Testing Water Quality Using Abiotic Factors

Definitions

• Abiotic – natural, never living objects– Example: rocks, rain, oxygen

• ppm- Parts Per Million. – The oxygen content is 6 ppm

• 6 parts of the million parts tested are oxygen

Oxygen

• Importance to Watershed:– Plants release and animals take in to survive

• Healthy average: 9-10 ppm• Under 3 ppm will not support fish

• Oxygen gets into water by…– Diffusion from surrounding air– Aeration of water over rocks and waterfalls– Waste product of photosynthesis

Carbon Dioxide

• Importance to Watershed:– Animals release and plants take in to survive

• Healthy average: 6-12 ppm• Under 6 ppm or over 20 ppm will not support fish

• Days of heavy cloud cover = more CO2. (No photosynthesis)

• This is good if alkalinity is high and bad if pond is acidic.

Alkalinity

• Importance to watershed: protects against pH change

• Healthy average: Above 20 ppm

• Sources: – Soil, limestone

pH

• Definition: measure of acidity in water

• Healthy average: 6-9

• New ponds are alkaline– Debris causes acids to build up

Nitrates

• Definition: Combination of nitrogen and oxygen compounds

• Source: fertilizers, scat, urine

• Too many nitrates can cause algae to grow.– These organisms can cloud the water and take

oxygen from fish and other species.

• Healthy average: under 4.4 ppm

Temperature

• Pond habitat: warmer temperatures

• Stream habitat: cooler temperatures

• Temperature range for fish: 32 – 97 degrees F

• Fish migrate, feed and reproduce based on temperatures

• Different fish live in different temperature ranges

Turbidity• Definition: dirt or sediment in the water

• Secchi disk is used to measure light penetration

• Clear Water: 24 or more inches of light penetration• Turbid Water: 23 or less inches of light penetration

Water ColorColor Cause Fish Food

Productivity

Clear Absence of plankton

Low

Green Algae Moderate

Brown Diatoms (microscopic life)

High

Dark Brown Peat, humus Low