Chapter 11 Questions
Chapter 11 Question 1
• Describe the collapse of the cod fishery in the
northwest Atlantic and some of its side effects
• Collapse: The overfishing through Industrial
fish harvesting methods caused the collapse
of Cod in the Northwest Atlantic in 1992.
• Side effects: Severely damaged New Finland’s
economy, 20,000 fishermen out of work, Cod
population still has not recovered, lead to
collapse of other species such as sharks.
• Describe the effects of trawler fishing, purse-seine fishing,
longlining, and drift-net fishing.
• 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.
• 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.
• Longlining fishing: Putting out line hung with thousands of baited
hooks. Hook large numbers of endangered sea turtles, dolphins,
and sea birds.
• Drift-net fishing: Fish are caught by huge drifting nets. Leads to
overfishing of the desired species and kills large quantity of
unwanted fish
• How have laws and treaties been used to sustain
aquatic species? Describe international efforts to
protect whales and sea turtles.
• Laws and treaties have been used to sustain aquatic
species by putting restrictions on the killing of
marine wildlife. Some restrictions include banning
the use of drift nets. People have worked to restore
habitats such as mangrove forests, coastal wetlands
and coral reefs. International efforts include the
International Whale Commission, Turtle Excluder
Devices, and the banning of long-line swordfish
fishing to help save dwindling sea turtles.
Chapter 11 Question 2
By Zach, John, and Meghan
Chapter 11 Question - 2
• Describe the use of marine protected areas and
marine reserves to help sustain aquatic
biodiversity and ecosystem services.
–Animals do not get killed which
preserves biodiversity and
ecosystem services.
–Preserves habitat and allows it to
develop on its own.
Chapter 11 Questions - 2
• What percentage of the world’s oceans is fully
protected from harmful human activities in
marine reserves?
0.1%
Chapter 11 Questions - 2
• Describe the roles of the fishing communities
and individual consumers in regulating fishing
and coastal development.
– Communities work with local government to
develop better ways to preserve fish populations
and habitats.
– Consumers prevent overfishing by buying
sustainably harvested fish.
– Communities focus more on in-shore fisheries.
– Government focus on off-shore fisheries.
Chapter 11 Questions - 2
• What is integrated coastal management?
–Community based effort to
develop and use coastal
resources more sustainably.
–Great Barrier Reef is
managed by integrated
coastal management.
Chapter 11 Question 3
By: Megan Nodolf, Kayla Sampson,
Patrick Barney
• Describe and discuss the limitations of three
ways to
estimate the sizes of fish populations.
• Maximum Sustained yield: Traditional approach that is used to
project the maximum number of fish that can be harvested
annually from a fish stock without causing a population drop. Yet
it has difficulty estimating the populations and growth rates of
fish stocks.
• Optimum Sustained Yield: Attempts to take in account
interactions among species and to provide more room for error.
• Multispecies Management: Takes into account species
competitive and predator prey interactions.
The limitation for these two is that there is much to learn
about the biology of fishes and changing ocean conditions.
• How can the precautionary principle help in
managing fisheries and large marine systems?
• The precautionary principle helps to
sharply reduce fish harvests, and can close
some overfished areas until they recover
and until we have more information about
what levels of fishing can be sustained.
• Describe the efforts of local fishing communities
in helping to sustain fisheries.
• Community management systems have often been
replaced by comanagement 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?
• It is estimated that governments around the world give
a total of about 30 to 40 billion dollars a year to help
fishers keep their businesses running. Such money can
help fishers by ships, fuel, and fishing equipment as
well as for research and management of fisheries. Yet
these subsidies encourage over fishing and the
expansion of the fishing industry. This allows for
methods to be used that cause overfishing such as
trolling nets.
Chapter 11 Question 4
Describe the advantages and disadvantages of using
individual transfer rights to manage fisheries.
• Advantages
– Can reduce overfishing due to government control
• Disadvantages
– Difficult to enforce
– Can squeeze out small businesses, encouraging
illegal fishing
– Limit on quota is hard to establish
Describe how consumers can help sustain fisheries, aquatic
biodiversity, and ecosystem services by making careful choices in
purchasing seafood.
• By purchasing sustainable seafood consumers
will encourage responsible fishing practices. By
only purchasing foods labeled with sustainable
harvesting, fisheries will be encouraged to
practice environmentally friendly tactics,
aquatic biodiversity will be protected, and the
ecosystem will be sustained.
Give two examples of threats to aquatic systems from invasive
species.
• Asian Carp- Reproduce quickly and have no natural
predators in bodies of water in North America. Asian
carp chase out native species by using up resources,
and grow much larger than most native fish. They
have spread to many different waters, have
unbounded growth in population and are very difficult
to get rid of once they are in an area.
• Zebra/Quagga Mussels- Invasive mussel species that
affect bodies of water in Northern United States. The
mussels breed quickly and travel via ballast water
between the lakes. Zebra mussels are the cause of
various diseases and envelop many structures in and
around water.
Describe the ecological experiment involving carp removal Lake
Wingra.
• A small portion of Lake Wingra was
sectioned off and treated to remove
carp. The area showed great
improvement in plant species
repopulation and also in water clarity.
Carp are now about half of the
biomass of fish population in the lake.
Chapter 11 Question 5
• What percentage of the US coastal wetlands
has been destroyed since 1900?
• The US has lost more than 50% of its coastal
and inland wetlands since 1900
• What are the three major ecological services
provided by wetlands?
• Filters toxic waste and pollutants
• Helps replenish stream flows during droughts
• Helping to maintain biodiversity by providing
habitats for a variety of species
• How does the US attempt to reduce wetland
losses?
• The US attempts to reduce wetlands losses by
using zoning laws to steer development away
from wetlands
• The US also uses mitigation banking which
allows existing wetlands to be destroyed as
long as an equal area of the same type of
wetland is created
• Describe efforts to restore the Florida Everglades.
• The worlds largest ecological restoration project (Comprehensive
Everglades Restoration Plan “CERP”)
– Restore the curing flow of more than half of the Kissimmee River
– Remove 250 miles of canals and levees blocking water flow south of lake
Okeechobee
– Buy 240 sp miles of farmland and allow it to be flooded to create artificial marches
that will filter agricultural runoff before it reaches Everglades National Park
– Create 18 large reservoirs and underground water storage areas to ensure an
adequate water supply for the south Florida’s current and projected population
and for the lower everglades
– Build new canals, reservoirs and huge pumping systems to capture 80% of the
water currently flowing out to sea and return it to the Everglades
Chapter 11 Question 6
Describe the major threats to the
world’s rivers and other freshwater
systems.
• Human activities on adjacent lands.
– Ex. Damming, overfishing, and increase in human
population.
• Climate Change
What major ecological services do
rivers provide?
• Deliver nutrients to sea to help sustain coastal
fisheries.
• Deposit silt that maintains deltas.
• Purify water.
• Renew and renourish wetlands.
• Provide habitats for wildlife.
Describe the invasions of nonnative
species into the Great Lakes.
• 162 nonnative species have invaded the Great
Lakes (continues to increase)
– Ex. Sea Lamprey, zebra mussel, quagga mussel,
Asian carp.
Chapter 11 Question 7
• How does climate change threaten aquatic
biodiversity?
• Climate Change causes sea levels to raise
destroying coral reefs, swamps, and mangrove
forests.
• Relate the ecological problems of Lake Victoria
to the four scientific principles of
sustainability.
• A predator, the Nile Perch, was introduced for
population control but it at many of the native
species causing less biodiversity.
• What are six priorities for protecting terrestrial
and aquatic biodiversity?
• Take inventory of what the earth has now.
• Stop logging in old-growth forests.
• Preserve the world’s terrestrial and aquatic
biodiversity hotspots.
• Protect and restore lakes and rivers.
• Conduct restoration projects to restore damage
done by humans.
• Make it financially reasonable for people to take
part in conservation initiatives.