2. Water Quality Chemical and Biological Indicators

3. Why is water quality important? Human health: drinking water Human health: drinking water Fisheries Fisheries Water for industry and Water for industry andagriculture Aesthetic reasons Aesthetic reasons Species habitat Species habitat Water for recreation Water for recreation (swimming, fishing, boating)

4. What types of tests do we use to measure water quality? Dissolved oxygen Dissolved oxygen Nitrogen (usually nitrate-nitrogen) Nitrogen (usually nitrate-nitrogen) pH pH Macroinvertebrates Macroinvertebrates Phosphorus (usually phosphate-phosphorus) Phosphorus (usually phosphate-phosphorus) Alkalinity Alkalinity Conductivity Conductivity Chloride Chloride Salinity Salinity Suspended solids Suspended solids Fecal coliform bacteria Fecal coliform bacteria

5. Dissolved Oxygen The presence of oxygen gas molecules (O 2 ) in the water. The presence of oxygen gas molecules (O 2 ) in the water. Why is it important? Why is it important? The oxygen in H 2 O is not dissolved oxygen. The oxygen in H 2 O is not dissolved oxygen. What’s coming out of the diffuser?

6. Dissolved Oxygen How does oxygen get into the water? -diffusion from the surrounding air -during the process of photosynthesis

7. DO levels are affected by: Altitude Altitude Temperature Temperature Speed of water movement (dams as well as natural differences and tides) Speed of water movement (dams as well as natural differences and tides) Addition of wastes Addition of wastes Vegetation Vegetation

8. Which do you think has more DO: the stream on the left or the stream on the right? Why? What else do you need to know? Hudson River near Warrensburg, NY, winter Hudson River near Newburgh, NY, summer

9. Different Organisms Require Different Amounts of DO Trout and salmon require high amounts of dissolved oxygen, as do most fish larvae Trout and salmon require high amounts of dissolved oxygen, as do most fish larvae Carp and catfish can survive with much less.

10. How do Humans Affect the Amount of DO in the Water? Addition of oxygen- consuming organic wastes Addition of oxygen- consuming organic wastes www.al.nrcs.usda.gov

11. Changing the Flow of the Water Which dam is this? The Croton Dam

12. Activities That Raise the Water Temperature Source: http://www.ger.com/indpt.jpg http://www.ger.com/indpt.jpg Riparian zone vegetation, power plant cooling

13. pH The measure of the acidity of a solution The measure of the acidity of a solution Acids produce H + (hydrogen ions) Acids produce H + (hydrogen ions) Bases produce OH - (hydroxide ions) Bases produce OH - (hydroxide ions)

14. Why is pH important? If the pH is too low, it could indicate pollution from acid rain If the pH is too low, it could indicate pollution from acid rain Acid rain can kill insects and other organisms, and harms vegetation, often killing forests (especially in high altitude areas because of acidic fog) Acid rain can kill insects and other organisms, and harms vegetation, often killing forests (especially in high altitude areas because of acidic fog) Photo courtesy of C. Harris

15. How is pH measured? -pH is measured on a scale of 0 to 14. -A solution with equal hydrogen and hydroxide ions would have a pH of 7 -What would the pH of a solution be that had more hydrogen than hydroxide ions? -A decrease of one unit on the pH scale is the result of a 10 fold increase in hydrogen ions. Drawing by J. Jenkins

16. basic neutral acidic

17. How Does pH Affect a River? It changes the availability of different nutrients and metals in the water, making it hard for some animals to survive It changes the availability of different nutrients and metals in the water, making it hard for some animals to survive Metals that leach from the soils when pH changes especially affect immature stages of aquatic insects and fish Metals that leach from the soils when pH changes especially affect immature stages of aquatic insects and fish www.nwfsc.noaa.gov Fish larvae exposed to biotoxins that cause morphological abnormalities.

18. What Causes a pH Change? Atmospheric deposition (acid rain) Atmospheric deposition (acid rain) Surrounding rocks and soils Surrounding rocks and soils Wastewater discharges from business and industry Wastewater discharges from business and industry Acid mine drainage Acid mine drainage

19. Acid Rain in U.S.

20. Nitrogen Pollution Do you contain nitrogen? Does the air contain nitrogen? What about plants and animals?

21. Nitrogen …so what? Plants and animals need nitrogen Plants and animals need nitrogen But…there can be too much of a good thing! But…there can be too much of a good thing! Too much nitrogen results in…. Too much nitrogen results in…. There is both cultural (human) and natural eutrophication

22. Nitrogen Pollution Too much nitrogen can cause: Eutrophication Increase in nutrients Increase in plant growth Dissolved oxygen declines as plants are decomposed Aquatic life suffers

23. Nitrogen in the Hudson Where does it come from? -human waste -acid deposition -fertilizer -agriculture: fixation and feed Where does it go?

25. Nitrogen: Why so muchfromthemiddle of the USA?

26. Source: Compiled from Landsat Thematic Mapper satellite imagery, Iowa Dept. of Natural Resources. 1850s Iowa – beige color is prairie 1990s Iowa – beige color is prairie, gray is row crops

27. Humans and the Nitrogen Cycle Last 100 years: humans have more than doubled the amount of fixed nitrogen that is pumped into the atmosphere every year. Consequences: acid rain, ground level ozone, groundwater contamination, surface water pollution, eutrophication

28. Phosphorous Where does it come from? Where does it come from? -not a gas -weathers from rock -reuse from already present phosphorous in detritus Why is it important? Why is it important? -less abundant and available than N -often the limiting nutrient in freshwater ecosystems

29. Phosphorus Cycle Phosphates in rocks are mined Phosphates in rocks are mined Dissolves in water Dissolves in water Plants take up inorganic phosphate Plants take up inorganic phosphate We create phosphate- rich fertilizer We create phosphate- rich fertilizer Organisms use organic phosphates Organisms use organic phosphates Decomposers convert organic waste back to inorganic P in the soil Decomposers convert organic waste back to inorganic P in the soil

30. Phosphorous in the Hudson Main source: detritus Main source: detritus Used by plants during the growing season Used by plants during the growing season Some P is lost to the ocean and some becomes buried in sediment Some P is lost to the ocean and some becomes buried in sediment

31. Macroinvertebrates Why do we sample invertebrates?? Why do we sample invertebrates?? It’s a way to measure the health of an ecosystem’s aquatic life It’s a way to measure the health of an ecosystem’s aquatic life Scientists usually take several samples, looking at diversity and abundance, as well as species evenness Scientists usually take several samples, looking at diversity and abundance, as well as species evenness Dobsonfly larvae (helgrammite). Photo from Cary Institute.

32. Aquatic Ecosystem Biodiversity www.hainaultforest.co.uk www.dkimages.com www.eduwebs.org www.fresc.usgs.gov

33. Species Diversity Diversity differs depending on: time of year, habitat, ecosystem, sampling location, and water quality Macroinvertebrates are one way to assess water quality, but other measurements should be taken to ensure accuracy Students from Tabernacle Christian Academy, Poughkeepsie

34. Alkalinity A measure of the capacity of water to neutralize (or buffer) acids A measure of the capacity of water to neutralize (or buffer) acids Streams with high alkalinity would be able to resist a change in pH more than a stream with low alkalinity Streams with high alkalinity would be able to resist a change in pH more than a stream with low alkalinity Alkalinity is reported as mg/L of CaCO 3 Alkalinity is reported as mg/L of CaCO 3

35. What are the Sources of Alkalinity? Compounds that create alkalinity include calcium carbonate, sodium bicarbonate, and calcium hydroxide. Compounds that create alkalinity include calcium carbonate, sodium bicarbonate, and calcium hydroxide. Limestone bedrock, like that in the Hudson River, produces water with relatively high alkalinity Limestone bedrock, like that in the Hudson River, produces water with relatively high alkalinity Photo by H. Malcom

36. Fecal coliform Fecal coliform bacteria refers to a group of micro- organisms that live in the digestive tracts of warm-blooded animals, such as humans Fecal coliform bacteria refers to a group of micro- organisms that live in the digestive tracts of warm-blooded animals, such as humans Indicates: sewage or manure Indicates: sewage or manure http://ucce.ucdavis.edu/files/filelibrary/5453/6581.gif

37. http://www.water-research.net/images/ICE-TEA2.GIF http://www.waterfilterreview.com/images/contaminants/ h20_contaminants_200/fecal_coliform_200.jpg Health risk for humans due to disease causing bacteria/viruses (hepatitis A and typhoid fever) Health risk for humans due to disease causing bacteria/viruses (hepatitis A and typhoid fever)

38. Suspended Solids Suspended solids is a measure of how many particles are suspended in the water Suspended solids is a measure of how many particles are suspended in the water Caused by soil erosion, sewage discharge, algal growth, and movement of the water Caused by soil erosion, sewage discharge, algal growth, and movement of the water It is often measured along with turbidity, which is faster to measure It is often measured along with turbidity, which is faster to measure Usually measured in mg/L Usually measured in mg/L Photo courtesy of C. Harris

39. Suspended particles can clog fish gills, smother eggs of fish and aquatic insects, and reduce growth rates. High suspended solids can decrease dissolved oxygen by blocking sunlight for plants and increasing the temperature of the water by absorbing light from the sun. http://www.kbac-hi.org/BMPs/images/tss2.gif Photo: C. Harris