unit 3-1b Unit 3-1b How To Measure How To Measure Water Quality Water Quality
Dec 31, 2015
REDUCING OUR FOOTPRINTREDUCING OUR FOOTPRINT
Unit 3-1bUnit 3-1b
How To MeasureHow To MeasureWater QualityWater Quality
How Is Water Evaluated?
Traditional Water Testing – Uses both chemical and physical tests to evaluate the condition of water
It is beneficial because…
• The standards of good water quality are universal
• It can quickly determine the exact cause of a disturbance
However it is limited because…
• It only checks for specific chemicals or factors
• Results can be affected greatly by the weather
Make a chart like this:
Test What it measures How
Leave some space at the bottom of the page.
Traditional Water Tests
Turbidity – Measures the concentration of undissolved particles that make water appear cloudy or murky
Measured with a Secchi disc
or Turbidity tube
Which of these tools would be used to measureturbidity for a stream and which is used for a
lake?
Traditional Water Tests
Total Dissolved Solids – Measures the concentration of dissolved solids including salt (NaCl) and other substances
pH – Concentration ofhydrogen ions (H+); Canindicate acid precipitation in the area
Nitrates & Phosphates– Nutrients that are usedin fertilizers & depositedin lakes and bays causingeutrophication
These are all determined using chemical indicators
Traditional Water Tests
Dissolved Oxygen – Needed by fish & other organisms; Effected by excessive algae or high temperatures
Sometimes fish come to thesurface for air if dissolvedoxygen levels are very low!
Biological Oxygen Demand– The BOD measures theamount of oxygen used bybacteria that break downwaste (feces) over five days
If the oxygen level drops significantly within five days,
describe the bacteria population & their food source.
These are all determined using chemical indicators
Traditional Water Tests
Fecal Coliform – A measure of the bacteria released by the decomposition of feces
These bacteria coloniescan be cultured in a Petri dish
Change in Temperature – This ismeasured from distant locationsat the site to find variations
Lake Michigan has temperature variations from 40oF – 75oF.
Calculating Water Quality
Water Quality Index – The WQI is a score based upon results from nine different chemical & physical tests
Calculating water quality is similar tofinding your marking period grade.
Some assignments, like tests,carry more weight and havea greater effect on your average.
The Q-Value for each test showswhich tests are most important tothe overall health of the ecosystem.
What is the most important factor whenevaluating water quality using the WQI?
Let’s Review… What have you learned in this unit?
1. What are the advantages &disadvantages of traditionalwater testing?
2. How can a powerful stormaffect a pond’s WQI score?
4. Explain the causes and effectsof eutrophication.
5. Describe the importance ofdissolved oxygen in an aquatic ecosystem.
REDUCING OUR FOOTPRINTREDUCING OUR FOOTPRINT
Unit 3-1cUnit 3-1c
BioassessmentBioassessmentOf An EcosystemOf An Ecosystem
What Is Bioassessment?
Bioassessment – Using biological factors to evaluate the health of an ecosystem.
It is beneficial because…
• It shows the true biological effects of a disturbance
• Recent disturbances can be detected even if the chemical pollutant has disappeared
If a pollutant was dumped in a river three months ago,
those chemicals might have washed away but the effects of it on organisms can still be observed.
How To Bioassess An Ecosystem
Macroinvertebrates - Species without backbones that are large enough to be seen without a microscope
These include types of insects, worms, andshellfish.
They are collected…
• Using a variety of nets
• By looking under rocks, near vegetation or in sediment
Indicators Of A Healthy EcosystemIn a healthy North American river you’ll find…
Pollution Sensitive SpeciesMayfly, Caddisfly, Planaria & Mussels
As more & more of these disappear, you’ll see more…
Pollution Semi-Tolerant SpeciesDragonfly, Damselfly, Scud & Clams
As more & more of these disappear, you’ll see more…
Pollution Tolerant SpeciesMidge, Mosquito, Leech & Snail
Understanding The IBI Score
Index of Biological Integrity - The IBI is a grade for an ecosystem based upon the organisms living there.
Higher populations ofpollution-sensitive species willshow the water is clean andresult in a higher IBI score.
Disadvantage -each test is unique to aspecific ecosystem.
New Jersey, Texas & Alaska have different native species, so each needs a different assessment.
Hand In Your Student Notes
What have you learned in this unit?
1. What are the advantages anddisadvantages of using bioassessment?
2. Describe how and wheremacroinvertebrates are collected.
3. Identify three species that canbe used to identify water quality.
4. Explain how to determine theIBI Score for a pond or river?