Name

LIMNOLOGY

EXAM 1

FEBRUARY 9, 2005

There are 18 questions on 3 pages worth a total of 100 points. Read each question very carefully, answer each question fully, and allocate your time accordingly.

True-False, Word Choice (2 pts each, 26 points total)

  1. Which aquatic habitats are NOT included in the study of Limnology (check all that apply).

Mountain Stream / DeepSea Vents / Estuary
Bogs / Salt Marsh / Limestone Spring
Swamp / Ocean / Farm Pond
Sargasso Sea / Red Sea / Missouri River
  1. Hydrogen-bonds in water tend to form / break as they are heated.
  1. T or F. Water is densest at a temperature of 4C, because this is the temperature at which the number of hydrogen bonds is maximized.
  1. T or F. Littoral zones tend to heat more quickly than pelagic zones in lakes.
  1. T or F. Monomictic lakes tend to occur most commonly in the northeast U.S., whereas Dimictic lakes tend to occur in the southeast.
  1. Round bodied, or spherical organisms will tend to sink more / less slowly than cylindrical organisms or organisms with long spines.
  1. You would expect the compensation point to be shallower / deeper in the riverine zone of a reservoir.
  1. You would expect secchi depth to be greatest (deepest) / lowest (shallowest) in the lacustrine zone of a reservoir.
  1. T or F. Most of the freshwater in the world is found within a few, very large lakes, whereas most of the freshwater ecosystems in the world are small streams, wetlands, and ponds.
  1. T or F. Most water enters streams through Hortonian Overland Flow.
  1. T or F. A gaining or effluent stream is a stream that receives water discharge from the groundwater aquifer.
  1. T or F. Intermittent streams are not aquatic ecosystems, because they do not have surface water in them at all times.
  1. According to Manning’s equation, flow velocity will tend to increase with increasing / decreasing bed roughness, increasing / decreasing depth, and increasing / decreasing gradient (or slope).

Short Answer

  1. (10 pts) List 5 ecosystem services supplied to humans by aquatic ecosystems.
  1. (21 pts) Based on the diagram below, answer the following questions:

  1. What is the temperature at the water surface in August 1962?
  1. What is the approximate depth of the top of the metalimnion in August 1962?
  1. What is the range of temperatures observed in the hypolimnion over the course of an entire year?
  1. Is this a monomictic or dimictic lake?
  1. Is this a holomictic or merimictic lake?
  1. What month did spring turnover occur?
  1. Walleye have a temperature preference of 14C. At what depth should you fish for them in April? May? August? December?

  1. (18 pts) Based on the diagram below, answer the following questions:

  1. What is the surface area of the entire lake?
  1. What is the surface area of the littoral zone?
  1. What is the surface area of the pelagic zone?
  1. What is the surface area of the profundal zone?
  1. What would the area of the littoral zone be if the compensation point went from 10m to 5m?
  1. What factors could cause the compensation point to change (become shallower)?
  1. (10 pts) List the 5 components of natural flow regimes that regulate ecological processes in river ecosystems (identified by Poff et al. 1997).
  1. (15 pts) Draw a simple diagram (on the back of this page) of the hydrologic cycle, including where water is stored (reservoirs) and fluxes among the storage compartments. How do human activities affect the fluxes?