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34 Cards in this Set
- Front
- Back
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Food from the sea represents nearly half of all food eaten by humans. A. True B. False |
B. False |
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Most of the world's fishing people are employed in high-tech fishing fleets. A. True B. False |
B. False |
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Seafood is very important to people because A. It can be cooked easily B. It is rich in protein C. It represents over 25% of all the food we eat D. It represents a resource that shows no sign of being overexploited. |
B. It is rich in protein
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The highest catches of finfish are for A. Herring, sardines, and related fishes B. Tuna C. Salmon D. Cods |
A. Herring, sardines, and related fishes |
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If one looks at the world commercial catches of seafood, the total amounts A. Have fluctuated widely between years B. Peaked in 1990 and then declined C. Are still increasing D. Are about one-half of what they were in 1975 |
B. Peaked in 1990 and then declined |
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Cods of the Grand and Georges Banks off eastern Canada and the northeastern United States once provided one of the richest fisheries in the world but now are nearly gone. A. True B. False |
A. True |
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Clupeid fishes are used to produce all of these products except A. Fish flour B. Protein supplements for livestock feeds C. Gourmet food D. Fertilizer |
C. Gourmet food |
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The commercial cod fishery A. Has collapsed just about everywhere B. Continues in the seas off Norway C. Has been reopened at Georges Bank D. May be reopened off the USA, thanks to good survival of juvenile cod |
A. Has collapsed just about everywhere |
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In a very large population of fish, A. The population growth rate is at its maximum B. The population growth rate has now natural means to keep it in check C. Competition can slow the growth rate D. Small harvests have no effect on the population |
C. Competition can slow the growth rate |
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The maximum sustainable yield for a fishery usually occurs when the harvested species population is at its highest possible level. A. True B. False |
B. False |
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The maximum sustainability yield of a harvested fish population depends on all of these except A. The size and age of fish caught B. The reproductive and growth rates and lifespans of the fish C. Interactions with competing species D. Whether the fish is demersal or pelagic |
D. Whether the fish is demersal or pelagic |
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Even if fishing is stopped on an overexploited species, it may not recover its population levels because of all of these factors but which one? A. Irregular natural cycles B. Competition from other species C. Predation on young D. Ability to speed up its growth rate |
D. Ability to speed up its growth rate |
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If only the largest fish in a population are caught, the population may decline because A. These are the most competitive fish B. These produce more eggs than small ones C. Smaller fish eat more food than big ones D. Smaller fish will escape from nets and never return to the area where they were caught |
B. These produce more eggs than small ones
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The term by-catch refers to currently underutilized species of marine animals caught when valuable species of animals are caught. A. True B. False |
A. True
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Recent studies have shown that around 90% of the original stocks of large-size marine fishes remain. A. True B. False |
B. False |
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Peru is one of the top fisheries countries because the Peruvian anchovy fisheries have been well managed since the 1950s. A. True B. False |
B. False |
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Fisheries in the EEZ of the USA are managed by A. Banning fishing vessels of all foreign nations B. Setting limits on mesh sizes of nets C. Strictly following free-market forces D. Maintaining an open fishery |
B. Setting limits on mesh sizes of nets |
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Overexploitation of cod in the North Atlantic has led to new fisheries for mackerel, which are eaten by cod. This is an example of A. Use of by-catch B. Fishing lower on the trophic pyramid C. A small-scale local fishery D. Ecological replacement |
B. Fishing lower on the trophic pyramid |
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Open mariculture refers to the practice of raising marine organisms in enclosures that are open to more-or-less natural conditions. A. True B. False |
A. True |
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Open mariculture is used to grow A. Animals under domestic conditions B. Fishes that can be bred and raised through their planktonic life cycle stages C. Oysters and seaweeds D. Sterile animals |
C. Oysters and seaweeds |
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Unlike most harvested marine animals, the large numbers of krill around Antarctica are continuing to provide an increasing harvest each year. A. True B. False |
B. False |
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Salmon ranching relies on the ability of salmon to return to the site where they were hatched after maturing at sea. A. True B. False |
A. True |
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Mariculture today is mostly used to grow luxury foods instead of cheap fish for the world's poor. This is because A. Fish suitable for mariculture do not live near poor countries B. It is only in the past 100 years that anyone has tried to raise marine organisms in ponds C. No one has considered using biotechnology to improve yields from mariculture D. It requires expensive machinery and trained personnel |
D. It requires expensive machinery and trained personnel |
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Recreational fisheries can damage fish stocks because they A. Waste fish B. Take almost as many fishes as commercial fisheries C. Target and deplete large predatory fishes D. Tend to stay near shore |
C. Target and deplete large predatory fishes |
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A potential biomedical product that has turned out to be ineffective is A. An extract of seaweeds, used to inhibit growth of tumors B. An adhesive from bacteria, used to seal wounds C. A toxin from puffers, used as a painkiller D. Shark cartilage, used to halt development of cancer |
D. Shark cartilage, used to halt development of cancer |
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Medically useful compound are being found in soft, immobile marine animals because these animals often defend themselves with noxious biochemicals. A. True B. False |
A. True |
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Desalination currently is being used in a few countries such as Saudi Arabia. What prevents it from being used to produce drinking water in arid parts of the USA? A. The technology is still being developed B. Seawater must be pumped from great depths C. Reverse osmosis cannot be used in small-scale projects D. It is expensive |
D. It is expensive |
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Evaporation of seawater to concentrate its minerals has been a technique used for centuries to obain NaCl. A. True B. False |
A. True |
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Managanese nodules are mounds of minerals created at the hydrothermal vents when hot water encounters cold seawater, triggering mineral precipitation. A. True B. False |
B. False |
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Manganese nodules on the seafloor may be economically useful because they contain not only manganese but other metals such as copper and cobalt. A. True B. False |
A. True |
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To generate electricity from tidal energy, modern schemes require A. A means to create a difference in water temperature B. Pumping nutrient-rich water from the depths C. Evaporating seawater D. Constructing barriers across narrow bays |
D. Constructing barriers across narrow bays |
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Navagation buoys can be powered by A. Thermal gradients B. Wave energy C. Tidal energy D. Methane |
B. Wave energy
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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. A. True B. False |
A. True |
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Offshore oil production involves all of these factors but which one? A. Platforms B. Pipelines C. Dredges D. Drilling ships |
C. Dredges |
