1. Human Impact

2. Biodiversity: Necessary for Healthy Ecosystems 1.Biodiversity: sum total of all the different species found in an ecosystem a.The greater the number of species in an ecosystem, the healthier the ecosystem. b.Organisms are sources of foods, medicines, and materials for clothing and shelter

3. Destroying Habitats Threatens Biodiversity Humans destroy habitats: Habitat loss- converting ecosystems into housing, shopping & industrial areas Habitat fragmentation- isolating populations into smaller portions of their habitat Habitat degradation- polluting habitat’s land, water and air Habitat Fragmentation

4. Other Threats to Biodiversity Over-hunting: reduces population of the species; can cause extinction Deforestation: bulldozing forests for agriculture and human developments Introduced / invasive species: new species brought to an ecosystems  Problem: no native predators; they out-compete native species for resources  EX: Fire ants & zebra mussels Deforestation

5. Introduced Species Introduced in 1930’s in Port of Mobil, AL Red Fire Ants:  Native To: South America  Possibly introduced in ships' ballast  Can attack and cause painful stings on humans, pets, and livestock

6. The Spread of an Invasive Species

7. Introduced Species Zebra mussels  Originated in the Balkans, Poland  1 st appeared in N. America in 1988 in Lake St. Clair, a small water body connecting Lake Huron and Lake Erie.  Young zebra mussels are small and free swimming, and can be easily spread by water currents.  Zebra mussels can colonize a clam shell to such an extent that the clam cannot open its shell to eat.

8. The Spread of Zebra Mussels One ship released ballast water in Lake Saint Clair in 1988 Current distribution (1/16/14)

9. Cold Call  What is biodiversity?  What is habitat fragmentation?  How does habitat fragmentation affect territorial wildlife?  What is the difference between an introduced and an invasive species?  Name two invasive species

10. Pollution: The Biggest Threat to Biodiversity 1.Pollutants damage / destroy abiotic factors in ecosystems a.Hard to get pollutants out of air & water b.Eventually destroys living things 2.Hard to rebuild destroyed ecosystems 3.Pollution prevention is the best method to keeping ecosystems healthy Smog over a city

12. Eutrophication: Pollution in Waterways 1.Eutrophication: enrichment of a lake / pond by N or P a.Rate is increased by fertilizer runoff & sewage discharge b.Algae have plenty of nutrients & reproduce rapidly c.Algae die & are decomposed by bacteria d.Decomposing bacteria consume all O 2 in water e.Fish die b/c there is not enough O 2 in water

14. Emissions to Atmosphere Nitrogen oxides Sulfur dioxide Chemical Transformation Nitric acid Sulfuric acid Precipitation Acid rain, fog, snow, and mist Dry Fallout Condensation particulates, gases Industry Transportation Ore smelting Power generation Go to Section: The Formation of Acid Rain 1.Acid rain lowers the pH of water & soil 2.Ca & Mg (essential nutrients) become less available at low pH (acidic) 3.Al & Fe (toxic) become more available at low pH & can kill plants

15. Effects of Pollution on Species: Biomagnification 1.Biomagnification: increasing concentration of harmful chemicals in organisms at higher levels in the food web a.Chemicals usually fat soluble – build up in body tissues b.If organism is food source for humans, then humans ingest chemical when they eat the organism

16. Biomagnification Also Harms Wildlife 1.Some chemicals (DDT) are not excreted after they are ingested 2.DDT accumulates in body tissues 3.DDT can cause harmful effects to offspring 4.If egg shells are weakened, they will break during incubation Egg of eagle; shell is weakened. Egg will be destroyed in incubation.

17. Pollution Destroys the Ozone Layer 1. Ozone layer in stratosphere protects us against UVA & UVB radiation 2. CFC’s (chlorofluorocarbons) react with ozone (O 3 ) can create holes in ozone layer allows UV radiation through stratosphere Causes Earth’s temp to increase UV radiation can damage DNA of organisms CFC’s were developed in 1930s and used in a variety of industrial, commercial, and household applications. They are non-toxic, non-flammable, and non-reactive with other chemical compounds. In 1973 we learned that chlorine accelerates ozone destruction

18. 1. Protection of endangered species – (when an animal or plant species becomes so rare that it is threatened with extinction). 2. Conservation involves managing renewable resources so that they will still be available in the future (freshwater, soil, forest, wildlife and fishery resources). 3. Pollution Prevention- is the best way to prevent damage to ecosystems. Reducing the Human Impact

19. Cold Call  What is biomagnification?  Why is ozone in the stratosphere important?  What chemical destroys ozone in the stratosphere?  What is eutrophication?  What causes eutrophication?