Sustaining Biodiversity: The Species Approach

1. Sustaining Biodiversity: The Species Approach Chapter 8

2. Section 8-1 What role do humans play in the extinction of species?

3. Extinctions are natural but sometimes they increase sharply • The disappearance of species canweaken or break some of the connections in the ecosystem. • The extinction of many species in a relatively short period of geologic time is called a mass extinction.

4. Wetland Food Web

5. Some human activities are causing extinction rates to rise • Extinction is a natural process but evidence indicates that extinction has accelerated as the human population has increased, consuming huge quantities of resources and creating large and growing ecological footprints. • Scientists from around the world have estimated that the current annual rate of species extinction is at least 100 to 1,000 times the background rate.

6. Endangered and threatened species are ecological smoke alarms • An endangered species has so few individual survivors that the species could soon become extinct over all or most of its natural range. • A threatened species (vulnerable species) still has enough remaining individuals to survive in the short term, but because of declining numbers, it is likely to become endangered in the near future. Know!!

7. Section 8-2 Why should we care about the rising rate of species extinction?

8. 3 reasons why we should care about extinctions • Species provide natural resources and natural services that help to keep us alive and support human economies. • It will take 5–10 million years for natural speciation to rebuild the biodiversity that we are likely to destroy during your lifetime. • Many people believe that each wild species has a right to exist, regardless its usefulness to us. Know!!

9. Section 8-3 How do humans accelerate species extinction?

10. Loss of habitat is the single greatest threat to species: Remember HIPPCO • HIPPCO summarizes the most important causes of extinction from human activities: • Habitat destruction/degradation/fragmentation. • Invasive (nonnative) species. • Population growth/increasing use of resources. • Pollution. • Climate change. • Overexploitation. Know!!

11. Reductions in the ranges of four species

12. Invasive Species After habitat loss and degradation, the biggest cause of animal and plant extinctions is the deliberate or accidental introduction of harmful invasive species into ecosystems.

13. Invasive Species Introduced species have no natural predators, competitors, parasites, or pathogens to help control their numbers in their new habitat.

14. Harmful invasive species

15. Deliberately Introduced Species Purple loosestrife European starling African honeybee (“Killer bee”) Nutria Salt cedar (Tamarisk) Purple loosestrife African honeybee (“Killer Bee”) Water hyacinth Japanese beetle European wild boar (Feral pig) Fig. 8-7a, p. 159

16. Accidentally Introduced Species Sea lamprey (attached to lake trout) Argentina fire ant Brown tree snake Formosan termite Zebra mussel Fig. 8-7b, p. 159

17. Florida invasive species • Iguanas • Pythons • Brazilian Pepper • Melaleuca

18. House overtaken by kudzu

19. Zebra mussels attached to a water current meter in Lake Michigan

20. Ways we can slow or prevent the spread of invasive species

21. DDT The pesticide DDT can be biomagnified about 10 million times in an estuary food chain, causing animals such as the osprey, brown pelican and bald eagles to die.

22. Bioaccumulation Know this!

23. DDT in fish-eating birds (ospreys) 25 ppm DDT in large fish (needlefish) 2 ppm DDT in small fish (minnows) 0.5 ppm DDT in zooplankton 0.04 ppm DDT in water 0.000003 ppm, or 3 ppt Fig. 8-11, p. 162

25. Mercury

26. Minamata Disease https://www.youtube.com/watch?v=ihFkyPv1jtU

27. Climate Change • Projected climate change could help drive a quarter to half of all land animals and plants to extinction by the end of this century.

28. CASE STUDY: Where Have All The Honeybees Gone? • A 30% - 40% drop in U.S. honeybee populations has been reported since the 1980s, due to: • Pesticide exposure. • Parasitic mites - can wipe out a colony in hours. • Invasion by Africanized honeybees. • A virus traced to Israel, and a certain fungus. • Poor nutrition because of a decrease in the natural diversity of flowers and other plants on which bees feed.

29. Colony Collapse Disorder • In 2010, about 34% of commercial honeybee colonies in the U.S. were lost in part to colony collapse disorder (CCD), causing adult bees to mysteriously disappear.

30. colony collapse disorder • Strategies to help honeybee populations: • Beekeepers are reducing CCD by practicing stringent hygiene, improving the diets of the bees, and trying to reduce viral infections. • Cut back on use of pesticides, especially at midday when honeybees are most likely to be searching for nectar. • Make our yards and gardens into buffets for honey bees by planting native plants that they like. • Bees need places to live, so some homeowners are purchasing bee houses from their local garden centers.

31. Section 8-4 How can we protect wild species from extinction?

32. International treaties and national laws can help to protect species • The 1975 Convention on International Trade in Endangered Species (CITES) • The Convention on Biological Diversity (CBD), ratified by 190 countries (but as of 2011, not by the United States), • The U.S. Endangered Species Act (1973)

33. CASE STUDY: Protecting Endangered Sea Turtles • Six of the world’s seven sea turtle species are critically endangered or endangered. • Two major threats to sea turtles are loss or degradation of beach habitat (where they come ashore to lay their eggs and the young hatch), and the legal and illegal taking of their eggs.

34. Endangered leatherback sea turtle tangled in a fishing net

35. We can establish wildlife refuges and other protected areas • In 1903, President Theodore Roosevelt established the first U.S. federal wildlife refuge at Pelican Island, Florida, to help protect birds such as the brown pelican from extinction. • The National Wildlife Refuge System grew to 553 refuges by 2011.

36. Gene banks • Gene or seed banks preserve genetic information and endangered plant species by storing their seeds in refrigerated, low-humidity environments. https://www.youtube.com/watch?v=sgNEOVlqils https://www.youtube.com/watch?v=RNg-EHU78kE https://www.youtube.com/watch?v=A7gtPAYZUt4&feature=endscreen

37. Gene banks, botanical gardens, and wildlife farms can help to protect species • botanical gardens • farms • zoos • aquariums