21) In 1992, the Canadian government ________.
A) ordered a complete ban on cod fishing
B) gave subsidies to fishers who were losing money because of low fish harvests
C) banned the use of trawling
D) enacted laws to protect many species of whales
E) started harvesting manganese nodules from the ocean floor
22) Most present–day fisheries managers ________.
A) wish to set aside areas of ocean where systems can function without human interference
B) favour individual transferable quotas, because privatization of marine resources will introduce
incentives to preserve fish stocks
C) favour short–term solutions to marine ecosystem problems
D) favour protection of commercially valuable species and not others
E) favour taxes on commercial fishing boats
23) Most marine protected areas ________.
A) are in the open oceans
B) have been established without the consent of the United States, which didn’t sign the
MARPOL convention
C) prohibit the installation of oil pipelines and fibre–optic cable lines within them
D) are along the coastlines of developed nations
E) ban fishing and extractive activities
24) Marine reserves ________.
A) are Coast Guard reservists who may be called upon to police coastal waters
B) are Coast Guard reservists who may be called upon to police open ocean waters
C) are “no–take” areas in the oceans
D) provide no benefits to fishers, so are unanimously opposed by them
E) are opposed by most environmentalists
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25) Approximately ________ of Earth’s human population lives within about 150 km of the
ocean.
A) 1/10
B) 1/3
C) 2/3
D) 1/2
E) 3/4
26) Red tides are caused by ________.
A) increased ocean oxygen content
B) increased ocean carbon dioxide content
C) nutrient upwelling
D) the position of the Moon
E) nutrient pollution leading to marine algal blooms
27) According to an FAO report on South and Central America shrimp fisheries, for each 1 kg of
shrimp
________ of other animals are caught, and ________ of them were discarded as trash.
A) 10-30 kg; 70%
B) 10-30 kg, 30%
C) 1-3 kg, 60%
D) 1-3 kg, 30%
E) 0.1-0.3 kg, 60%
28) Bycatch refers to ________.
A) fishing using two types of fishing gear
B) fishing for two species of fish concurrently
C) the capture of animals not meant to be caught
D) fishing using mobile fishing gear
E) the practice of returning female and young fish back to the ocean
29) Mid-ocean ridge is NOT ________.
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A) a location of many hydrothermal vents
B) a divergent boundary
C) more shallow than most of the ocean bottom
D) part of the continental shelf
E) a place where the ocean plates are created
30) Some of the CO2 emitted by humans into the atmosphere is taken up by the surface waters
and is then transferred into the deep ocean by water mixing. The greater the temperature
difference, the more difficult it is to mix the surface waters with the deep waters. Therefore, the
transfer of anthropogenic CO2 into the deep ocean is most likely to take place in the ocean near
the coast of ________.
A) Greenland
B) Equatorial Guinea
C) Florida
D) Brazil
E) Nova Scotia
31) Sea turtles belong to ________.
A) nekton
B) phytoplankton
C) benthos
D) zooplankton
E) intertidal community
32) Barnacles belong to ________.
A) nekton
B) phytoplankton
C) benthos
D) zooplankton
E) intertidal community
13.5 True/False Questions
1) Approximately 80% of the planet’s surface is covered by ocean.
2) Into the mid-twentieth century, it was common for Canadian coastal cities to dump untreated
waste water into the ocean.
3) The majority of the oil polluting our oceans is from large spills.
4) In oceans, water density increases with depth.
5) Regardless of latitude, the deep waters have similar temperature.
6) The deepest zones of the ocean are void of life.
7) Humans have had relatively little effect on the overall biodiversity of ocean ecosystems.
13.6 Essay Questions
1) Discuss the importance of the goods and services that ocean ecosystems provide for humans.
2) What are the two main types of marine ecosystems? What affects organisms living in both of
them? How does the ocean’s depth further modify conditions within both divisions?
3) Discuss the impacts of human–made pollution on ocean ecosystems.
4) Discuss how fishing practices can damage ecosystems. Include problems associated with
driftnets, longline fishing, and bottom-trawling.
5) What concept has traditional fisheries management been based on? What approach do
scientists think would improve current management techniques?
6) Summarize some of the positive effects, and challenges, of establishing marine reserves.
7) Why are large predatory fish stocks on the verge of collapse, and why have some already
collapsed? Why do we have to resort to “fishing down the food chain”?
8) Why should we care about the formation of North Atlantic Deep Water (NADW)? What are
the meteorological conditions required for NADW to form?
9) When on the western coast of Vancouver Island the wind blows from the north, Vancouver
Island experiences cool and rainy summers. What oceanic process is responsible for this?
Explain how this process works. Why is this process important biologically and economically?
10) What is El Niño and why during El Niño did the Peruvian fisheries suffer great losses?
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13.7 Scenario-Based Questions
Read the following scenario and answer the questions below.
Diets that incorporate seafood can be healthy for us and kind to the environment. However, all
seafood is not comparable, so choice is important. Mollusks such as oysters, mussels, and
scallops are good choices if they are grown suspended in water, because dredging damages
seafloors. On fish farms, this involves growing organisms on nets, trays, or racks. Because
mollusks are filter feeders, farmed mollusks can actually improve water quality by removing
organic and inorganic matter suspended in water. Although shrimp are also filter feeders, shrimp
farms, especially in Southeast Asia, are often built in coastal areas where mangroves are
destroyed to make room for farms. As long as excessive quantities of grain or wild fish are not
used for feed, aquaculture can be a very good alternative to open ocean fishing because it can
reduce bycatch, the pressure on wild stocks, and the fossil fuel use required at sea. Exceptions
are farms that raise transgenic salmon, which often spread disease, or where the farmed fish
become oversized and outcompete the native fish. These salmon consume massive quantities of
fish feed, so better fish choices are farm-raised tilapia, striped bass, and sturgeon. In the wild,
Pacific halibut, salmon, sablefish, and sardines are good choices because they are fished
selectively. Wild grouper, shark, swordfish, tuna, and orange roughy must be consumed
cautiously because the water they inhabit usually contains high levels of mercury, PCBs, dioxins,
or pesticides, which can biomagnify in food webs and bioaccumulate in fish tissues. Wild
Chilean sea bass, Atlantic cod, and Atlantic halibut should be avoided because their populations
have been overfished. Orange roughy have been overfished, reproduce slowly, and are fished
with bottom–trawlers that frequently damage bottom habitat.
1) The main environmental problem caused by harvesting mollusks is ________.
A) removal of keystone species
B) introduction of invasive species
C) habitat destruction
D) high bycatch
E) bioaccumulation
2) Farm–raised shrimp are NOT a good environmental seafood choice because ________.
A) shrimp farms are often associated with destruction of mangrove forests
B) of the bioaccumulation of toxins
C) of high bycatch
D) trawling destroys coral reefs
E) they require high quantities of wild fish feed
3) Which of the following is NOT true about aquaculture?
A) It can be resource intensive.
B) It can result in habitat destruction.
C) It can release mutants that harm native species.
D) It has a large fossil fuel footprint compared to fishing wild stocks.
E) It can be sustainable.
4) Why are marine reserves ecologically better than fish farms?
A) They seed the seas.
B) Farmed fish are quickly depleted.
C) They are met with less opposition by fishers because they provide tremendous economic
benefits.
D) They require no government regulation.
E) Farmed fish are genetically inferior.
5) Which of the following seafood is the worst choice for a healthy diet?
A) mussels
B) oysters
C) wild salmon
D) albacore tuna
E) tilapia
6) Which of the following can be a problem associated with mussel farms?
A) trawling
B) overfishing
C) high bycatch
D) habitat destruction
E) the reduction of food available to wild plankton eaters
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