What is the trend?

1. What is the trend? • #1) For the ecosystem shown below, calculate the % of energy in Kilocalories transferred from one level to the next. • Level # of Kilocalories Available % of Kilocalories Reta ined • Producers 20,810 -------------------- • Primary Consumers 3,368 • Secondary Consumers 383 • Tertiary Consumers 21

9. 1970 Clean Air & Water Act

15. WQI

16. WATER QUALITY INDEX • 1970 National Sanitation Foundation devised a standard scale to rate or “grade” the quality of water • The WQI is based on nine different biotic and abiotic factors • We will test six of these factors in our investigation: temperature, dissolved oxygen, pH, total dissolved solids, benthic macroinvertebrate diversity and fecal coliform levels

19. Physiology of Mammalian Diving Reflex • In response to need to conserve oxygen, cold water causes reduction in heartbeat (bradycardia), constriction of bloodflow and a shift of blood to the thoracic cavity • True only of homeotherms

20. Why is this response necessary in homeotherms?

21. Biological Oxygen Demand (B.O.D.) • Fish, invertebrates, plants, and aerobic bacteria all require oxygen for respiration. • The amount of oxygen required by an ecosystem is its Biological Oxygen Demand (B.O.D.)

22. Dissolved Oxygen (D.O.) • Amount of oxygen gas dissolved in 1million molecules of water • Can range from 0-18ppm normally • 5-6ppm needed to sustain most complex aquatic life

23. Sources of Dissolved Oxygen • Much of the dissolved oxygen in water comes from the atmosphere. After dissolving at the surface, oxygen is distributed by current and turbulence. • Algae and rooted aquatic plants also deliver oxygen to water through photosynthesis.

24. How Do Organisms Stay Underwater All Winter?

25. Temperature v. Dissolved Oxygen • Purpose: To determine the nature of the relationship (if any) between dissolved oxygen concentration and temperature. • Hypothesis: What do you think the relationship is between these variables? Direct, indirect, optimal or no relationship? What is your reasoning for this?

26. Getting Started • 1) Plug in the Dissolved oxygen probe to Channel 1 of the LabQuest • 2) Plug in the Stainless Steel Temperature Probe to Channel 2 of the LabQuest • 3) Power up LabQuest • 4) Set up sensors for channels 1 & 2 from sensors menu • 5) D.O. probe must be “warmed up” for 10 minutes before data collection

27. Applying The Variable • Fill one 250 mL beaker with ice & water • Fill one 250 mL beaker with 40-50 water (use hotplate & thermometer) • Place 100 mL of ice water in milk jug & shake for 2 minutes • Pour “aerated water” from jug into paper cup and place both temp & D.O. probe into cup. Let the values stabilize for about 1 minute • Record the temp & D.O. of the water in the cup in data table

28. Repeat • Pour 75 mL of the ice water from the cup back into the milk jug • Add 25 mL of the 40-50 °C water to the milk jug • Re-aerate/shake for 2 minutes and repeat temp/D.O. sampling • Repeat previous sampling steps until water temp in paper cup is appx. 35 °C.

30. Why Did The Catfish Survive?

31. 1) Temperature • High temperatures may indicate thermal pollution and place organisms at risk • Temperatures may also increase the rate of metabolism, raising the biological oxygen demand (B.O.D.) • Temperatures negatively impact the amount of dissolved oxygen

33. The change in temperature with depth is called a THERMOCLINE

34. 2) DISSOLVED OXYGEN • Measures the amount of oxygen dissolved in water • Important for aquatic organisms regarding cellular respiration • Can also indirectly measure the amount of autotrophs in an aquatic ecosystem

37. pH • Measurement of acidity or alkalinity in the water source • Extremely acidic or basic pH may indicate industrial runoff (i.e. soaps, batteries, etc.) • Moderately acidic pH may indicate higher rates of decomposition (due to CO2 output)

38. Different aquatic organisms have different ranges of pH tolerance

39. 4) Total Dissolved Solids (TDS) • Measurement of how much organic and inorganic matter is being carried in the water • High TDS values indicate high amounts of erosion upstream • Dissolved solids may also blocksunlightand/or their decomposition may reduce the dissolved oxygen of the water source

41. Q Values • Each biotic or abiotic measurement should be compared with its unweighted Q value table • The Q value is the “grade” for that aspect of the water quality • For dissolved oxygen, the Q value is obtained by dividing the measured D.O. (from the probe) by the saturated O2 level This % is used to find Q

42. FINAL ABIOTIC WQI SCORE • Each of the four Q values is multiplied by its relative weight to determine the abiotic WQI • D.O. Q Score x 0.38 • pH Q Score x 0.24 • Temp. Q Score x 0.22 • TDS Q Score x 0.16 • Sum of Weighted Q Scores = WQI

43. Biotic Measures of Water Quality

44. Fecal Coliform

45. Fecal v. General Coliform • General Coliform = bacteria that has come in contact with plant or animal life • Fecal Coliform = Bacteria from the digestive tract of mammals or birds

48. Benthic Macroinvertebrates • Bottom-dwelling, spineless animals • Some species are very pollution tolerant while others are not • Depending upon the diversity of macroinvertebrates, one may indirectly assess the river’s health re: nitrogen and phosphorus