Extinction

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Transcript Extinction

Humans & Extinction
Chapter 9
Extinction
- Natural
- All species become extinct
 Mass Extinction-extinction of many species in a relatively
short period of geologic time
 3-5 mass extinctions on earth so far
-Human activity has ACCELERATED extinctions
Extinction rates are RISING:
1. Projected growth of human population and its growing use
of resources per person
a) Human influence on climate change
2. Current & projected rates are much higher in biodiversity
hotspots
a) Tropical rainforests, estuaries, tropical coral reefs, and wetlands
3. Eliminating, degrading, fragmenting, & simplifying many
biological diverse environments that serve as potential
colonization sites for new species.
4 Reasons WHY we should CARE about EXTINCTION
1. World species are a vital part of the earth’s life
support system
2. Contribute to economic services
3. Will take double the time (5-10 million years) for
natural speciation
4. Ethical responsibility that each wild species has
the right to live
Ecological Smoke Alarms
Endangered Species
Threatened Species
• So few individual survivors that
the species could soon become
extinct
• Sumatran tiger, panda bear,
Florida panther
• http://www.fws.gov/endangere
d/
• Still has enough individuals to
survive in the short term
• Polar bear
• http://www.iucnredlist.org/sear
ch
Most important, Direct causes of extinction, resulting from
human activities: HIPPCO
•H
•I
•P
•P
•C
•O
--Habitat Destruction, degradation, & fragmentation
--Invasive Species
--Population growth & increasing use of resources
--Pollution
--Climate Change
--Overexploitation
Habitat Fragmentation
• Large, intact area of habitat
is divided into smaller, isolated patches or
“habitat islands.”
• National parks & reserves
Invasive Species
• Cause economic and ecological
damage that average at least
$162,000 an hour, worldwide
• Ex: Kudzu Vine (Pro/con?)
Prevention of Invasive Species:
1)Fund massive research program to
identify possible invaders, etc.
2)Increase ground surveys & Satellite
observations to track invasive species
and develop better models for
predicting how they will spread
3)Establish international treaties that
ban harmful invader species
4)Require Cargo ships to discharge their
ballast water or sterilize water, pump
nitrogen into water
5)Educate the public about the effects
of releasing exotic plants & animals
Protecting the Species from Extinction
• International treaties and National Laws can help protect species
• International ban on the sale of poached ivory, 1989.
• U.S. agency for International development (USAID) introducing alternative food
sources (rather than bush meat) such as farmed fish or breeding large rodents
• Problem: illegal wildlife has huge payoffs with little consequences and chance of
getting caught
1975 Convention on International Trade in
Endangered Species (CITES)
• PRO: Bans the hunting, capturing, & selling of threatened
or endangered species
• Signed by 175 countries
• CON: Enforcement varies from country to country
• Small fines for convicted violators
• Member countries can exempt themselves from listed
species
• Nonmember countries is still a problem
Convention on Biological Diversity (CBD)
• PRO: Participating governments to reducing the global
rate of biodiversity loss & to equitably sharing the
benefits from use of the world’s genetic resources
• Includes prevention of spread of invasive species
• Focuses on ecosystem rather than individual species
• CON: no severe penalties or other enforcement
mechanisms
• slow to take up
• U.S. as of 2010 not apart of this
1973 Endangered Species Act (ESA)
• PRO: Designed to identify & protect endangered species in the U.S. and abroad
• Most far reaching environmental law, controversial
• Identify & list all endangered and threatened species
• Must be based on biological factors alone NOT political or economical
• Forbids federal agencies to carry out, fund, or authorize projects that would
jeopardize any endangered or threatened species (excludes defense
department)
• Offenses committed: fines as high as $100,000 & 1 year in prison
• Organizations (USFWS & NMFS) have to prepare a plan to help each listed
species
• CONS: not caught or small fines when bringing in exotics
Wildlife Refuges
• PRO: Vital for protecting species
• Usually birds, wetland sanctuaries
• CONS: Little money so the refuges are falling apart
• Harmful activities occur such as oil drilling, mining, & use
of off road vehicles
• GENE BANKS- seed banks, preserve genetic information &
endangered plant species
• Opening one in artic, safer because no fires, wars, etc.
• BOTANICAL GARDENS & WILDLIFE FARMS
• ZOOS & AQUARIUMS- long term goal of reintroducing
• Captive population of endangered species must be # 100-500
individual species in order to avoid extinction through accident,
disease or loss of genetic diversity
• 10,000 + for evolution
-When substantial preliminary evidence suggests that an activity
can harm human health & environment, prevent or reduce the
activity
1.How do we allocate limited resources between protecting
species and protecting their habitats?
2.How do we decide which species should get the most
attention in our efforts to protect as many species as possible?
3.How do we determine which habitat areas are the most critical
to protect?