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.