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EOSC 474 (Marine Pollution) Example Final Exam Questions from Past Exams

6.    Which of the following statements are FALSE about wild and farmed salmon in British Columbia?

I.     Wild salmon spawn in rivers and live most of their adult life in the ocean.

II.    Both wild and farmed salmon deliver marine nutrients to terrestrial ecosystems.

III.   Farmed salmon are genetically identical to wild salmon.

A.    I only

B.    II only

C.    III only

D.    I and II only

E.    I and III only

F.    II and III only

7.    Which of the following is FALSE about fresh water and seawater?

A.   Seawater is denser than fresh water at all temperatures.

B.   Seawater is densest right at its freezing point.

C.    Fresh water is densest 4oC above its freezing point.

D.   Sea ice is less dense than both seawater and fresh water.

E.    Water forms small clusters linked by hydrogen bonds only in fresh water.

F.    None of the above are false.

8.    Which of the following is TRUE about most plastics in the ocean?

A.    Plastics degrade on timescales of weeks due to decomposition by bacteria.

B.    Plastics degrade on timescales of years due to chemical oxidation.

C.    Plastics degrade on timescales of decades to centuries due to physical stress.

D.   Plastics fragment on timescales of weeks due to decomposition by bacteria.

E.    Plastics fragment on timescales of years due to chemical oxidation.

F.    Plastics fragment on timescales of decades to centuries due to physical stress.

9.    Which of the following is TRUE? Atmospheric CO2  today is                .

A.   about 50% higher than it was during previous interglacial periods

B.    over twice as high than it was during previous glacial periods

C.    continuing to increase at a faster rate over the last 50 years

D.   expected to continue increasing over the next 50 years

E.    All of the above

10. Which of the following is NOT a characteristic/consequence of biological invasions?

A.   highly unpredictable

B.   a result of the combination of species, communities and environmental interactions

C.    has a lasting effect on an ecosystem

D.   easier to manage than to prevent

11. Which of the following is/are NOT considered a component of BOD in wastewater or surface run-off?

[NOTE: There may be multiple correct answers. Choose all that apply for full marks; there is a penalty for selecting an incorrect answer.]

A.   table scraps (food)

B.    by-products of salmon/fish processing

C.    organic fertilizers from farms

D.   human and animal waste

E.    sulfates from industrial plants

F.    gasoline, grease, motor oil from roads and parking lots

G.   nitrate and phosphate fertilizers from golf courses

12. What role do bacteria play in the cycling of metals in the marine environment?

A.   they increase the toxicity of Hg through methylation

B.   they increase the toxicity of Pb through methylation

C.   they increase the toxicity of Fe through methylation

D.   they increase the toxicity of Hg through demethylation

E.    they increase the toxicity of Pb through demethylation

F.    they increase the toxicity of Fe through demethylation

13.  How does adding CO2  to the oceans affect the pH, the carbonate concentration [CO32-], and the aragonite saturation horizon (depth where Ω = 1)? Adding CO2                          .

A.   decreases pH, decreases [CO32-], and deepens aragonite saturation horizon

B.   decreases pH, decreases [CO32-], and shallows aragonite saturation horizon

C.    decreases pH, increases [CO32-], and shallows aragonite saturation horizon

D.   increases pH, decreases [CO32-], and deepens aragonite saturation horizon

E.    increases pH, increases [CO32-], and shallows aragonite saturation horizon

14. A eutrophic coastal water body can be returned to its oligotrophic state by                .

A.   building a seawall to protect the coast from erosion

B.    upgrading a primary WWTP that delivers effluent to the water body to a secondary WWTP

C.    dredging (removing) the thick sediments from the bottom

D.   improving the circulation within the water body to replenish O2  to the water column

E.    transplanting many species of corals and fish to increase its biodiversity

15. Which of the following is the BEST statement about bioplastics and biodegradable plastics?

A.    Bioplastics are made from plant-based fibres like cellulose and therefore degrade rapidly in the environment. B.    Bioplastics are made by plants and/or bacteria and therefore rapidly degrade in the environment.

C.    Bioplastics are made from plant-based fibres like cellulose but may not degrade any faster than other plastics.

D.   Biodegradable plastics constitute a large percentage of the plastics produced today largely due to pressure from environmental organizations.

E.    Biodegradable plastics are broken down into CO2  and H2O within months in the marine environment.

16.  PCBs most closely resemble which of the following categories of pesticides with respect to their chemistry and toxicity?

A.   carbamates

B.   chlorinated organics

C.    pyrethroids

D.   organophosphates

17.  In case of an accidental tanker oil spill somewhere near the Lion’s Gate Bridge, the role of personnel from the Fisheries and Oceans Canada (DFO) include all of the following EXCEPT                .

A.   assist in the cleanup of marine mammals and birds that get coated with oil

B.    provide information on possible exposure and sensitivity of marine biota to the oil

C.    assess the recovery of marine biota from effects from the spill

D.   provide advice on clean-up based on results from mapping and imaging of the area

E.    provide information on the physical environment of the area such as depth, sediment type, salinity, temperature

PART 2. Short Answer Questions

Write in the spaces provided. 2-3 sentences max. Point form is okay.

18. Compare the acids produced from N and S pollution with the acid produced from C pollution in terms of acid strength and their relative contributions to ocean acidification.

27. BOD and Oxygen Sag

The BC government just gave the go ahead to build a mining community in the pristine wilderness in Northern BC. The mining community, once established, will host about 200 full time employees. Because the community is in the

wilderness, a primary WWTP was permitted based on cost, with the outflow to be discharged into a nearby lake. The

sewage outfall will be piped to the bottom of the lake (just above the sediments), right at its center. At this location, the lake is only 10 m deep.

A) (2 points) DRAW a diagram showing the changes in dissolved oxygen and BOD with distance from the outfall.

B) (1.5 points) INDICATE on your drawing the 3 points/zones at which the balance between the input and output of oxygen (INPUT – OUTPUT) is (1) greater than, (2) less than, and (3) equal to zero (0).

C) (3 points) What are the main processes (NAME and DESCRIBE) that are causing the changes in dissolved oxygen and BOD in the water column?

D) (1.5 points) What can the community do to prevent the lake from becoming eutrophic? Describe the action/process and how it will affect the lake environment.

28. Minamata Disease in humans

A) (3 pts) Which pollutant was the cause of Minamata Disease? Where did it come from? How did it make its way into humans?

B) (2 pts) What are the main natural sources of this toxin to the marine environment?

C) (1 pts) Discuss what was done when the cause of Minamata disease was discovered, and how long it took for this to happen.