320 Oceanography Mid-term Examination March 5, 2003
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1) The concentration of pollutant X is 40 ppm on trophic level five and 5 ppm on trophic level two. If the ecological efficiency of the food chain is 20%, with what efficiency is pollutant X transferred from one trophic level to the next? a) 10% b) 20% c) 30% d) 40% 2) Indicate whether the following transformations are examples of primary production (P), secondary production (S), or neither (N). a) Conversion of herbivore biomass to primary carnivore biomass b) Conversion of CO2 to organic carbon via photosynthesis c) Conversion of organic detritus to detritivore biomass d) Conversion of organic carbon to CO2 via respiration e) Conversion of CO2 to organic carbon via chemosynthesis 3) The tendency for biomass in a food chain to decrease with increasing trophic level number is associated with which one of the following? a) Low ecological efficiency b) Eutrophication c) The microbial loop d) Carnivory e) Herbivory 4) The tendency of the production of organic matter to exceed the consumption of organic matter is associated with which one of the following? a) Ecological pyramids b) Eutrophication c) Food chain magnification d) Detritus food chain e) Grazing food chain
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5) Which of the following statements is true of the critical depth? a) Net community production is zero at the critical depth. b) Net photosynthesis is zero at the critical depth. c) Gross photosynthesis is zero at the critical depth d) Chemosynthesis and photosynthesis are equal at the critical depth e) All of the above f) None of the above 6) If water becomes murky because of sediment runoff a) Both the critical depth and the compensation depth would increase b) Both the critical depth and the compensation depth would decrease c) The critical depth would increase, and the compensation depth would decrease d) The critical depth would decrease, and the compensation depth would increase 7) Phosphorus chemically bound in sediments is likely to be released when the sediments become anoxic because a) Polyphosphate is hydrolyzed to phosphate b) Anaerobic metabolism produces methane and carbon dioxide c) Calcium and magnesium are sequestered by organic chelators d) Ferric iron is reduced to ferrous iron 8) The trace element that is believed to limit nitrogen fixation rates in the ocean is a) Iron b) Phosphorus c) Vanadium d) Copper 9) Denitrification has a greater impact on the nitrogen cycle in the ocean than in lakes because a) Denitrification is limited by the low concentrations of phosphate in lakes b) High iron concentrations inhibit denitrification in lakes c) The residence time of bottom waters is much greater in the ocean d) Calcium and magnesium, both required for the production of nitrogenase, are much more abundant in the ocean 10) A student performs a nutrient enrichment experiment involving nutrients X, Y, and Z. Nutrient additions are made as follows:
Flask Control A B C D E F
Nutrients added No additions X Y Z X+Y Y+Z X+Y+Z
Result Water remains clear Water remains clear Water remains clear Water remains clear Water remains clear Water turns green Water turns green
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A logical interpretation of these results would be a) X and Y are both limiting. Z is not limiting b) Y and Z are both limiting. X is not limiting c) X and Z are both limiting. Y is not limiting c) X, Y, and Z are all limiting A lake is receiving wastewater in which the ratio of nitrogen to phosphorus is 6. The ratio of nitrogen to phosphorus in the algae in the lake is 12. 11) What would happen to the algae in the lake if the N were reduced by a factor of 8? a) No change b) Reduced by a factor of 2 c) Reduced by a factor of 4 d) Reduced by a factor of 8 12) What would happen to the algae in the lake if the P were reduced by a factor of 8? a) No change b) Reduced by a factor of 2 c) Reduced by a factor of 4 d) Reduced by a factor of 8 13) What would happen to the algae in the lake if the N were increased by a factor of 8? a) No change b) Increased by a factor of 2 c) Increased by a factor of 4 d) Increased by a factor of 8 14) What would happen to the algae in the lake if the P were increased by a factor of 8? a) No change b) Increased by a factor of 2 c) Increased by a factor of 4 d) Increased by a factor of 8 15) A freshwater lake in which the temperature never falls below 4oC is likely to be a) Monomictic with overturning occurring during the winter b) Monomictic with overturning occurring during the summer c) Dimictic with overturning occurring during the fall and spring d) Dimictic with overturning occurring during the summer and winter 16) During winter in the North Atlantic Ocean, production is low and light limited in the surface waters because a) The compensation depth is deeper than the critical depth b) The mixed layer is deeper than the critical depth c) The compensation depth is deeper than the mixed layer d) The euphotic zone is deeper than the compensation depth
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17) Which of the following kinds of lakes is most susceptible to seasonal oxygen depletion? a) A shallow lake in which the epilimnion extends to the bottom b) A lake of intermediate depth in which the thickness of the hypolimnion is small compared to the depth of the lake c) A deep lake in which the thickness of the hypolimnion is more than 75% of the depth of the lake. 18) In an estuary the net movement of water is a) Into the estuary near the bottom at the mouth and out of the estuary near the surface at the mouth b) Into the estuary near the surface at the head and out of the estuary near the bottom at the mouth c) Into the estuary near the surface at the mouth and out of the estuary near the surface at the head d) Into the estuary near the bottom at the head and out of the estuary near the bottom at the mouth. 19) The extent of anoxia in the bottom waters of the Chesapeake Bay during the summer is positively correlated with the flow of the Susquehanna River in spring. The explanation for this relationship is a) Due to industrial discharges of high BOD wastewater, the Susquehanna River has a very low oxygen concentration b) The freshwater from the Susquehanna River intensifies the stratification of the water column in the bay and isolates the bottom waters from the atmosphere c) The sediment transported by the Susquehanna River reduces light transmission through the water column in the bay and hence reduces the production of oxygen by benthic plants d) Due to the lack of riparian shade, the Susquehanna River water is much warmer than the water in the bay. The higher temperature increases the respiration rate of organisms and hence causes the oxygen concentration to decline more rapidly than usual. 20) The term stranded filth refers to a) Solids associated with sanitary sewage that are stranded in the pipes of a combined sewer system during dry weather b) Fecal material deposited by dogs, cats, and other animals on impervious surfaces in urban areas c) Sanitary sewage that is stranded on city streets when sewer lines back up during heavy rains d) Trash and garbage that are not set out in a secure container and subsequently find their way to storm sewers when stray animals and/or the wind tip over garbage cans.
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21) The figure above shows concentrations of nitrate and phosphate from late winter until early summer in a lake. The straight line is a linear regression fit to the data. The concentrations of both nutrients are high at the end of the winter and low by the beginning of summer. The drawdown of both nutrients is due to uptake by phytoplankton. Based on the pattern of nitrate and phosphate concentrations, which nutrient would you judge to be limiting phytoplankton biomass in the lake? a) Phosphate b) Nitrate 22) Discharges of secondary treated sewage into Kaneohe Bay during the 1960s and early 1970s adversely affected corals in the bay because a) The water in the bay became murkier due to increased concentrations of plankton b) Higher concentrations of plankton provided food for benthic filter feeders, which grew rapidly and crowded out corals c) The nutrients in the sewage stimulated the growth of bubble algae, which overgrew and enveloped many coral heads d) All of the above e) None of the above 23) Between 1983 and 1990 the abundance of bubble algae on the barrier reef that separates Kaneohe Bay from the open ocean increased at depths shallower than six meters. The most likely explanation for this increase in bubble algae is 5
a) stimulation of growth by nutrients derived from land runoff b) improved water clarity associated with El Nio cycle c) increase in water temperature due to greenhouse effect of increased atmospheric CO2 concentrations d) removal of too many herbivorous fish by fishermen 24) The principal objection to combined sewer systems versus separate (sanitary and storm) sewer systems is a) Combined systems are more expensive to build and operate b) Combined systems release raw sanitary sewage during heavy rains c) Combined have systems serious odor problems d) Combined systems release greenhouse gases during anaerobic decomposition of organics in the pipes 25) The first flush effect is more likely to be apparent in a location where the interval between rainfalls is short than in a location where the interval between rainfalls is long. a) True b) False 26) The detention basin/artificial marsh constructed by the City of Tallahassee to reduce the impact of land runoff on Lake Jackson has been rather ineffective because a) The system does a poor job of removing solids b) Much runoff must bypass the system during moderate and large rains c) The system does an inefficient job of removing nutrients 27) Treatment systems for urban runoff such as the Chicago Tunnel and Reservoir Plan (TARP) are very expensive because a) They must have much greater storage capacity than a sanitary sewer system b) The composition of urban runoff is highly variable c) Urban runoff contains toxic substances such as lead and pesticides that are present at much lower concentrations in sanitary sewage d) The chemical oxygen demand of urban runoff is much higher than the biochemical oxygen demand of sanitary sewage 28) The Sand Island and Honouliuli primary wastewater treatment plants have a much easier time meeting federal requirements for removal of suspended solids than BOD because a) In both cases their design capacity has been greatly exceeded by present wastewater fluxes b) Methane and carbon dioxide are produced in their primary clarifiers as a result of the anaerobic decomposition of organics in the wastewater c) The wastewater entering the plants contains toxic substances from the many industrial activities in Honolulu Harbor and Pearl Harbor d) About half of the BOD is dissolved 29) Indicate whether the following statements are true (T) or false (F)
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a)
Trickling filters have more of a fly and odor problem than activated sludge wastewater treatment plants b) Trickling filters tend to remove more BOD and suspended solids than activated sludge wastewater treatment plants c) Trickling filters are more resilient to changes in the characteristics of the wastewater than activated sludge wastewater treatment plants d) Trickling filters produce more sludge than activated sludge wastewater treatment plants 30) The most commonly used tertiary treatment methods for removing nitrogen from wastewater are a) Nitrogen fixation and breakpoint chlorination b) Breakpoint chlorination and denitrification c) Denitrification and ammonia stripping d) Ammonia stripping and nitrogen fixation 31) Recycling of sewage sludge is much more common in the United States than recycling of treated wastewater because a) Sludge can be transported much more economically than wastewater b) In most places it is still cheaper to pump groundwater than to recycle wastewater c) Sewage sludge has found widespread use for restoring strip-mined land d) All of the above e) None of the above 32) The principal purpose of the builder in laundry detergents is to a) Separate dirt from fabric b) Soften the water c) Stabilize the pH d) Kill germs 33) Ultraviolet light is gradually replacing chlorine as a means of disinfecting treated wastewater before it is released because a) Chlorine is a very toxic /corrosive gas that is hazardous to treatment plant workers b) Wastewater disinfected with chlorine must be dechlorinated before it is released c) Chlorine can combine with dissolved organics to produce chlorinated organics, some of which may be carcinogenic d) All of the above e) None of the above 34) Which of the following pathogens produces an encysted egg that is not effectively killed by chlorine? a) Leptospira b) Vibrio cholera c) Salmonella d) Shigella e) All of the above
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f)
None of the above
35) Which one of the following pathogens is associated with typhoid fever? a) Salmonella b) Norwalk virus c) Legionella d) Campylobacter jejuni 36) One of your friends foolishly goes swimming in the Ala Wai Canal. A few days later your friend complains of dermatitis and inflammation of his ears and eyes. Which one of the following pathogens might be responsible for these symptoms? a) Cryptosporidium parvum b) Hepatitis A virus c) Escherichia coli d) Pseudomonas aeruginosa 37) The incidence of disease caused by which one of the following pathogens has been effectively controlled by vaccination? a) Vibrio cholera b) Schistosoma c) Polio virus d) Shigella 38) The United States Environmental recommends the use of Enterococcus bacteria counts as an indicator of the presence of fecal pollution in recreational waters. Hawaii public health authorities feel the use of the counts of this organism as an indicator of fecal pollution is of no value in Hawaii because a) Important pathogens such as Vibrio cholera survive much longer in saltwater than Enterococcus b) The concentrations of Enterococcus are too low to be a reliable indicator of fecal pollution in Hawaii c) Enterococcus is found living in the soil in Hawaii d) Epidemiological studies have shown no correlation between Enterococcus counts and the incidence of gastroenteritis among recreational swimmers in Hawaii e) All of the above f) None of the above 39) Why is the use of ultraviolet light unlikely to replace chlorination as a means disinfecting public water supplies? a) Ultraviolet light does not provide a residual of killing power in the water distribution system b) Chlorine does a m...