HealthyHealthy Rivers Rivers

Water ChemistryWater Chemistry

Dissolved OxygenDissolved Oxygen

Why is Dissolved Oxygen (DO) Why is Dissolved Oxygen (DO) Important?Important? Aquatic organisms need oxygen to Aquatic organisms need oxygen to

breathe.breathe.

What Are Some Physical What Are Some Physical Factors That Influence DO?Factors That Influence DO?

TemperatureTemperature Oxygen is more soluble in water at lower Oxygen is more soluble in water at lower

temperatures.temperatures. Altitude/Atmospheric PressureAltitude/Atmospheric Pressure

The higher the elevation the lower the The higher the elevation the lower the oxygen solubility.oxygen solubility.

Physical Influences on DOPhysical Influences on DO

MixingMixing The more The more

turbulence in water turbulence in water the more surface the more surface area there is to area there is to absorb oxygen.absorb oxygen.

Biological Influences On Biological Influences On Dissolved OxygenDissolved Oxygen

Photosynthesis by aquatic plants and Photosynthesis by aquatic plants and algaealgae Produces OProduces O22 during the day. during the day.

Respiration by aquatic plants and Respiration by aquatic plants and animalsanimals Consumes DO during the day and night.Consumes DO during the day and night.

Biological Influences On Biological Influences On Dissolved OxygenDissolved Oxygen

Decomposition of organic materialsDecomposition of organic materials Dead algae, shoreline vegetation, wastewater Dead algae, shoreline vegetation, wastewater

decreases DO.decreases DO.

What do the numbers What do the numbers mean?mean?

Measured in parts per million (PPM)Measured in parts per million (PPM) Mosquito larvae can survive in water Mosquito larvae can survive in water

that has 1 PPM and abovethat has 1 PPM and above Salmon eggs and young can survive Salmon eggs and young can survive

in 7 and above PPM waterin 7 and above PPM water Mayflies/Stoneflies can survive in 4.5 Mayflies/Stoneflies can survive in 4.5

PPM and above water.PPM and above water.

TurbidityTurbidity

What is turbidity?What is turbidity? The amount of suspended soil particles The amount of suspended soil particles

(sediment) or algae present in water.(sediment) or algae present in water.

Why is turbidity a concern?Why is turbidity a concern? Blocks light needed for photosynthesis.Blocks light needed for photosynthesis. Reduces visibility for visual feeders.Reduces visibility for visual feeders. Smothers fish and amphibian eggs.Smothers fish and amphibian eggs. Increases water temp by absorbing more Increases water temp by absorbing more

sunlight thus reducing the dissolved oxygen.sunlight thus reducing the dissolved oxygen.

What Causes Turbidity?What Causes Turbidity?

Erosion of soil.Erosion of soil. Human disturbance Human disturbance

increases erosion of increases erosion of soil and organic soil and organic matter and nutrient matter and nutrient runoff which runoff which enhances algal enhances algal growthgrowth

What Causes Turbidity?What Causes Turbidity?

Suspended algae can be a major Suspended algae can be a major problem in the summer.problem in the summer.

Wind, waves, bottom feeding fish, and Wind, waves, bottom feeding fish, and mammals walking through a stream can mammals walking through a stream can re-suspend settled sediment.re-suspend settled sediment.

What doe the numbers What doe the numbers mean?mean?

Measured in Jackson Turbidity UnitsMeasured in Jackson Turbidity Units 0-10 JTU is excellent water quality 0-10 JTU is excellent water quality

ratingrating 10.1-40 is good10.1-40 is good 40.1-150 is fair40.1-150 is fair Above 150 is poor water quality.Above 150 is poor water quality.

What is pH?What is pH?

A measure of how A measure of how acidic or basic a acidic or basic a solution is.solution is.

pHpH

Why is pH important?Why is pH important? Aquatic organisms are Aquatic organisms are

sensitive to high or low sensitive to high or low pH, especially less than pH, especially less than 6.5 or more than 8.5.6.5 or more than 8.5.

The reproductive The reproductive portion of the growth portion of the growth cycle is particularly cycle is particularly sensitive, so while sensitive, so while adults may continue to adults may continue to live, they will not live, they will not reproduce.reproduce.

What Causes pH Changes?What Causes pH Changes?

Algal blooms may Algal blooms may raise pHraise pH

Industrial processes Industrial processes and mining release and mining release acids and basesacids and bases

Cars release Cars release sulfides and nitrous sulfides and nitrous oxides which react oxides which react with water to form with water to form acid rain.acid rain.

Water Chemistry QuestionsWater Chemistry Questions

What effect(s) What effect(s) would a dam have would a dam have on the water on the water chemistry of a chemistry of a river? Why?river? Why?

Healthy RiversHealthy Rivers

In groups of four, come up with five In groups of four, come up with five ideas to improve the health of a ideas to improve the health of a river.river.

Include how your suggestions would Include how your suggestions would effect the water chemistry of the effect the water chemistry of the river and why they would make the river and why they would make the river more healthy.river more healthy.