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

Fill in the Blank

As temperature increases in a body of water, the metabolism of cold-blooded animals increases as well. So, as the supply of oxygen decreases, the demand _________________.

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

Fill in the Blank

The Secchi disc reading at Waller Mill was 2.5 meters. The limit of effective light penetration was _____ meters.

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

Fill in the Blank

Mayflies, caddisflies and gill snails all indicate high water quality. They are classified as Group ____ organisms.

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