For each of the statements below, pick the disease discussed in class that the statement best describes (30 points – 5 points each). Diseases discussed in class: West Nile virus, Lyme Disease, Chytrid fungus, Ribeiroia ondatrae (trematode), Chronic Wasting Disease, White-nosed syndrome (answer may be used as many times as needed)
- May be involved in amphibian decline through disruption of amphibian’s skin.
- A fungus that may be responsible for a massive number of bat deaths.
- Tick-born disease that causes a bull eyes rash on infected human and potentially resulting in chronic disease.
- May cause terratogenic-like affects in amphibians.
- Carried by mosquitoes and mainly infects birds.
- Caused by a prion and mainly effects deer and elk (family Cervidae).
- Based on your knowledge of Lyme disease, what types of ecological data in an oak forest would help you predict the magnitude of the disease in the following year? Concisely, how could your answer be linked to human infection? (8 points)
- What environmental conditions are necessary for survival and spread of the Chytrid fungus? (8 points)
- What is coral bleaching and why is it important? (8 points)
- Other than toxic compounds, name two “pollutants” that can harm algae and briefly describe the mechanism. (8 points)
- Scientists are trying to determine the best management practices for reducing the eutrophication of a freshwater lake. Water samples were collected and the following data was obtained for chlorophyll a (ug/L) following an incubation experiment where either nitrogen, phosphorus or both were added. Measurements were taken 48 hours after the addition.
| Nitrogen Added | Phosphorous Added | ||
| 0 mg/L | 0.1 mg/L | 0.5 mg/L | |
| 0 mg/L | 15 | 24 | 27 |
| 1 mg/L | 18 | 30 | 38 |
| 5 mg/L | 18 | 42 | 65 |
What was the limiting factor(s)? Briefly describe how you know. (8 points)
- A scientist hypothesizes that an effluent from a factory is causing oxygen depletion in the receiving stream. To test his hypothesis, he sets up four beakers with 100 ml of water. In the first beaker, he adds an additional 100 ml of effluent (50% effluent), to the second 25 ml of effluent (20% effluent), to the third 12.5 of effluent (10% effluent) and to the fourth 6.25 ml of effluent (5% effluent). All beakers were incubated for 48 hours in the dark and then DO was measured three times in each beaker. Name the three major problems with this method design. (8 points)
- In midsummer, a scientist measured the DO in the
top few inches of water in a highly oligotrophic lake at midday and the
measurement was 7 mg/L. If he measured
first thing in the morning, predict how his measurement would turn out. Circle the best answer. (6 points)
- much higher than at midday
- much lower than at midday
- relatively close to the midday measurement
- In a calm eutrophic lake with a strong
thermocline (much warmer on top than bottom), the DO was measured in the top
few inches of water at midday and the measurement was 7 mg/L. If measurements
were taken near the bottom, predict how his measurement would turn out. Circle the best answer. (6 points)
- much higher than the top
- much lower than the top
- relatively close to the top measurement
- Which system is more likely to have DO drop to low levels? Circle the best answer. (6 points)
- eutrophic with DO at 10 mg/L measure at mid-day
- oligotrophic with DO at 7mg/L measured at mid-day
- What are the important chemical characteristics of the water from the Mississippi Rover that leads to the formation of a large dead zone in the Gulf of Mexico? (8 points)
- At what nitrogen to phosphorus ratio are blue-green algae more common? (6 points)
- What types of environmental hazard or damage are increased when blue-green algae are common? (8 points)
- Define (5 points each; 25 points)
- BOD
- DO
- Eutrophication
- Redfield ratio
- anoxia
- You are asked to investigate a bacteria found on dead amphibian from a pond where nearly all the frogs died rapidly. What experiment would you conduct to demonstrate that the bacteria is the disease causing pathogen? (Think Koch’s postulates). (8 points).
