Download Biodiversity

Biological Wealth
• Goods and services provided by
biodiversity.
• ~$38 Trillion per year
Examples of Goods and Services
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Gas, climate, and water regulation
Water supply
Erosion control
Soil formation
Pollination
Biological Wealth = $38
Trillion/Year
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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
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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