APES Chapter 11 Study Guide Questions and Answers
Terms in this set (43)
Describe how human activities have threatened whale populations (Core Case Study)
commercial hunting and whale harvesting from 1925 to 1975 have killed 1.5 million whales and drove 8 of the 11 major whale species to commercial extinction.
What is the International Whaling Commission (IWC)?
was established to regulate the whaling industry by setting annual quotas for various whale species to prevent overharvesting.
What has the International Whaling Commission (IWC) done to protect whales?
At first, it was based off of insufficient data or the quotas were ignored by whaling countries. Then, in 1986, it began imposing a moratorium on commercial whaling which drastically dropped the amount of whales being killed from 42,480 in 1970 to 1,500 in 2009.
How much do we know about the habitats and species that make up the earth's aquatic biodiversity?
Only 1% of the life forms in the sea have been properly identified and studied.
What are three general patterns of marine biodiversity?
The greatest type occurs in coral reefs, estuaries, and the deep ocean floor, it is higher near the coasts, and it is generally higher in the bottom of the ocean.
Describe the threat to marine biodiversity from bottom trawling.
it destroys the ocean floor, which takes hundreds to thousands of years to regenerate.
How have coral reefs been threatened?
by shore development, pollution, and ocean acidification.
What are two causes of disruption of freshwater habitats?
Dam building and excessive water withdrawal from rivers for irrigation.
Give two examples of threats to aquatic systems from invasive species and two of the same for freshwater systems.
Ballast water stored in cargo ship tanks and ships crossing the ocean, and consumers
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 variety of producers and habitat in coastal areas and because of greater habitat and food variety
Why is marine biodiversity higher on the ocean's bottom than at its surface?
the ocean floor has more biodiversity than the ocean surface. because of greater variety of habitat and food sources.
Give two examples of threats to aquatic systems from invasive species. Describe the ecological experiment of carp removal in Wisconsin's Lake Wingra.
First the carp devoured the algae which held sediment down onto the bottom of the lake which then in return caused turbidity in the lake. Second this reduced the number of plants that were growing there because of not having adequate conditions in order to grow. The experiment is that with the carp gone the lake could lose its cloudiness and plants will be able to grow again and also getting rid of the turbidity of the water.
Summarize the story of how invasive species have disrupted Lake Victoria's ecosystem
Before the early 1980s, the lake was rich in biodiversity. Since 1980, many fish species found in Lake Victoria have become extinct and others remain in danger of following the same fate. This loss was from a large increase in the Nile perch population, an invasive species that overtook the competition, frequent thick blooms of algae, and invasions from the water hyacinth that blocked sunlight and oxygen from staying at healthy levels for fish.
What are two harmful effects on aquatic systems resulting from the increase in the human population in coastal areas?
Oceans are becoming more crowded and noisier.
Give two examples of how pollution is affecting aquatic systems.
Chemicals such as DDT, PCBs, and mercury are polluting their habitat. Plastics in the ocean are killing up to 1 million marine mammals.
What are three ways in which projected climate change could threaten aquatic biodiversity?
Average sea levels have risen, increased carbon dioxide level, and warming of the oceans.
a concentration of a particular wild aquatic species suitable for commercial harvesting in a given ocean area or inland body of water.
What are three major harmful effects of overfishing?
1. commercial extinction
2. Larger individuals of commercially valuable species wild species are becoming
scarce, such as cod, tuna, and swordfish
3. Invasive species are rapidly reproducing
Describe the collapse of the Atlantic cod fishery and the resulting effects on the fishery's ecosystem.
it collapsed due to overfishing which led to commercial extinction, where fishers could no longer make profits on harvesting the affected fish species. The results effects on the fishery's economy included at least 20,000 fishers and fish processors and damage to Newfoundland's economy.
What is a fish print?
is defined as the area of ocean needed to sustain the fish consumption of an average person, a nation, or the world.
Describe the factors leading to the near extinction of the blue whale.
They are easy to kill and are being overharvested.
Describe the effects of trawler fishing.
Used to catch fish and shellfish that live on or near
the ocean floor. Involves a funnel shaped net along the ocean floor. Destroys ocean floor habitats.
Describe the effects of purse- seine fishing.
A spotter plane locates a school of fish and a
fishing vessel encloses the fish with a large net. Large numbers of dolphins have been killed due to getting stuck in the nets .
Describe the effects of longlining fishing.
Putting out line hung with thousands of baited
hooks. Hook large numbers of endangered sea turtles, dolphins, and sea birds.
Describe the effects of drift- net fishing.
Fish are caught by huge drifting nets. Leads to
overfishing of the desired species and kills large quantity of unwanted fish
What is bycatch?
Unwanted fish captured in the process of drift-net fishing.
How have laws and treaties been used to help sustain aquatic species?
They have been used to identify and protect endangered and threatened marine species.
How can the precautionary principle help in managing fisheries and large marine systems?
This would reduce fish harvests and close some overfished areas until they recover and we have more information about what levels of fishing they can sustain.
Describe the efforts of local fishing communities in helping to sustain fisheries
Community management systems have often been replaced by co management in which coastal communities and government work together to manage fisheries. Government will set limits for harvesting of species and then divide the limits among the communities. Governments also limit seasons and times of harvest. Communities enforce the quota among their separate fisheries and small communities.
How can government subsidies encourage overfishing?
This causes too many people to chase small amounts of fish.
Describe how consumers can help to sustain fisheries and aquatic biodiversity and ecosystem services.
They can demand sustainable seafood, which will encourage more responsible fishing properties.
List five ways to manage global fisheries more sustainably.
Fishery regulations, bycatch, economic approaches, aquaculture, and consumer information
What percentage of the U. S. coastal and inland wetlands has been destroyed since 1900?
Only .1% of the world's oceans are fully protected from human activities, and less than 1% of the world's oceans are in marine reserves.
What are major ecological services provided by wetlands?
They are supporting the aquatic biodiversity that includes commercially important fish and shellfish species as well as millions of migratory waterfowl and other birds. They also barriers against storms and floods, filter out toxins and pollutants, absorb carbon dioxide, and moderate climate
How does the United States attempt to reduce wetland losses?
In the US we have made zoning laws to steer development away from this. Also we have created a policy known as Mitigation Banking which allows destruction of existing ones as long as an equal area of the same type is created or restored.
Describe efforts to restore the Florida Everglades.
To help preserve the wilderness in the lower end of this system, in 1 947, the U.S. government established Everglades National Park, which contains about a fifth of the remaining Everglades. In 1990, Florida's state government and the federal government agreed on the world's largest ecological restoration project, known as the Comprehensive Everglades Restoration Plan (CERP) in which the U.S. Army Corps of Engineers is supposed to carry out this joint federal and state plan to partially restore the Everglades.
Describe the major threats to the world's rivers and other freshwater systems.
invasive species, pollution, and climate change threaten these ecosystems along with the over harvesting that is occurring. (Remember hIPpCo)
What major ecological services do rivers provide?
They deliver nutrients to the sea, deposit silt that maintains deltas, purify water, renew and renourish wetlands, and provide habitats for wildlife.
Describe ways to help sustain rivers.
Protect the watershed from pollutants and to much nutrients, taking down dams and restoring river flow, and providing incentives.
Describe invasions of the U. S. Great Lakes by nonnative species.
Some have been invaded by the sea lamprey which reached the western great lakes. These parasites kill their hosts by sucking all the blood from them. Currently the U.S pays up to 15 million dollars a year to kill the parasites using chemicals.
What are three ways to protect freshwater habitats and fisheries?
Three ways to protect freshwater habitats and fisheries are laws, economic incentives, and restoration efforts.
How can we apply the ecosystem approach to sustaining aquatic diversity?
We can adapt the ecosystem approach and apply it to sustaining aquatic biodiversity.
List six steps that we can take to adapt the ecosystem approach and apply it to sustaining aquatic biodiversity.
Complete the mapping of the world's aquatic biodiversity, identify and preserve the world's biodiversity hotspots, create large and fully protected marine reserves, protect and restore the world's lakes and river systems, initiate ecological restoration projects worldwide, and find ways to raise the incomes of people who live in or near protected lands and waters.