Discussion Questions:

• A number of kangaroos died during the research study due to predation or automobile collisions. How does this impact the data gathered? How can researchers anticipate and address the loss of subjects?
• If GPS tracking collars were not available, what other methods could have been used to track kangaroo movement?
• What did the research reveal? How would you use this information to influence government policy? What policies would you put in place to protect the people who live in Canberra? What policies would you put in place to protect the kangaroos who reside in Canberra?

Background Essay:

Kangaroos are iconic to the Australian landscape and are known for their unique locomotion. The eastern gray kangaroo is a formidable marsupial that can grow to be 7 feet tall (2.1 m) and can weigh up to 120 pounds (54 kg). Their hind legs and feet are strong and help to propel the kangaroo into the air. Their tails are particularly muscular and work to maintain balance and direction when they are hopping.

The kangaroo’s strong legs allow this animal to bound 25 feet (8 m) in a single leap and jump up to 10 feet high. They can reach speeds of up to 35 miles per hour (56 km) and can travel for long distances over hilly terrain at an average of 15 miles per hour.

There are tens of thousands of eastern gray kangaroos in the Australian Capital Territory (ACT), inhabiting a widespread area from the grassy plains and river valleys to the hills and into the developing city. Each year there are approximately 2,000 motor vehicle collisions with kangaroos in Canberra alone. As a result, the government is investigating kangaroo behavior so they can develop programs to protect the area inhabitants, both human and marsupial.  In this video segment, government researchers Claire Wimpenny and Don Fletcher discuss their research study to track the movements and behavior of twenty-five eastern gray kangaroos in and around Canberra using GPS-enabled collars. This research will provide the government with evidence to make policy decisions regarding future kangaroo control programs, and potentially reduce the risk of motor vehicle collisions.

At the start of this research study, each selected kangaroo is darted with a tranquillizer and then fitted with a radio collar. Such collars were first used for research in 1994 and since their introduction, the size and weight have been reduced, longevity increased, and data storage and retrieval ability improved. Today’s standard collar consists of a GPS receiver and antenna, a VHF beacon system, data storage hardware, and a battery power supply. Each unit records the animal’s positions at every hour of every day over the course of an entire year.  After the period of one year, the collars are preprogrammed to automatically release from the kangaroo and fall off. Once the scientists collect the collars, the information is downloaded and compiled to create a detailed map of the kangaroo’s movements.

The use of GPS technology for wildlife tracking is still relatively new to the field of science. As the technology improves, the depth of the research will also improve. For example, advances in the collar structure have allowed for lighter units to be built for use on smaller animals such as the wolf. Additionally, as the awareness of such research studies spread, government agencies will begin to see the policy implications of such animal movement and behavior pattern data.

For more information, go to:

• Kangaroo Mob: Kangaroo Fact Sheet
• Kangaroo Research
• Movement Behaviour of Kangaroos in Urban Canberra

National Science Education Standards

Grades 5-8:

Content Standard C: Life Science

Fundamental concepts and principles that underlie this standard include:

• Regulation and Behavior
  • An organism’s behavior evolves through adaptation to its environment. How a species moves, obtains food, reproduces, and responds to danger are based in the species’ evolutionary history.

Content Standard D: Earth and Science

Fundamental concepts and principles that underlie this standard include:

• Science and Technology
  • Science and technology are reciprocal. Science helps drive technology, as it addresses questions that demand more sophisticated instruments and provides principles for better instrumentation and technique. Technology is essential to science, because it provides instruments and techniques that enable observations of objects and phenomena that are otherwise unobservable due to factors such as quantity, distance, location, size, and speed. Technology also provides tools for investigations, inquiry, and analysis.
  • Technological designs have constraints. Some constraints are unavoidable, for example, properties of materials, or effects of weather and friction; other constraints limit choices in the design, for example, environmental protection, human safety, and aesthetics.

Content Standard G: History and Nature of Science

Fundamental concepts and principles that underlie this standard include:

• Nature of Science
  • Scientists formulate and test their explanations of nature using observation, experiments, and theoretical and mathematical models. Although all scientific ideas are tentative and subject to change and improvement in principle, for most major ideas in science, there is much experimental and observational confirmation. Those ideas are not likely to change greatly in the future. Scientists do and have changed their ideas about nature when they encounter new experimental evidence that does not match their existing explanations.

Grades 9-12:

Content Standard C: Life Science

Fundamental concepts and principles that underlie this standard include:

• The Behavior of Organisms
  • Organisms have behavioral responses to internal changes and to external stimuli. Responses to external stimuli can result from interactions with the organism’s own species and others, as well as environmental changes; these responses either can be innate or learned. The broad patterns of behavior exhibited by animals have evolved to ensure reproductive success. Animals often live in unpredictable environments, and so their behavior must be flexible enough to deal with uncertainty and change. Plants also respond to stimuli.

Content Standard E: Science and Technology

Fundamental concepts and principles that underlie this standard include:

• Understandings About Science and Technology
  • Science often advances with the introduction of new technologies. Solving technological problems often results in new scientific knowledge. New technologies often extend the current levels of scientific understanding and introduce new areas of research.
  • Creativity, imagination, and a good knowledge base are all required in the work of science and engineering.
  • Science and technology are pursued for different purposes. Scientific inquiry is driven by the desire to understand the natural world, and technological design is driven by the need to meet human needs and solve human problems. Technology, by its nature, has a more direct effect on society than science because its purpose is to solve human problems, help humans adapt, and fulfill human aspirations. Technological solutions may create new problems. Science, by its nature, answers questions that may or may not directly influence humans. Sometimes scientific advances challenge people’s beliefs and practical explanations concerning various aspects of the world.

Content Standard G: History and Nature of Science

Fundamental concepts and principles that underlie this standard include:

• Nature of Scientific Knowledge
  • Scientific explanations must meet certain criteria. First and foremost, they must be consistent with experimental and observational evidence about nature, and must make accurate predictions, when appropriate, about systems being studied. They should also be logical, respect the rules of evidence, be open to criticism, report methods and procedures, and make knowledge public. Explanations on how the natural world changes based on myths, personal beliefs, religious values, mystical inspiration, superstition, or authority may be personally useful and socially relevant, but they are not scientific.
  • Because all scientific ideas depend on experimental and observational confirmation, all scientific knowledge is, in principle, subject to change as new evidence becomes available. The core ideas of science such as the conservation of energy or the laws of motion have been subjected to a wide variety of confirmations and are therefore unlikely to change in the areas in which they have been tested. In areas where data or understanding are incomplete, such as the details of human evolution or questions surrounding global warming, new data may well lead to changes in current ideas or resolve current conflicts. In situations where information is still fragmentary, it is normal for scientific ideas to be incomplete, but this is also where the opportunity for making advances may be greatest.

Discussion Questions:

• How can the cull be considered an example of a practice that is “cruel to be kind”?
• Can culling be done humanely?  Defend your answer.
• What are the limitations to the humane practices of kangaroo sanctuaries and contraception?
• What do you think the best solution is to the surging kangaroo population: the cull, kangaroo sanctuaries or contraception? Explain your rationale.
• Is it wrong to kill an animal that has become part of the Australian identity?  Why or why not?

Background Essay:

The kangaroo is one of Australia’s most iconic animals, but their growing numbers have resulted in a controversy of epic proportions. In the last 50 years the kangaroo population in the Australian capital city of Canberra has exploded from a few hundred to tens of thousands, thusly earning the moniker “Urban Kangaroos.”

The area surrounding Canberra has been in a drought for the past 15 years. As a result, eastern gray kangaroos have been forced from their natural habitat in the hills above the city into suburban lawns and urban parks to graze on grass. Further exacerbating the situation is urban development and a lack of predation.  Urban expansion has resulted in land clearing that provides open pastures for grazing. Additionally, population control has all but wiped out the kangaroos’ natural predator, the dingo.

Overgrazing reduces grassy fields to dust and destroys the natural habitat of a number of endangered species, including the grassland earless dragon, the striped legless lizard, and the golden sun moth. With the kangaroo numbers continuing to grow, the government solution has been to reduce the population though culling, a process that is conducted under the strict environmental controls provided by the Australian Government’s Environment Protection and Biodiversity Conservation Act of 1999. The cull is carried out by experienced marksmen who shoot adult kangaroos in the head, while crushing or decapitating the young joeys. Media coverage and protest groups have brought a great deal of attention to this government practice and have prompted a national debate over the appropriateness of the cull.

The heated debate is leading many scientists to look for more humane and efficient solutions to the surging population that is currently damaging the ecosystem. One alternative is to move a portion of the kangaroos from overpopulated areas to dedicated sanctuaries that can easily accommodate them. Scientists have captured, rehabilitated, and released injured kangaroos into protected areas where the kangaroos can live in their natural habitat without threat or intrusion. Critics of this solution believe there are far too many kangaroos to safely and economically capture and release a large enough number to have a positive impact on the ecosystem. Scientists are also researching methods to limit the reproduction of kangaroos. The research is aimed at developing a species-specific, orally-delivered contraceptive vaccine that can be easily spread out in the wild for eastern gray kangaroos. Current research reveals the vaccine can provide sterility for at least three years. Ongoing drug trials will take researchers approximately 10 years to establish the long-term effectiveness of the drug and its environmental and ecological safety. Until this time, the cull will be the only safe and economic solution to the kangaroo population problem.

For more information, go to:

• Kangaroo Mob: Kangaroo Fact Sheet
• Birth Control for Kangaroos: Scientists’ Population Control Plan
• Kangaroo Population Control Methods
• Environment Protection and Biodiversity Conservation Act
• RSPCA Australia Knowledgebase

National Science Education Standards

Grades 5-8:

Content Standard C: Life Science

Fundamental concepts and principles that underlie this standard include:

• Regulation and Behavior
  • All organisms must be able to obtain and use resources, grow, reproduce, and maintain stable internal conditions while living in a constantly changing external environment.
• Populations and Ecosystems
  • A population consists of all individuals of a species that occur together at a given place and time. All populations living together and the physical factors with which they interact compose an ecosystem.
  • The number of organisms an ecosystem can support depends on the resources available and abiotic factors, such as quantity of light and water, range of temperatures, and soil composition. Given adequate biotic and abiotic resources and no disease or predators, populations (including humans) increase at rapid rates. Lack of resources and other factors, such as predation and climate, limit the growth of populations in specific niches in the ecosystem.
• Diversity And Adaptations of Organisms
  • Extinction of a species occurs when the environment changes and the adaptive characteristics of a species are insufficient to allow its survival. Fossils indicate that many organisms that lived long ago are extinct. Extinction of species is common; most of the species that have lived on the earth no longer exist.

Grades 9-12:

Content Standard C: Life Science

Fundamental concepts and principles that underlie this standard include:

• The Interdependence of Organisms
  • Organisms both cooperate and compete in ecosystems. The interrelationships and interdependencies of these organisms may generate ecosystems that are stable for hundreds or thousands of years.
  • Living organisms have the capacity to produce populations of infinite size, but environments and resources are finite. This fundamental tension has profound effects on the interactions between organisms.
• Matter, Energy, and Organization in Living Systems
  • The distribution and abundance of organisms and populations in ecosystems are limited by the availability of matter and energy and the ability of the ecosystem to recycle materials.

Content Standard E: Science and Technology

Fundamental concepts and principles that underlie this standard include:

• Understandings About Science and Technology
  • Scientists in different disciplines ask different questions, use different methods of investigation, and accept different types of evidence to support their explanations. Many scientific investigations require the contributions of individuals from different disciplines, including engineering. New disciplines of science, such as geophysics and biochemistry often emerge at the interface of two older disciplines.

Discussion Questions:

• What do the Amazon basin and Queensland, Australia have in common? What is the driving force behind this? Which do you think is more important—the needs of human populations or the need to conserve natural habitats and protect the species which live in them? How would you propose striking a balance between the two?
• What are some of the hazards faced by koalas in the suburban habitats in which they now find themselves living?
• Are large highways impassable for koalas? How did scientists learn the answer?
• What measures are Australian authorities taking to protect koala populations from cars? Are they working? How do they know?

Background Essay:

Despite being one of the most recognizable and beloved icons of Australia, the koala is a threatened species. Although the exact size of the current koala population is unknown—ranging from several hundred thousand to as few as 43,000—what is clear is that environmental trends are all working against the species, which once roamed freely across eastern Australia.

As is so often the case, the primary threat to the species has been human activity. The koala population never recovered from the early 20^th century, when millions of koalas were hunted and trapped for their fur. Laws have since been passed throughout Australia prohibiting the harming of koalas, or even ownership of them as pets. Today, the main threat from humans is far less intentional, but far more difficult to stop: land development.

It’s a story familiar to anyone who’s followed the plight of bears, wolves, and many other formerly wild animals whose natural habitat has been cleared and converted into an ever-growing mass of suburban sprawl. Koalas are especially vulnerable as their habitat is restricted to their single food source: eucalyptus gum trees. Koalas require large expanses of healthy, connected eucalyptus forest in which to travel in search of new mates to maintain their genetic diversity. As Australia’s suburbs have expanded over the course of the past century, 80% of its eucalyptus forests have been cleared and partitioned by roads, isolating koala populations in ever smaller and more crowded pockets of “bush.” This isolation in itself presents a serious problem, as increasingly inbred koala populations have proven highly susceptible to sexually transmitted diseases like chlamydia—symptoms of which have been noted in 50% of the koala population of the Australian state of Queensland.

Although individual humans generally regard their furry new neighbors with affection, their suburban environment presents challenges like traffic accidents and dog attacks with which koalas are ill-equipped to contend. Having identified cars as the number one killer of koalas—accounting for over one third of all deaths—Australian authorities have begun planting eucalyptus trees on highway overpasses, building highway underpasses along identified corridors of koala travel, and establishing protected habitats where koalas can live without the hazards of modern human conveniences.

National Science Education Standards

Life Science – Content Standard C
As a result of their activities in grades 9-12, all students should develop understanding of:

• Interdependence of organisms
  • Living organisms have the capacity to produce populations of infinite size, but environments and resources are finite. This fundamental tension has profound effects on the interactions between organisms.
  • Human beings live within the world’s ecosystems. Increasingly, humans modify ecosystems as a result of population growth, technology, and consumption. Human destruction of habitats through direct harvesting, pollution, atmospheric changes, and other factors is threatening current global stability, and if not addressed, ecosystems will be irreversibly affected.

• Behavior of organisms
  • Organisms have behavioral responses to internal changes and to external stimuli. Responses to external stimuli can result from interactions with the organism’s own species and others, as well as environmental changes; these responses either can be innate or learned. The broad patterns of behavior exhibited by animals have evolved to ensure reproductive success. Animals often live in unpredictable environments, and so their behavior must be flexible enough to deal with uncertainty and change. Plants also respond to stimuli.

Science in Personal and Social Perspectives – Content Standard F
As a result of activities in grades 5-8, all students should develop understanding of

• Populations, resources, and environments
  • When an area becomes overpopulated, the environment will become degraded due to the increased use of resources.
  • Causes of environmental degradation and resource depletion vary from region to region and from country to country.

• Natural hazards
  • Human activities also can induce hazards through resource acquisition, urban growth, land-use decisions, and waste disposal. Such activities can accelerate many natural changes.

As a result of activities in grades 9-12, all students should develop understanding of

• Natural resources
  • Humans use many natural systems as resources. Natural systems have the capacity to reuse waste, but that capacity is limited. Natural systems can change to an extent that exceeds the limits of organisms to adapt naturally or humans to adapt technologically.
• Environmental quality
  • Human activities can enhance potential for hazards. Acquisition of resources, urban growth, and waste disposal can accelerate rates of natural change.
• Science and technology in local, national, and global challenges
  • Humans have a major effect on other species. For example, the influence of humans on other organisms occurs through land use—which decreases space available to other species—and pollution—which changes the chemical composition of air, soil, and water.

Discussion Questions:

• What is the Exclusion Zone and why was it established?
• What happened to require the political division of the Exclusion Zone?
• How does radiation released into the air by the Chernobyl accident in 1986 get into the bodies of animals today?
• What are the three fundamental questions that German scientists Barbara and Kristoff Promberger have come to the Exclusion Zone to answer? What will the answers tell them?
• How does the Pripyat River contribute to spreading the radioactive pollution of the Chernobyl disaster?
• Who were the Liquidators? Who were most of the people relocated after the Chernobyl disaster?

Background Essay:

On April 26, 1986 an accident in one of the reactors at the Chernobyl nuclear power plant in the Soviet Union caused a meltdown. The resulting fire sent a billowing cloud of radioactive smoke over an area of 100,000 square kilometers of the Soviet Union and Eastern Europe.

The reactor fire was eventually contained by the valiant self-sacrifice of the plant’s firefighters, many of whom died shortly thereafter from acute radiation sickness.  600,000 workers, known as “liquidators,” were then brought in to clean up the contaminated site. Their main task was the construction of a containment structure—known as the “sarcophagus”—over the damaged reactor to prevent further meltdown and seal off radiation leaks.  Even though they wore heavy protective gear, liquidators working in the areas of greatest radioactivity around the reactor had to be rotated out every 40 seconds. By the time the sarcophagus had been completed in December 1986, the liquidators had, on average, sustained the official lifetime limit of radiation exposure.

Chernobyl was the single greatest nuclear accident in history, releasing 400 times more radioactivity into the atmosphere than the Hiroshima bomb and tripling the world’s “background” radiation level.  It is one of only two nuclear disasters classified as a “Level 7”—the highest severity—the other being the 2011 Fukushima Daiichi disaster in Japan. The Soviet Union only officially announced the disaster three days after the explosion, after scientists in Sweden noticed radiation on their shoes before entering a nuclear facility. Soviet authorities eventually evacuated approximately 400,000 people from Ukraine, Belarus, and Russia—the areas of most concentrated contamination.

Today, an area extending 19 miles in all directions from the plant is known as the “exclusion zone,” uninhabited by humans except for several hundred elderly residents of the area who have chosen to live out their lives in their contaminated homes. The area has largely reverted to its original forest and swamp environment, and many animal species are thriving in the restored habitat, but radiation levels remain so high that the workers who are in the process of building a new sarcophagus around the damaged reactor are only allowed to work five hours a day for one month before taking 15 days of rest. Ukrainian officials estimate the area will not be completely safe for human life again for another 20,000 years.

A United Nations report directly attributed 64 deaths to fallout radiation from Chernobyl, but the long-term health consequences for the millions exposed to radioactivity are difficult to ascertain.  The UN estimates that upwards of 4,000 people may eventually die of disease—mostly cancer and leukemia—linked to their exposure, and other sources estimate over 200,000 premature deaths linked to the disaster.

National Science Education Standards

Science in Personal and Social Perspectives – Content Standard F

As a result of activities in grades 5-8, all students should develop understanding of

• Personal health
  • Natural environments may contain substances (for example, radon and lead) that are harmful to human beings. Maintaining environmental health involves establishing or monitoring quality standards related to use of soil, water, and air.
• Populations, resources, and environments
  • Causes of environmental degradation and resource depletion vary from region to region and from country to country.
• Natural hazards
  • Human activities also can induce hazards through resource acquisition, urban growth, land-use decisions, and waste disposal. Such activities can accelerate many natural changes.
• Risks and benefit
  • Risk analysis considers the type of hazard and estimates the number of people that might be exposed and the number likely to suffer consequences. The results are used to determine the options for reducing or eliminating risks.
  • Students should understand the risks associated with natural hazards (fires, floods, tornadoes, hurricanes, earthquakes, and volcanic eruptions), with chemical hazards (pollutants in air, water, soil, and food), with biological hazards (pollen, viruses, bacterial, and parasites), social hazards (occupational safety and transportation), and with personal hazards (smoking, dieting, and drinking).

As a result of activities in grades 9-12, all students should develop understanding of

• Personal and community health
  • Hazards and the potential for accidents exist. Regardless of the environment, the possibility of injury, illness, disability, or death may be present. Humans have a variety of mechanisms—sensory, motor, emotional, social, and technological—that can reduce and modify hazards.
• Natural and human-induced hazards
  • Human activities can enhance potential for hazards. Acquisition of resources, urban growth, and waste disposal can accelerate rates of natural change.
  • Some hazards, such as earthquakes, volcanic eruptions, and severe weather, are rapid and spectacular. But there are slow and progressive changes that also result in problems for individuals and societies. For example, change in stream channel position, erosion of bridge foundations, sedimentation in lakes and harbors, coastal erosions, and continuing erosion and wasting of soil and landscapes can all negatively affect society.
  • Natural and human-induced hazards present the need for humans to assess potential danger and risk. Many changes in the environment designed by humans bring benefits to society, as well as cause risks. Students should understand the costs and trade-offs of various hazards—ranging from those with minor risk to a few people to major catastrophes with major risk to many people. The scale of events and the accuracy with which scientists and engineers can (and cannot) predict events are important considerations.
• Science and technology in local, national, and global challenges
  • Humans have a major effect on other species. For example, the influence of humans on other organisms occurs through land use—which decreases space available to other species—and pollution—which changes the chemical composition of air, soil, and water.

Discussion Questions:

• What does the existence of newborn wolf pups in the Exclusion Zone prove about the local wolf population?
• Is there any evidence that long term radiation exposure is affecting the health of white lab rats?
• What is the Red Forest?
• Why is a windy day particularly dangerous in the Zone?
• What is the rate of genetic abnormalities in the dormice in the Zone? What impact does this have on the dormouse population more generally?
• How does the reproduction rate of dormice inside the Zone compare with those outside it? What might be responsible for this?

Background Essay:

We tend to think of radiation as something inherently harmful to living things. When getting X-rayed, we shield ourselves with heavy lead aprons from as much of the processes’ radiation as possible; we use radiation therapy to destroy cancerous cells; and we are grimly aware from grainy newsreel footage of the horrific damage done to human bodies by the radioactive blasts of the Hiroshima and Nagasaki atom bombs in World War II. These are all, however, exceptional instances of artificially intensified radiation.

Radiation is most simply defined as the process by which energy particles or waves move through space. It is commonly differentiated into “ionized” and “non-ionized” types, with the latter including such relatively safe and familiar phenomena as heat, light, and radio waves. Ionized radiation, however, has sufficient energy to “ionize” atoms by stripping them of electrons, and in sufficient quantities, it can be particularly damaging to the cell structure and genetic code (DNA) of living organisms.

A certain amount of ionized radiation—called “background radiation”—is all around us, all the time. It is a naturally occurring part of the environment, coming from both outer space in the form of “cosmic” radiation, and the earth itself as “terrestrial” radiation. It is common in certain building materials like brick and stone, and certain potassium-rich foods like bananas and Brazil nuts. It is found in the air that we breathe, which is laced with radon gas from the earth’s crust. Overall, these natural sources account for about half of a U.S. citizen’s total annual average radiation exposure, with the other half coming mostly from diagnostic medical procedures like X-rays and CT scans. No adverse health effects have been discerned from normal doses of radiation exposure.

Occasionally, however, humans have been exposed to much higher levels of radiation. Firefighters and other first-response emergency workers at the Chernobyl nuclear power plant meltdown in 1986 received up to 16,000 times the maximum recommended annual radiation exposure. Such intensely high exposure—even if only for a short duration—destroys cells and triggers Acute Radiation Syndrome, the massive and painful organ failure which killed 28 of the emergency workers within three months.

Lower doses of radiation over longer periods of time tend to damage or alter the DNA of irradiated cells rather than killing them outright. Cancers—often undetected for extended latency periods—are the most common consequence of low-level radiation. Genetic effects include an increased risk of still birth and low birth weight, infant and childhood mortality, and congenital abnormalities and mutations that may or may not affect later generations. Research on humans who have suffered long-term exposure is inconclusive and heavily debated, but research in the Exclusion Zone surrounding the site of the Chernobyl disaster suggests that while animal populations there may suffer a higher rate of individual birth defects, their overall health is robust and their population is booming.

National Science Education Standards

Science in Personal and Social Perspectives – Content Standard F

As a result of activities in grades 5-8, all students should develop understanding of

• Personal health
  • Natural environments may contain substances (for example, radon and lead) that are harmful to human beings. Maintaining environmental health involves establishing or monitoring quality standards related to use of soil, water, and air.
• Populations, resources, and environments
  • Causes of environmental degradation and resource depletion vary from region to region and from country to country.
• Risks and benefits
  • Risk analysis considers the type of hazard and estimates the number of people that might be exposed and the number likely to suffer consequences. The results are used to determine the options for reducing or eliminating risks.
  • Students should understand the risks associated with natural hazards (fires, floods, tornadoes, hurricanes, earthquakes, and volcanic eruptions), with chemical hazards (pollutants in air, water, soil, and food), with biological hazards (pollen, viruses, bacterial, and parasites), social hazards (occupational safety and transportation), and with personal hazards (smoking, dieting, and drinking).

As a result of activities in grades 9-12, all students should develop understanding of

• Personal and community health
  • Hazards and the potential for accidents exist. Regardless of the environment, the possibility of injury, illness, disability, or death may be present. Humans have a variety of mechanisms—sensory, motor, emotional, social, and technological—that can reduce and modify hazards.
• Natural and human-induced hazards
  • Human activities can enhance potential for hazards. Acquisition of resources, urban growth, and waste disposal can accelerate rates of natural change.
  • Some hazards, such as earthquakes, volcanic eruptions, and severe weather, are rapid and spectacular. But there are slow and progressive changes that also result in problems for individuals and societies. For example, change in stream channel position, erosion of bridge foundations, sedimentation in lakes and harbors, coastal erosions, and continuing erosion and wasting of soil and landscapes can all negatively affect society.
  • Natural and human-induced hazards present the need for humans to assess potential danger and risk. Many changes in the environment designed by humans bring benefits to society, as well as cause risks. Students should understand the costs and trade-offs of various hazards—ranging from those with minor risk to a few people to major catastrophes with major risk to many people. The scale of events and the accuracy with which scientists and engineers can (and cannot) predict events are important considerations.
• Science and technology in local, national, and global challenges
  • Humans have a major effect on other species. For example, the influence of humans on other organisms occurs through land use—which decreases space available to other species—and pollution—which changes the chemical composition of air, soil, and water.

Discussion Questions:

• What massive project did the Soviet Union undertake in the Pripyat Marshes in the 1920s? What did it entail?
• What was the purpose of “land improvement?”
• Since the Chernobyl disaster, how has wildlife helped restore the land to its original state?

Background Essay:

The Pripyat Marshes is the vast “inland delta” of the Pripyat River and its tributaries covering approximately 100,000 square miles of the Eastern European nations of Belarus and Ukraine.  The landscape of swampy rivers, sandy floodplains, and dense forests has never been particularly hospitable to human habitation. They were for centuries a largely impassable wilderness and a major strategic obstacle for invaders ranging from Ghenghis Khan to Hitler.

In the 1870s, when the marshes fell within Tsarist Russia’s borders, the first attempts were made to drain the land and put it to agricultural use.  These efforts were revived with considerably greater fervor in the 1920s, with the establishment of the Soviet Union and its aggressive Five Year Plans to modernize and expand the Soviet economy.  This “land improvement” involved clearing vast swathes of forest, damming rivers into reservoirs, and digging thousands of miles of canals. Thousands of settlers were brought in to work on newly established government-owned “collective farms,” where they worked together to help grow and harvest the rye, barley, wheat, and flax which made Ukraine the “breadbasket of the Soviet Union.”

While making parts of the Pripyat Marshes much more habitable and productive for the Soviets, land improvement destroyed much of the natural wetland ecosystem which had once thrived there. The elk, wolves, foxes, and other game animals which survived were aggressively hunted, as were beavers, considered vermin because their dams obstructed canals.

Even after the agricultural settlement of the southern Pripyat Marshes, the overall human population there remained relatively sparse, and this, combined with the availability of water from the Pripyat River, determined the government’s decision in 1970 to build the Chernobyl Nuclear Power Plant on the river, along with an adjoining city of modern steel and concrete called Pripyat to house the plant’s workers.

Pripyat was evacuated on April 27, 1986—the day after the accident at Chernobyl. Told only to bring the bare necessities, Pripyat’s residents would never return, leaving the city an eerie time capsule of that day. The sudden death of nearby pines in what would become known as “The Red Forest” seemed to confirm fears that nuclear contamination would render the area a desert.  An “Exclusion Zone” was established around Chernobyl, cordoning off the area of greatest radioactivity from everyone but official government workers.

Nature in the Exclusion Zone has proven far more resilient than expected. Suddenly and completely free of the humans who had hunted them for centuries and destroyed so much of their natural habitat, however, and despite lingering levels of radioactivity that would be unacceptable for humans, wildlife has flourished. With it has come a gradual return of the land itself to its natural, pre-“improvement” state. Forests are overgrowing abandoned cities and beavers are busily damming rivers and canals, returning hard-won agricultural land to swampy marsh and reestablishing the complex wetlands ecosystem which once thrived there. Much like the Chernobyl disaster itself, the new wilderness of the Exclusion Zone is a stark reminder of human limitations.

National Science Education Standards

Life Science – Content Standard C

As a result of their activities in grades 5-8, all students should develop understanding of

• Populations and ecosystems
  • The number of organisms an ecosystem can support depends on the resources available and abiotic factors, such as quantity of light and water, range of temperatures, and soil composition. Given adequate biotic and abiotic resources and no disease or predators, populations (including humans) increase at rapid rates. Lack of resources and other factors, such as predation and climate, limit the growth of populations in specific niches in the ecosystem.

As a result of their activities in grades 9-12, all students should develop understanding of

• Interdependence of organisms
  • Living organisms have the capacity to produce populations of infinite size, but environments and resources are finite. This fundamental tension has profound effects on the interactions between organisms
  • o Human beings live within the world’s ecosystems. Increasingly, humans modify ecosystems as a result of population growth, technology, and consumption. Human destruction of habitats through direct harvesting, pollution, atmospheric changes, and other factors is threatening current global stability, and if not addressed, ecosystems will be irreversibly affected.

Science in Personal and Social Perspectives – Content Standard F

As a result of activities in grades 5-8, all students should develop understanding of

• Populations, resources, and environments
  • Causes of environmental degradation and resource depletion vary from region to region and from country to country.
• Natural hazards
  • Human activities also can induce hazards through resource acquisition, urban growth, land-use decisions, and waste disposal. Such activities can accelerate many natural changes.

As a result of activities in grades 9-12, all students should develop understanding of

• Science and technology in local, national, and global challenges
  • Humans have a major effect on other species. For example, the influence of humans on other organisms occurs through land use—which decreases space available to other species—and pollution—which changes the chemical composition of air, soil, and water.

Discussion Questions:

Before watching the video:

• What species do you think might be affected by salmon?
• In what ways might these species be impacted by the presence or absence of salmon?

After watching the video:

• In the video, rancher and river guide Jerry Myers says, “You understand by living out here that things are connected and a big, huge part of that is salmon.” Provide examples from the video to support this statement.
• How do bears, birds, invertebrates and trees each benefit from the presence of salmon?
• In the video, author David James Duncan states, “As much as any species of plant and animal in the Pacific Northwest, if this creature is removed from the tapestry, the tapestry will unravel.” Provide reasons to support or refute the statement.
• Why are scientists depositing salmon carcasses and artificial substances into streams? How are they evaluating the impact of these efforts?

Background Essay:

Salmon live in the northern Atlantic and Pacific Oceans. Most are anadromous, meaning they are born in freshwater, migrate to the sea where they live for most of their lives, and then return to freshwater streams to spawn. In recent years, the number of salmon has decreased dramatically due to a combination of natural and human-related factors. In the Colorado River, the salmon population is approximately 3% of what it was in the early 1800s.

Some factors posing threats to salmon are rising stream and river temperatures, due to climate change; pollution, which is damaging and sometimes deadly to salmon and their prey; overharvesting (through commercial fishing, etc.); natural predators; and dams on the rivers, which obstruct passage to spawning areas. For example, the Hells Canyon Complex, located on the Oregon-Idaho border and completed in 1967, includes three dams, which prevent passage of salmon to the Upper Snake River Basin.

When salmon are removed from an ecosystem, the number of grizzly bears decreases. Other species, such as mink, orcas, birds, river otter and microorganisms, which depend on salmon for food, also suffer when the number of salmon declines.  The decrease of these animals, in turn, impacts plant life in forests and mountains. For example, bear droppings and salmon carcasses, which bears leave in the forest and mountains, are rich in both phosphorous and nitrogen, and support plant life. When the number of bears decreases, the amount of salmon-generated nutrients plants receive from bears is reduced as well.

In order to increase the number of salmon, scientists have created fish hatcheries, which produce, raise and release salmon into the wild. Columbia basin hatcheries release more than 100 million salmon into the Columbia River and its tributaries each year.

For more information, go to:

• Grizzly Details: Salmon Collapse Could be Bad News for Bears
• Pacific Salmonids: Major Threats and Impacts
• Salmon/ Salmoniformes

National Science Education Standards:

Grades 9-12:

Content Standard C: Life Science

Fundamental concepts and principles that underlie this standard include:

• The Interdependence of Organisms
  • Energy flows through ecosystems in one direction, from photosynthetic organisms to herbivores to carnivores and decomposers.
  • Organisms both cooperate and compete in ecosystems. The interrelationships and interdependencies of these organisms may generate ecosystems that are stable for hundreds or thousands of years.
  • Living organisms have the capacity to produce populations of infinite size, but environments and resources are finite. This fundamental tension has profound effects on the interactions between organisms.
  • Human beings live within the world’s ecosystems. Increasingly, humans modify ecosystems as a result of population growth, technology, and consumption. Human destruction of habitats through direct harvesting, pollution, atmospheric changes, and other factors is threatening current global stability, and if not addressed, ecosystems will be irreversibly affected.

Content Standard F: Science in Personal and Social Perspectives and Technology
Fundamental concepts and principles that underlie this standard include:

• Science and Technology in Local, National, and Global Challenges
  • Humans have a major effect on other species. For example, the influence of humans on other organisms occurs through land use—which decreases space available to other species—and pollution—which changes the chemical composition of air, soil, and water.

Discussion Questions:

• Considering that they are excellent swimmers, why is thin, melting ice such a problem for polar bears?
• Given current rates of pack ice loss, how much longer until the entire polar ice cap has melted?
• Considering how effectively polar bears have evolved to survive in their harsh arctic environment, why is it unlikely that they’ll be able to adapt to their new, warmer world?

Background Essay:

The polar bear is both the world’s largest bear and largest land carnivore. Although born on land, polar bears are excellent swimmers, spending so much of their time at sea and on sea ice that their scientific name—“Ursus maritimus”—translates to “maritime bear.”  While closely enough related to the brown bears more common in temperate zones that rare interbreeding has been documented, polar bears have evolved unique adaptations to their arctic and largely aquatic environment: a longer nose helps warm cold air; smaller ears reduce radiated heat loss; large, scooped feet distribute weight when walking on ice and provide better propulsion when swimming; and a thick layer of blubber provides insulation, buoyancy, and sustenance when food is scarce.

Polar bears possess an extremely keen sense of smell, and are able to detect their primary food source—ringed and bearded seals—up to a mile distant. They primarily hunt at and around the edge of pack ice—the ice shelf that extends in winter months from land—often sneaking up and catching their prey as they surface in ice holes to breathe. When the pack ice recedes in summer and early fall and polar bears are unable to hunt seals, they live primarily off their fat reserves. Polar bears have been known to supplement their diet with a wide variety of plants and other animals, but their digestive systems are specially adapted to seal meat and blubber, and cannot derive sufficient caloric intake from other sources.

Because of their reliance on seals, polar bears are especially vulnerable to the polar warming associated with global climate change. The relatively thin pack ice shelf from which polar bears hunt seals is climatically fragile; rising temperatures melt this ice earlier and further with each passing spring, forcing polar bears to land before they have amassed sufficient fat reserves to survive the lean summer and early fall. Reductions in the thickness and area of pack ice also force bears to swim more frequently and for longer distances in search of food, further depleting their energy and occasionally leading to drowning.

While some may insist on debating the causes of climate change, its consequences on the worldwide polar bear population are undeniable. For example, polar bears’ feeding season in the western Hudson Bay is three weeks shorter than it was 30 years ago; in the same period, the polar bear population has declined over 22%, with the average weight of pregnant females dropping 20%. This insufficient nourishment also leads to lower reproductive rates among adults and lower survival rates among cubs.

National Science Education Standards:

Life Science, Content Standard C

As a result of their activities in grades 9-12, all students should develop understanding of

• Biological evolution
  • Species evolve over time. Evolution is the consequence of the interactions of (1) the potential for a species to increase its numbers, (2) the genetic variability of offspring due to mutation and recombination of genes, (3) a finite supply of the resources required for life, and (4) the ensuring selection by the environment of those offspring better able to survive and leave offspring.
  • Interdependence of organisms
    • Living organisms have the capacity to produce populations of infinite size, but environments and resources are finite. This fundamental tension has profound effects on the interactions between organisms.
    • Matter, Energy, and Organization in Living Systems
      • The distribution and abundance of organisms and populations in ecosystems are limited by the availability of matter and energy and the ability of the ecosystem to recycle materials.
      • Behavior of organisms
        • Organisms have behavioral responses to internal changes and to external stimuli. Responses to external stimuli can result from interactions with the organism’s own species and others, as well as environmental changes; these responses either can be innate or learned. The broad patterns of behavior exhibited by animals have evolved to ensure reproductive success. Animals often live in unpredictable environments, and so their behavior must be flexible enough to deal with uncertainty and change. Plants also respond to stimuli.
        • Like other aspects of an organism’s biology, behaviors have evolved through natural selection. Behaviors often have an adaptive logic when viewed in terms of evolutionary principles.

Science in Personal and Social Perspectives, Content Standard F

As a result of activities in grades 9-12, all students should develop understanding of

• Environmental quality
  • Materials from human societies affect both physical and chemical cycles of the earth.
  • Many factors influence environmental quality. Factors that students might investigate include population growth, resource use, population distribution, overconsumption, the capacity of technology to solve problems, poverty, the role of economic, political, and religious views, and different ways humans view the earth.
• Natural and human-induced hazards
  • Human activities can enhance potential for hazards. Acquisition of resources, urban growth, and waste disposal can accelerate rates of natural change.
  • Some hazards, such as earthquakes, volcanic eruptions, and severe weather, are rapid and spectacular. But there are slow and progressive changes that also result in problems for individuals and societies. For example, change in stream channel position, erosion of bridge foundations, sedimentation in lakes and harbors, coastal erosions, and continuing erosion and wasting of soil and landscapes can all negatively affect society.
  • Natural and human-induced hazards present the need for humans to assess potential danger and risk. Many changes in the environment designed by humans bring benefits to society, as well as cause risks. Students should understand the costs and trade-offs of various hazards—ranging from those with minor risk to a few people to major catastrophes with major risk to many people. The scale of events and the accuracy with which scientists and engineers can (and cannot) predict events are important considerations.

• Science and technology in local, national, and global challenges
  • Humans have a major effect on other species. For example, the influence of humans on other organisms occurs through land use—which decreases space available to other species—and pollution—which changes the chemical composition of air, soil, and water.

Discussion Questions:

• Observe and note the different shapes of coral present in the ocean reefs.  Why do you think coral grows in these various shapes?
• Why are Cuba’s coral reefs thriving?
• How might different countries and environmental groups around the world address the threats facing coral reefs today?
• Why is elkhorn coral so special to Cuba’s coral reefs, and the Caribbean region?

Background Essay:

Even though at first appearance corals may look like plants or even rocks, they are in fact animals, related to sea anemones and jellyfish.  Corals live in colonies of genetically identical, multicellular organisms called polyps.  The polyps secrete skeletons of calcium carbonate that form the hard structure we recognize as large corals and coral reefs (and so often mistake for rocks).  Corals are usually found at shallow depths in tropical waters, and depend on sunlight to survive.  They feed on small organisms including plankton and tiny fish, and many corals are dependent on a specific type of algae which helps produce energy as well as assisting with calcification of the corals’ skeleton.  Coral structures can grow in many different shapes, some resembling brains, cabbages, table tops, antlers, wire strands, or pillars.

Coral reefs, the large structures built out of millions and millions of coral skeletons over time, are extremely diverse ecosystems that are home to thousands of species.  It is estimated that 25% of all marine species live in and around coral reefs, including over 4,000 species of fish, 700 types of coral, and thousands of other plant and animal species.  The most common type of coral reef is called a fringing reef, found near coastlines of islands and continents, separated from the mainland by a small channel or lagoon.  These are the types of coral reefs found in and around Cuba.  Other types of coral reefs include barrier reefs, atolls, and patch reefs.

Cuba is home to large fringing coral reefs at Archipelago de los Colorados along the northwest coast, and the Jardines de la Reina in the south.  These reefs are home to the largest fish populations in Cuba – possibly even in the entire Caribbean!  However, these fish populations are consistently sought out by local, touring, and commercial fishermen, and overfishing is the main threat currently facing Cuba’s coral reefs.  As a result, fishing is banned in the area, specifically a 386-square mile area surrounding the Jardines de la Reina, now set aside as a marine reserve area.

Coral reefs are extremely sensitive to environmental changes, and depend on clear, clean saltwater to survive.  Pollution and agricultural runoff can have a huge impact on the health of a coral reef.  In this sense, Cuba’s Communist government may have inadvertently helped protect the Cuban reefs for many years, by preventing the flow of fresh water to the sea as well as strictly limiting the availability and use of fertilizer and pesticides.  However, as Cuba begins to open its doors to the rest of the world, increased commercialism and tourism is once again increasing levels of pollution, sedimentation, and development in coastal area, which creates a negative effect on the corals.

National Science Education Standards:

Life Science

Content Standard C

THE INTERDEPENDENCE OF ORGANISMS

Organisms both cooperate and compete in ecosystems. The interrelationships and interdependencies of these organisms may generate ecosystems that are stable for hundreds or thousands of years.

Human beings live within the world’s ecosystems. Increasingly, humans modify ecosystems as a result of population growth, technology, and consumption. Human destruction of habitats through direct harvesting, pollution, atmospheric changes, and other factors is threatening current global stability, and if not addressed, ecosystems will be irreversibly affected.

GRADE LEVEL: 8-10

TIME ALLOTMENT: Two or three 45-minute class periods

OVERVIEW: In this lesson, students use segments from Nature: Salmon: Running the Gauntlet to explore ways in which humans have impacted salmon populations. In the Introductory Activity, students explore different ways in which human actions have helped and hindered salmon populations, including efforts to artificially produce and raise salmon. In Learning Activity 1, students learn about challenges salmon face after being released from hatcheries into the wild, as well as efforts that humans are taking to restore streams and salmon runs. In Learning Activity 2, students explore issues surrounding dams and conduct research on specific dams in the US northwest. In the Culminating Activity, students review information presented in the lesson and debate the merits of human efforts to save salmon. Students write a critical essay about human impact on salmon and propose ideas for future actions. Students discuss their projects with the class.

SUBJECT MATTER: Science

Learning Objectives:

Students will be able to:

• Describe why humans are artificially producing salmon and then releasing them into the wild.
• Discuss at least four actions that humans have taken that have impacted salmon populations. Describe positive and/or negative impacts these actions have had on salmon.
• Describe the role of hatcheries.
• Describe obstacles salmon face in nature.
• Explain the issues surrounding dams and how dams impact salmon populations.
• Provide details about one specific dam and issues surrounding it.
• Describe efforts that humans are taking to restore streams and salmon runs.

STANDARDS

National Science Education Standards

Grades 9-12:

Content Standard C: Life Science

Fundamental concepts and principles that underlie this standard include:

• Biological Evolution
  • Species evolve over time. Evolution is the consequence of the interactions of (1) the potential for a species to increase its numbers, (2) the genetic variability of offspring due to mutation and recombination of genes, (3) a finite supply of the resources required for life, and (4) the ensuing selection by the environment of those offspring better able to survive and leave offspring.
  • The great diversity of organisms is the result of more than 3.5 billion years of evolution that has filled every available niche with life forms.
  • Natural selection and its evolutionary consequences provide a scientific explanation for the fossil record of ancient life forms, as well as for the striking molecular similarities observed among the diverse species of living organisms.
• The Interdependence of Organisms
  • Organisms both cooperate and compete in ecosystems. The interrelationships and interdependencies of these organisms may generate ecosystems that are stable for hundreds or thousands of years.
  • Living organisms have the capacity to produce populations of infinite size, but environments and resources are finite. This fundamental tension has profound effects on the interactions between organisms.
  • Human beings live within the world’s ecosystems. Increasingly, humans modify ecosystems as a result of population growth, technology, and consumption. Human destruction of habitats through direct harvesting, pollution, atmospheric changes, and other factors is threatening current global stability, and if not addressed, ecosystems will be irreversibly affected.
• The Behavior Of Organisms
  • Organisms have behavioral responses to internal changes and to external stimuli. Responses to external stimuli can result from interactions with the organism’s own species and others, as well as environmental changes; these responses either can be innate or learned. The broad patterns of behavior exhibited by animals have evolved to ensure reproductive success. Animals often live in unpredictable environments, and so their behavior must be flexible enough to deal with uncertainty and change. Plants also respond to stimuli.
  • Like other aspects of an organism’s biology, behaviors have evolved through natural selection. Behaviors often have an adaptive logic when viewed in terms of evolutionary principles.

Content Standard E: Science and Technology

Fundamental concepts and principles that underlie this standard include:

• Understandings about Science and Technology
  • Science often advances with the introduction of new technologies. Solving technological problems often results in new scientific knowledge. New technologies often extend the current levels of scientific understanding and introduce new areas of research.
  • Creativity, imagination, and a good knowledge base are all required in the work of science and engineering.
  • Science and technology are pursued for different purposes. Scientific inquiry is driven by the desire to understand the natural world, and technological design is driven by the need to meet human needs and solve human problems. Technology, by its nature, has a more direct effect on society than science because its purpose is to solve human problems, help humans adapt, and fulfill human aspirations. Technological solutions may create new problems. Science, by its nature, answers questions that may or may not directly influence humans. Sometimes scientific advances challenge people’s beliefs and practical explanations concerning various aspects of the world.

Content Standard F: Science in Personal and Social Perspectives and Technology

Fundamental concepts and principles that underlie this standard include:

• Natural Resources
  • Human populations use resources in the environment in order to maintain and improve their existence. Natural resources have been and will continue to be used to maintain human populations.
  • The earth does not have infinite resources; increasing human consumption places severe stress on the natural processes that renew some resources, and it depletes those resources that cannot be renewed.
  • Humans use many natural systems as resources. Natural systems have the capacity to reuse waste, but that capacity is limited. Natural systems can change to an extent that exceeds the limits of organisms to adapt naturally or humans to adapt technologically.

• Science and Technology in Local, National, and Global Challenges
  • Humans have a major effect on other species. For example, the influence of humans on other organisms occurs through land use—which decreases space available to other species—and pollution—which changes the chemical composition of air, soil, and water.

MEDIA COMPONENTS

Nature: “Salmon: Running the Gauntlet,” selected segments

Access the video segments for this lesson at the Video Segments Page.

Clip 1: “Producing Salmon”

A look at how humans are producing salmon in an effort to protect the species.

Clip 2: “Humans and Salmon”

An overview of how humans have impacted salmon populations for more than 150 years.

Clip 3: “Salmon’s Journey”

An overview of salmon’s journey after being released from the hatcheries into the wild.

Clip 4: “Restoring Streams”

A look at efforts to remove dams and restore streams and salmon runs.

Websites:

Bonneville Lock and Dam

This page on the US Army Corps of Engineers, Portland District website provides information about the Bonneville Lock and Dam and includes links to Bonneville Dam Fish Ladder Camera Views at the Oregon Shore and Washington Shore Counting Stations, featuring live images, updated every few seconds, of fish passing through the counting windows.

Dam Breaching and the Lower Snake River Dams

This fact sheet, created by the Bonneville Power Administration, provides information about the estimated costs and impact of breaching (removing the earthen portion of) the four Lower Snake River Dams.

Hatcheries and Dams of the Pacific Northwest

This page on the Nature website features a map of major hatcheries and dams in the Pacific Northwest, as well as the approximate spawning grounds for each salmon species.

Large Dams in the Western United States

This website provides information about the positive and negative effects of dams and specifically highlights the Glen Canyon Dam on the Colorado River and the Bonneville Dam on the Columbia River.

Save Our Wild Salmon

This website provides information about maintaining and restoring wild salmon populations. The following pages could be used in this lesson:

• Myths and Facts about Lower Snake River Dam Removal

• Why remove the 4 Lower Snake River Dams?

Snake River Dam Operation

This website provides information about the Snake River Dams.

The Dam Challenge (Optional)

This online activity, which is used in the optional activity in Learning Activity 2, challenges users to consider different scenarios where dams exist and to choose whether to repair the dam, keep the dam as is or remove it.

MATERIALS

For the class:

• Computers with internet access.
• Computer, projection screen and speakers (for class viewing of online/downloaded video segments).

PREP FOR TEACHERS

Prior to teaching this lesson, you will need to:

Preview all of the video segments and websites used in the lesson.

Download the video clips used in the lesson to your classroom computer(s) or prepare to watch them using your classroom’s internet connection.

Bookmark any websites that you plan to use in the lesson on each computer in your classroom. Using a social bookmarking tool such as del.icio.us or diigo (or an online bookmarking utility such as portaportal) will allow you to organize all the links in a central location.

Proceed to Lesson Activities