LIMNOLOGYSPRING 2009

BIOL 362 / WMAN 446

QUESTION OF THE DAY

(updated 3/4/2009)

Begin test 1 material

14 January 2009

  • Define an ecosystem, give an example of an aquatic ecosystem, and list three services provided by natural aquatic ecosystems.
  • Contrast “point-source” pollutants with “non-point-source” pollutants. Give 2 examples of each.
  • T or F. Execution of the Cleat Water Act has been equally effective in controlling “point-source” and “non-point-source pollutants.
  • Contrast point source pollutants with non point source pollutants and give two examples of each.
  • Define “Best Management Practices” (BMPs) and give 2 examples of a BMP.

16 January 2009

  • Explain why a basic understanding of aquatic ecosystem structures and functions is important.

21 January 2009

  • Diagram and label the pools and fluxes of water in the global hydrologic cycle.

23 January 2009

  • What is the fate of most water (two most likely outcomes) that falls as precipitation on a forested watershed? How does this change when a watershed becomes increasingly more developed?

26 January 2009

  • Why does adding salt decrease the temperature at which water freezes?
  • Why do many planktonic organisms have irregularly shaped bodies (i.e., why do they often have long projections)?

28 January 2009

  • The amount of rooted or submerged aquatic vegetation (SAV) in the Chesapeake Bay has declined dramatically over the last several years. The primary culprits are increased sediment and nutrient loads. What is the mechanism by which increased nutrients and sediments can cause a reduction in SAV?
  • The compensation point in a lake would increase or decrease as a result of increased nutrients and sediments?

30 January 2009

  • List the different habitats of a natural lake and describe how light determines the distribution of each habitat.
  • Which habitat in a lake is most productive? Why?

2 February 2009

  • Define secchi depth and list factors that can influence this depth. Support the following statement: “factors that reduce secchi depth are also likely to reduce the relative availability of littoral zone habitats.”
  • List 4 different categories of lakes based on seasonal mixing patterns. Which type is most common throughout WV (and other areas of the mid-west)? Which type would you expect to become increasingly prevalent with increased warming from climate change?

4 February 2009

  • What two processes are most responsible for lake formation in the U.S.?
  • What is the largest (by volume) freshwater lake in the world? Where is it? How was it formed?
  • What is the largest (by surface area) freshwater lake in North America? Where is it? How was it formed?
  • Describe two different ways that lakes are formed by glacial activity?
  • Describe the waste water problem that results from drilling for natural gas in the Marcellus Shale geologic layer.

6 February 2009

  • Deeper lakes will tend to have a higher / lower water retention time than shallow lakes.
  • Which hypsographic curve represents a lake with the most extensive littoral zone? What is the surface area of the littoral zone of each lake?
  • How much of the littoral zone would be lost from the lake if the compensation depth was reduced by 2 m? What processes could lead to a reduction in compensation depth and loss of littoral zone habitat?
  • Reservoirs tend to be more / less dendritic than naturally formed lakes.
  • What is the term used for a coldwater fishery that develops downstream of a large reservoir? Describe why rivers downstream of reservoirs may be so much colder than other natural rivers in the area.
  • Using the hypsographic curve below, answer the following questions: which lake is probably the most productive? What is the max depth? What is the total surface area? What is the surface area of the littoral zone (given that the compensation depth is at 4 m)? What percentage of the lake surface area is littoral zone? How much littoral zone would be lost if the compensation depth was reduced to 2 m?

Begin test 2 material

11 February 2009

  • Describe changes in stream flow regimes that result from increasing development in a watershed (with respect to the amount of water that flows overland into a stream, baseflow patterns, and stormflow patterns).
  • Describe the structural and flow related differences among ephemeral, intermittent, and perennial stream channels.
  • Describe how intensive development of a watershed can result in the conversion of small perennial streams to intermittent and intermittent to ephemeral.
  • What streams does the CWA protect? How can we defend federal jurisdiction over ephemeral and intermittent streams?
  • What is the purpose of a stream gaging station?
  • Describe how you would measure discharge at a particular location in a stream using the “area-velocity” method.

13 February 2009

  • Define bankfull discharge.
  • What is the return interval of a bankfull discharge?
  • List the steps used to identify the discharge level of a stream that represents the 10-yr flood event.
  • Define the 7Q10 of a stream. Why is this value important?

16 February 2009

  • List and define 5 hydrologic components identified in the NFRP that regulate ecological processes in river ecosystems.
  • List 5 watershed characteristics that interact to determine a river’s flow regime.
  • In what ways has the natural flow regime of the Colorado River been altered by the construction of large dams?

18 February 2009

  • Define and list components of the “hydrogeomorphic template.” List 5 watershed characteristics that influence this template.
  • Describe the “urban stream syndrome” as it relates to stream hydrology and geomorphology.
  • List the three variables included in the Manning’s Equation that influence river velocity. Describe how each varies as velocity increases.

20 February 2009

  • Define a watershed. What is a Hydrologic Unit Code (HUC)? Give 5 examples of 8-digit HUC watersheds in WV.
  • Label each stream segment with its appropriate strahler order, link order, and downstream link order difference. Which segments are most likely to have small stream fishes and larger river fishes living in sympatry?

23 February 2009

  • List sediment size categories of the Wentworth scale. Which size classes are most easily eroded? Which size classes are the predominant sediments in the “wash load”? Which size classes are the predominant sediments in the “bed load”?
  • Discuss why moderate stream flows (i.e., stream flows that have a recurrence of every 1 – 2 years are considered to be the “effective discharge” of any given stream or river. Be sure to define effective discharge.

25 February 2009

  • How do you quantify cross-sectional area of the bankfull channel of a stream?
  • How do you quantify entrenchment?
  • How do you quantify stream sinuosity?
  • How do you quantify stream slope?

27 February 2009

  • List 6 characteristics of stream channels that are used in the “Rosgen” stream channel classification procedure.
  • Describe the characteristics of A, B, C, D, and E type stream channels.
  • Be prepared to take information on stream channel characteristics and place a stream into a particular Rosgen stream type.

2 March 2009

  • Define a habitat.
  • Define and describe the functional role of the floodplain and the riparian zone.
  • Define and describe the functional role of the hyporheos in streams and rivers.
  • Define Hydraulic Channel Units, list 6 different types found in a typical stream, and place HCUs along a spatial hierarchy (i.e., list other stream habitats at smaller and larger scales).
  • What is the typical sequence of HCUs moving from upstream to downstream?

4 March 2009

  • Give two reasons why habitat complexity is important to ecosystem functions of a river or stream.
  • At which spatial scale does “habitat quality” most strongly influence the life cycle of most stream fishes?
  • List 7 functions of riparian vegetation.
  • Compare and contrast the effects of urbanization and intense agriculture on stream habitats and morphology.
  • From the paper by Walters and Merrit (2007), compare and contrast stream morphology from “pre-european settlement” to the 1600s-1800s to post 1900.

Begin test 3 material

13 March 2009

  • What filter pore size cutoff is used to separate particulate matter from matter dissolved in a water sample?
  • Which type of particles does not settle in water, colloidal or gravitoidal?
  • In addition to Hydrogen and Oxygen atoms, list 6 types of materials found in natural waterbodies?
  • List the 8 major ions (4 anions and 4 cations) dissolved in water. Be sure to get the superscripts and subscripts correct.
  • What are the units, in mass per volume, of “parts per million”? “parts per billion”?
  • Define: TSS, TDS, salinity, hardness, conductivity

23 March 2009

  • Define pH, alkalinity, and acidity
  • What is the pH of natural rainwater? Why is it slightly acidic?
  • What is the difference between a “weak” acid and a “strong” acid?
  • Which bedrock geology will tend to produce surface waters with high hardness: sandstone, shale, or limestone?
  • Which bedrock geology will tend to be the most susceptible to the effects of acid precipitation?

25 March 2009

  • List the 4 forms of dissolved inorganic carbon found in surface waters.
  • Describe how pH changes in a lake over the course of a day as a result of the DIC complex.
  • Would a highly productive lake be expected to have high or low diel variation in pH? Why?
  • Uplift of the Himilayan Mtns is believed to have caused an increase in global temperatures via an effect on the DIC complex of the ocean. What’s up with that?

27 March 2009

  • Describe the causes of acid precipitation and its effects on surface water chemistry.
  • Describe the effects of acid precipitation on biological communities and the mechanisms by which these effects operate.
  • Discuss the findings of McClurg et al. (2007) with regard to the effectiveness of acid remediation through instream application of limestone sand. What gets fixed? What doesn’t? Why is restoration limited? Can it be improved, and if so, how?

30 March 2009

  • Describe the causes of acid mine drainage and its effects on surface water chemistry.
  • Define “yellow boy” and give the chemical equations that describe its formation.
  • At what pH does Fe precipitate? Al? Mn?
  • Why is “at-source-active” treatment of AMD so expensive? Discuss the benefits and short-comings of “in-stream” and “at-source-passive” treatment.

1 April 2009

  • Diagram a simple, aquatic food chain.
  • Why are Nitrogen and Phosphorusimportant nutrients? What are they building blocks for?
  • List the forms of nitrogen in aquatic ecosystems?
  • List the N-transformation processes and indicate which processes occur under aerobic conditions and which occur under anerobic conditions?

3 April 2009

  • Describe the central role of Blue Green Algae in making nitrogen found in N2 gas available to other algae.
  • What is a heterocyst? What is nitrogenase?
  • Explain why floodplain wetlands are so effective in reducing nitrate loading into coastal ecosystems.

6 April 2009

  • Compare and contrast nitrogen and phosphorus with regards to: 1-sources and sinks; 2-interactions with sediments; 3-role of microbial activity in affecting cycling; and 4-relative availability in the biosphere.
  • Define orthophosphate.
  • Define alkaline phosphatase.
  • What is the fate of most biologically active phosphorus in a lake?
  • Describe how oxygen affects P adsorption and desorption from sediments.
  • Which types of sediments adsorb the most P?
  • Describe the processes by which P that is adsorbed to sediments in a fertilized field is desorbed once is enters an oxygenated stream.
  • Describe how macrophytes within the littoral zone of a lake act as a Phosphorus Pump.

8 April 2009

  • Ammonium is rare in the surface water of small, high gradient streams. Why?
  • Cleacutting a forest leads to an increase in nitrate concentrations in streams. Why?
  • Define structural and biological retentiveness in streams and how increasing retentiveness influences nutrient spiraling.
  • Describe how urbanization affects nutrient spiraling length. How can this contribute to high levels of nitrate loading downstream?
  • In the stream studied by Newbold et al. (1983), what organism contributed to the short spiraling length of phosphorus?

13 April 2009

  • Why is phosphorus such a strong limiting factor in freshwater lakes and streams?
  • Describe the whole lake experiments that Schindler conducted in the 1970s? What role did blue green algae play in this study?
  • Define the redfield ratio? If N:P ratio = 60, is the stream likely limited by nitrogen or phosphorus?
  • Give 2 reasons why N and P tend to co-limit aquatic ecosystem productivity.

15 April 2009

  • Define primary production and give equation
  • Define respiration and give equation
  • Define gross and net primary production.
  • If NPP is greater than zero, then dissolved oxygen concentration will tend to increase or decrease?
  • Describe how dissolved oxygen changes with increasing temperature, increasing pressure, and increasing respiration.
  • Contrast orthograde, clinograde, and heterograde patterns of dissolved oxygen in lakes. Which pattern(s) is indicative of a highly productive lake?
  • During which months of the year would you expect to find anoxic conditions in the hypolimnion of a productive lake?

17 April 2009

  • What are the dominant human-related sources of nutrients to aquatic systems?
  • Describe the physical, chemical, and biological responses to excessive nutrients in aquatic systems?
  • Describe the shift in fish community structure as a system goes from oligotrophic, to mesotrophic, to eutrophic? Discuss these shifts with regard to the “temperature-oxygen squeeze.”
  • List 5 agricultural BMPs that can be used to reduce the amount of nutrients running off of farmlands.
  • Describe biomanipulation as it relates to managing eutrophication. Discuss the pros and cons of this approach relative to nutrient reduction efforts.

20 April 2009

  • SEE QUESTIONS ON THE CARPENTER ET AL. 1998 READING GUIDE RELATING TO NUTRIENT POLLUTION AND EUTROPHICATION.

22 April 2009

  • Diagram a typical lake or pond food web.
  • Define phytoplankton.
  • List (scientific and common names) the “big 5” taxonomic groups of phytoplankton.
  • Be able to match common algae genera to their taxonomic division (e.g., Anabaena = Cyanobacteria).
  • Define “mixotrophic.” Which phytoplankton group is mixotrophic? What type of lakes would you tend to fine this group?
  • Why do blue green algae dominate in lakes affected by phosphorus enrichment?
  • Describe changes in algal community structure that occur as a lake moves from oligotrophic to mesotrophic to eutrophic.
  • In most lakes there are two pulses of algae productivity: one in spring and one in fall. There also is a summer period of very low algal biomass, referred to as a “clear-water phase” during the summer. Describe how bottom up and top down forces interact to produce the pulses and clear-water phase.

24 April 2009

  • List (scientific and common names) of the “big 5” taxonomic groups of zooplankton.
  • Be able to match common zooplankton genera to their taxonomic division (e.g., Asplanchna = Rotifer).
  • Describe/Diagram the life history of copepods.
  • Describe/Diagram the life history of cladocerans.
  • Define parthenogenesis. What does this enable rotifers and cladocerans to do?
  • Define cyclomorphis. What does this enable rotifers and cladocerans to do?
  • There are 5 phenomena characteristic of lentic habitats that underscore the importance of predation in structuring lake food webs. List and describe each of these phenomena and emphasize each with respect to predator-prey interactions in lakes.
  • Describe the study design, results and conclusions of the study conducted by Brooks and Dodson (1967).
  • Contrast the Size Efficiency Hypothesis with the Intermediate Predator Hypothesis

27 April 2009

  • Support the following statement: “The trophic cascade hypothesis is a holistic view that recognizes the combined influence of top-down and bottom-up forces in lake food webs.”
  • Describe the study design and results from Carpenter et al.’s experimental test of TCH.
  • Describe the study design and results from Mittlebach et al.’s experimental test of TCH.
  • Describe how the research of Pace, McQueen, Vanni, and Devries has added to the traditional TCH model. What complexities in lake food webs has their research identified?
  • Define biomanipulation as it relates to TCH and eutrophication. How does the research of Vanni et al. call into question the long-term effectiveness of biomanipulation?

29 April 2009

  • See questions from reading guides for articles on top-down and bottom-up forces in lake food webs.