Water Quality

Indicators of Water Quality

1) Nitratesa) Eutrophicationb) Algae Blooms

2) pH3) Turbidity4) Temperature5) Dissolved Oxygen6) Bioindicators

1. Nitrates (NO3) A naturally occurring form of nitrogen found in soil.

Nitrates

o Nitrogen is essential to all life. o Most crop plants require large quantities to

sustain high yields.

o Causes Eutrophication

o Common sources of nitrate include:• fertilizers and manure,• animal feedlots,• municipal wastewater and sludge,• septic systems

Nitrates• Too much nitrates in a lake or pond will cause

Eutrophication

a) EutrophicationExcessive richness of nutrients in a lake or

body of water. Frequently due to runoff from the land, which causes a dense growth of plant life and then death of animal life from lack of oxygen.

a) Eutrophicationhttp://www.youtube.com/watch?v=L-tfCEpUr7M&fea

ture=relatedEutrophication

b) Algal BloomA large occurrence of algae build-up caused by

an excess of fertilizer, waste water, and storm water runoff.

b) Algal BloomLake Chaohu, China—

site of the sailing portion of the 2008 Olympics

http://seawayblog.blogspot.com/2008/07/qingdao-and-algae-bloom.html

http://seawayblog.blogspot.com/2008/06/thick-green-waters-of-lake-chaohu.html

http://www.youtube.com/watch?v=LT3gK1pr6WU&feature=related

2. pHThe measurement of how acidic or basic a

substance is

The scale goes from 0 to 14 0=high acid 14=high base 7=neutral

Common Substances’ pHSubstance pH Acid or Base

Battery Acid 0 Acid Vinegar 2 AcidSoda Pop 3 Acid Saliva 6 AcidWater 7 Neutral Baking Soda 9 Base Soapy Water 12 Base Lye 13 BaseLiquid Drain Cleaner 14 Base

3. TurbidityIs the cloudiness, or haziness, of water caused

by suspended particles and dissolved solids

3. Turbidity

Low Turbidity◦ Clear◦ Can See Through It

High Turbidity◦ Unclear◦ Can NOT See Through It

4. Temperaturethe degree of hotness or coldness of a body

or environment.

5. Dissolved Oxygen (DO) is a relative measure of the amount of oxygen

that is dissolved or carried in a given mediumIt’s important for fish and other aquatic

organisms that require oxygen to live.

6. BioindicatorsAre species used to monitor the health of an

environment or ecosystem

The Relationship Between . . .

Temperature

Dissolved Oxygen

Bioindicators

Temperature affects . . . The amount of oxygen that can be dissolved in the

water (Dissolved Oxygen)

The temperature of the organisms within the water and their activity, rate of growth and reproduction (Bioindicator)

The rate of photosynthesis by plants in the water (Bioindicator)

The health of organisms in the water (Bioindicator)

How does temperature affect the amount of dissolved oxygen in water?

Water temperature and dissolved oxygen are inversely related to each other.

Dissolved Oxygen

Temperature

Temperature

Dissolved Oxygen

What does that mean? When temperature goes up the amount of dissolved oxygen goes down When temperature goes down the amount of dissolved oxygen goes up

Month Temperature (°C) Temperature (°F) Dissolved Oxygen (mg/L)

January 10.6 51.1 8.1February 9.8 49.6 8.2March 11.9 53.4 7April 13.4 56.1 6.3May 15.5 59.9 5June 17.8 64 4.6July 21.9 71.4 4.1August 26.6 79.9 3.1September 24.8 76.6 3.7October 21 69.8 4November 15 59 5.2December 12.2 54 6.9

How does temperature affect aquatic organisms’ growth rate and

reproduction?

Growth Rate

As temperature increases an organism’s activity and growth rate increases.

More activity = Need for more Oxygen

Growth rate will double if temperature increases by 10°C (18°F) within the organism’s "preferred" range.

ReproductionReproductive systems are sensitive to

temperature

Therefore, aquatic organisms tend to reproduce best at a particular time of year (seasonal changes)

Example: Salmon Run in Fall

How does temperature affect the rate of photosynthesis by plants in the water?

As water temperature increases, plants tend to produce oxygen, to grow faster, and to die at a faster rate.

How does temperature affect the health of organisms in the water?Temperatures that are higher or lower than

normal can make an organism more sensitive to pollutants and diseases

Organisms that are exposed to these situations are referred to as “being stressed”

What factors can change the temperature of a body of water?

1. Air Temperature2. Sunlight3. Soil Erosion4. Thermal Pollution

Soil Erosion—The cutting down of trees along the banks of riversWhich causes the banks to wash awayMaking the water turbid & turbid water absorbs heat easily

Thermal Pollution—Warm water being discharged from an electric power

generating stationRain water draining off heated streets, sidewalks, or parking

lotsDamming rivers and exposing water to the sun while it’s

stationary

Water Quality

GOOD: Drinking Waterhttp://www.youtube.com/watch?v=_R_vpNQ0fJc