Transcript Chapter 18
Chapter 18 Conservation of Biodiversity How do coral reefs form? Core Case Study: Why Should We Care about Coral Reefs? (1) • Biodiversity • Formation • Important ecological and economic services – – – – – – Moderate atmospheric temperatures Act as natural barriers protecting coasts from erosion Provide habitats Support fishing and tourism businesses Provide jobs and building materials Studied and enjoyed Core Case Study: Why Should We Care about Coral Reefs? (2) • Degradation and decline – Coastal development – Pollution – Overfishing – Warmer ocean temperatures leading to coral bleaching – Increasing ocean acidity The 6th Mass Extinction Extinction- when there are no longer any of the species in the world. We are currently losing approximately 50,000 species per year. Genetic Diversity Scientists want to conserve genetic diversity so that the species can survive environmental change and inbreeding will not occur. Inbreeding occurs when individuals with similar genotypes, generally relatives, breed with each other. Categories of Endangerment Extinct- no known species exist today Threatened- species with a high risk of extinction in the future Near-threatened- species that are likely to become threatened in the future Least concern- species are widespread and abundant Core Case Study: The Passenger Pigeon - Gone Forever • Once the most numerous bird on earth. • In 1858, Passenger Pigeon hunting became a big business. • By 1900 they became extinct from over-harvest and habitat loss. Figure 11-1 SPECIES EXTINCTION • Species can become extinct: – Locally: A species is no longer found in an area it once inhabited but is still found elsewhere in the world. – Ecologically: Occurs when so few members of a species are left they no longer play its ecological role. – Globally (biologically): Species is no longer found on the earth. Global Extinction • Some animals have become prematurely extinct because of human activities. Figure 11-2 Endangered and Threatened Species: Ecological Smoke Alarms • Endangered species: so few individual survivors that it could soon become extinct. • Threatened species: still abundant in its natural range but is likely to become endangered in the near future. Figure 11-3 Grizzly bear Utah prairie dog Kirkland’s warbler Knowlton cactus Florida manatee Swallowtail butterfly Humpback chub Golden lion tamarin African elephant Siberian tiger Fig. 11-3, p. 224 Giant panda Black-footed Whooping crane ferret Mountain gorilla Florida panther California condor Northern spotted owl Hawksbill sea turtle Blue whale Black rhinoceros Fig. 11-3, p. 224 HIPCO H- Habitat Loss I- Invasive Species P- Pollution C- Climate Change O- Overharvested Habitat Loss For most species the greatest cause of decline and extinction is habitat loss. Most habitat loss is due to human development Invasive Species Alien species (exotic species)- species that live outside their historical range. Invasive species- when alien species spread rapidly across large areas. E.g.- Kudzu Vine, Zebra Mussel, Silver Carp INVASIVE SPECIES • Many invasive species have been introduced intentionally. Figure 11-11 INVASIVE SPECIES • Many invasive species have been introduced unintentionally. Figure 11-11 Pollution Threats to biodiversity can come from toxic contaminants such as pesticides, heavy metals, acids, and oil spills. Climate Change The concern is how climate change will affect temperature and precipitation around the world, and how this will impact biodiversity. Overharvesting When individuals of a species are removed at a rate faster than the population can replace them. Ex- dodo, American bison, passenger pigeon. Lacey Act One of the earliest laws in the U.S. to control the trade of wildlife. First passed in 1900, the act prohibited the transport of illegally harvested game animals, primarily birds and mammals, across state lines. CITES Convention on International Trade in Endangered Species of Wild Fauna and Flora Developed in 1973 to control the international trade of threatened plants and animals. Today, CITES is an international agreement between 175 countries of the world. Red List The IUCN keeps a list of threatened species, known as the red list. Each country has its own way to monitor and regulate the import and export of animals on the list. Conservation Legislation Marine Mammal Protection Act- prohibits the killing of all marine mammals in the U.S. and prohibits the import or export of any marine mammal body parts. Endangered Species Act Endangered Species Act- first passed in 1973, it authorizes the U.S. Fish and Wildlife Service to determine which species can be listed as threatened or endangered and prohibits the harming of these species. Trading these species is also illegal. The act also authorizes the government to purchase habitat that is critical to the species. Regulatory Takings • Eminent Domain requires compensation for loss of value of land • Restriction on development of land because of protection of habitat for endangered species also results in loss of value • Takings legislation is intended to compensate land owner for future loss of earnings Convention on Biological Diversity In 1992, nations came together and made a treaty to protect biodiversity. The treaty had three objectives: conserve biodiversity, sustainably use biodiversity, and equitably share the benefits that emerge from the commercial use of genetic resources such as pharmaceutical drugs. Size, Shape and Connectedness When designing and managing protected areas we must consider how close to another area they should be, how large the area is, and the amount of edge habitat the area contains. Edge habitat- the area where two different communities come together, typically forming an abrupt transition. Ex. A grassy field meeting a forest. Theory of Island Biogeography • Applies to “islands” of habitat • Given limited funding and limited undeveloped area, would one large parcel or several small ones be preferable for maintaining a population? • Considerations – Edge habitat – Metapopulations? Biosphere Reserves Protected areas consisting of zones that vary in the amount of permissible human impact. NATURE RESERVES • Large and medium-sized reserves with buffer zones help protect biodiversity and can be connected by corridors. Costa Rica has consolidated its parks and reserves into 8 megareserves designed to sustain 80% if its biodiversity. Figure 10-10B Debt for Nature Swaps • Debtor nations may pay off their loans with payments to environmental organizations • Payments may be used to purchase land, pay rangers to protect from poaching and illegal logging, pay for population studies • Program is in place with Guatemala • Debt probably wouldn’t be repaid anyway – Win-Win