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?