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Describe how human activities have upset ecological processes in East Africa’s Lake Victoria (Core Case Study).
The factors causing this loss of biodiversity include: 1) introduction of Nile perch, a large predator, and 2) large algae blooms from agricultural and urban runoff. Poverty has increased in the local population due to mechanized fishing for Nile perch, which has put small- cale fishermen out of business, and has caused local forests to be depleted of firewood, which is used to smoke the perch. Now, the Nile perch is declining as its food supply diminishes
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What are three general patterns of marine biodiversity?
Scientist have observed that: 1) coral reefs, estuaries and the deep-ocean floor have the greatest marine diversity, 2) biodiversity is higher near the coasts, and 3) because of greater habitat and food variety, the ocean floor has more biodiversity than the ocean surface.
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Why is marine biodiversity higher (a) near coasts than in the open sea and (b) on the ocean’s bottom than at its surface?
biodiversity is higher near the coasts, because of greater variarty of producers and habitat in coastal areas and because of greater habitat and food variety, the ocean floor has more biodiversity than the ocean surface. because of greater varity of habitat and food sources
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Describe the threat to marine biodiversity from bottom trawling. Give two examples of threats to aquatic systems from invasive species.
- Dredging operations and fishing boats that use
- trawls are degrading the ocean bottom. In freshwaterb aquatic zones, dams and bexcessive water withdrawal from lakes and rivers disrupts flow and habitats.
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Describe
the ecological experiment involving carp removal in Wisconsin’s Lake Wingra.
How does climate change threaten aquatic biodiversity?
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What is a fishprint? Describe the collapse of the cod fishery in the northwest Atlantic and some of its side effects
fishprint is defined as the area of ocean needed to sustain the consumption of an average person, a nation, or the world. The study found that all nations together are overfishing the world’s global oceans by an unsustainable 157%.
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Describe the effects of trawler fishing, purse-seine fishing, longlining, and drift-net fishing.
- Trawler fishing-.It involves dragging a funnel-shaped net held open at the neck along the ocean bottom. It is weighted down with chains or metal plates and scrapes up almost everything that lies on the ocean floor and often destroys bottom habitats—somewhat like clearcutting the ocean floor
- purse-seine fishing-.Nets used to capture yellow fin tuna in the eastern tropical Pacific Ocean have killed large numbers of dolphins that swim on the surface above schools of tuna.
- longlining-which involves putting out lines up to 130 kilometers (80 miles) long, hung with thousands of baited hooks. The depth of the lines can be adjusted to catch open-ocean fish species such as swordfish, tuna, and sharks or bottom fishes such as halibut and cod. Longlines also hook and kill large numbers endangered sea turtles, dolphins, and seabirds each year.
- drift-net fishing- drifting nets that can hang as deep as 15 meters (50 feet) below the surface and extend to 64 kilometers (40 miles) long. This method can lead to overfishing of the desired species and may trap and kill large quantities of fish
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How have laws and treaties been used to help sustain aquatic species? Describe international efforts to protect whales from overfishing and premature extinction.
In 1946, the International Convention for the Regulation of Whaling established the International Whaling Commission (IWC). Its mission was to regulate the whaling industry by setting annual quotas to prevent overharvesting and commercial extinction.
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What
percentage of the world’s oceans is fully protected from harmful human
activities in marine reserves?
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Describe
the roles of fishing communities and individual consumers in regulating fishing
and coastal development.
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What
is integrated coastal management?
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Describe
and discuss the limitations of three ways to estimate the sizes of fish
populations. How can the precautionary principle help in managing fisheries and
large marine systems?
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Describe
the efforts of local fishing communities in helping to sustain fisheries. How
can government subsidies encourage overfishing?
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Describe
the advantages and disadvantages of using individual transfer rights to help
manage fisheries.
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Describe how consumers can help to sustain fisheries, aquatic biodiversity and
ecosystem services by making careful choices in purchasing seafood.
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What
percentage of the U.S. coastal and inland wetlands has been destroyed since
1900? What are three major ecological services provided by wetlands?
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How
does the United States attempt to reduce wetland losses? Describe efforts to
restore the Florida Everglades
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Describe
the major threats to the world’s rivers and other freshwater systems. What
major ecological services do rivers provide?
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Describe
invasions of the U.S. Great Lakes by nonnative species.
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Describe
ways to help sustain rivers
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What
are six priorities for protecting terrestrial and aquatic biodiversity?
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Relate the ecological problems of Lake Victoria (Core Case Study) to the four scientific principles of sustainability.
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