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The Benefits of Healthy Ecosystems

The Benefits of Healthy Ecosystems

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The Benefits of Healthy Ecosystems

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  1. The Benefits of Healthy Ecosystems • Ecosystem services are the benefits people obtain from ecosystems. Many of the services listed here are interlinked. • Provisioning Services. These are the products obtained from ecosystems, including: • Food. This includes the vast range of food products derived from plants, animals, and microbes. • Fibre. Materials such as wood, jute, cotton, hemp, silk, and wool. • Fuel. Wood and other biological materials serve as sources of energy. • Genetic resources. This includes the genes and genetic information used for animal and plant breeding and biotechnology. • Biochemicals, natural medicines, and pharmaceuticals. Many medicines and food additives such as alginates, and biological materials are derived from ecosystems. • Ornamental resources. Animal and plant products, such as skins, shells and flowers are used as ornaments and whole plants are used for landscaping and ornaments. • Freshwater. Freshwater in rivers is also a source of energy. Because water is required for other life to exist, it could also be considered a supporting service. SCIE 103 Life Sciences

  2. The Benefits of Healthy Ecosystems • Regulating Services. These are the benefits obtained from the regulation of ecosystem processes, including: • Air quality regulation. Ecosystems both contribute chemicals to and extract chemicals from the atmosphere, influencing many aspects of air quality; • Climate regulation. Ecosystems influence climate both locally and globally. Changes in land cover can affect both temperature and precipitation. • Water regulation. The timing and amount of runoff, flooding, and aquifer recharge can be strongly influenced by changes in land cover. • Erosion regulation. Vegetation plays an important role in soil retention and the prevention of landslides. • Water purification and waste treatment. Ecosystems can help to filter out and decompose organic wastes introduced into inland waters and coastal ecosystems. • Disease regulation. Changes in ecosystems can directly change the abundance of human disease. • Pest regulation. Ecosystem changes affect the frequency of crop and livestock pests and diseases. • Pollination. Ecosystem changes affect the distribution, abundance, and effectiveness of pollinators. SCIE 103 Life Sciences

  3. The Benefits of Healthy Ecosystems • Cultural Services. These are the non-material benefits people obtain from ecosystems through spiritual enrichment, reflection, recreation, and aesthetic experiences, including: • Cultural diversity. The diversity of ecosystems is one factor influencing the diversity of cultures. • Spiritual and religious values. Many religions attach spiritual and religious values to ecosystems or their components. • Knowledge systems (traditional and formal). Ecosystems influence the types of knowledge systems developed by different cultures. • Educational values. Ecosystems and their components and processes provide the basis for both formal and informal education in many societies. • Inspiration. Ecosystems provide a rich source of inspiration for art, national symbols, architecture, and advertising.Aesthetic values. Many people find beauty or aesthetic value in ecosystems, as reflected in the support for parks, scenic drives, and the selection of housing locations. • Social relations. Ecosystems influence the types of social relations that are established in particular cultures. • Sense of place. Many people value the "sense of place" that is associated with recognized features of their environment. • Cultural heritage values. Many societies place high value on the maintenance of either historically important landscapes ("cultural landscapes") or culturally significant species. • Recreation and ecotourism. People often choose where to spend their leisure time based in part on the characteristics of the natural or cultivated landscapes in a particular area. SCIE 103 Life Sciences

  4. The Benefits of Healthy Ecosystems • Supporting Services. Supporting services are those that are necessary for the production of all other ecosystem services. They differ from provisioning, regulating, and cultural services in that their impacts on people are often indirect or occur over a very long time. • Soil Formation. Because many provisioning services depend on soil fertility, the rate of soil formation influences human well-being in many ways. • Photosynthesis. Photosynthesis produces oxygen necessary for most living organisms. • Primary Production. The assimilation or accumulation of energy and nutrients by organisms. • Nutrient cycling. Approximately 20 nutrients essential for life, including nitrogen and phosphorus, cycle through ecosystems and are maintained at different concentrations in different parts of ecosystems. • Water cycling. Water cycles through ecosystems and is essential for living organisms. SCIE 103 Life Sciences

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  7. Threats to biodiversity • In part because the value of biodiversity and the resulting ecosystem services are poorly understood by a lot of people, nature's “cogs and wheels” are going missing at an alarming rate — on the order of 100 to 1000 times the background rate, estimated from fossil records to be from one to ten species/year (Pimm, et al., 1995 and others). Some estimates of current rates are much higher. There have been five mass extinctions in the past 500 million years, the most recent about 65 million years ago (Raup and Sepkoski, 1982). We appear to be in the sixth, with the major difference being that for this one, the cause appears to be not a major physical catastrophe such as severe volcanism or a meteor strike, but a single species: us. • The Millennium Ecosystem Assessment (2005) reports that there has been a substantial and largely irreversible loss in the earth's biodiversity, with some 10-30% of mammal, bird and amphibian species currently threatened with extinction, and 15 of 24 ecosystem services being degraded. Fortunately, it comes at a time when the earth probably contains more species than ever before (Rhode and Muller, 2005), and there's some redundancy built into the system. We can lose some species — some — before things start to really unravel. SCIE 103 Life Sciences

  8. Threats to biodiversity • The causes of these losses are varied and can be encompassed in the term HIPPOC: • Habitat loss: Habitat loss, alteration and fragmentation directly affect the species that rely on the habitat that is being changed. SCIE 103 Life Sciences

  9. Threats to Biodiversity – Habitat Destruction • Habitat destruction – single greatest threat to biodiversity SCIE 103 Life Sciences

  10. Deforestation of tropical forests SCIE 103 Life Sciences

  11. Deforestation Closer to Home SCIE 103 Life Sciences

  12. Threats to Biodiversity – Habitat Destruction • Fragmentation of a forest ecosystem SCIE 103 Life Sciences

  13. Threats to Biodiversity • The history of habitat reduction and fragmentation in a Wisconsin forest SCIE 103 Life Sciences

  14. Threats to Biodiversity – Habitat Destruction • Tropical forests house between 50 and 90 percent of species live on earth. About 17 million hectares of tropical forests – an area four times the size of Switzerland –are now being cleared annually, and scientists estimate that at these rates roughly 5 to 10 percent of tropical forest species may face extinction within the next 30 years. • Rates of tropic forest loss are accelerating, and some particularly species-rich forests are likely to be largely destroyed in our lifetime. Some scientists believe that about 60,000 of the world's 240,000 plant species, and perhaps even higher proportions of vertebrata and insect species, could lose their lease on life over the next three decades unless deforestation is slowed immediately. SCIE 103 Life Sciences

  15. Threats to Biodiversity – Habitat Destruction • Tropical forests are by no means the only sites with endangered biodiversity. Worldwide, nearly as much temperate rainforest – once covering an area nearly the size of Malaysia – has also been lost. Although the total extent of forest in the northern temperate and boreal regions has not changed much in recent years, in many areas the species-rich, old-growth forests have been steadily replaced by second-growth forests and plantations. Evidence of accelerating clearance of temperate forests is also appearing: between 1977 and 1987, 1.6 million hectares of forest was lost in the United States alone. • In several spots in Europe, fungal species diversity has dropped by 50 percent or more over the past 60 years. In such "Mediterranean" climates as California, South Africa, central Chile, and Southwest Australia, at least 10 percent of all plant and animal species are imperiled. The largest number of recent extinctions has been on oceanic islands: some 60 percent of plant species endemic to the Galapagos Islands are endangered, as are 42 percent of the Azores' endemic species and 75 percent of the endemic plant species of the Canary Islands. SCIE 103 Life Sciences

  16. zebra mussel plum pox virus Threats to biodiversity • The causes of these losses are varied and can be encompassed in the term HIPPO(C): • Invasive (Introduced) species: Invasive species are harmful non-native species whose introduction or spread threatens the environment, the economy and society, including human health. Invasive species originate from other continents, adjacent countries or from other ecosystems within Canada. Free from predation and competition that would normally limit their distribution and abundance in their natural habitats, many invasive species reproduce rapidly and damage, displace or destroy native species in our forests (e.g., emerald ash borer), agricultural areas (e.g., plum pox virus), wetlands (e.g., purple loosestrife) and lakes and rivers (e.g., zebra mussel). The zebra mussel disrupts ecosystem composition and structure, clogs water intake pipes, and affects public beaches. emerald ash borer SCIE 103 Life Sciences

  17. Threats to Biodiversity – Introduced Species • Introduced Species • Ranking second to habitat loss as a cause of biodiversity crisis • Species that humans move from the species’ native locations to new geographic regions. • Of all 1,880 imperiled species in the United States, 49% are endangered because of introduced species alone or because of their impact combined with other forces. • Introduced species are a greater threat to native biodiversity than pollution, harvest, and disease combined. • Through damage to agriculture, forestry, fisheries, and other human enterprises, introduced species inflict an enormous economic cost, estimated at $137 billion per year to the U.S. economy alone. • Some introduced species (such as most of our food crops and pets) are beneficial. However, others are very damaging. SCIE 103 Life Sciences

  18. Threats to Biodiversity – Introduced Species • The Asian chestnut blight fungus virtually eliminated American chestnut from over 180 million acres of eastern United States forests in the first half of the 20th century. It was a disaster for many animals that were highly adapted to live in forests dominated by this tree species. For example, ten moth species that could live only on chestnut trees became extinct. • The Australian paperbark tree has replaced native plants, such as sawgrass, over 400,000 acres of south Florida, because it has a combination of traits (for example, spongy outer bark and flammable leaves and litter) that increase fire frequency and intensity. Many birds and mammals adapted to the native plant community declined in abundance as paperbark spread. SCIE 103 Life Sciences

  19. Threats to Biodiversity – Introduced Species • Pump house and water control structure for green-tree impoundment at Montezuma National Wildlife Refuge in central New York. Waterfowl broods produced in adjacent flooded forest found excellent foraging conditions among floating and emergent aquatic plants in the foreground, 18 June 1968. • Ten years later, purple loosestrife had displaced native food and cover plants in the waterway surrounding the green-tree impoundment at the Montezuma Refuge. Biologist holding stadia rod in middle foreground is obscured by mature plants. Note the abundance of Lythrum salicaria seedlings along the water line, 16 August 1978. SCIE 103 Life Sciences

  20. Threats to Biodiversity – Introduced Species • Zebra mussels (Dreissena polymorpha) are small, fingernail-sized mussels native to the Caspian Sea region of Asia. They are believed to have been transported to the Great Lakes via ballast water from a transoceanic vessel. The ballast water, taken on in a freshwater European port was subsequently discharged into Lake St. Clair, near Detroit, where the mussel was discovered in 1988. Since that time, they have spread rapidly to all of the Great Lakes and waterways in many states, as well as Ontario and Quebec. Diving ducks and freshwater drum eat zebra mussels, but will not significantly control them. Likely means of spread: Microscopic larvae may be carried in livewells or bilgewater. Adults can attach to boats or boating equipment that is in the water. SCIE 103 Life Sciences

  21. Threats to Biodiversity – Introduced Species • Nile perch (Lates niloticus), a voracious predator introduced to Lake Victoria as a food fish, has already extinguished over one hundred species of native cichlid fish there. • The introduction of Nile perch into Australia was considered after a reduction in Queensland barramundi stocks, but this was decided against due to the devestation they caused in several African lakes. SCIE 103 Life Sciences

  22. Threats to Biodiversity – Introduced Species • A parasite can be similarly devastating. The sea lamprey reached the Great Lakes through a series of canals and, in combination with overfishing, led to the extinction of three endemic fishes. SCIE 103 Life Sciences

  23. Threats to Biodiversity – Introduced Species • Scientific name: Boiga irregularis • Common name: Brown tree snake • Native To: Australia • Date of U.S. Introduction: First detected in Guam in the 1950s, introduced in cargo from the Admiralty Islands. • Means of Introduction: Arrived in Guam accidentally in imported cargo • Impact: Preys on native lizards and birds, has eliminated ten of the eleven native bird species from the forests of Guam; causes frequent power outages by climbing on electrical wires • Current U.S. Distribution: Guam SCIE 103 Life Sciences

  24. Threats to Biodiversity – Introduced Species • The first Argentine ants set foot on U.S. soils in the late 1890's, as coffee ships from Brazil unloaded their cargo in New Orleans. Being prolific breeders and constantly on the go, they moved across the southern half of the United States. A single colony may contain 10,000 female workers, and there may be hundreds of colonies around your home; the total number of ants could easily reach a million. Although they cannot sting, they can bite; however, they are only about 3 mm long and there tiny mandibles are too small to hurt humans. But, in the world of insects, these ants are truly a living terror. They are very aggressive and readily overtake other ant species, even ants that are much larger and with powerful stings. Argentine ants are relentless and simply outnumber their adversaries until the enemy colony is destroyed. They even attack paper wasp nests under the eaves of a house, forcing the huge wasps to flee their nests in terror. Even nests of large carpenter bees are no match for these relentless ants. A "killer bee" nest probably could not withstand an invasion of Argentine ants. They also will attack bird nests, driving off the mother bird and killing the helpless young. One possible redeeming quality about these little warriors is that they may attack dry-wood (aerial) termite colonies in your home. SCIE 103 Life Sciences

  25. Posidonia Threats to Biodiversity – Introduced Species • Beauty can be a trap, and despite the appeal of the Caulerpa taxifolia with its lovely green flowers, this invasive species represents a great danger for neritic Mediterranean habitats. These algae preferentially invade posidonia prairies, impoverishing the already threatened marine flora and fauna. Caulerpa taxifolia SCIE 103 Life Sciences

  26. Threats to Biodiversity – Introduced Species Some impacts of invaders are subtle but nonetheless destructive to native species:  • North American gray squirrels are driving native red squirrels to extinction in Great Britain and Italy by foraging for nuts more efficiently than the native species. Such competition for resources is not easy to observe, but the end result is the loss of a native species.  • Hybridization, or cross-breeding, of introduced species with natives is an even subtler impact (no lineage goes extinct), but it is insidious because it leads gradually to the extinction of many native species, as their gene pools inevitably evolve to become those of the invader. Introduced mallards, for instance, are driving the native Hawaiian duck to a sort of genetic extinction by breeding with them.  • Of 26 animal species that have gone extinct since being listed under the Endangered Species Act, at least three were wholly or partly lost because of hybridization with invaders. One was a fish native to Texas, eliminated by hybridization with introduced mosquito fish.  SCIE 103 Life Sciences

  27. white-headed duck ruddy duck Threats to Biodiversity – Introduced Species • Rainbow trout introduced widely in the United States as game fish are hybridizing with five species listed under the Endangered Species Act, such as the Gila trout and Apache trout.  • The endangered, endemic Hawaiian duck is being lost to hybridization with North American mallards introduced for hunting.  • The rarest European duck (the white-headed duck) is threatened by hybridization with the North American ruddy duck, which was originally kept as an amenity in a British game park. The ruddy duck escaped, crossed the English Channel SCIE 103 Life Sciences

  28. Threats to Biodiversity – Introduced Species • Often invaders interact with one another to generate a problem where either species alone would be harmless. For example, ornamental fig trees in the Miami area for over a century stayed where planted, in people's yards, because they were sterile. Each fig species requires a particular wasp to pollinate it, and the wasps were absent. About fifteen years ago, the pollinating wasps for three fig species arrived independently in the region, and now these fig species are reproducing. At least one has become invasive, with seedlings and saplings being found many miles from any planted figs. More cases of this phenomenon, termed "invasion meltdown," are likely to arise as more species are introduced and have the opportunity to interact with each other. SCIE 103 Life Sciences

  29. Threats to biodiversity • The causes of these losses are varied and can be encompassed in the term HIPPO(C): • Pollution: Pollution is emitted in many different forms, including atmospheric pollution, soil and water pollution, pesticides,particulate matter, and heavy metals. There are thousands of pollutants circulating through the Earth's ecosystems, and many of these materials have significant, large-scale impacts on forests and aquatic ecosystems. Acid precipitation, for example, has had a significant impact on Ontario's maple forests and industrial pollutants such as DDT is known to have caused significant declines in populations of many bird species including Peregrine Falcon and Bald Eagles. Pollution can also disrupt ecological processes. For example, scientists are now linking light pollution to declines in migratory songbirds. • Population growth: Human population growth adds to the impact of all the other causes because more people require more space and more resources. There are now about 6 billion people on Earth, more than twice as many as in 1950. While the rate of increase is slowing, it still adds more than 90 million people each year. Habitats, even healthy ones, can support just somany of anything, including people. • Over-consumption or unsustainable use: Over-consumption is the harvest of species at a rate higher than can be sustained by the natural reproduction of the population. In Ontario, for example, wild American ginseng has been over-harvested from its natural rich woodland habitat to the point of being Endangered. • Climate Change and other Cumulative impacts: People have added carbon dioxide, nitrous oxide, methane and other greenhouse gases to the atmosphere by extracting and burning fossil fuels such as coal, oil and natural gas. The effect of these gases has been to trap heat and accelerate the rate of global warming and climate change. Climate change is a major threat to the world's biodiversity. The cumulative impacts of pollution, habitat modification, the global redistribution of species and over-harvesting place many ecosystems at risk. These cumulative impacts cause alteration, reduction and loss of ecosystem function, populations and species, degradation, loss and fragmentation of habitat. They also damage human health. SCIE 103 Life Sciences

  30. Threats to Biodiversity - Overconsumption • Refers generally to the human harvesting of wild plants and animals at rates exceeding the ability of the populations of those species to regenerate. • Logging, hunting and fishing • Especially susceptible are large species with low intrinsic reproductive rates. • Eg. Elephants, whales, rhinoceroses, and species on small islands. SCIE 103 Life Sciences

  31. Threats to Biodiversity - Overconsumption • A new global study concludes that 90 percent of all large fishes have disappeared from the world's oceans in the past half century, the devastating result of industrial fishing. • The study, which took 10 years to complete and was published in the international journal Nature, paints a grim picture of the Earth's current populations of such species as sharks, swordfish, tuna and marlin. • The authors used data going back 47 years from nine oceanic and four continental shelf systems, ranging from the tropics to the Antarctic. Whether off the coast of Newfoundland, Canada, or in the Gulf of Thailand, the findings were dire, according to the authors. SCIE 103 Life Sciences

  32. Threats to Biodiversity - Overconsumption SCIE 103 Life Sciences

  33. Threats to Biodiversity - Overconsumption SCIE 103 Life Sciences

  34. Blue-Ringed Dancer (Argia sedula) Reducing the threats to biodiversity • The global response to HIPPOC has been the promotion of sustainable development, defined by the OBS as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” • But what does that mean, in a practical sense? One way is to link biodiversity to sustainable development through the concept of “sustainable use: the use of components of biodiversity in a way and at a rate that does not lead to their long-term decline, thereby maintaining the potential for future generations to meet their needs and aspirations” (OBS, 2005). We don't want to lose species because it will eventually degrade our natural capital, and any reduction in ecological services is a sure sign that biodiversity is eroding. • The loss of a single species is not “the end of the world as we know it,” but cumulatively it may be. Losing species destabilizes ecosystems and weakens their ability to deal with natural disasters such as floods, droughts and fire and with human-caused stresses such as pollution and climate change. The precautionary principle states, when in doubt do no harm. In this case, stopping all species loss where possible is probably the best rule of thumb. SCIE 103 Life Sciences

  35. What can you do to help? • Learn more. Knowledge is power. The more we know about the causes, consequences and how to prevention of biodiversity loss, the more power we will have to act. Also, our actions will be more efficient and focused. • Tell others. As we learn more about biodiversity, we need to let others know as well that biodiversity conservation is worth pursuing. We can discuss it among groups we belong to. We can write letters or emails to editors and others of influence. • Help monitor biodiversity. Citizen science, the monitoring of species and ecosystems by individuals and groups, is growing across the world. It's a good way to involve people who already have an interest and perhaps knowledge of nature. Learn more and make a difference! • Get organized. Work is ongoing on many of the Action Items. If you belong to organizations that should be involved, contact that group, encourage involvement and offer to help.  • Reduce our Ecological Footprints. We all do things every day which directly or indirectly affect biodiversity by putting pressure on our natural systems. Reduce such pressure by:  • Being aware of Species at Risk and taking action to protect their populations or habitat. • Being knowledgeable of Invasive Species, and acting to limit their spread. • Creating habitat for wild things on your property - planting butterfly or wildflower gardens with native plants and trees, maintaining brush piles, or participating in a local habitat restoration project. • Avoiding pesticides, herbicides and chemical fertilizers. • Buying locally grown food whenever possible. • Reducing energy use in homes, businesses and institutions and vehicles.  • Influence politicians. Let politicians at all levels know that biodiversity conservation is a critical issue that the government needs to do more about. SCIE 103 Life Sciences

  36. What is a "Species at Risk?" • A species at risk is any native plant or animal that is at risk of extinction or of disappearing from its natural environment. • “Endangered species” – one that is in danger of extinction throughout all or a significant portion of its range. • “Threatened species” – those that are likely to become endangered in the foreseeable future throughout all or a significant portion of their range. • http://www.iucnredlist.org/info/tables/table5 SCIE 103 Life Sciences

  37. Threats to Biodiversity • The Great Auk is an extinct flightless bird that has become a symbol of destruction of the Earth and its life forms. The last authenticated sighting of this species was from Fire Island off the coast of Cape Reykjanes, Iceland, on June 3, 1844. At that time a pair of adult Great Auks were caught and killed by collectors. The adults had laid an egg and were incubating. That was probably the last egg ever laid of this species. Great Auk specimens soon came to rest in major collections and museums in Europe and North America. This was largely due to bequests of private collections, integration of collections into one facility and purchases of collections from estates. One of Canada's few specimens, at the Royal Ontario Museum, arrived there from such a purchase.  SCIE 103 Life Sciences

  38. Threats to Biodiversity • Greater mouse-eared bat (Myotis myotis) • The greater mouse-eared bat is one of the larger European bats and has become extinct in England. Its fur is a medium-brown colour on the upper body, and greyish-white underneath. It has large ears with a very prominent tragus, the organ which is part of the bat’s echolocation system. • Status:  Classified as Extinct in the UK. Listed under Appendix II of the Bonn Convention, Annex II of the Berne Convention, Annex II & IV of the EC Habitats Directive and Schedule 5 of the Wildlife and Countryside Act (as amended). SCIE 103 Life Sciences

  39. A hundred beats from extinction: Most Endangered Species of 2007 • The western lowland gorilla (Gorilla gorilla gorilla) is one of many new additions to the World Conservation Union (IUCN)'s 2007 Red List of Threatened Species, which was made public today. Since 2006, the annual assessment of the planet's imperiled wildlife has grown by more than a thousand species and now totals 41,415. • Many great apes end up on the list, as their habitat is continually under threat from human activities. • Western lowland gorilla populations in central Africa have collapsed due to the commercial bushmeat trade and the Ebola virus. And in Indonesia, orangutans are critically endangered because of forest logging and clearing land for palm oil plantations. (National Geographic Sept. 12, 2007) SCIE 103 Life Sciences

  40. A hundred beats from extinction: Most Endangered Species of 2007 • The baiji (Lipotes vexillifer), or Chinese river dolphin— deemed "functionally extinct" by a team of scientists in December—was downgraded from "endangered" to "critically endangered (possibly extinct)" on the IUCN's 2007 Red List. • Populations of the light blue-gray animal, which lives in China's polluted Yangtze River, have plummeted over the last 30 years. • A possible sighting in August 2007 is currently being investigated by Chinese scientists, but even if one or two dolphins are found, the baiji is almost certainly doomed. • “Freshwater dolphins are very vulnerable, because rivers tend to be heavily used by humans and there is nowhere else for the dolphins to go,” Caroline Pollock, a Red List program officer, told National Geographic News. SCIE 103 Life Sciences

  41. A hundred beats from extinction: Most Endangered Species of 2007 • The Egyptian vulture, a new addition to IUCN's 2007 Red List, has declined along with many other vulture species. Five species of vulture, including the Egyptian, have been reclassified to a higher threat level since 2006. Asian vultures have declined rapidly over the last eight years due to the use of a livestock drug called diclofenac. • African vultures are struggling due to habitat loss, a lack of food, and collisions with power lines. • The scavengers are also being killed by insecticide-laden carcasses, which have been deliberately baited to poison livestock predators such as hyenas. SCIE 103 Life Sciences

  42. A hundred beats from extinction: Most Endangered Species of 2007 • Mexico’s Santa Catalina Island rattlesnake has been classified as critically endangered on the 2007 IUCN Red List. The snake, found on just one island, sports highly desirable patterned skin that has made it a collector's item for hunters. • New reptile surveys are revealing the fragile nature of many reptile populations. • For instance, a major survey of North American reptiles has bumped up the region's Red List reptile species to a total of 738. • The main culprit behind their decline is habitat loss due to expanding cities, Caroline Pollock, a Red List program officer, told National Geographic News. • “Unlike birds and mammals, we haven't assessed all the reptiles on the planet,” Pollock added. SCIE 103 Life Sciences

  43. A hundred beats from extinction: Most Endangered Species of 2007 • The Banggai cardinal fish's popularity as a pet for the home aquarium has landed it on the 2007 IUCN Red List. In the wild, the striped fish is only found in the Banggai Archipelago off Indonesia. • Human pressures such as the aquarium trade are the main reason for the fish's decline, with habitat loss and climate change also posing major threats. • Fish stocks are in free-fall all over the world, both from overfishing and the aquarium trade. Scientists estimate current extinction rates are at least a hundred to a thousand times higher than natural rates. • “We need to protect the world's biodiversity in order to ensure a sustainable future for all of us,” Caroline Pollock, a Red List program officer, told National Geographic News. SCIE 103 Life Sciences

  44. A hundred beats from extinction: Most Endangered Species of 2007 • Reptiles such as the gharial are becoming more prominent on the IUCN's Red List each year. Despite its fearsome appearance and lengths of up to 19 feet (6 meters), the Indian gharial is not a man-eater and prefers to eat fish. • Its long, thin snout, which makes it easily distinguishable from a crocodile, also allows it to quickly capture fish. • Habitat loss and poaching is driving the animal toward extinction. SCIE 103 Life Sciences

  45. A hundred beats from extinction: Most Endangered Species of 2007 • For the first time, corals were added to the 2007 Red List. A recent scientific survey on the Galápagos Archipelago has added ten corals to the list, including the Floreana coral. • In the 1980s, frequent El Niño weather patterns—which made ocean temperatures fluctuate—likely led to the poor state of the Galápagos corals. • Some scientists worry that global warming may make El Niño events more regular and prevent corals from recovering. • Until recently, scientists had not properly assessed the health of the world's tropical corals. Scientists estimate that human activities—such as pollution, global warming, and sedimentation—could kill 30 percent of reefs in the next three decades. • Coral reefs in the Indian and Pacific Ocean, for example, are vanishing faster than rain forests. SCIE 103 Life Sciences

  46. A hundred beats from extinction: Most Endangered Species of 2006 • Polar bears and hippos for the first time join more than 16,000 species threatened with extinction, according to the World Conservation Union. • The Switzerland-based nonprofit, known as IUCN, released its 2006 Red List of Threatened Species on May 2. The list shows a significant increase in the number of species on the brink since the last list was released in 2004. • The Red List now marks polar bears as vulnerable, largely because of habitat loss linked to global warming. Due to decreasing sea ice in the Arctic, "polar bears are predicted to suffer more than a 30% population decline in the next 45 years," the group wrote in a press release. • The following images highlight other Red List species, from pink pigeons to blue poison frogs. SCIE 103 Life Sciences

  47. A hundred beats from extinction: Most Endangered Species of 2006 • Manta rays, familiar denizens of tropical and subtropical ocean-shelf waters, are classified as near threatened on the 2006 IUCN Red List. Of the 547 shark and ray species assessed, the group says, 20 percent are in danger of extinction. SCIE 103 Life Sciences

  48. A hundred beats from extinction: Most Endangered Species of 2006 • Native to the Indian Ocean island of Mauritius, the pink pigeon has been suffering from decades of habitat loss and introduction of invasive predators. The population dropped to a mere 12 known birds by 1986, according to the nonprofit Mauritian Wildlife Foundation. The bird is now listed as endangered on the IUCN Red List. SCIE 103 Life Sciences

  49. A hundred beats from extinction: Most Endangered Species of 2006 • In addition to land and marine animals, the IUCN Red List includes a number of plants and fungi, such as the Italian funcia di basiliscu. This fungus, which grows on the island of Sicily, is listed as critically endangered. SCIE 103 Life Sciences

  50. A hundred beats from extinction: Most Endangered Species of 2006 • Amphibian populations in Central and South America have been declining rapidly, a trend that many experts link to environmental factors. The blue poison frog of Suriname, which grows up to one and three quarters of an inch (four and a half centimeters) long, is given "vulnerable" status on the 2006 IUCN Red List. SCIE 103 Life Sciences