Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Conservation biology wikipedia , lookup
Introduced species wikipedia , lookup
Latitudinal gradients in species diversity wikipedia , lookup
Overexploitation wikipedia , lookup
Theoretical ecology wikipedia , lookup
Molecular ecology wikipedia , lookup
Wildlife crossing wikipedia , lookup
Island restoration wikipedia , lookup
Biodiversity wikipedia , lookup
Habitat conservation wikipedia , lookup
Biological Wealth • Goods and services provided by biodiversity. • ~$38 Trillion per year Examples of Goods and Services • • • • • Gas, climate, and water regulation Water supply Erosion control Soil formation Pollination Biological Wealth = $38 Trillion/Year • • • • • • Biological control Food production Recreation Raw materials Nutrient cycling Waste treatment Two Kinds of Value • Instrumental: beneficial to humans – Sources for agriculture, forestry, aquaculture, and animal husbandry – Recreational, aesthetic, and scientific value – Sources of medicine • Intrinsic: value for its own sake Source for Agriculture: Wild or Cultivated? • Highly adaptable to changing environments • Have numerous traits for resistance • Lack genetic vigor Source for Agriculture: Wild or Cultivated? • High degree of genetic diversity • Represents the genetic bank • Need highly controlled environmental conditions • High degree of genetic diversity • Need highly controlled environmental conditions Sources for Medicine: Vincristine Sources of Medicine • Vincristine from rosy periwinkle cures leukemia. • Capoten from the venom of the Brazilian viper controls high blood pressure. • Taxol from the bark of the pacific yew used to treat ovarian, breast, and small-cell cancers. Recreational, Aesthetic, and Scientific Value • Ecotourism: largest foreign exchangegenerating enterprise in many developing countries • $104 billion spent on wildlife-related recreation • $31 billion spent to observe, feed, or photograph wildlife Intrinsic Value • Value for Their Own Sake. – Why? – Philosophical/Moral issue. – Not a scientific issue. Saving Wild Species • Game animals in the United States • Acts protecting endangered species Past Wildlife Management Problems • Restoring the numbers of many game animals, e.g., deer, elk, turkey • Passing laws to control the collection and commercial exploitation of wildlife • Poaching and over hunting Contemporary Wildlife Management Problems • • • • • • Road-killed animals Population explosion of urban wildlife Lack of natural predators Wildlife as vectors for certain diseases Pet predation by coyotes Changed societal attitudes towards animals Acts Protecting Endangered Species • Lacey Act: forbids interstate commerce of illegally killed wildlife • Endangered Species Act (ESA): protects endangered and threatened species Species at Risk: United States • Total endangered U.S. species = 987 (388 animals, 599 plants) • Threatened U.S. species = 276 (129 animals, 147 plants) The Status of U.S. Species Causes of Animal Extinctions Reasons for Biodiversity Decline • Habitat alterations – Conversions – Fragmentation – Simplification Reasons for Biodiversity Decline • Pollution – Examples • Acid Rain – Caused by combustion of fossil fuels (SO2 and NO2) – 10% of lakes in eastern US affected • DDT – DDT used to kill insect pests – Biological amplification causes high levels in secondary and tertiary consumers » Causes fragile shells in predatory birds » Decline in Bald Eagle, Osprey, Peregrine Falcon etc… Reasons for Biodiversity Decline • Introduction of exotic species, e.g., Starling, House Sparrow, Oriental Bittersweet, Multiflora Rose etc… Reasons for Biodiversity Decline: Human Population Growth Reasons for Biodiversity Decline: Overuse • Examples – Harvest of 50 million songbirds for food – Southern Europe – Trafficking in wildlife and products derived from wild species – $10 billion/year • 90% decline in rhinos • 1.6 tons of tiger bones = 340 tigers • Parrot smuggling: 40 of 330 species face extinction What steps should we take to reduce biodiversity decline? DDT Fact or Myth? • Science Fact? – DDT caused the reduction of birds of prey – DDT thins the shells of bird eggs – DDT causes cancer in humans Birds of Prey • Bald Eagle – Considered threatened by 1921 – Extinct in North East by 1937 – First use of DDT – 1943 to kill lice in Europe and in US army – Extensive use in nature started ~1955, peaked in 1962 – Bald Eagle population increased during the peak period! Biological Amplification • DDT is fat soluble – Cannot be flushed out of body – Accumulates in tissues • Organisms high on the food chain most effected Egg Shell Thinning • Numerous Laboratory Experiments – Insignificant shell thinning at 100’s of times the possible natural dose – At environmental doses – no observable effect Egg Shell Thinning Data from Krantz, WC. 1970. Pesticides Monitoring Journal 4(3):136-140. State Thickness (mm) DDE residue (ppm) Florida Maine Wisconsin 0.50 0.53 0.55 About 10 About 22 About 4 DDT Causes Cancer • Primates – 33,000 times the average daily human exposure to DDT (as estimated in 1969 and 1972) – Result "inconclusive with respect to a carcinogenic effect of DDT in nonhuman primates.“ – [J Cancer Res Clin Oncol 1999;125(3-4):219-25] DDT Reduces Malaria