Marine
Biology Last Lecture review questions
A
1 Mangrove forests in the tropics are being destroyed for human uses such as
shrimp farming.
b
2 Coral bleaching occurs primarily when coral polyps and their zooxanthellae are dead.
b
3 Increased atmospheric carbon dioxide may be increasing the earth's
temperature because this gas absorbs more infrared radiation from space coming
from the sun.
a
4 A great drop in atmospheric ozone levels, thought to be caused by CFCs,
currently occurs over
b
5 Eutrophication occurs when excess nutrients enter
the ocean and feed decay bacteria, which deplete oxygen.
b
6 Dumping of sludge (treated sewage) in the oceans has relatively little effect
on marine life compared to dumping of raw sewage.
a
7 Oil spilled in the ocean may last for years, but not forever because some of
it evaporates and natural bacteria break down the rest.
a
8 Oil spills can kill seabirds and some marine mammals by reducing their
B
9 Most of the polluting oil in
b
10 As chlorinated hydrocarbon pesticides enter a marine food chain, about
80-90% are degraded or lost at each trophic step
(similar to the loss in production).
a
11 One major result of the use of DDT as a pesticide was a large reduction in
the reproduction rate of some marine birds due to weakened eggshell production.
b
12 The use of DDT and other chlorinated hydrocarbon pesticides has been banned
worldwide, and the problems they caused are now gone.
b
13 PCBs can evaporate, condense upon cooling,
then get carried to the surface by precipitation, so that these toxins now are
found in high concentrations in polar regions.
a
14The heavy metal mercury is more dangerous as an organic compound than as a
metal.
b
15Radioactive waste must be ingested to have effects on marine life.
b
16Though marine thermal pollution is detrimental in the tropics, it is not much
of a problem in colder regions because the increase in heat boosts ocean
productivity.
a 17
The European green crab is an example of a widespread alien species since now
it is found in non-native habitats on both coasts of North America and in the
southern hemisphere.
a
18One of the major contributors to the spread of exotic or alien species is
ship ballast water.
a 19 Threatened or endangered species
include some whales, some sea turtles, and some shark species.
a 20 Sustainable development refers to human
use of resources that meet today's needs without affecting the ability of
future generations to meet their needs.
a 21 Planting vegetation that helps
stabilize sand is a way to control beach erosion.
d 22 Ccoral reefs
are being threatened and destroyed by dynamite and cyanide fishing. clearing of
terrestrial forests for agriculture. an
increase in bacterial and fungal diseases.
c 23 The term endangered species is defined
as a species in immediate danger of
extinction.
b
23 The largest volume of seaborne
trade is for food transport.
b 24 Side-scan sonar can profile underwater
archaeological sites covered with sediment.
b
25 Virtually all maritime cultures
now have adapted modern methods including powered boats and large nets.
b
26 Tourism has greatly reduced harm
to marine environments, since beautiful marine sites generally are preserved
for tourists rather than being exploited for food or materials.
b
27 The establishment of exclusive
economic zones requires that foreign ships remain 200 miles away from the coast
of a particular country.
a
28 The United Nations Conference on
Environment and Development in 1992 led to an agreement to protect the earth's
biodiversity and the interests of traditional fisheries of native peoples.
b 29 Food
from the sea represents nearly half of all food eaten by humans.
b
30 Most of the world's fishing
people are employed in high-tech fishing fleets.
a
31 Much of the clupeoid
catch of the world is not eaten directly but rather converted into fish meal
for use as animal feed.
a
32 Cods of the Grand and Georges Banks off eastern
a
33 Purse seines are nets used to surround and trap large schools of fishes.
b
34 The maximum sustainable yield for a fishery usually occurs when the
harvested species population is at its highest possible level.
b
35 Recent studies have shown that around 90% of the original stocks of
large-size marine fishes remain.
a
36 The term by-catch refers to currently underutilized species of marine
animals caught when valuable species of animals are caught.
b
37
b
38 Unlike most harvested marine animals, the large numbers of krill around
a
39 Open mariculture refers to the practice of raising
marine organisms in enclosures that are open to more-or-less natural
conditions.
a
40 Salmon ranching relies on the ability of salmon to return to the site where
they were hatched after maturing at sea.
b 41 Manganese nodules are mounds of minerals
created at the hydrothermal vents when hot water encounters cold seawater,
triggering mineral precipitation.
a
42 Manganese nodules on the seafloor may be economically useful because they
contain not only manganese but other metals such as copper and cobalt.
a
43 Evaporation of seawater to concentrate its minerals has been a technique
used for centuries to obtain NaCl.
b
44 Construction of devices to capture the renewable energy of the tides has no
significant negative effects on the environment.
a
45 Ocean thermal energy conversion is a technique that works best if the
surface waters are much warmer than deeper waters, such as where there is a
strong thermocline.
d
46 The most important group of demersal fish caught for human use are the cods and relatives.
47 The
maximum sustainable yield of a harvested fish population depends on the size
and age of fish caught.
the
reproductive and growth rates and lifespans of the
fish. interactions with competing
species.
a
48Medically useful compounds are being found in soft, immobile marine animals
because these animals often defend themselves with noxious biochemicals.