Unit 8: Water Quality

Unit 8: Water Quality

Review Abiotic and Biotic Water Quality Indicators

Properties of Water

• Polar

• Hydrogen Bonds

• Cohesion and Adhesion

• High Surface Tension

• Excellent Solvent

• High Heat Capacity

• Ice is Less Dense

Properties of Water

• Look at your Application - any questions??

Multiple Choice

What are the bonds called between two water molecules?

• polar covalent bonds

• hydrogen bonds

• ionic bonds

Multiple Choice

What are the bonds called between the hydrogen and oxygen in one water molecule?

• polar covalent bonds

• hydrogen bonds

• ionic bonds

Importance to Life?

• capillary action

• high surface tension

• high heat capacity (specific heat)

• high heat of vaporization

• ice is less dense

Abiotic Water Quality Indicators

• Find your Abiotic Water Quality Indicators Application - you will need it!

• Oxygen - colder water holds more; reduced by nutrients, temperature and sediment

• Nitrogen - primary plant nutrient; found in proteins; high in many fertilizers

• Phosphate - binds to soil particles; chicken and swine produce a lot

• pH - acid vs. base; connected to CO₂ cycle

Abiotic Water Quality Indicators (cont.)

• Hardness - affects how soap lathers; high in limestone country; clogs pipes; sink stains

• Alkalinity - water's ability to neutralize acids; low in acidic waters

Multiple Choice

Dissolved oxygen in a body of water should be ___________ to support life.

• less than 5 ppm

• less than 2 ppm

• less than 0.5 ppm

• greater than 5

Multiple Choice

Phosphate in a body of water should be ___________ to maintain high quality.

• less than 5 ppm

• less than 2 ppm

• less than 0.5 ppm

• greater than 5

Multiple Choice

Nitrogen in a body of water should be ___________ to maintain high quality.

• less than 5 ppm

• less than 2 ppm

• less than 0.5 ppm

• greater than 5

Multiple Choice

Acts as a buffer for aquatic systems...

• Nitrogen

• Phosphate

• Hardness

• Alkalinity

Multiple Choice

A small change greatly affects organisms...

• Alkalinity

• pH

• Hardness

• Temperature

Multiple Choice

Legumes, like clover, fix it...

• Oxygen

• Nitrogen

• Phosphate

• Alkalinity

Geophysical Properties of Water

Multiple Select

Which of the following are characteristics of the hypolimnion? (Select all that apply.)

• high in oxygen

• high in carbon dioxide

• high in nutrients

• high pH

Multiple Choice

At the compensation depth, the rate of photosynthesis ______________ the rate of cellular respiration.

• is greater than

• is equal to

• is less than

Multiple Choice

Where is the thermocline in Lake A?

• 3-6 meters

• 5-8 meters

• 0-4 meters

• there is no thermocline

Multiple Choice

Where is the thermocline in Lake B?

• 3-6 meters

• 5-8 meters

• 0-4 meters

• there is no thermocline

Measuring Aboitic Water Quality

• CO₂ and O₂ --> photosynthesis!

• CO₂ and pH --> carbonic acid!

• Temp and O₂

• pH and Alkalinity

• Secchi disc --> transparency, turbidity; x2 to get limit of effective light penetration

Multiple Select

CO₂ went down at night. Is this what we would expect?

• Yes

• No

Multiple Select

CO₂ went from 15 ppm to 12 ppm and the pH went from 6.4 to 6.7. Is this what we would expect?

• Yes

• No

Multiple Select

The salinity of Waller Mill reservoir was measured as 6 ppt. Is this what we would expect?

• Yes

• No

Canaries of the Stream

• Find your assignment - you will need it!

• benthic macroinvertebrates

• riffle vs. pool

• keys written by a lay person

• monitoring water quality with biotic vs. aboitic

Biotic Water Quality Indicators

• Group 1, 2, and 3

• Find the Excel file (Biotic Water Quality Score Worksheet) - you will need it!

SCI

• run/total organisms

• should never by above 1

• indicates diversity of a sample

• advantage - you don't need to be able to identify the organisms, only tell that they are different from each other

Dip Netting

• jab method vs. rocky bottom method

• look for areas that might provide habitat - submerged woody debris, stream banks, riffles, submerged aquatic vegetation

• a single sample consists of 20 jabs