Part 1:

Biotic Indicators

Fresh Water Studies: Water Quality & Living Organisms

Tuckahoe Swamp

Aquarium

Types of aquatic habitats

Trout? Dragonflies?

Spirogyra (algae)?

Minnows?

E. coli (bacteria)?

Best Quality for life

River/Stream

Swamp

Aquarium

Tap water

(drinking)

Abiotic Factors

Abiotic Factors

• “abiotic”- without life

Refers to those environmental factors that are not alive, the non-living components of the environment.

Abiotic Factors

1. Temperature

Abiotic Factors

Factors that Affect Water Temperature

exposu re tosunlig ht

M ediumLow Low High

exposu re tosunlig ht

Which water will be warmer?

Air Temperature Amount of shade

Soil erosion increasing turbidity

4. Thermal pollution from human activities

Temperature increases from human activities

Photo: Dominion Virginia Power – North Anna Power Station

Confluence of streams

Photo: Virginia Academy of Science

Abiotic Factors

1. Temperature

Effects of Water Temperature

• Solubility of dissolved oxygen

• Rate of plant growth

• Metabolic rate of organisms

• Resistance in organisms

Abiotic Factors

1. Temperature

2. Oxygen (Dissolved)

Abiotic Factors

1. Temperature

2. Oxygen (Dissolved)

Where does the oxygen come from? How does it get into the water?

Diffusion from atmosphere

Aeration as water moves over rocks and debris

Aeration from wind and waves

AND

Photo: NOAA

Photosynthesis from aquatic plants

Photo: M.B. Elder

Factors that affect DO levels are:

• Temperature of water

• Decaying plants in the water

• Flow Rate

• Human activity

• Altitude and atmospheric pressure

Photo: M.B. Elder

Abiotic Factors

1. Temperature

2. Oxygen (Dissolved)

3. pH

What is pH?

0-7 water is acidic (more H+ ions, less OH- ions)

7 water is neutral (equal number of H+ and OH- ions)

7-14 water is basic (less H+ ions, more OH- ions)

What is the optimum freshwater pH?

Rainfall: 5 – 6.5

Most freshwater systems: 7 - 8

Most aquatic organisms: 6.5 – 8.2

Abiotic Factors

1. Temperature

2. Oxygen (Dissolved)

3. pH

4. Turbidity

Turbidity- An optical property of water based on the amount of light reflected by suspended particles. –USEPA, 1999

Secchi Disk

Abiotic Factors

1. Temperature

2. Oxygen (Dissolved)

3. pH

4. Turbidity

5. Total Dissolved Solids (TDS) from hard water, fertilizer, urban runoff, acid rain, tidal mixing

Abiotic Factors

1. Temperature

2. Oxygen (Dissolved)

3. pH

4. Turbidity

5. TDS

6. Stream Flow

Stream Flow

The volume of water that moves through a specific point in a stream during a given period of time.

Stream Flow

The volume of water that moves through a specific point in a stream during a given period of time.

Factors influencing water speed.

1. Depth of the water channel

2. Width of the water channel

3. Roughness of the stream bottom

4. Slope or incline of the surrounding terrain.

Factors influencing water volume

1. Weather or climate

2. Seasonal changes

3. Merging tributaries

4. Human impact

Conclusion• Water quality is determined by conducting physical and chemical measurements of the ABIOTIC factors of a freshwater environment.

• ABIOTIC factors include temperature, dissolved oxygen, pH, turbidity, total dissolved solids, and stream flow.

• ABIOTIC factors determine the BIOTIC factors (what can live) in the freshwater environment.

1. R.B.Elder2. M.B. Elder3. M.B. Elder4 - 9* 10. M.B. Elder11. Dominion Virginia Power -North Anna Power Station12. Virginia Academy of Science

13 - 15 *16. National Oceanographic & Atmospheric Administration (NOAA)17 & 18 M.B. Elder19 - 22 *23 & 24 M.B. Elder25 - 30 *

* Background slide - R.B. Elder (all rights reserved)

Photo credits-used with Permission