Name _____________________________________________
Period ______________
Ocean in Action End-of-Cycle Study Guide
Ocean Circulation
1. Using the map of ocean surface currents above, what would be the most likely
location for plastics and other solid waste pollution to collect?
A
2. What happens as warm water along the coast is blown away by wind and moved back
out to sea, as cold, nutrient rich water is pushed up from along the land.
upwelling
3. Which of the following are the 2 main drivers of global deep ocean currents?
1) Temperature
2) Salinity
4. What causes the wind and currents to curve/not travel in a straight line due to
the rotation of the earth? In the north it curves to the right, and in the south it
curves left.
The coriolis effect
1
5. What is the temperature and direction of the California Current, which flows
along the west coast of North America?
Temperature
Cold
Direction
south
6. How would a colder Scandanavia and Great Britain affect the thermohaline
circulation of currents? (increase it, decrease it, cause it to shut down).
Shut it down
7. During an El Niño-Southern Oscillation (ENSO) event, which of the following
best describes conditions in the eastern part of the tropical Pacific Ocean (e.g.,
near Peru and Ecuador)? What happens to the high and low pressure areas in
the eastern and western Pacific?
The high ad low pressure areas are switched, so that the normal cold upwelling
along the coast of the South America (Eastern Pacific) is replaced with higher sea
surface temperatures and higher precipitation levels.
2
Fisheries and Aquaculture
8. Give four results of salmon farming (aquaculture).
1. Environmental stress to salmon after their release
2. Resource competition between farmed and wild salmon
3. Increased susceptibility to diseases due to genetic uniformity
4. Pollution of surrounding ocean with waste and excess feed
9. How is bottom trawling is detrimental to benthic organisms?
A boat drags a large net across the bottom of the ocean floor, destroying habitats,
stirring up sedimentation, reducing spawning grounds, and catching unwanted
bycatch.
10. Why has the maximum sustainable yield for ocean fisheries has been exceeded?
(what happens annually? Refer to your Tragedy of the commons activity)
Too many marine fish of reproductive age are harvested annually
11. What is an economic approach to reduce overfishing/what could government
eliminate for fisherman?
Eliminating subsidies
12. Which of the following laws was implemented in the US to govern the
conservation and management of ocean fisheries?
Magnuson Fishery Conservation and Management Act
13. One of the world’s largest exporters of shrimp is Thailand, where coastal
mangrove swamps are often destroyed to make room for shrimp farms. What
are 4 ecological impacts of the destruction of mangrove forests for this type of
aquaculture?
1. Exposes the surrounding shorelines to coastal erosion
2. Opens coastal areas to severe damage from storms and hurricanes
3. Reduces biodiversity in important spawning and nursery areas
4. May increase spread of diseases to wild populations of shrimp
Aquatic Biomes
14. Which part of the ocean would a marine biologist studying areas of high
biodiversity be most likely to conduct research in?
3
Coral reefs in the neritic zone, above the continental shelf
15. Why are sharks are at the top of the food chain and their removal would have
far-reaching consequences for the entire ecosystem. What is the term to describe
an organism that would cause such a drastic change to the ecosystem, if it were
removed?
Keystone species
16. Which of the following terms best describes an area where salt and freshwater
mix that has a very high level of productivity? (3% salt water or brackish water
exists here)
An estuary
17. Put the following aquatic biomes into the following catagories of salinity: River,
Lake, Esturary, Coral Reefs (Coastal Marine Ecosystem), Deep ocean Marine
Ecosystem.
Oligotrophic (0.5-5 psu)
Mesotrophic (5-18psu)
Polytrophic (18-30 psu)
Estuary
Coral Reefs
River
Deep Ocean Marine
Lake
Ecosystem
18. Wetlands surrounding a river, provide what ecosystem services?
1) Prevention of Flooding
2) remediation of toxic chemicals and excess nutrients
19. What does phytoplankton (the most abundant primary producer in the world)
produce through photosynthesis in the ocean?
1) dissolved oxygen
2) glucose
20. The ecosystems with the world’s highest net primary productivity (NPP) per
unit area are located in which part of the ocean?
Euphotic zone
4
Water Pollution
21. In a river ecosystem, dissolved oxygen concentrations drop quickly downstream
from a point-source input of organic matter into the river. What is this effect
most likely due to?
Increasing bacterial activity due to decay of organic matter
[Source: http://mdk12.org/instruction/clg/public_release/biology/G3_E5_I2.html]
22. Which organism in the food web above would be most likely to accumulate the
highest concentration of a fat-soluble pollutant?
The Killer whale because of biomagnification, in which toxic pollutants are not broken
down, and travel up the food chain, accumulating at the top.
23. In what way does the Great Pacific Garbage Patch represent a “tragedy of the
commons”?
Pacific Rim countries are polluting the water in a way that affects the quality
of the ocean for all, but no one is accountable for it.
24. Which of the following is the most common cause of cultural eutrophication in
surface waters?
5
Runoff of nitrate into bodies of water
25. How does logging/ deforestation lead to non-point source pollution?
Logging and deforestation leads to sedimentation, which lowers water quality. It is
not easily identifiable, and therefore is considered a non-point source of pollution.
26. When we did our toxicity lab, we found that worm (we used black worms) tend
to be very tolerant of pollution, and resistant to high toxicity levels. Explain why
the presence of black worms or sludge worms and anaerobic bacteria are
indicators of polluted water.
Sludge worms and anaerobic bacteria
27. What is the number 1 source of oil pollution in the ocean? (surprisingly)
Storm water runoff from land
28. What are three of the most common methods employed to clean up oil spills?
Large floating booms, skimmer boats, and chemical dispersants
29. Name 3 point sources of pollution.
1) Factory effluent (emissions and discharge)
2) A specific active or inactive mine
3) Sewage Treatment plant
30. A marine scientist suspects that runoff from nearby farms is creating a hypoxic
zone (area of low oxygen content) in a coastal area. Which of the following water
quality tests would be best suited to determining whether the area is actually
hypoxic?
Dissolved oxygen
31. Environmental conditions in coastal estuaries vary hourly and seasonally. What are
TWO important causes for the variation in the temperature and/or salinity of an
estuary. Be sure to include the connection between each cause and temperature and/or
salinity.
1) The tides, which are controlled by the moon bring more salinic water into the
estuary at different points in the day, and in different variations depending on the
time of the month and year (tilt of the earth’s axis).
6
2) Vertical mixing by the natural ebb and flow of waves causes the waters of various
densities to circulate and mix. Meanwhile if there is little movement, the freshwater
or warm water will float to the top where it can be blown away by the wind,
allowing for cold, salinic upwelling.
32. What are 2 reasons that wetlands are ecologically important?
1) They provide a habitat for various wildlife.
2) They are usually very biodiverse and provide spawning grounds for fish and birds.
3) They provide nutrient cycling, or soak up excess nutrients.
33. What are 2 reasons that wetlands are economically important?
1) They provide phytoremediation, through plants that soak up toxic chemicals
2) They provide a location for fishing, canoeing, hiking, and other sources of recreation
3) they reduce flooding and erosion
34. Explain THREE ways in which humans have had a negative impact on or have degraded
coastal wetlands.
1) They have removed wetlands for agricultural purposes or to develop urban areas.
2) They have over used groundwater which causes salt water intrusion and reduces the
balance of the ecosystem.
3) They have polluted the waters, harvested the plants and hunted the birds.
4) They have attempted to use wetlands like esturaries for aquaculture, which can lead
to other wildlife getting caught in nets, excess nutrients/nitrogen produced, escaped
species, increased disease, and a decrease in genetic stability and health of organisms
and the ecosystem.
35. What are 2 pieces of legislation that could reduce the negative impacts that humans
have on the wetlands, and explain using the provisions of each act how they might
prevent/reduce wetland degradation.
1) Magnueson Fisheries conservation and management Act
2) Marine Mammal Act
7
3) Endangered species Act
4) National Environmental Protection Act
5) Clean water Act
(look them up in your environmental policy notes to see what they do)
36. Excess carbon dioxide (CO2 ) dissolved in the ocean (due to increased pollution) could
affect pH. pH is the amount of H+ that can be donated. Write the chemical equation, that
explains why excess CO2 may increase the acidity of the ocean?
CO2 + HOH  H2CO3 (carbonic acid) which further dissociates in water donating
hydrogen ions. Carbon dioxide and water form carbonic acid, which makes the water
more acidic, therefore decreasing the pH of the water.
37. Coral reefs are produced when corals acquire calcium ions (Ca2+) and carbonate ions
(CO32-) from seawater and deposit solid CaCO3 to form their exoskeletons. How might
coral reefs be affected by excess CO2?
There would an access of H2CO3 formed from the Carbon dioxide, reducing the CaCO3
formed or the amount of coral formed, because there is less CO3 ions available in the
water, as more will be used initially to form carbonic acid. As a result of ocean
acidification, it is expected that in 2050 the mass of CaCO3 deposited will be 20% less
than it is currently if pH remains at its current value.
1.5 x 1012 x (2x10-1) = 3x1011 kg CaCO3
8
38. Look at the chart above. Explain 2 reasons why the movement of carbon into the
ocean has been increasing since 1850, as a result of CO2 production by humans.
As CO2 increases, it reacts with water to form H2CO3 which is the acidic. Acids are
compounds that donate hydrogen protons (H+). H2CO3 donates 2 H+ as it dissociates
in the sea water, so it decreases the pH of the water. The lower the pH, the more
acidic the solution.
In order to model the effects of ocean acidification on coral reefs, some simplifying
assumptions can be made. Use the assumptions in the table below to perform the
calculations that follow.
Assume that the total global area of corals growing in reefs is 2.5 x 1011m2
Assume that corals grow only vertically and that the average vertical growth rate of
corals is 3 mm/year.
Assume that the average density of CaCO3 in corals is 2 x 103 kg/m3.
(i)
Calculate the current annual global increase in volume, in m3 per year, of
CaCO3 in coral reefs. Show all steps in your calculation.
Step 1: What is the total global
area (m2) of coral reefs?
2.5 x 1011m2
Step 2: convert mm to m, to
determine the vertical m/year.
3 mm/yr x 1m/1000mm=.003 m/yr
9
In scientific notation
3x10-3 m/year
Step 3: What is the volume (m3)
per year CaCO3? (Volume= area
times vertical height)
(ii)
(2.5x1011)(3x10-3) = 7.5 x108
m3/year
Calculate the current annual global increase in mass, in kg, of CaCO3 in
coral reefs. Show all steps in your calculation.
Step 1: What is the annual global
volume increase that you
calculated in part (i)?
Step 2: What is the density of
CaCO3 in kg/m3?
Step 3: Using the formula for
density (D=m/v) what is the
increase in global mass in kg of
CaCO3 in coral reefs?
7.5x108 m3/year
2 x 103 kg/m3.
(2 x 103 kg/m3)=m/(7.5x108
m3/year)
m=(2 x 103 kg/m3) (7.5x108
m3/year)
m=15x1011=1.5x1012 kg
(iii)
Because of ocean acidification, it is expected that in 2050 the mass of
CaCO3 deposited annually in coral reefs will be 20 percent less than is
deposited currently. Calculate how much less CaCO3, in kg, is expected to
be deposited in 2050 than would be deposited if ocean water pH were to
remain at its current value.
Step 1: What is the annual global
increase in mass in kg of CaCO3 in
coral reefs? (from part ii)
Step 2: find 20% of that mass using
multiplication.
1.5x1012 kg
(1.5x1012)(.2) = 0.3x1012kg=3x1011
kg
39. Give 4 reasons why destroying coral reefs would be harmful to the environment,
10
and why?
Impact
Loss of Habitat
Loss of
biodiversity of
species
diversity/richness
Decreased
protection of
coastal areas from
wave/storm
surges
Loss of carbon
sink
Why





elimination of food source for marine life
loss of breeding grounds for fish and bird species
loss of shelter – hiding places
decrease in the number, variety, or distribution of
species
Decrease in populations of species/reduction in gene
pool


destruction of coastal habitats
accelerated erosion of shoreline habitats

less carbon storage in coral reefs
40. What are 3 environmental problems (other than one due to ocean acidification
or loss of coral reefs) that humans cause and affect marine ecosystems on a global
scale?
1) over fishing, destructive fishing practices
2) thermal pollution (increased ocean temperature)
3) Introduction of Invasive species
4) Eutrophication: nutrient pollution  leads to Hypoxia/Dead Zones
5) Garbage/Plastic debris
6) Oil Spills/Off shore oil drilling
7) Mercury Pollution
8) Pesticide Pollution
11
12