CH-11-12 Sustaining Aquatic Biodiversity – Living in the Environment: Principles, Connections, and Solutions : Book Guide

This Document Contains Chapters 11 to 12 Chapter 11 Sustaining Aquatic Biodiversity Summary 1. Aquatic biodiversity refers to the composition of plants and animals in the fresh and salt waters of the planet. The economic importance of aquatic diversity lies in the conservative estimate of the value of their ecological services, which is $21 trillion a year. Additionally, at least 3.5 billion people depend on the seas for their primary source of food and this number could double to 7 billion in 2025. Many medicines have been developed from sea organisms: sponges, anemones, puffer fish, porcupine fish, seaweeds, etc. The waters are used for extensive recreational activities, not to mention commercial transportation. 2. Human activities are undermining aquatic biodiversity by destroying and degrading coastal wetlands, coral reefs, seagrass beds, kelp beds, mangroves, and the ocean bottom. 3. We can protect and sustain marine biodiversity by using laws, international treaties, and education. We must identify and protect species that are endangered and/or threatened. This entails cleaning up aquatic environments, as well as inventing fishing methods that do not destroy animals and birds inadvertently caught in fishing nets. Poaching and illegal harvesting of marine creatures must also be eliminated. Public aquariums can also educate the public about protecting marine animals and birds. Marine sanctuaries and coastal management can protect aquatic environments as well as their creatures. 4. The world’s marine fisheries can be managed by setting catch limits below the maximum sustained yield limits, by reducing/eliminating fishing subsidies, and by charging fees for fishing in publicly owned offshore waters. Some areas can be protected from any kind of fishing; there should be more marine protected areas and more integration of coastal management practices. Develop net-escape devices for fishing boats. Restriction of coastal locations for fish farms, control of pollution, and decreasing the pollution of ship ballast water into the sea will all protect marine fisheries. Multispecies management of large marine systems offers hope for conserving marine resources and for renewing those resources. 5. Wetlands can be protected, sustained, and restored by government regulations that prevent wetland loss. Destroyed wetlands can also be restored and adequately monitored for their protection. Development can be kept away from wetland areas and control of nonnative species needs to be instituted to prevent invasion into wetlands. 6. Freshwater fisheries, lakes, and rivers can be protected, sustained, and even restored by building and protecting populations of desirable species, by prevention of overfishing, and by decreasing populations of less desirable species. Laws can be enacted, and enforcers of these laws must be funded to protect scenic rivers; they should be protected from development and dam construction projects. Key Questions and Concepts 11-1 What are the major threats to aquatic biodiversity? CORE CASE STUDY: An estimated 1.5 million whales were killed between 1925 and 1975 and this overharvesting led to the commercial extinction of 8 of the 11 major species. In 1946, the International Whaling Commission was established to regulate the whaling industry with quotas. In 1970, the United States stopped all commercial whaling and banned imports of whale products. In 1986, the IWC imposed a moratorium on whaling. Nevertheless, Japan and Norway have ignored the moratorium and Iceland stopped observing it in 2006. These three nations now pressure the IWC to revise the moratorium. We know very little about the earth’s aquatic biodiversity because there has been so little exploration of the water on this “water planet.” A. Three patterns of marine biodiversity are: 1. The greatest marine biodiversity occurs in coral reefs, estuaries, and on the deep-sea ocean floor. 2. Biodiversity is higher near the coasts because of great variety of producers, habitats, and nursery areas. 3. Biodiversity is higher in the bottom region than in the surface region of the ocean. B. The greatest threat to the biodiversity of oceans is loss and degradation of habitats. 1. Coral reefs, mangrove forests, and coastal wetlands are under great pressure from human activities. 2. Trawling and dredging are major threats to sea bottom habitats. 3. Dams and excessive water withdrawal are destroying freshwater habitats. C. Harmful invasive species increasingly threaten marine biodiversity. 1. Blamed for 2/3 of fish extinctions in the United States, and may cost the nation about $16 million/hour. SCIENCE FOCUS: One obstacle to protecting ocean biodiversity is lack of information. Researchers hope to gather more data by deploying a series of small robotic devices that can take measurements and send the information back to the lab. CASE STUDY: Lake Victoria was once known for its endemic cichlid fish diversity. Since 1980, 200 species of cichlids have gone extinct. One cause was the introduction of Nile perch. Another factor is algal blooms caused by nutrient rich runoff and sewage. SCIENCE FOCUS: Lake Wingra in Wisconsin receives excessive nutrients from runoff and is populated by invasive species, including carp and purple loosestrife. The carp devour the algae that would normally stabilize sediments on the lake bottom. Scientific experiments that involved excluding carp from a study area showed that algae recolonized and the lake water became noticeably clearer. There is now an effort to remove the carp from the rest of the lake to alleviate the effects of this invasive species. D. By 2020, 80% of the world’s population will live near coasts. Population growth and pollution have drastic effects on ocean systems. 1. Pollutants such as nitrogen from fertilizers can cause algal blooms and eutrophication. 2. Toxic pollutants can kill some aquatic life forms. 3. Plastic garbage in the oceans is having detrimental effects on wildlife. E. Climate change threatens aquatic biodiversity and ecosystems services. F. Overfishing can have drastic effects on biodiversity. 1. Global fishing is taking 57% more than sustainable yield. 2. Overfishing can lead to commercial extinction, which occurs when it is no longer profitable to continue fishing the affected species. 3. When populations of predatory species dwindle, invasives can take over. CASE STUDY: Industrial fishing dominates the global fishing industry. Trawler fishing extracts fish and shellfish from the ocean floor. Purse-seine fishing is used to catch surface dwelling species. Longlining strings out thousands of baited hooks as much as 80 miles long. Finally, drift netting involves massive nets that can lead to overfishing. In 1992, the UN limited the size of driftnets that could be used in international waters, but compliance is voluntary. SCIENCE FOCUS: Clashing scientific views on the state of global seafood stocks led two scientists to devise new methods for relating the catch of a given species to its estimated population. They formulated new targets based on population data and overall ecosystem health. They agreed that efforts to change correct fishing methods can be successful, and that at least 63% of global fish stocks are being overexploited. A. Many fish species are threatened with extinction. 1. 27% of marine species and 71% of freshwater species may face extinction within the next 60-70 years. 11-2 How can we protect and sustain marine biodiversity? A. Protecting marine biodiversity is challenging because it is difficult to monitor the impact of the human ecological footprint, oceans are unseen by most people, oceans are often thought to be inexhaustible resources, and most of the ocean area lies outside of the jurisdiction of any nation. 1. National and international laws and treaties include CITES, the 1979 Global Treaty on Migratory Species, the US Marine Mammal Protection Act, the Endangered Species Act, the US Whale Conservation and Protection Act, and the International Convention on Biological Diversity. CASE STUDY: The International Whaling Commission’s moratorium on whaling has been successful in helping some species to recover. As a result some nations are calling for the moratorium to be lifted. Still, many think it should remain in place to ensure a more complete recovery of whale populations. B. Biodiversity can be valuable to local communities that develop eco-tourism markets. CASE STUDY: Six of the seven species of marine turtles are endangered. Leatherback turtles are being heavily impacted by human activities. Fishing practices, pollution, and climate change all threaten their survival. However, there has been progress. Some local communities are reducing their impacts on beaches where turtles lay their eggs, Turtle Excluder Devices are now required on trawlers by the U.S. government, and some communities are focusing on the economic advantages of protecting these species C. A country’s offshore fishing zone extends 370 kilometers from its shores. 1. Ocean areas beyond these Exclusive Economic Zones, called the high seas, are difficult to monitor. 2. The World Conservation Union helped establish a global system of marine protected areas (MPAs). 3. There are about 4,000 MPAs; however, most MPAs allow ecologically harmful activities like trawling, dredging, and resource extraction. D. Scientists are advocating an ecosystems approach to sustaining marine biodiversity. 1. This would entail a network of protect marine reserves, closed to extractive activities. 2. Studies show that fish are larger, reproduce more often, and are present in greater variety. 3. Less than 1% of the world’s ocean area is closed to fishing in marine reserves. E. Reconciliation ecology can be directed at bringing back reefs, mangrove forests, coastal marshes and sea grass beds. F. Integrated coastal management is a community-based effort to develop and use coastal resources more sustainably. 1. The idea is to find cost-effective, adaptable solutions to preserve biodiversity while meeting economic and social needs. 11-3 How should we manage and sustain marine fisheries? A. One way to prevent overfishing is to develop better ways to protect fish populations. The maximum sustained yield mathematical model is used, but indications are that it has hastened the collapse of most commercially valuable stocks for several reasons. B. Optimum sustained yield is a concept that takes into account interactions with other species and allows more room for error. Another approach is multi-species management of a number of interaction species, which accounts for competition and predator-prey interactions. 1. There has been limited management of several large marine systems, such as the Mediterranean Sea. 2. Many fisheries scientists and environmentalists are interested in using the precautionary principle for management of fisheries and marine systems. C. Some fishing communities regulate fish harvests on their own and others work with the government to regulate them. Influx of large modern fishing boats and fleets has weakened the ability to regulate and sustain local fisheries. Many community management systems are now co-managed, where community and government work together to manage fisheries. 1. Central government sets quotas for various species and divides the quotas among communities. 2. Government may also limit fishing seasons and regulate gear to be used. 3. Each community then allocates its quota among members. D. Government subsidies that are intended to keep businesses afloat can encourage overfishing. E. Individual transfer rights (ITRs) are assigned to each fisherman, and these can then be bought, sold, or leased like private property. F. Individuals can help sustain aquatic diversity by demanding sustainably harvested seafood. 1. Labeling seafood would inform consumers. 11-4 How should we protect and sustain wetlands? A. Coastal and inland wetlands are important reservoirs of aquatic biodiversity; they provide ecological and economic services. 1. Despite their value, the U.S. has lost more than half of its coastal and inland wetlands since 1900. 2. Wetland loss in the U.S. will get worse as global warming leads to rising sea levels, which will put many coastal wetlands under water. B. In the U.S., a federal permit is required to fill or deposit dredge material into many wetlands. 1. The U.S. federal policy is a zero net loss goal; mitigation banking allows destruction of some wetlands as long as the same type of wetland is created elsewhere. CASE STUDY: An ambitious restoration project is trying to undo the human damage in South Florida’s Everglades. The natural Everglades is half its original size and is drying out, leaving it vulnerable to fire and invasion by nonnative species. Everglades National Park was set up in the lower part of the Everglades, but water didn’t flow into it and human activity caused disturbances. Ninety percent of the wading birds are gone and other vertebrates are reduced in number by 75–95%. Florida Bay has become saltier and warmer due to lack of water flow from the Everglades and the Kissimmee River. Loss of water flow and input from crop fields and cities has caused large algal blooms on the bay. These blooms threaten coral reefs and hinder diving, fishing, and the tourist industry of the bay and the Florida Keys. The U.S. Army Corp of Engineers has begun a restoration project funded by the state and the federal government to restore the meandering river and flow of water to the Everglades. It has several ambitious goals, which include restoring curving flow of more than half of the Kissimmee River, removing 250 miles of canals and levees south of Lake Okeechobee, buying 93 square miles of farmland and allowing it to flood to create artificial marshes, creating a network of artificial marshes, creating 18 large reservoirs to ensure water for south Florida’s present and future population and the lower Everglades, and building new canals, reservoirs, and pumping stations to capture and return to the Everglades 80% of the water flowing out to sea. 11-5 How can we protect and sustain freshwater lakes, rivers, and fisheries? A. There are many threats to freshwater ecosystems, including habitat destruction, invasive species, climate change and overharvesting fish. CASE STUDY: Invasions by nonnative species have upset the ecological functioning of the Great Lakes for decades, with more invaders coming. At least 162 nonnative species have invaded the Great Lakes since the 1920s. Measures have been taken to control a number of these species. Sea lampreys are one of the biggest threats and have depleted a number of the sport fish species in the lakes. Zebra mussels were brought into the lakes in ballast and have become very aggressive pests since they have no known natural enemies. They have displaced native mussel species, clogged pipes and piers, fouled beaches, and have spread to other parts of the U.S. Quagga mussels invaded the Great Lakes in 1991 and Asian Carp are now found within a few miles of Lake Michigan.. B. Rivers/streams are important ecological and economic resources, but they can be degraded by overfishing, pollution, dams, and water withdrawal. C. The Columbia River has been altered by 119 dams and withdrawal of water for agriculture. D. To protect rivers and lakes from excess pollutants, watersheds need to be protected. E. The National Wild and Scenic Rivers Act was passed in 1968 to protect rivers and river segments with outstanding scenic, recreational, geological, wildlife, historical, or cultural values. F. Congress established a three-tiered classification scheme: 1. Wild rivers are relatively inaccessible; they are not permitted to be widened, straightened, dredges, filled or dammed. 2. Scenic rivers are free from dams, mostly undeveloped, of great scenic value, and accessible in some places by roads. 3. Recreational rivers are readily accessible by roads and may have some dams or development along their shores. 4. In 2009, Congress increased the total length of wild and scenic rivers by half. Still, less than 1% of the country’s total river length is protected. G. Sustainable management of freshwater fish involves encouraging populations of commercial/sport fish species, prevents overfishing, and reduces or eliminated less desirable fish populations. 11-6 What should be our priorities for sustaining aquatic biodiversity? A. There is evidence that the harmful effects of human activities on biodiversity can be reversed over the next two decades. 1. This must entail an ecosystem approach to protecting biodiversity. 2. Priorities should be mapping aquatic biodiversity, identifying and preserving hotspots, creating fully protected marine reserves, protecting and restoring lakes and rivers, initiating ecological restoration projects worldwide, and finding ways to raise the incomes of people who live near protected waters. Teaching Tips Large Lecture Courses: In what ways do our ordinary activities impact the aquatic environment? Explore this question with your students, using a diagram of the hydrologic cycle for reference. Focus on households, the campus, and the immediate environment. What activities lead to pollution or other alterations in these systems? What is the outcome of such changes? Once you have exhausted the many effects of our mundane activities, begin to synthesize a list on the board of ways that we could diminish our impact. Smaller Lecture Courses: Assign your students to locate information on the web (the EPA is a good source) regarding water quality in local streams, lakes, bays, etc. Each small group can take a particular body of water. Then, as a class, compare the findings. Which waterways are cleanest? Which contain coliform bacteria? Now, looking at these waterways on a map from Google Earth, stimulate the students to suggest reasons why the waters are either polluted or clean. Are the local waters clean and well-managed? Key Terms fishery fish print Term Paper Research Topics 1. Food resources obtained from aquatic ecosystems 2. Resources (other than food) obtained from aquatic ecosystems 3. Damage caused by human activities in aquatic environments 4. Problems and solutions associated with overfishing 5. Strategies to protect marine environments 6. Ecological services of wetlands and wetland restoration projects 7. Wetlands protection 8. Prevention of beach erosion 9. Coastal cleanup strategies 10. Endangered species of the coast 11. What can be done to prevent coral bleaching? Discussion Topics 1. What is the best way to manage coastal development to both provide protection and economic use of the resource? Answer: The best way to manage coastal development involves a combination of regulatory frameworks and sustainable practices. Implementing coastal zone management plans that integrate land-use regulations, environmental protection, and community involvement helps balance economic growth with ecological preservation. Additionally, investing in natural buffers like mangroves and wetlands can reduce the impact of development on coastal ecosystems. 2. What is the value of wetland areas? Answer: Wetland areas are invaluable for their ecological and economic benefits. They act as natural water filters, reducing pollution and controlling flooding. Wetlands also provide crucial habitat for diverse wildlife, support fisheries, and offer recreational opportunities. Their ability to sequester carbon makes them important in climate regulation and helps mitigate the effects of climate change. 3. Is development of beachfront property for human recreation worth the potential danger from hazards associated with the coastal environment? Answer: Development of beachfront property involves balancing economic benefits with potential hazards such as erosion, flooding, and storm surge. While beachfront development can boost local economies and provide recreational opportunities, the associated risks often necessitate costly mitigation measures and insurance. Weighing these factors requires careful planning and risk management to ensure long-term sustainability and safety. 4. Are developed countries exploiting the marine resources of developing countries? Answer: Developed countries often exploit the marine resources of developing countries through overfishing, illegal fishing practices, and environmental degradation. This exploitation undermines the sustainability of marine ecosystems and threatens the livelihoods of local communities that rely on these resources. Efforts to address this issue include strengthening international regulations, promoting fair trade practices, and supporting sustainable fisheries management in developing countries. 5. Should the United States take a global leadership role in protecting marine ecosystems? Why or why not? Answer: Yes, the United States should take a global leadership role in protecting marine ecosystems due to its significant impact on global marine health and its capacity to influence international policies. Leading efforts to safeguard marine environments aligns with environmental stewardship and can drive collaborative solutions to global challenges like overfishing and pollution. Leadership can also enhance the U.S.'s reputation and strengthen international partnerships in marine conservation. Activities and Projects 1. As a class field trip, visit a coastal area, managed lake, or wetland area. Invite a biologist/ecologist to explain the processes taking place in the system. What specific methods are used to curb ecosystem damage in managed systems? 2. Invite a representative of an agency involved with aquatic system management to speak to the class about issues regarding the agency’s impacts on the resource, the public’s benefit from the agency’s management, and what the agency is doing to minimize the ecological impacts of their activities. 3. Consider the ecological problems that confront(ed) Lake Victoria in East Africa and the Great Lakes in the United States. How are the factors that harm(ed) ecological diversity similar and how are they different? What lessons can the United States learn from the devastation in Lake Victoria? 4. Are inland wetlands being drained and filled in your locale? Is there a nearby stream or river being subjected to excessive levels of pollution? Is it feasible for you and your class to "adopt" one of these disturbed ecosystems and help restore it to health? 5. Arrange a debate on the problems and alternatives of coastal zone management. Debate the proposition that we should severely restrict engineering approaches to beach stabilization and adopt a "retreat from the beach" strategy, emphasizing the preservation of coastal ecosystems and the ecosystem services they provide. Attitudes and Values 1. Have you ever visited developed seashore? How did you feel about the patterns of development? Do you think this type of development should be allowed to continue? Answer: Yes, I have visited developed seashores and observed that while development can boost local economies, it often leads to environmental degradation and loss of natural habitats. The patterns of development, such as extensive construction and beach alteration, can compromise coastal ecosystems and increase vulnerability to natural hazards. Sustainable development practices should be adopted to balance economic benefits with ecological preservation. 2. What benefits do you receive from aquatic ecosystems where you live? Answer: Aquatic ecosystems provide numerous benefits, including clean water, recreational opportunities, and support for local biodiversity. They also play a crucial role in regulating climate by sequestering carbon. Additionally, aquatic ecosystems often support commercial and subsistence fisheries that are vital for food security and local economies. 3. Where are the nearest locations in your area to go to observe aquatic ecosystems? What kinds of aquatic ecosystems occur where you live? Answer: The nearest locations to observe aquatic ecosystems include local wetlands, rivers, and coastal areas. The types of aquatic ecosystems in my area may include freshwater lakes and streams, estuaries, and tidal marshes. Each of these ecosystems supports diverse plant and animal species and provides valuable ecological functions. 4. What are your feelings toward aquatic ecosystems? Answer: I feel that aquatic ecosystems are vital and deserving of protection. They are crucial for maintaining biodiversity, supporting human livelihoods, and sustaining ecological processes. Their health impacts not only the environment but also the well-being of communities that depend on them. 5. Do you feel that humans have the right to develop aquatic ecosystems in any way they wish? If not, what limits do you see on human behavior toward aquatic ecosystems? Answer: Humans do not have the right to develop aquatic ecosystems in any way they wish. There should be limits to ensure that development does not compromise the ecological integrity and sustainability of these systems. Regulations should focus on minimizing environmental impact, preserving biodiversity, and maintaining ecosystem services for future generations. 6. Do you use products that come from the ocean? Do the products you use result in destruction of, or the continued sustainable use of, the ocean? Answer: Yes, I use products that come from the ocean, such as seafood and certain medicinal products. Efforts should be made to ensure that these products are sourced sustainably, minimizing harm to marine environments. Supporting practices like sustainable fishing and responsible aquaculture helps promote the continued health of ocean ecosystems. 7. How do you feel when you see pictures of the beach erosion and economic loss following a hurricane? Answer: Seeing pictures of beach erosion and economic loss following a hurricane evokes concern and sadness. It highlights the vulnerability of coastal areas to natural disasters and underscores the need for effective coastal management and disaster preparedness. Addressing these issues requires a balance between development and environmental resilience to better protect affected communities. News Videos Natural Wonders: the Hawaiian Islands; Environmental Science in the Headlines, 2007; DVD; ISBN 0495385433 Whale Watch: In Search of the Blues; Environmental Science in the Headlines, 2008; DVD; ISBN 0495561908 Carbon Dioxide’s Impact on Our Oceans; The Brooks/Cole Environmental Science Video Library, 2009; DVD 0538733551 Additional Video Resources After the Storm (Documentary, free DVD or VHS) Looks at watersheds and their importance in various parts of the U.S. http://www.epa.gov/weatherchannel/video.html Blue Planet (Video Series from Discovery Channel, 2001) Mammoth series, five years in the making, taking a look at the rich tapestry of life in the world's oceans. http://dsc.discovery.com/convergence/blueplanet/blueplanet.html Conserving America: The Wetlands (PBS, 1994) A four-part series on American conservation of wetlands. The End of the Line (DVD, 2010). This documentary explores the effects of current fishing methods and the state of our oceans. The Habitable Planet: A Systems Approach to Environmental Science (Documentary series, 2007). Videos 3, 8 and 9 explore the oceans, water resources, and biodiversity. http://www.learner.org/resources/series209.html Planet Earth Series—Discovery Channel (TV Series) Series contains excellent documentaries on major aquatic biomes. http://dsc.discovery.com/convergence/planet-earth/planet-earth.html Ocean Oasis (Documentary, San Diego Natural History Museum, 2001) Biodiversity in the Sea of Cortez, and the deserts of Baja. http://www.oceanoasis.org/toc.html We all Live Downstream (Documentary, 1991) A look at pollution in the Mississippi River and the effects on human health. http://www.videoproject.com/wea-281-v.html Web Resources Ocean Conservancy Excellent information on a variety of aquatic issues. http://www.oceanconservancy.org/site/PageServer?pagename=home Suggested Answers to End of Chapter Review Questions Review Questions 1. Review the Key Questions and Concepts for this chapter on p. 251. Describe how human activities have threatened whale populations (Core Case Study). What is the International Whaling Commission and what has it done to protect whales? Answer: • Whale hunting has followed the pattern of the tragedy of the commons, driving 8 of the 11 major species to commercial extinction. The IWC initially set quotas for major species to avoid overharvesting. In 1986, they imposed a moratorium on commercial whaling. 2. How much do we know about the habitats and species that make up the earth’s aquatic biodiversity? What are three general patterns of marine biodiversity? Describe the threat to marine biodiversity from bottom trawling. How have coral reefs been threatened? What are two causes of disruption of freshwater habitats? Give two examples of threats to aquatic systems from invasive species and two of the same for freshwater systems. Why is marine biodiversity higher (a) near coasts than in the open sea and (b) on the ocean’s bottom than at its surface? Give two examples of threats to aquatic systems from invasive species. Describe the ecological experiment of carp removal in Wisconsin’s Lake Wingra. Summarize the story of how invasive species have disrupted Lake Victoria’s ecosystem. Answer: • Only about 5% of the earth’s oceans have been explored and we know relatively little about its biodiversity. • First, the greatest marine biodiversity occurs in coral reefs, estuaries, and the deep- ocean floor. Second, biodiversity is higher near coasts than in the open sea because of the greater variety of producers and habitats in coastal areas. Third, biodiversity is higher in the bottom region of the ocean than in the surface region because of the greater variety of habitats and food sources on the ocean bottom. • Bottom trawling causes loss and degradation of many sea-bottom habitats. Trawlers drag huge nets weighted down with heavy chains and steel plates like giant submerged bulldozers over ocean bottoms to harvest a few species of bottom fish and shellfish. Trawling nets reduce coral reef habitats to rubble and kill a variety of creatures on the bottom by crushing them, burying them in sediment, and exposing them to predators. Each year, thousands of trawlers scrape and disturb an area of ocean floor about 150 times larger than the area of forests that are clear- cut annually. • Coral reefs are threatened by development, pollution, and ocean acidification resulting from greatly increased levels of carbon dioxide emissions. • Habitat disruption is a major problem in freshwater systems. The main causes of disruption are dam building and excessive water withdrawal. Many of the world’s freshwater wetlands have been destroyed. Invasive species, pollution, and climate change threaten many freshwater ecosystems and freshwater fish stocks are overharvested. • Two examples of invasive species are the Asian swamp eel and purple loose strife. The Asian swamp eel has invaded the water-ways of south Florida (USA). This rapidly reproducing eel eats almost anything. It can elude cold weather, drought, and predators by burrowing into mud banks. It is resistant to waterborne poisons because it can breathe air, and it can wriggle across dry land to invade new waterways. Eventually, this eel could take over much of the waterways of the southeastern United States. The purple loose strife is a perennial plant that grows in wetlands in parts of Europe. Since the 1880s, it has been imported and used in gardens as an ornamental plant in many parts of the world. A single plant can produce more than 2.5 million seeds a year, which are spread by flowing water and by becoming attached to wildlife, livestock, hikers, and vehicle tire treads. It reduces wetland biodiversity by displacing native vegetation and reducing habitat for some forms of wetland wildlife. An example from marine environments is an invasive brown seaweed called Undaria, or wakame, which is spreading along the California coast. It grows rapidly and forms thick forests, choking out native kelps that provide habitat for sea otters. Another marine example is the lionfish, which competes with popular reef fish species like grouper and snapper, taking their food and eating their young. • Carp were introduced to Lake Wingra and they devour the algae, which would normally cover the lake bottom and stabilize its sediments. As a consequence, fish movements and winds stir these sediments, which causes much of the water’s excessive turbidity, or cloudiness. Scientists removed carp from an enclosure within the lake and within a short time, the waters within the barrier were noticeably clearer, and within a year, the difference in clarity was dramatic. • Until the early 1980s, Lake Victoria had 500 species of endemic fish. About 80% of them were known as cichlids. Some 200 cichlid species have become extinct, and some of those that remain are in trouble. Several factors caused this dramatic loss of aquatic biodiversity. First, there was a large increase in the population of the Nile perch, a large predatory fish that was deliberately introduced into the lake, despite warnings by biologists that this huge fish would reduce or eliminate many native fish species. By 1986 the Nile perch had wiped out over 200 cichlid species. Frequent algal blooms also caused a loss of biodiversity. These blooms became more common in the 1980s, due to nutrient runoff from surrounding farms and deforested land, spills of untreated sewage, and declines in the populations of algae- eating cichlids. 3. What are two harmful effects on aquatic systems resulting from the increase in the human population in coastal areas? Give two examples of how pollution is affecting aquatic systems. What are three ways in which projected climate change could threaten aquatic biodiversity? Define fishery. What are three major harmful effects of overfishing? Describe the collapse of the Atlantic cod fishery and the resulting effects on the fishery’s ecosystem. What is a fish print? Describe the factors leading to the near extinction of the blue whale. Describe the effects of trawler fishing, purse- seine fishing, longlining, and drift- net fishing. What is bycatch? Answer: • Two harmful effects resulting from human populations are habitat destruction and increased pollution. • Nitrate fertilizers can cause algal blooms and disrupt ecosystem services, and the influx of toxic pollutants can poison aquatic life. • Climate change is expected to cause substantial sea level rise, which will result in declining coral reefs, the disappearance of low-lying islands, and the swamping of productive coastal wetlands. • A fishery is a concentration of a particular wild aquatic species suitable for commercial harvesting. • Three major effects of overfishing are that large individuals become scarce, as large species become overfished the fishing industry shifts its focus to smaller species, and as larger predatory species dwindle invasive species can take over. • In 1992, Canada’s 500- year- old Atlantic cod fishery off the coast of Newfoundland collapsed and was closed. This put at least 20,000 fishers and fish processors out of work and severely damaged Newfoundland’s economy. After the cod were fished out, fishers began harvesting sharks, which provide important ecosystem services and help to control the populations of other species. Since then, overfishing of big sharks has cut Atlantic stocks of those species by 99%. With the large sharks essentially gone from the northwest Atlantic, populations of rays and skates, which the sharks once fed on, have exploded and have wiped out most of the region’s bay scallops, which in turn had served as a food source for other species, including humans. As large species are overfished, the fishing industry has begun working its way down marine food webs by shifting to smaller species. This reduces the breeding stock needed for recovery of depleted species, which unravels marine food webs and disrupts marine ecosystems and their ecosystem services. • The fish print is defined as the area of ocean needed to sustain the consumption of an average person, a nation, or the world. • Blue whales have been hunted for their oil, meat and bone. As a result, their population has declined from 250,000 in 1900 to less than 5,000 today. • The harmful ecological effects of: ○ Trawler fishing—major threat is loss and degradation of many sea-bottom habitats because trawlers drag huge nets weighted down with heavy chains and steel plates over ocean bottoms to harvest a few species of bottom fish and shellfish. ○ Purse-seine fishing—uses nets to capture fish, but also have killed large numbers of dolphins that swim on the surface above schools of tuna. ○ Longlining—hooks and kills large numbers of endangered sea turtles, dolphins, and seabirds each year. ○ Driftnet fishing—can lead to overfishing of the desired species and may trap and kill large quantities of unwanted fish, marine mammals, sea turtles, and seabirds. • Bycatch is the unwanted fish that are harvested in fishing operations. 4. How have laws and treaties been used to help sustain aquatic species? What is the main problem that interferes with enforcing international agreements? Describe international efforts to protect whales from overhunting and premature extinction. How can economic incentives help sustain aquatic diversity? Give two examples of where this has happened. Describe threats to the leatherback turtle and efforts by some people to protect the species. Answer: • The U.S. Endangered Species Act and international agreements have been used to identify and protect endangered and threatened marine species such as seals, sea lions, sea turtles, and whales. National and international laws and treaties to help protect marine species include the 1975 Convention on International Trade in Endangered Species, the 1979 Global Treaty on Migratory Species, the U. S. Marine Mammal Protection Act of 1972, the U. S. Endangered Species Act of 1973, the U. S. Whale Conservation and Protection Act of 1976, and the 1995 International Convention on Biological Diversity. • It is difficult to get all nations to comply with international agreements, which can weaken their effectiveness. • In 1946, the International Convention for the Regulation of Whaling established the International Whaling Commission. Its mission was to regulate the whaling industry by setting annual quotas to prevent overharvesting and commercial extinction. But IWC quotas often were based on inadequate data or were ignored by whaling countries. Without powers of enforcement, the IWC was not able to stop the decline of most commercially hunted whale species. In 1970, the United States stopped all commercial whaling and banned all imports of whale products. The IWC imposed a moratorium on commercial whaling starting in 1986. It worked. The estimated number of whales killed commercially worldwide dropped from 42,480 in 1970 to about 1,400 in 2009. However, despite the ban, more than 33,000 whales s were hunted and killed between 1986 and 2010. • Conserving biodiversity can prove to be more valuable to communities than the harvesting and selling of these resources by providing a foundation for ecotourism. This has occurred in Florida and Costa Rica with the sea turtle populations. • Sea turtles are hunted for meat and leather, and their eggs are taken for food. They often drown after becoming entangled in fishing nets and lines. Shrimp trawling fisheries kill large numbers sea turtles. Pollution is another threat; sea turtles can mistake discarded plastic bags for jellyfish and choke to death on them. Beachgoers sometimes trample their nests. Artificial lights can disorient hatchlings as they try to find their way to the ocean; going in the wrong direction increases their chances of ending up as food for predators. Global warming will raise sea levels, which will flood nesting and feeding habitats, and change ocean currents, which could disrupt the turtles’ migration routes. Many people are working to protect the leatherback turtles. On some Florida beaches, lights are turned off or blacked out during hatching season. Nesting areas are roped off. Since 1991, the U. S. government has required offshore shrimp trawlers to use turtle excluder devices (TEDs), which help to keep sea turtles out of their nets and to allow caught turtles to escape. TEDs have been adopted in 15 countries that export shrimp to the United States. In Costa Rica’s Playa Junquillal, volunteers have gone out to find and rescue leatherback turtle nests before they could be poached, and they have built hatcheries to protect the eggs. 5. Describe the use of marine protected areas and marine reserves to help sustain aquatic biodiversity and ecosystem services. What percentage of the world’s oceans is fully protected from harmful human activities in marine reserves? Describe the roles of fishing communities and individual consumers in regulating fishing and coastal development. Give two examples of the restoration of marine systems. Describe threats from increasing ocean acidity. What is integrated coastal management? Answer: • Protecting marine biodiversity in marine protected areas and marine reserves helps maintain biodiversity and provides ecosystem services because the natural processes still occur without as much human degradation of the resource. • Despite their importance, less than 1% of the world’s oceans are closed to fishing and other harmful human activities in marine reserves, and only 0.1% are fully protected—compared to 5% of the world’s land. Thus, humans have reserved essentially 99.9% of the world’s oceans to use as they see fit. Many marine scientists argue that in order to sustain marine biodiversity, we must protect at least 30% of the world’s oceans as marine reserves. • Coastal communities can establish integrated coastal management in which fishers, scientists, conservationists, citizens, business interests, developers, and politicians collaborate to develop and use coastal areas and resources more sustainably. • Coastal communities must closely monitor and regulate fishing and coastal land development and prevent pollution from land- based activities. Coastal residents must also think carefully about the chemicals they put on their lawns, and the kinds of waste they generate and where it ends up. And individuals can reduce their carbon footprints to slow climate change and its numerous harmful effects on marine and other ecosystems. • Two examples of the restoration of marine systems include the Japan’s attempt to restore its largest coral reef by seeding it with new corals, and the attempt in Israel to heal coral fragments at an ecotourism restaurant and rebuild the surrounding reef. • Rising acidity can kill off coral reefs, make the seawater less able to absorb sounds generated by humans (thus affecting whales), and dissolve the calcium carbonate of which the structures of corals and shellfish are comprised. • One strategy emerging in some coastal communities is integrated coastal management— a community- based effort to develop and use coastal resources more sustainably. The goal is for fishers, business owners, developers, scientists, citizens, and politicians to identify shared problems and goals in their use of marine resources. The idea is to develop solutions that help to preserve biodiversity and environmental quality while also meeting various economic and social goals. This requires all participants to seek reasonable short- term trade- offs that can lead to long- term ecological and economic benefits. For example, fishers might have to give up fishing in certain areas until stocks recover enough to restore biodiversity in those areas, which might then provide fishers with a more sustain-able future for their businesses. 6. 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? Describe the efforts of local fishing communities in helping to sustain fisheries. How can government subsidies encourage overfishing? Answer: • The traditional approach to estimating the size of a fish populations has used a maximum sustained yield model to project the maximum number of fish that can be harvested annually from a fish stock without causing a population drop. However, the MSY concept has not worked very well because of the difficulty in estimating the populations and growth rates of fish stocks. Also, harvesting a particular species at its estimated maximum sustainable level can affect the populations of other target and nontarget fish species and other marine organisms. In recent years, the optimum sustained yield concept has been used. It attempts to take into account interactions among species and to provide more room for error. Similarly, another approach is multispecies management of a number of interacting species, which takes into account their competitive and predator–prey interactions. An even more ambitious approach is to develop complex computer models for managing multispecies fisheries in large marine systems. However, it is a political challenge to get groups of nations to cooperate in planning and managing such large systems. There are uncertainties built into any of these approaches because there is much to learn about the biology of fishes and because of changing ocean conditions. • Using the precautionary principle for managing fisheries and large marine systems means sharply reducing fish harvests and closing some overfished areas until they recover and until we have more information about what levels of fishing can be sustained. • Traditionally, many coastal fishing communities have developed allotment and enforcement systems that have sustained their fisheries, jobs, and communities for hundreds and sometimes thousands of years. • Governments around the world give a total of about $ 30– 34 billion per year to fishers to help them keep their businesses running. Some marine scientists argue that, each year, $ 10– 14 billion of these subsidies are spent to encourage overfishing and expansion of the fishing industry. 7. Describe how consumers can help to sustain fisheries and aquatic biodiversity and ecosystem services. List five ways to manage global fisheries more sustainably. Answer: • Bottom- up pressure from consumers demanding sustainable seafood will encourage more responsible fishing practices and thus help sustain aquatic biodiversity and ecosystem services. Consumers can choose seafood that has the Fish Forever” eco- label that certifies that the seafood was caught using environmentally sound and socially responsible practices. • Ways to manage global fisheries more sustainably include setting low catch limits, improving monitoring and enforcement, certifying sustainable fisheries, establishing no-fishing areas, and using nets that allow smaller fish to escape. 8. What percentage of the U. S. coastal and inland wetlands has been destroyed since 1900? What are major ecological services provided by wetlands? How does the United States attempt to reduce wetland losses? Describe efforts to restore the Florida Everglades. Answer: • The United States has lost more than half of its coastal and inland wetlands since 1900. • Ecological services provided by wetlands include: ○ Filtering and degrading toxic wastes and pollutants. ○ Reducing flooding and erosion by absorbing storm water and releasing it slowly and by absorbing overflows from streams and lakes. ○ Helping to replenish stream flows during dry periods. ○ Helping to recharge groundwater aquifers. ○ Helping to maintain biodiversity by providing habitats for a variety of species. • Zoning laws can be used to steer development away from wetlands. A U. S. law requires a federal permit to fill in or to deposit dredged material into wetlands occupying more than 3 acres. However, only about 6% of remaining U. S. inland wetlands are under federal protection, and state and local wetland protection is inconsistent and generally weak. The stated goal of current U. S. federal policy is zero net loss in the function and value of coastal and inland wetlands. A policy known as mitigation banking allows destruction of existing wetlands as long as an equal area of the same type of wetland is created or restored. However, a 2001 found that at least half of the attempts to create new wetlands failed to replace lost ones, and most of the created wetlands did not provide the ecological functions of natural wetlands. Private investment bankers make money by buying wetland areas and restoring or upgrading them. This creates wetland banks or credits that they can sell to developers. • The efforts to restore the Florida Everglades revolve around five goals. ○ Restore the curving flow of more than half of the Kissimmee River. ○ Remove 400 kilometers of canals and levees blocking water flow south of Lake Okeechobee. ○ Buy 240 square kilometers of farmland and allow it to be flooded to create artificial marshes that will filter out agricultural runoff. ○ Create 18 large reservoirs and underground water storage areas to ensure an adequate water supply for the lower Everglades and for south Florida’s population. ○ Build new canals, reservoirs, and pumping systems to capture 80% of the water currently flowing out to sea and return it to the Everglades. 9. Describe the major threats to the world’s rivers and other freshwater systems. What major ecological services do rivers provide? Describe invasions of the U. S. Great Lakes by nonnative species. Describe ways to help sustain rivers. What are three ways to protect freshwater habitats and fisheries? Answer: • Human activities are disrupting and degrading freshwater systems. Forty percent of the world’s rivers have been dammed or otherwise engineered and vast portions of the world’s freshwater wetlands have been destroyed. Worldwide, aquatic species have been crowded out of at least half of their habitat areas. Invasive species, pollution, and climate change threaten the ecosystems of lakes, rivers, and wetlands. Freshwater fish stocks are overharvested. Increasing human population pressures and global warming make these threats worse. • Ecological services provided by freshwater systems include: deliver nutrients to sea to help sustain coastal fisheries, deposit silt that maintains deltas, purify water, renew and renourish wetlands and provide habitats for wildlife. • The Great Lakes have been invaded by at least 162 nonnative species and the number keeps rising. Many of the alien invaders arrive on the hulls or in bilge-water discharges of oceangoing ships. • Freshwater ecosystems can be protected through laws, economic incentives, and restoration efforts. Restoring rivers will probably require taking down some dams and restoring river flows. In 1968, the U. S. Congress passed the National Wild and Scenic Rivers Act to establish protection of rivers with outstanding scenic, recreational, geological, wildlife, historical, or cultural values. • Three ways to protect freshwater habitats and fisheries include supporting populations of commercial and sport fish species, preventing such species from being overfished, and reducing or eliminating populations of harmful invasive species. 10. How can we apply the ecosystem approach to sustaining aquatic diversity? List six steps that we can take to do so. What are the three big ideas of this chapter? How can we apply the three principles of sustainability to protecting whales (Core Case Study) and other aquatic species and to sustaining aquatic biodiversity and ecosystem services? Answer: • The ecosystem approach involves: ○ Completing the mapping of the world’s aquatic biodiversity. ○ Identifying and preserving the world’s aquatic biodiversity hotspots. ○ Creating large and fully protected marine reserves. ○ Protecting and restoring the world’s lakes and river systems. ○ Initiating ecological restoration projects worldwide. ○ Finding ways to raise the incomes of people who live in or near protected lands and waters. • This chapter’s big ideas are: ○ The world’s aquatic systems provide important ecological and economic services, and scientific investigation of these poorly understood ecosystems could lead to immense ecological and economic benefits. ○ Aquatic ecosystems and fisheries are being severely degraded by human activities that lead to aquatic habitat disruption and loss of biodiversity. ○ We can sustain aquatic biodiversity by establishing protected sanctuaries, managing coastal development, reducing water pollution, and preventing overfishing. • The three principles of sustainability involve valuing and protecting biodiversity in these systems. In so doing, the cycling of nutrients through such systems would be protected, and the reliance on solar energy to sustain the trophic pyramid would be ensured. Critical Thinking The following are examples of the material that should be contained in possible student answers to the end of chapter Critical Thinking questions. They represent only a summary overview and serve to highlight the core concepts that are addressed in the text. It should be anticipated that the students will provide more in-depth and detailed responses to the questions depending on an individual instructor’s stated expectations. 1. Explain how hunting some whale species to the brink of extinction (Core Case Study) has violated at least two of the principles of sustainability. Answer: Hunting whales to the brink of extinction is obviously a compromise to biodiversity. Additionally, these activities are detrimental to the overall cycling of nutrients in the ocean environment, as these very large animals are removed, and nothing is being put back into the system. 2. Write a short essay describing how each of the six factors summarized by HIPPCO has affected whales (Core Case Study) or will affect them further. Look for and describe connections among these factors. For example, how does one factor enhance the effects of one or more other factors? Suggest ways in which each of the factors could be reduced. Answer: Habitat Loss: The oceans that provide habitat for whales have been greatly compromised by overharvesting of resources and pollution. Invasives: The oceans are known to have many invasives, which disrupt ecological services. Population: Human population puts pressure on coastal environments. Pollution: Population pressures lead to pollution that ends up downstream, ultimately collecting in our oceans. Climate change: Also, related to population and overconsumption of resources, climate change is altering the pH of oceans and leading to changes in migration timing for many species. Overfishing: This had obviously been paramount in bringing on the decline of whale species. Most of these factors point to human population growth and overconsumption of resources as root causes. Some approaches to alleviating the problem would be to lessen the amount of pollution we generate, take less resources from the oceans, limit the crowding near coastlines, and be more responsible about our waste products, many of which flow downstream and end up in the oceans. 3. What do you think are the three greatest threats to aquatic biodiversity? Why? Overall, why are aquatic species more vulnerable to premature extinction from human activities than terrestrial species are? Why is it more difficult to identify and protect endangered marine species than to protect endangered terrestrial species? Answer: I think that three of the greatest threats to aquatic biodiversity are habitat destruction, increased pollution from increasing population growth, and overharvesting. Aquatic species are more vulnerable to premature extinction due to the delicate balance of marine and freshwater ecosystems. Small changes in pH or temperature changes in the water can have a major effect on aquatic areas, for example, coral reefs and fish-spawning grounds. Also, because we cannot actually “see” what is living under the surface of the oceans, lakes, and seas, there is danger of harvesting species in numbers that exceed the maximum sustainable yield. On the land, if you cut down a forest you can see that it has gone, but you cannot look into the ocean and directly relate to the impact that overfishing is having as it is “hidden” from view. For this reason it is difficult to identify and monitor rare species in aquatic environments. Also, it is very difficult to protect species that range over parts of the ocean that are not under the jurisdiction of any nation. 4. Why is marine biodiversity higher (a) near coasts than in the open sea and (b) on the ocean’s bottom than at its surface? Answer: (a) There are a greater variety of producers and habitats near the coast. (b) The bottom region has a greater variety of habitats and food sources. 5. Why do you think no-fishing marine reserves recover their biodiversity faster and more surely than do areas where fishing is allowed but restricted? Answer: The most obvious reason is that populations will grow faster when they are not being harvested from outside of the system. There will always be predation, but harvesting adds another obstacle to the growth of the population. Additionally, when fishing is allowed but restricted, it can be very difficult to monitor the catch to make sure that it is in compliance with regulations. 6. How might continue overfishing of marine species affect your lifestyle? How could it affect the lives of any children or grandchildren you might have? What are three things you could do to help prevent overfishing? Answer: Continued overfishing will have the effect of diminishing the biodiversity in our oceans and severely disrupting ecosystem function as food webs are disturbed. Ultimately, invasive species will spread widely as these populations dwindle. This means that seafood lovers, and those who like to observe nature through whale watching or SCUBA diving will inevitably have to sacrifice something they enjoy. To prevent overfishing, it is important to be a responsible consumer, to advocate for marine sanctuaries, and to help spread the word. Most people do not know what happens in the oceans because they are in effect, out of sight and out of mind. 7. Should fishers harvesting fish from a country’s publicly owned waters be required to pay the government fees for the fish they catch? Explain. If your livelihood depended on commercial fishing, would you be for or against such fees? Answer: I think that taking fish from publicly owned waters should be applicable for a tax or fee of some sort. The money could be used for research and/or monitoring purposes. If I was a commercial fisherman I would want my livelihood to continue. If charging fees meant that the fishing industry would become more sustainable then I would be for it. The fees paid would be reflected in higher fish prices and may help regulate the industry and keep fishing families who have been in the business for many generations from going bankrupt or having to close their operations. 8. Do you think the plan for restoring Florida’s Everglades will succeed? Give three reasons why or why not. Answer: No I do not believe the Everglades restoration project will work. The powerful political lobbying groups will affect how elected state and federal officials view this issue, and the sugarcane and agriculture industry will probably win out in the end. Secondly, a comprehensive plan has to be implemented about who gets what in terms of the amount of water that is supplied to homes and industries, and how much they will have to pay for it. Also, how much water gets redirected back into the Everglades ecosystem? This too has to be established and followed through on. Third, a sustainable funding source must be established and maintained for each step of the project in order for it to be successful. The money cannot come in fits and starts depending on how much financial commitment there is from one year to the next. 9. Congratulations! You are in charge of protecting the world’s aquatic biodiversity and ecosystem services. List the three most important points of your policy to accomplish this goal. Answer: Monitor the health of the world’s aquatic ecosystems from a number of perspectives. One, perform a global biodiversity inventory to be undertaken over several years, maybe even decades, and introduce measures to protect vulnerable species. Second, conduct a thorough pollution monitoring and prevention program and establish enforcement and monitoring measures to prevent further pollution of the aquatic ecosystems that could lead to loss of biodiversity. Third, based on the results of the first two initiatives, global cooperation and new legislation needs to be established to protect all aquatic life on earth. 10. List two questions that you would like to have answered as a result of reading this chapter. Answer: 1. How can brands effectively adapt their strategies to different geographical markets? 2. What are the challenges of managing brand consistency across diverse market segments? Ecological Footprint Question A fish print provides a measure of a country’s fish harvest in terms of area. The unit of area used in fish print analysis is the global hectare (gha), a unit weighted to reflect the relative ecological productivity of the area fished. When compared with the fishing area’s sustainable biocapacity, its ability to provide a stable supply of fish year after year in terms of area, it indicates whether the country’s fishing intensity is sustainable. The fish print and biocapacity are calculated using the following formulae: Fish print in (gha) = metric tons of fish harvested per year/productivity in metric tons per hectare X weighting factor. Biocapacity in (gha) = sustained yield of fish in metric tons per year/productivity in metric tons per hectare X weighting factor. 1. Based on the graph (a) What is the current status of the global fisheries with respect to sustainability? (b) In what year did the global fish print begin exceeding the biological capacity of the world’s oceans? (c) By how much did the global fish print exceed the biological capacity of the world’s oceans in 2000? 2. Assume a country harvests 18 million metric tons of fish annually from an ocean area with an average productivity of 1.3 metric tons per hectare and a weighting factor of 2.68. What is the annual fish print of that country? 3. If biologists determine that this country’s sustained yield of fish is 17 million metric tons per year (a) What is the country’s sustainable biological capacity? (b) Is the county’s fishing intensity sustainable? (c) To what extent, as a percentage, is the country under- or overshooting its biological capacity? 1. Answer: (a) Currently the global fisheries are greatly overfishing the sustainability of the oceans. (b) The global fisheries catch or fish print began to exceed the biological capacity of the oceans in about 1970, and this trend continues today. (c) In 2000, the global fish print exceeded the biological capacity of the world’s oceans by 36 billion global hectares (gha). 2. Answer: The country’s fish print is 18 million metric tons per year/ 1.3 metric tons per hectare = 13.8 metric tons X 2.68 = 37.1 global hectares (gha) 3. Answer: (a) The country’s sustainable biological capacity is 17 million metric tons per year/1.3 metric tons per hectare = 13.1 metric tons X 2.68 = 35.0 global hectares (gha) (b) No, the country’s fishing intensity is not sustainable. (c) The country is overshooting its biological capacity at a rate of 37.1 gha – 35.0 gha = 2.1 gha /37.1 = 5.6% per year. SUSTAINING NATURAL RESOURCES Chapter 12 Food, Soil, and Pest Management Summary 1. Even though food production has leveled off in the last 25 years, the world still produces enough food to meet the basic nutritional needs of people. However, the food cannot be evenly distributed throughout the world, leading to malnutrition and starvation. Many of these deaths come from malnutrition, which leads to a lack of resistance to diseases. Modern agricultural techniques create significant environmental harm, but the green revolution is also responsible for large increases in agricultural productivity. 2. Three systems produce foods for human consumption. Croplands produce mostly grains, about 77% of the world’s food. Rangelands provide meat, about 16% of the world’s food. Ocean fisheries supply about 7% of the world’s food. 3. Soils are degraded and eroded by water, wind, and people. Soil erosion is primarily caused by flowing water and wind. Human activities, such as farming, logging, construction, off-road vehicles, etc., also disturb soil and hasten erosion. In much soil there is also salt buildup and waterlogging. Crops can be planted today with less soil disturbance through conservation-tillage, tillage, contour farming, and strip farming. Farmers may also use cover crops to help hold the soil in place. Several crops planted between trees and shrubs, alley cropping, help preserve soil and its productivity. And windbreaks are used to prevent soil from being blown away. Conservation and fertilization can be used to restore soil fertility, but fertilizing with commercial pesticides brings its own set of problems. 4. The green revolution uses particular methods to raise crops. Monocultures are developed and planted, bred selectively, or genetically engineered to produce high yields of particular crops. Large amounts of fertilizer, pesticides, and water are added to the crops. Yields of crops are increased through multiple cropping throughout the year. The second green revolution since 1967 involved using fast-growing dwarf varieties of wheat and rice in countries with tropical and subtropical climates. Traditional agriculture: uses interplanting, several crops grown together on the same area of land; uses agroforestry, which grows crops and trees together; and applies polyculture, where various plants are planted together but mature at different times. 5. Food production can be increased by using crossbreeding techniques on similar organisms and using genetic engineering on different organisms. Genetic engineering, including using advanced tissue culture techniques, is growing in use; but many people are concerned about the potential harm such crops may cause. Irrigating more land and cultivating more land are additional solutions but they may not prove sustainable. Rangelands can be managed more efficiently, with the land area better protected; but a meat-based diet requires substantially more resources than a plant-based diet. Overfishing and habitat degradation dominate the marine environment; better management of this food source and protection of the marine environment would ensure continued availability of fish worldwide. 6. More sustainable agricultural systems can be created by reducing resource throughput and working with nature. Technologies based on ecological knowledge are used to increase crop production, to control pests, and to build soil fertility. Such low-input organic farming is often more friendly to the environment by using less energy than conventional farming demands, and by improving soil fertility. Low-input organic farming is also more profitable for farmers. 7. Pesticides are chemicals that kill or control populations of organisms we consider undesirable. Types include insecticides, herbicides, fungicides, and rodenticides. The advantages of using pesticides include the fact that they save lives, increase food supplies, lower food cost, increase profit for farmers, and work fast. The disadvantages include the acceleration of pest resistance to pesticides and pesticides dispersing widely, harming wildlife, and threatening human lives. The Federal Insecticide, Fungicide, and Rodenticide Act established in 1947 and amended in 1972, as well as the 1996 Food Quality Protection Act regulate pesticide use in the United States. Alternatives to pesticides include integrated pest management, cultivation practices, food irradiation, genetic engineering, biological control, hot water, and pheromones. These all reduce pesticide use but may prove timely, costly, and not as reliable. Key Questions and Concepts 12-1 What is food security and why is it difficult to attain? CORE CASE STUDY: Organic agriculture is a component of sustainable agriculture in which crops are grown without synthetic pesticides, synthetic inorganic pesticides and genetically modified seeds. Between 2002 and 2008 the global market for organic food doubled, however, it is only practiced on less than 1% of the world’s farmland. Organic farming has a number of environmental advantages over conventional agriculture, though the latter generally leads to higher yields. A. Food security means that all or most people in a country have daily access to enough food to be healthy and active. 1. Global food production has stayed ahead of population growth, but one in six people in developing countries cannot grow or buy the food they need (face food insecurity). B. The root cause of food insecurity is poverty. 1. Other obstacles include political upheaval, war, corruption, and drought or other prolonged weather conditions. 2. It is projected that by the end of the century there is a greater than 90% chance that half of the world’s population will face food shortages due to climate change. C. People need fairly large amounts of macronutrients (protein, carbohydrates, fats) and smaller amounts of micronutrients (vitamins such as A, C, E) and minerals (iron, iodine, calcium). 1. Chronic undernutrition, or hunger, is when people do not have access to enough food to meet basic energy needs. 2. Chronic malnutrition occurs when there is a deficiency of protein or other key nutrients. 3. Famine occurs when there is a severe shortage of food in an area that results in mass starvation. D. One in three people has a deficiency of one or more vitamins and minerals, especially vitamin A, iron, and iodine. E. In the developed world, the problem is overnutrition, which leads to obesity, reduced life quality, poor health, and premature death. 12-2 How is food produced? A. Food production from croplands, rangelands, ocean fisheries, and aquaculture has increased dramatically. B. Wheat, rice, and corn provide more than half of the calories in the food consumed by the world’s people. C. About 80% of the world’s food supply is produced by industrialized agriculture. 1. Plantation agriculture is a form of industrialized agriculture that involves producing cash crops. 2. Increasingly industrialized agriculture is relying on greenhouses. CASE STUDY: Hydroponics involves growing plants in nutrient solutions instead of soil. The advantages over conventional systems are the crops can be grown indoors, yields are increased, crops can be grown on rooftops, fertilizer and water use are reduced, and there is little or no need for pesticides if crops are grown in a controlled environment. Three main drawbacks are that it takes a large investment to get started, many fear that is requires too much technical knowledge, and it could threaten the profits of companies that produce chemicals and farm equipment. D. Many farmers in developing countries use traditional agriculture to grow a variety of crops on each plot of land. 1. Traditional subsistence agriculture uses labor and draft animals to supply food for a family, with little left over. 2. Traditional intensive agriculture involves increased inputs of fertilizer and water to obtain higher crop yields. 3. Polyculture involves growing several crops simultaneously. 4. Slash and burn agriculture is subsistence agriculture that burning and clearing small plots of tropical forest on a rotational basis. E. The large increases in crop production over the last half of the 20th century are the result of the green revolution. This includes selective breeding of crops, use of fertilizers, pesticides and irrigation, and multiple cropping systems. SCIENCE FOCUS: Soil is a complex mix of rock, nutrients, organic material, air, water, and living organisms. Although topsoil is a renewable resource, it is renewed very slowly. CASE STUDY: Food production in the US is characterized by agribusiness, with a small number of multinational companies controlling food production and distribution. As a result Americans spend only a very small portion of their income on food, but are typically not aware of the hidden costs, such as environmental costs and taxes for subsidies. F. Traditionally, farmers have relied on crossbreeding through artificial selection to develop improved varieties. Today genetic engineering is used to develop improved strains. 1. Genetically modified organisms are planted on about 12% of the world’s cropland. 2. More than 80% of the corn, soybeans and cotton grown in the US are genetically engineered. G. Between 1961 and 2007 world meat production has increased more than fourfold and per capita consumption has doubled. 1. About half the world’s meat comes from rangelands and pastures. The other half is raised on crowded feedlots and in concentrated animal feeding operations (CAFO’s). 2. As a country’s income grows, people tend to eat more meat. H. A fishery is a concentration of a particular aquatic species suitable for commercial harvest. Aquaculture is the process of raising fish in ponds or enclosures. 1. At least 63% of ocean fisheries are depleted or overexploited. 2. Aquaculture is the world’s fastest growing type of food production. I. Industrial food production is heavily reliant on the availability of energy, primarily oil and natural gas. 1. It takes about 10 units of nonrenewable energy to put 1 unit of food energy on the table. 12-3 What environmental problems arise from food production? A. Soil erosion lowers soil fertility and can overload nearby bodies of water with eroded sediment. Soil is eroding faster than it is forming on more than one-third of the world’s cropland. B. About one-third of the world’s land has lower productivity because of drought and human activities that reduce or degrade topsoil. C. Desertification occurs when the productive potential of topsoil falls by 10% or more. 1. 70% of the world’s drylands used for agriculture are threatened by desertification. D. Repeated irrigation can reduce crop yields by causing salt buildup in the soil (salinization) and waterlogging of croplands. E. Agricultural activities produce significant amounts of air pollution 1. Industrialized livestock production accounts for more greenhouse gasses than all of the world’s cars, busses, and planes emit (18%). F. Crops grown for biofuels production are expanding, particularly in tropical zones, leading to losses of agrobiodiversity. 1. Since 1900, roughly ¾ of the genetic diversity of agricultural crops have been lost. 2. Crop varieties are now stored in gene banks, agricultural research centers, and botanical gardens around the world. G. New genetically modified food crops could have unintended negative ecological consequences. H. Meat production systems have numerous environmental impacts. They use huge amounts of energy, produce a lot of waste, pollute groundwater, lead to erosion and degradation of rangelands. Another concern is the widespread use of antibiotics. I. Aquaculture now accounts for roughly half of global seafood production. 1. Advantages include high efficiency, high yield, reduced overharvesting of fisheries, low fuel use, and high profits. 2. Disadvantages include large inputs of feed and water, large waste output, loss of habitat, some species are fed fish meal, and dense populations can be vulnerable to disease. 12-4 How can we protect crops from pests more sustainably? A. Organisms found in nature control populations of most pest species as part of the earth’s free ecological services. B. We use chemicals to repel or kill pest organisms as plants have done for millions of years. To help control pest organisms we have developed a variety of pesticides. C. Pesticide use has increased 50-fold and toxicity has increase 10–100 times. Many pesticides are persistent in the environment and have significant impacts on human and animal health. D. Modern pesticides save lives, increase food supplies, increase profits for farmers, and are fast acting. E. Pesticides do not work forever, as pest species evolve resistance to particular chemicals (coevolution). F. Pesticides can promote genetic resistance to their effects, wipe out natural enemies of pest species, create new pest species, end up in the environment, and sometimes harm wildlife and people. G. Pesticides have not reduced crop loss overall. CASE STUDY: There are many unintended effects of pesticide use. An example comes from a program directed at ridding North Borneo of malaria in the 1950’s. It was successful, but soon other insects began to disappear, then the lizards that fed on them, and finally the cats that fed on the lizards. In the absence of cats, rats flourished and the people became threatened by sylvatic plague. H. In the US the Food and Drug Administration (FDA), the Department of Agriculture (USDA) and the Environmental Protection Agency (EPA) regulate the sale and use of pesticides under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). 1. Less than 10% of the active ingredients in pesticides have been tested for health effects. I. There are cultivation, biological, and ecological alternatives to conventional chemical pesticides. A number of methods are available. 1. Fool the pest using cultivation practices such as crop rotation. 2. Provide homes for pest enemies. 3. Implant genetic resistance. 4. Bring in natural enemies. 5. Use insect pheromones to lure pest insects into traps or to lure natural predators to crop fields. 6. Use hormones that disrupt the normal insect life cycle and prevent them from reaching maturity. The disadvantages are that they take weeks to kill an insect, are often ineffective if the infestation is large, and must be applied at the right time in the life cycle. J. Integrated pest management (IPM) is an ecological approach to pest control that uses a mix of cultivation and biological methods, and small amounts of selected chemical pesticides as a last resort. 12-5 How can we improve food security? A. Governments use policies to influence food production. 1. Control prices. 2. Provide subsidies. B. Simple and relatively inexpensive actions can have large impacts. One-half to two-thirds of nutrition-related childhood death could be prevented for $5–10 per child per year. 1. Provide immunization. 2. Prevent dehydration. 3. Prevent blindness with a vitamin A capsule twice a year. 12-6 How can we produce food more sustainably? A. Sustainable agriculture through soil conservation—Soil conservation seeks ways to reduce soil erosion and restore soil fertility, mostly by keeping the soil covered with vegetation. Some additional methods include terracing, contour planting, strip cropping, agroforestry and the use of windbreaks. CASE STUDY: Soil erosion in the United States during the dust bowl years lead to dramatic changes in agricultural policy. B. Restore soil fertility using organic fertilizers, reduce soil salinization and desertification, and use sustainable aquaculture techniques. C. Eat lower on the food chain and slow population growth. CASE STUDY: The largest salmon producer in Canada has turned toward sustainable aquaculture by mimicking a natural ecosystem. D. Meat production is highly inefficient and could be improved by shifting toward more grain-efficient forms of animal protein, such as poultry and plant eating fish as well as by reducing meat consumption. E. Five strategies to make the transition to a more sustainable agriculture: 1. Increase research 2. Establish training programs 3. Set up an international fund to give farmers in poor countries access to sustainable agriculture 4. Establish subsidies that encourage sustainable agriculture 5. Mount a massive education program SCIENCE FOCUS: Perennial polycultures have many advantages, including no tilling requirement, reduced erosion, less irrigation, and less chemical fertilizers. F. Sourcing food locally is an important component of sustainable food production. 1. Community Supported Agriculture (CSA) and farmer’s markets provide this. Teaching Tips Large Lecture Classes: Use individual response systems (clickers) or show of hands to poll the class on whether they favor the use of genetically modified organisms. Repeat poll after presenting the pros and cons of this technology. Have students discuss their opinion with their neighbor in the class for two minutes. Poll the class again. Ask the class using response systems (as above) if we in the U.S. would have an ethical or moral obligation to prevent hunger if the cost was $5000 per U.S. resident per year. Ask again if the cost was $5 per U.S. resident per year. Pose the question of how to balance moral obligations against practical considerations. Link this back to policy and ethics chapter. Smaller Lecture Classes: Ask for thoughts on the use of genetically modified organisms. Have a three-minute mini-debate between two students by assigning each student a pro or con GMO perspective. Set ground rules about how the debate should occur (e.g., no raised voices, etc.). Have the class develop a sustainable agricultural system for their location. What would be involved in this system? How would fertilizers be added? Where would the water come from? What kind of crop rotation and IPM system would be appropriate to the class location? Key Terms animal manure aquaculture chronic undernutrition chronic malnutrition compost desertification famine fishery food security food insecurity green manure green revolution high-input agriculture hunger hydroponics industrialized agriculture integrated pest management (IPM) irrigation organic fertilizer overnutrition pest pesticides plantation agriculture polyculture salinization slash-and-burn agriculture soil conservation soil erosion traditional intensive agriculture traditional subsistence agriculture waterlogging Term Paper Research Topics 1. Agricultural systems: inorganic fertilizers, history of development of one crop or livestock species, green revolution, crops with designer genes, politics of American agriculture, feedlot beef cattle production in the Corn Belt, range livestock production in the American West, urban growth and the loss of prime cropland, modern food storage and transportation, comparisons of environmental impacts of traditional and industrial agricultural practices. 2. Human impact on the soil: overgrazing and desertification, acid deposition as a threat to soil quality, sediment as a water pollutant, irrigation impacts. 3. Soil conservation and fertility strategies: conservation-tillage farming, organic and inorganic fertilizers, agroforestry. 4. Hunger and food distribution: history of great famines, malnutrition and learning, the geography of malnutrition. 5. Fishing: overfishing, aquaculture, the Peruvian anchovy story. 6. Pesticides: pesticides as hazardous waste; pesticide hazards to agricultural workers; chlorinated hydrocarbons; organophosphates and carbamates; pyrethroids and rotenoids; biological amplification of persistent pesticides; DDT and malaria control; Agent Orange; the Bhopal accident; pesticide residues in foods; pesticide runoff as a threat to agriculture. 7. Pesticide alternatives: integrated pest management; food irradiation; genetic control by sterilization: the screwworm fly; pheromones; Bacillus thuringensis. 8. Sustainable agriculture: organic home gardening, neglected edible plants, composting, crop rotation, organic fertilizers, windbreaks. 9. Global policy: UN food conferences; 1982 UN Conference on the Law of the Sea; agricultural training and research centers in the developing countries; Georges Banks: conflict between Canada and Spain. 10. National policy: Soil Conservation Service; policies, such as farm bills, which affect soil quality. Discussion Topics 1. What is the best way to manage food distribution for foreign aid? Answer: The best way to manage food distribution for foreign aid involves ensuring efficient logistics, transparency, and local engagement. Implementing a needs-based approach, coordinating with local organizations, and using technology for real-time tracking can optimize distribution. Prioritizing direct aid and addressing local market conditions helps prevent dependency and supports sustainable development. 2. Is using lifeboat ethics the best way to decide who gets to eat? Answer: Lifeboat ethics, which prioritizes resource allocation based on perceived merit or need, can be controversial and may lead to ethical dilemmas. It often neglects considerations of equality and fairness, potentially exacerbating social inequalities. Alternative approaches, such as equitable distribution and international cooperation, may offer more ethical and sustainable solutions to food allocation. 3. What are the pros and cons of Aldo Leopold's land ethic? Answer: Aldo Leopold's land ethic promotes the idea that humans should view themselves as part of a community that includes the land and all its inhabitants. Pros include fostering environmental stewardship and promoting sustainable practices. Cons might include the difficulty in applying the ethic to specific policies and the challenge of balancing human needs with ecological preservation. 4. Is the rapid deterioration of agricultural soils in the United States a sufficiently serious problem to warrant strict federal laws with heavy fines for farmers or ranchers failing to employ wise soil-conservation methods? Arrange a class debate on this issue. Answer: Affirmative: The rapid deterioration of agricultural soils undermines long-term agricultural productivity, contributes to environmental degradation, and threatens food security. Strict federal laws with heavy fines can enforce soil conservation practices, ensure compliance, and protect valuable natural resources. Negative: Heavy fines may disproportionately affect small farmers and ranchers, creating economic hardship. Voluntary programs and incentives could be more effective in promoting soil conservation while respecting individual circumstances. Education and support for best practices might lead to better outcomes without punitive measures. 5. Evaluate pesticide advertising. What does it tell? What doesn't it tell? Answer: Pesticide advertising often emphasizes effectiveness, ease of use, and benefits for crop yield. It may downplay or omit potential health risks, environmental impact, and long-term consequences of chemical use. Advertisements typically focus on immediate benefits, leaving out critical information about safety precautions and sustainable alternatives. 6. Which do you prefer: unblemished fruits and vegetables that may contain pesticide residues or blemished fruits and vegetables without pesticide residues? Answer: Preference may vary based on individual priorities. Some might prefer unblemished produce for its appearance and perceived quality, accepting the risk of pesticide residues. Others might choose blemished produce for its reduced pesticide exposure, prioritizing health and environmental concerns over cosmetic appeal. 7. Rachel Carson's Silent Spring. Answer: "Silent Spring" by Rachel Carson is a seminal work that raised awareness about the dangers of widespread pesticide use, particularly DDT. The book highlighted the environmental and health impacts of pesticides, leading to increased public concern and contributing to the eventual establishment of regulatory measures and the environmental movement. 8. Which is better: a broad-spectrum or a narrow-spectrum pesticide? Answer: Narrow-spectrum pesticides target specific pests, reducing the impact on non-target species and ecosystems, making them generally preferable for minimizing environmental damage. Broad-spectrum pesticides kill a wide range of organisms, which can lead to unintended consequences, such as disrupting ecological balance and promoting resistance in pests. 9. Should pesticides banned in the United States be exported to other countries? Answer: No, pesticides banned in the United States should not be exported to other countries. Exporting banned pesticides can contribute to environmental and health risks in less regulated regions. Instead, efforts should focus on promoting safe alternatives and supporting global standards for pesticide use and environmental protection. Activities and Projects 1. Have your students locate and bring to class photographs, paintings, or history passages describing the effects of hunger and starvation. 2. Take a class field trip to several farms or ranches in your locale that offer you the opportunity to contrast excellent soil management practices with poor ones. 3. With your class, visit several construction sites in your locale. Look for evidence of human-accelerated soil erosion and methods or practices employed to minimize it. 4. Invite a county agricultural agent to your class to discuss local agricultural problems and opportunities. What major changes in agricultural practices are likely to occur in the coming decades? With what consequences? What types of farming activities are carried on in your locale? What is the balance between large and small farms? What are the major products? How much of the produce is used in local areas? How much is shipped out and where does it go? 5. Invite an organic farmer or experienced organic gardener to address your class on the subject of alternatives to energy-intensive agriculture. If possible, arrange a field trip to investigate organic farming practices. 6. As a class, plan a daily menu for a family of four receiving minimum welfare payments (consult local welfare agencies for current payment levels and use current food prices). Ask your students how they would like subsisting solely on this diet. 7. As a class exercise, determine what percentage of your diet—as individuals and as a group—consists of meat. What are some ecological implications of this amount of meat in the diet? What are the health implications? What are the alternatives? 8. Arrange a class debate on the proposition that food-exporting nations should use population control and resource development as criteria to determine which of the food-importing nations will receive top priority. Conduct a mock trial and follow it with mock appeals hearings for denied nations. 9. With the help of a chemist or other appropriate consultant, have your students evaluate the ingredients, uses, and warning labels of a representative sample of pesticides sold for home and garden applications. Are the instructions for use, storage, and disposal adequate? How much additional information should be supplied to further reduce the likelihood of harm to people and wildlife? 10. Are people generally aware of and concerned about the hazards of using pesticides on a large-scale, long-term basis? As a class project, conduct a survey of students or consumers to address these and related questions. What do the results imply for the role that education should play in dealing with pesticide-related problems? 11. Have your students interview the college landscaping staff about which pesticides, if any, they use on campus. What tradeoffs did they consider when deciding to use those pesticides? Attitudes and Values 1. Do we have a moral obligation to prevent malnutrition and starvation? If so, how should we act on this obligation? Answer: Yes, there is a moral obligation to prevent malnutrition and starvation, as it is a fundamental aspect of human rights and dignity. To act on this obligation, we should support international aid programs, invest in sustainable agricultural practices, and advocate for policies that address the root causes of food insecurity. Collaboration between governments, organizations, and communities is crucial for effective and equitable solutions. 2. Was the Green Revolution worth it? In what ways has it improved the human condition and in what ways has it hurt human society? On balance, is our agricultural system improving the quality of life on earth? Answer: The Green Revolution increased agricultural productivity and helped alleviate hunger by introducing high-yield crops and advanced technologies. However, it also led to environmental issues, such as soil degradation, water depletion, and increased chemical use. While it has improved food security for many, the overall impact on quality of life is mixed, with ongoing challenges in sustainability and equity. 3. What obligation do we have to prevent environmental harm in our practice of agriculture? How do you personally balance the need to produce food against the potential environmental costs of agriculture? Answer: We have an obligation to minimize environmental harm in agriculture by adopting sustainable practices and reducing pollution and resource depletion. Balancing food production with environmental costs involves using efficient farming methods, supporting conservation efforts, and promoting responsible consumption. Personal choices, such as supporting sustainable agriculture and reducing food waste, also contribute to this balance. 4. What are the ethical issues associated with the creation of genetically modified organisms? How does the precautionary principle play into consideration of GMO use? Answer: Ethical issues with genetically modified organisms (GMOs) include concerns about environmental impact, health risks, and corporate control over seeds. The precautionary principle suggests that GMOs should be thoroughly tested and regulated to prevent potential harm before widespread adoption. This principle advocates for caution and transparency, ensuring that potential risks are carefully assessed and managed. News Videos Bald Eagle Soars Again: Taken Off Endangered List; Environmental Science in the Headlines, 2008; DVD; ISBN 0495561908 Doomsday Vault: Creating Hope for the Future; Environmental Science in the Headlines, 2008; DVD; ISBN 0495561908 Kalahari Desert Could Double in Size; The Brooks/Cole Environmental Science Video Library, 2009; DVD 0538733551 What is the Environmental Cost for Your Food; The Brooks/Cole Environmental Science Video Library, 2009; DVD 0538733551 Additional Video Resources American Experience: Rachel Carson’s Silent Spring (PBS Documentary Series) “Her warning sparked a revolution in environmental policy and created a new ecological consciousness.” American Experience: Surviving the dust bowl (PBS Documentary Series) A look at the catastrophic drought, the farming techniques, and environmental impact. Main website: http://www.pbs.org/wgbh/amex/dustbowl/ Teacher’s Guide: http://www.pbs.org/wgbh/amex/dustbowl/ Cane Toads: An Unnatural History (Documentary, 1988) A documentary detailing the spread of Hawaiian sugar-cane toads through Australia in a botched effort to introduce them as counter pests. Fed Up! Genetic Engineering, Industrial Agriculture and Sustainable Alternatives (2002) Using Interviews and archival footage, this documentary provides an overview of current American food production. http://www.wholesomegoodness.org/movies.html Food, Inc. (Documentary, 2009). This is a feature length documentary focusing in conventional food production. It closes with a look at alternative agricultural systems. Frontline: World, Tortilla omics (Web-based slide shows with audio, 2008, Online) How did the surge in American corn-based biofuel research affect the staple food supply of Mexico? http://www.pbs.org/frontlineworld/fellows/mexico_2008/ The Future of Food (2005) This documentary takes a look at the economic and political forces behind genetically modified foods. http://www.thefutureoffood.com/ The Meatrix Series (Animated, 2003, Online) An animated series about factory farms, which focuses on how animals for meat, dairy, and eggs are raised. http://www.themeatrix.com/ NOVA/Frontline: Harvest of Fear (Video series, PBS, 2001) This episode explores the debate over genetically modified foods. http://www.pbs.org/wgbh/harvest/ NOVA/Frontline: The Desert Doesn't Bloom Here Anymore (Video series, NOVA, , PBS, 2001) This episode examines water and irrigation policies and how they affect soil quality and can lead to desertification. Putting Aside Pesticides (Documentary, 1987) EPA film on the long-term effects of pesticides and exploration of alternatives. Common Ground: Farming and Wildlife (National Audubon Documentary, 1987) The debate between dividing farmers and environmentalists over the use of chemicals. Web Resources University of California Sustainable Agriculture Research and Education Programhttp://www.sarep.ucdavis.edu/Concept.htm U.S. Government Citizen resources for agricultural questions, agricultural statistics and other issues. http://www.usa.gov/Citizen/Topics/Environment_Agriculture/Agriculture.shtml Sustainable Agriculture Research and Education Sustainable Agriculture Research and Education (SARE) program funded by the Cooperative State Research, Education and Extension Service, U.S. Department of Agriculture. Contains video and photo links for use in the classroom. http://www.sare.org/coreinfo/educators.htm Suggested Answers to End of Chapter Questions Review Questions 1. Review the Key Questions and Concepts for this chapter on p. 278. Define organic agriculture and compare its main components with those of conventional industrialized agriculture. Answer: • Organic agriculture is a type of sustainable agriculture that differs from conventional industrial agriculture insofar as crops are grown without synthetic pesticides, synthetic inorganic pesticides and genetically modified seeds. 2. Define food security and food insecurity. What is the root cause of food insecurity? Distinguish between chronic undernutrition (hunger) and chronic malnutrition and describe their harmful effects. What is a famine? Describe the effects of diet deficiencies in vitamin A, iron, and iodine. What is overnutrition, and what are its harmful effects? Answer: • Food security means having enough food to meet basic nutritional needs. Food insecurity not getting enough to eat and—living with chronic hunger and poor nutrition. • Most agricultural experts agree that the root cause of food insecurity is poverty, which prevents poor people from growing or buying enough food. Other obstacles to food security are environmental degradation, political upheaval, war, and corruption. • People who cannot grow or buy enough food to meet their basic energy needs suffer from chronic undernutrition, or hunger. Many suffer from mental retardation or stunted growth or die prematurely from infectious diseases such as measles and diarrhea, which rarely kill children in developed countries. • Many of the world’s poor can afford only to live on a low-protein, high-carbohydrate, vegetarian diet consisting mainly of grains such as wheat, rice, or corn causing chronic malnutrition—deficiencies of protein and other key nutrients. This weakens them, makes them more vulnerable to disease, and hinders the normal physical and mental development of children. • A famine is a severe food shortage that can result in mass starvation, deaths, and social disruption. • Lack of vitamin A can cause children younger than age 6 to go blind each year and double chances of dying within a year. Having too little iron causes anemia which results in fatigue, makes infection more likely, and increases a woman’s chances of dying from hemorrhage in childbirth. Chronic lack of iodine prevents proper functioning of the thyroid gland, which produces hormones that control the body’s rate of metabolism, and can cause stunted growth, mental retardation, and goiter—a swollen thyroid gland that can lead to deafness. • Overnutrition occurs when food energy intake exceeds energy use and causes excess body fat. Too many calories, too little exercise, or both can cause overnutrition. People who are underfed and underweight and those who are overfed and overweight face similar health problems: lower life expectancy, greater susceptibility to disease and illness, and lower productivity and life quality. 3. What three systems supply most of the world’s food? Define irrigation. Distinguish among industrialized agriculture (high-input agriculture), plantation agriculture, hydroponics, traditional subsistence agriculture, traditional intensive agriculture, polyculture, and slash- and- burn agriculture. What are the major advantages and disadvantages of raising food hydroponically in greenhouses? How does conventional agriculture violate the three principles of sustainability? Define soil and describe its formation and the major layers in mature soils. What is a green revolution? Describe industrialized food production in the United States. Answer: • Croplands produce mostly grains, rangelands, pastures, and feedlots produce meat, and fisheries and aquaculture provide us with seafood. • Irrigation means supply water to crops artificially. • Industrialized agriculture, or high-input agriculture, uses heavy equipment and large amounts of financial capital, fossil fuel, water, commercial inorganic fertilizers, and pesticides to produce single crops, or monocultures. • Plantation agriculture is a form of industrialized agriculture used primarily in tropical developing countries. It involves growing cash crops such as bananas, soybeans (mostly to feed livestock), sugarcane (to produce sugar and ethanol fuel), coffee, palm oil (used as a cooking oil and to produce biodiesel fuel), and vegetables. Crops are grown on large monoculture plantations, mostly for export to developed countries. Producing such monoculture crops in the tropics increases yields but decreases biodiversity when tropical forests are cleared or burned to make way for crop plantations. • Hydroponics involves growing plants by exposing their roots to a nutrient-rich water solution instead of soil, usually inside of a greenhouse. • Traditional subsistence agriculture supplements energy from the sun (for photosynthesis) with the labor of humans and draft animals to produce enough crops for a farm family’s survival, with little left over to sell or store as a reserve for hard times. • In traditional intensive agriculture, farmers increase their inputs of human and draft-animal labor, animal manure for fertilizer, and water to obtain higher crop yields. If the weather cooperates, they produce enough food to feed their families and have some left to sell for income. • Many traditional farmers grow several crops on the same plot simultaneously, a practice known as polyculture. • Slash- and- burn agriculture is a type of polyculture. This type of subsistence agriculture involves burning and clearing small plots in tropical forests, growing a variety of crops for a few years until the soil is depleted of nutrients, and then shifting to other plots. • The advantages of hydroponics are that crops can be grown indoors under controlled conditions almost anywhere, yields and availability are increased because crops are grown year round, crops can be grown on rooftops, with artificial lighting, and on floating barges, thus requiring much less land, fertilizer and water use are reduced, and the need for pesticides is diminished. The disadvantages are the amount of capital required to start an operation, the fear of technical knowledge required, and the opposition of well-established corporations that produce farm supplies and chemicals. • Modern industrialized agriculture violates the principles of sustainability because it relies heavily on nonrenewable fossil fuels, does not rely on a diversity of crops as a form of ecological insurance, and neglects the conservation and recycling of nutrients in topsoil. • Soil is a complex mixture of eroded rock, mineral nutrients, decaying organic matter, water, air, and billions of living organisms, most of them microscopic decomposers. Soil formation begins when bedrock is slowly broken down into fragments and particles by physical, chemical, and biological processes, called weathering. • Most soils that have developed over a long period of time, called mature soils, contain distinct horizontal layers, or horizons. Most mature soils have at least three of the possible horizons. The roots of most plants and the majority of a soil’s organic matter are concentrated in a soil’s two upper layers, the O horizon of leaf litter and the A horizon of topsoil. Bacteria and other decomposer microorganisms break down some of the soil’s complex organic compounds. The result is a porous mixture of the partially decomposed bodies of dead plants and animals, called humus, and inorganic materials such as clay, silt, and sand. The B horizon (subsoil) and the C horizon (parent material) contain most of a soil’s inorganic matter, mostly broken-down rock consisting of varying mixtures of sand, silt, clay, and gravel. • Since 1950, about 88% of the increase in global food production has come from using high-input industrialized agriculture to increase yields in a process called the green revolution. • See Case Study: Industrialized Food Production in the United States. 4. Distinguish between crossbreeding through artificial selection and genetic engineering. Describe the second gene revolution based on genetic engineering. Describe the growth of industrialized meat production. What is a fishery? What is aquaculture? Summarize the use of energy in industrialized food production. Why does it result in an energy loss? Answer: • Traditional crossbreeding is a slow process, typically taking 15 years or more to produce a commercially valuable new crop variety, and it can combine traits only from species that are genetically similar. Genetic engineering involves altering an organism’s genetic material through adding, deleting, or changing segments of its DNA to produce desirable traits or to eliminate undesirable ones. It enables scientists to transfer genes between different species that would not interbreed in nature. The resulting organisms are called genetically modified organisms (GMOs). • The second gene revolution involves altering an organism’s genetic material by adding, deleting, or changing segments of its DNA to produce desirable traits or to eliminate undesirable ones. It also allows for the transfer of genetic material between organisms that would not be able to interbreed in nature. • Meat production produced through an energy intensive industrialized system in which animals are raised mostly in densely packed feedlots and confined animal feeding operations where they are fed grain or meal produced from fish. For example, large numbers of cattle are brought to feedlots where they are fattened up for about four months before slaughter. Between 1961 and 2007, world meat production increased more than fourfold and average meat consumption per person more than doubled. • A fishery is a concentration of a particular aquatic species (usually fish or shellfish) suitable for commercial harvesting in a given ocean area or inland body of water. • Aquaculture involves the raising of marine and freshwater fish in ponds and underwater cages instead of hunting and gathering them. • Energy is used in food production to run farm machinery, irrigate crops, and produce pesticides (mostly from petrochemicals) and commercial inorganic fertilizers. Fossil fuels are also used to process and transport food. • This results in a net energy loss because it takes about 10 units of nonrenewable fossil fuel energy to put 1 unit of food energy on the table. 5. What are two major advantages of high-yield modern agriculture? What are the major harmful environmental impacts of agriculture? What is soil erosion and what are its two major harmful environmental effects? What is desertification and what are its harmful environmental effects? Distinguish between salinization and waterlogging of soil and describe their harmful environmental effects. What is the biggest problem resulting from excessive use of water for irrigation in agriculture? Answer: • The major advantages of modern agriculture are that large amounts of food are produced per unit area and prices are low. • See Figure 12- 10 Major harmful environmental effects of food production. Future food production may be limited by soil erosion and degradation, desertification, water and air pollution, climate change from greenhouse gas emissions, and loss of biodiversity. • Soil erosion is the movement of soil components, especially surface litter and topsoil, from one place to another by the actions of wind and water. Soil erosion causes loss of soil fertility through depletion of plant nutrients in topsoil, and water pollution in nearby surface waters. This can kill fish and shellfish and clog irrigation ditches, boat channels, reservoirs, and lakes. Additional water pollution occurs when the eroded sediment contains residues of pesticides. • Desertification occurs when the productive potential of soil falls by 10% or more because of a combination of prolonged drought and human activities that reduce or degrade topsoil. Desertification can caused drops in food production, water shortages and environmental refugees. • Repeated annual applications of irrigation water in dry climates lead to the gradual accumulation of salts in the upper soil layers—a soil degradation process called salinization. It stunts crop growth, lowers crop yields, and can eventually kill plants and ruin the land. Irrigation can cause waterlogging, in which water accumulates underground and gradually raises the water table. Farmers often apply large amounts of irrigation water to leach salts deeper into the soil. Without adequate drainage, waterlogging occurs and saline water then surrounds the deep roots of plants, lowering their productivity and killing them after prolonged exposure. • The biggest problem with excessive irrigation is that it contributes to the depletion of groundwater and surface water supplies. 6. Summarize agriculture’s contribution to projected climate change. Explain how industrialized food production systems reduce biodiversity in areas where crops are growing. What is agrobiodiversity and how is it being affected by industrialized food production? Describe the advantages and disadvantages of using genetic engineering in food production. What factors can limit green revolutions? Compare the advantages and disadvantages of industrialized meat production. What is the connection between feeding livestock and the formation of ocean dead zones? Describe the use of energy in industrialized agriculture. Compare the advantages and disadvantages of aquaculture. Answer: • Agricultural activities create a great deal of air pollution. They also account for more than a quarter of the human-generated emissions of the greenhouse gases carbon dioxide, methane, and nitrous oxide, which are helping to warm the atmosphere • Biodiversity is threatened when forests are cleared and grasslands are plowed up and replaced with croplands. • Agrobiodiversity is the world’s genetic variety of animal and plant species used to provide food. Industrialized food production has led to a sharp decline in agrobiodiversity. Some estimate that the ¾ of all crop diversity has been lost since 1900. • Projected advantages of genetically modified crops and foods include needing less fertilizer and less water; more resistant to insects, disease, frost, and drought; grow faster; can grow in slightly salty soils; may need less pesticides; tolerate higher levels of herbicides; higher yields; and less spoilage. Projected disadvantages include irreversible and unpredictable genetic and ecological effects, harmful toxins in food from possible plant cell mutations, new allergens in food, lower nutrition, increase in pesticide-resistant insects, herbicide-resistant weeds, and plant diseases, can harm beneficial insects, and lower genetic diversity. • There are several factors that have limited the success of the green revolutions to date and that may limit them in the future. Without huge inputs of fertilizer, pesticides, and water, most green revolution crop varieties produce yields that are no higher than those from traditional strains. These high inputs cost too much for most subsistence farmers in developing countries. • Producing meat by using feedlots and other confined animal production facilities increases meat production, reduces overgrazing, and yields higher profits. However, such systems use large amounts of energy and water and produce huge amounts of animal waste that sometimes pollutes surface water and groundwater and saturates the air with their odor. • Large amounts of manufactured inorganic fertilizers are used in the mid-western United States to produce corn for animal feed. Much of this fertilizer runs off cropland and eventually goes into the Mississippi River The added nitrate and phosphate nutrients overfertilize coastal waters in the Gulf of Mexico, where the river flows into the ocean, creating a “dead zone.” • Advantages of aquaculture include: high efficiency, high yield in small volume of water, can reduce overharvesting of fisheries, low fuel use, and high profits. Disadvantages include: needs large inputs of land, feed, and water; large waste output; can destroy mangrove forests and estuaries; uses grain, fish meal, and fish oil to feed some species; and dense populations vulnerable to disease. 7. What is a pest? Define and give two examples of a pesticide. Describe Rachel Carson’s contribution to environmental science. Describe the advantages and disadvantages of modern pesticides. Describe the use of laws and treaties to help protect us from the harmful effects of pesticides. List and briefly describe seven alternatives to conventional pesticides. Define integrated pest management (IPM) and discuss its advantages and disadvantages. Answer: • A pest is any species that interferes with human welfare by competing with us for food, invading lawns and gardens, destroying building materials, spreading disease, invading ecosystems, or simply being a nuisance. • Pesticides are chemicals used to kill or control populations of organisms that we consider undesirable such as insects, weeds, rats, and mice. Examples are chlorinated hydrocarbon compounds, such as DDT, and organophosphate compounds, such as malathion and parathion. • See Individuals Matter: Rachel Carson. • Advantages of conventional chemical pesticides include: save lives, increase food supplies, profitable, work fast, and safe if used properly. Disadvantages include: promote genetic resistance, kill natural pest enemies, pollute the environment, can harm wildlife and people, and are expensive for farmers. • In the United States, three U.S. federal agencies, the EPA, the USDA, and the FDA, regulate the sale and use of pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act. The Food Quality Protection Act requires the EPA to reduce the allowed levels of pesticide residues in food by a factor of 10 when there is inadequate information on the potentially harmful effects on children. There is controversy over how well U.S. citizens are protected from the harmful effects of pesticides, with some scientists calling FIFRA the weakest and most poorly enforced U.S. environmental law. • Alternatives to conventional pesticides include: ○ Fool the pest. ○ Provide homes for pest enemies. ○ Use biological controls. ○ Implant genetic resistance. ○ Bring in natural enemies. ○ Bring in the hormones. • Integrated Pest Management involves using a combination of cultivation, biological, and chemical tools and techniques to reduce crop damage to an economically tolerable level., When an economically damaging level of pests is reached, farmers first use biological methods (natural predators, parasites, and disease organisms) and cultivation controls (such as rotating crops, altering planting time, and using large machines to vacuum up harmful bugs). Insecticides are used only as a last resort and in the smallest amounts possible. • IPM program can reduce pesticide use and pest control costs by 50– 65% without reducing crop yields and food quality. IPM can also reduce inputs of fertilizer and irrigation water, and slow the development of genetic resistance, because pests are assaulted less often and with lower doses of pesticides. IPM is an important form of pollution prevention that reduces risks to wildlife and human health. 8. What are the two main approaches used by governments to influence food production? How have governments used subsidies to influence food production and what have been some of their effects? What are three other ways in which organizations are improving food security? Answer: • Ways that governments influence food production include: ○ Control prices. Use price controls to keep food prices artificially low. ○ Provide subsidies. Give farmers price supports, tax breaks, and other subsidies to keep them in business and to encourage them to increase food production. • Governments give farmers price supports, tax breaks, and other financial support to keep them in business and to encourage them to increase food production. This can result in overproduction. • Organizations are improving food security by working to reduce population growth, buying food from small farmers to increase food security, and issuing small loans to help people start businesses and buy land. 9. What is soil conservation? Describe six ways to reduce soil erosion. Summarize the history of soil erosion and soil conservation in the United States. Distinguish among the uses of organic fertilizer, manufactured inorganic fertilizer, animal manure, green manure, and compost as ways to help restore topsoil fertility. Describe ways to prevent and clean up soil salinization. How can we reduce desertification? How can we make aquaculture more sustainable? Describe ways to produce meat more efficiently and sustainably. Summarize three important aspects of making a shift to more sustainable food production. Describe the advantages of organic farming and its role in shifting to more sustainable agriculture. What five strategies could help farmers and consumers shift to more sustainable agriculture? What are three important ways in which individual consumers can help to promote more sustainable agriculture? Answer: • Soil conservation involves using a variety of ways to reduce soil erosion and restore soil fertility, mostly by keeping the soil covered with vegetation. • Soil conservation methods include: terracing, contour planting and strip cropping, alley cropping, windbreaks, cover crops, conservation tillage farming, no-till, and minimum-tillage farming. • See Case Study. Soil erosion in the United States – Learning from the Past • To restore soil nutrients, farmers can use organic fertilizer made from plant and animal wastes or commercial inorganic fertilizer produced from various minerals. ○ Commercial inorganic fertilizers contain nitrogen, phosphorus, and potassium. Inorganic fertilizer use has grown more than elevenfold since 1950. These fertilizers can run off the land and pollute nearby bodies of water and coastal estuaries where rivers empty into the sea. These fertilizers can replace depleted inorganic nutrients, but they do not replace organic matter. To completely restore nutrients to soil, both inorganic and organic fertilizers should be used. ○ There are many different types of organic fertilizer. Animal manure is the dung and urine of cattle, horses, poultry, and other farm animals. It adds organic nitrogen and stimulates the growth of beneficial soil bacteria and fungi. Green manure consists of freshly cut or growing green vegetation that is plowed into the topsoil to increase the organic matter and humus available to the next crop. Compost is produced when microorganisms in soil break down organic matter such as leaves, crop residues, food wastes, paper, and wood in the presence of oxygen. • Methods for preventing soil salinization include: reduce irrigation and switch to salt-tolerant crops (such as barley, cotton, and sugar beet). Clean-up includes: flush soil (expensive and wastes water), stop growing crops for 2–5 years, and install underground drainage systems (expensive). • We can reduce desertification by reducing population growth, overgrazing, deforestation, and destructive methods of planting, irrigating, and mining, which have left much land vulnerable to desertification. We can also decrease the human contribution to global climate change. • Ways to make aquaculture more sustainable and to reduce its harmful effects: ○ Restrict locations of fish farms to reduce losses of mangrove forests and estuaries. ○ Improve management of aquaculture wastes. ○ Reduce escape of aquaculture species into the wild. ○ Raise some aquaculture species in deeply submerged cages to protect them from wave action and predators and to allow dilution of wastes into the ocean. ○ Certify sustainable forms of aquaculture and label products accordingly. • A more sustainable form of meat production and consumption involves shifting from less grain-efficient forms of animal protein, such as beef, pork, and carnivorous fish produced by aquaculture, to more grain-efficient forms, such as poultry and herbivorous farmed fish. Another approach is to find alternatives to growing grain to feed livestock. India’s dairy industry based mostly on feeding dairy cows roughage such as rice straw, wheat straw, corn stalks, and grass gathered from roadsides. Developing meat substitutes is an alternative. • Three important aspects of shifting to more sustainable food production are that it would require less energy, would restore topsoil fertility and reduce erosion, and be more profitable for families while enhancing food security. • In organic farming crops are grown with little or no use of synthetic pesticides, synthetic fertilizers, or genetically engineered seeds. Livestock are raised without use of genetic engineering, synthetic growth regulators, or feed additives. Fields must be free of chemicals for 3 years before crops grown there can be certified as organic. Since 1990, organic farming has been the fastest growing sector of the agricultural economy. • Five strategies for shifting to a more sustainable agriculture include: ○ Increasing research on more sustainable organic farming. ○ Establishing education and training programs in more sustainable agriculture. ○ Setting up an international fund to give farmers in poor countries access to forms of more sustainable agriculture. ○ Replacing government subsidies for environmentally harmful forms of industrialized agriculture with subsidies that encourage more sustainable agriculture. ○ Mounting a massive program to educate consumers about the true costs of the food they buy. • Individual consumers can: ○ Use organic farming to grow some of their own food. ○ Buy certified organic food. ○ Eat locally grown food. 10. What are the three big ideas of this chapter? Describe the relationship between industrialized agriculture and the three principles of sustainability. How can these principles be applied toward making a shift to more sustainable food production systems. Answer: • The three big ideas are: ○ More than 1 billion people have health problems because they do not get enough to eat and 1.1 billion people face health problems from eating too much. ○ Modern industrialized agriculture has a greater harmful impact on the environment than any other human activity. ○ More sustainable forms of food production will greatly reduce the harmful environmental impacts of current systems while increasing food security. • Industrialized agriculture diminished biodiversity, neglects the natural cycling of nutrients by degrading topsoil, and relies on fossil fuel inputs. • These principles call for a more sustainable agricultural system that conserves biodiversity, cycles nutrients and is solar powered. Critical Thinking The following are examples of the material that should be contained in possible student answers to the end of chapter Critical Thinking questions. They represent only a summary overview and serve to highlight the core concepts that are addressed in the text. It should be anticipated that the students will provide more in-depth and detailed responses to the questions depending on an individual instructor’s stated expectations. 1. Do you think that the advantages of organic agriculture (Core Case Study) outweigh its disadvantages? Explain. Do you eat or grow organic foods? If so, explain your reasoning for making this choice. If not, explain your reasoning for the food choices you do make. Answer: Many people are finding that organic agriculture is advantageous for various reasons. Personal health and health of ecosystems are commonly cited reasons. Many suggest that we should embrace sustainable approached to food production now, as food prices in a conventional system are closely tied to oil prices, because of the substantial energy requirements. As oil becomes scarcer and more expensive, it will become necessary for society to rely on more environmentally sustainable approaches. Nevertheless, many people cite cost as a reason for not embracing organic production. 2. What are the three most important actions you would take to reduce chronic hunger and malnutrition: (a) in the country where you live, and (b) in the world? Answer: (a) In the U.S. I would: provide more food subsidy programs to underprivileged people, especially those with children in the household; educate about good nutrition and try to move people away from eating “junk” food; and provide free health care and immunizations especially for children and the elderly. (b) Globally I would: initiate programs that alleviate poverty; increase education of women, including nutrition and family planning programs; and provide sources of clean drinking water for children and adults. 3. Explain why you support or opposed greatly increased use of: a) genetically modified food, b) organic polyculture, and c) hydroponic agriculture. Answer: Answers will vary but may include potential nutritional benefits of GMOs, decreased use of pesticides and potential increases in agricultural productivity. Note that none of these are completely clear-cut. Polyculture can aid biodiversity, promote genetic diversity in food crops, and may benefit smaller farms. Hydroponics is a wonderful option for developed nations (because of the investment required) that are dealing with water shortages and wish to reduce the use of chemical pesticides. a) Genetically Modified Food: Supports increased yields and improved nutrition. b) Organic Polyculture: Enhances biodiversity and sustainability. c) Hydroponic Agriculture: Efficient in water use and ideal for urban farming. 4. Suppose you live near a coastal area and a company wants to use a fairly large area of coastal marshland for an aquaculture operation. If you were an elected local official, would you support or oppose such a project? Explain. What safeguards or regulations would you impose on the operation? Answer: Supporting or opposing the project will depend on student perspectives. Issues include such things as mangrove destruction, water pollution, and potential escape of organisms (genetically modified or otherwise) from the operation. Safeguards would be aimed at addressing these issues by protecting native mangroves and wetlands and improving management of wastes. 5. Explain how widespread use of a pesticide can: (a) increase the damage done by a particular pest, and (b) create new pest organisms. Answer: (a) The target pest could develop resistance to the pesticide. All the susceptible members would be killed, but a small number may be genetically resistant to the pesticide and over several breeding generations could become a bigger problem than the initial outbreak. This is called a resurgence of the pest. (b) The pesticide could wipe out a species that may be a natural predator of another organism. Without the natural predator to hold the other organism population in check, their numbers could increase to the point that they now become a problem. This way an organism that previously was not considered to be a pest has now been turned into a “pest.” 6. If a local mosquito population threatened you with malaria or West Nile virus, would you spray DDT in your yard and inside your home to reduce the risk? Explain. What are the alternatives? Answer: No, I would not spray DDT. I would use mosquito nets to sleep under in bedrooms, put screens on all doors and windows, make sure that there are no containers outside where standing water could collect, install many bat houses around the property, use an insect repellant like DEET, and wear long sleeves and long pants when I go outside. 7. List three ways in which your lifestyle directly or indirectly contributes to topsoil erosion. Answer: Our lifestyles tend to support erosion indirectly by virtue of supporting conventional agriculture, supporting meat production systems that lead to overgrazing, and supporting industries that deforest or otherwise denude the landscape. 8. According to physicist and philosopher Albert Einstein, “Nothing will benefit human health and increase chances of survival of life on Earth as much as the evolution to a vegetarian diet.” Are you willing to eat less meat or no meat? Explain. Answer: Answers will depend on the student—the argument to eat less meat (or different types of meat) however makes a great deal of sense from an environmental and resource use perspective. Yes, I'm willing to eat less meat. Reducing meat consumption can benefit personal health, reduce environmental impact, and promote animal welfare. 9. Congratulations! You are in charge of the world. List the three most important features of: (a) your agricultural policy, (b) your policy to reduce soil erosion, (c) your policy for more sustainable harvesting and farming of fish and shellfish, and (d) your global pest management strategy. Answer: (a) Agriculture: crop rotation, efficient irrigation, and use of organic fertilizers. (b) Soil erosion: limit grazing; promote contour farming and strip cropping; use no-till agriculture, and many other soil conservation strategies. (c) Fisheries: eliminate government subsidies on commercial fishing, mandate fish catches below the maximum sustainable yield, and establish a global monitoring organization. (d) Global pest management: use biological controls, introduce integrated pest management (IPM) strategies, and move towards polycultures rather than monocultures. 10. List two questions that you would like to have answered as a result of reading this chapter. Answer: 1. How does a vegetarian diet specifically contribute to improving human health and environmental sustainability? 2. What are the challenges and potential solutions for individuals transitioning to a vegetarian or plant-based diet? Data Analysis 1. Use the world fish harvest and population data in the table to calculate the per capita fish consumption from 1990-2003 in kilograms/person. (Hints: 1 million metric tons equals one billion kilograms; and per capita consumption can be calculated directly by dividing the total amount consumed by a population figure for any year.) Data from United Nations Food and Agricultural Organization 2. Has per capita fish consumption generally increased or generally decreased between 1990 and 2003? 3. In what years has the per capita fish consumption decreased? 1. Answer: See table below. 2. Answer: It has generally increased. 3. Answer:1990, 1997, 2000, 2002 Solution Manual for Living in the Environment: Principles, Connections, and Solutions G. Tyler Miller, Scott Spoolman 9780538735346