Transcript Chapter 11
Chapter 12 & 13 Sustaining Biodiversity: Terrestrial and Aquatic Species 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 overharvest and habitat loss. Figure 12-1 SPECIES EXTINCTION Species OBJ 12.1 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 12-2 OBJ 12.2 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 12-3 OBJ 12.3 SPECIES EXTINCTION Some species have characteristics that make them vulnerable to ecological and biological extinction. Figure 12-4 SPECIES EXTINCTION The International Union for the Conservation of Nature and Natural Resources (IUCN) publishes an annual Red List, listing the world’s threatened species. The 2010 Red List contains 18,351 species at risk for extinction. US – listed by the Fish and Wildlife Service • www.fws.gov Figure 11-5 SPECIES EXTINCTION Percentage of various species types threatened with premature extinction from human activities. Figure 12-5 Overview of Aquatic Biodiversity Little is actually know about biodiversity of marine and freshwater systems; only explored about 5% of global oceans Most Aquatic Biodiversity: Found near shorelines and deep parts of ocean Coral reefs, wetlands, estuaries, coastal areas and deep ocean floor IMPORTANCE OF WILD SPECIES We should not cause the premature extinction of species because of the economic and ecological services they provide. Some believe that each wild species has an inherent right to exist. (intrinsic value) Aquatic Ecological and Economic Services Globally, 6% of total protein for food consumption comes from marine fish and shellfish Seaweed and other organisms provide pharmaceuticals, cosmetics, food stabilizers and preservatives (ie. carrageen in yogurts and ice cream) OBJ 12.5 WHY??? Conservation biologists summarize the most important causes of premature extinction as “HIPPO”: Habitat destruction, degradation, and fragmentation Invasive species Population growth Pollution Overharvest Human Impacts on Aquatic Biodiversity Greatest threat is habitat loss- destruction and development of coastal wetlands, coral reefs (tourism), mangroves (coastal development & shrimp aquaculture) and the ocean floor (trawling/dredging) Trawling HABITAT LOSS, DEGRADATION, AND FRAGMENTATION Reduction in ranges of four wildlife species, mostly due to habitat loss and overharvest. Figure 12-7 Case Study: A Disturbing Message from the Birds Human activities are causing serious declines in the populations of many bird species. Figure 12-8 Case Study: A Disturbing Message from the Birds The majority of the world’s bird species are found in South America. Threatened with habitat loss and invasive species. Flyways Migration pathways used by birds moving from southern wintering ground to northern breeding grounds. Tend to follow 4 major pathways, along coasts, mountain ranges, and major river valleys. Flyway City- major urban area located within a flyway that breaks the connecting natural habitats and can create impassable barriers. Flyway Cities Coalition Creating connected areas of habitat to help wildlife adjust to habitat fragmentation www.flywaycities.org (creating landscapes that provide food, cover and water needed for wildlife; ensuring native plants thrive) Migratory Bird Hunting and Conservation Stamp Act (1934) The "Duck Stamp Act; requires each waterfowl hunter 16 years of age or older to possess a valid Federal hunting stamp. Human Impacts on Biodiversity Introduction and invasion of nonnative species Most arrive to aquatic areas in the ballast of ships that discharged water in arrival ports *Solutions: discharge at sea, sterilize or pump nitrogen into ballast water before dispersion - Release of exotic pets *Alligator and Burmese python– Everglades Lake Victoria, E. Africa - cichlids and Nile perch Perch deliberately introduce to stimulate local economy and fishing industry * Declining cichlid pops. led to increase in poverty and malnutrition (cichlids cheaper), eutrophication of the lake algal blooms, invasion of water hyacinth with block sunlight and leads to oxygen deprivation Perch– large, carnivorous Cichlids – algae eaters Characteristics of Successful Invader Species • High reproductive rate, short generation time (r-selected species) • Pioneer species • Long lived Characteristics of Ecosystems Vulnerable to Invader Species • Climate similar to habitat of invader • Absence of predators on invading species • Early successional systems • High dispersal rate • Release growth-inhibiting chemicals into soil • Low diversity of native species • Absence of fire • Generalists • High genetic variability • Disturbed by human activities Fig. 11-13, p. 236 INVASIVE SPECIES Many Kudzu vine was introduced in the southeastern U.S. to control erosion. It has taken over native species habitats. OBJ 12.6 nonnative species provide us with food, medicine, and other benefits but a a few can wipe out native species, disrupt ecosystems, and cause large economic losses. INVASIVE SPECIES Many invasive species have been introduced intentionally. OBJ 12.7 INVASIVE SPECIES Many invasive species have been introduced unintentionally. Great Lakes- zebra mussels (invasive species) Interactive map showing progression of zebra mussel populations from 1988-2008 (scroll over dates to see distribution) OBJ 12.8 INVASIVE SPECIES Prevention is the best way to reduce threats from invasive species, because once they arrive it is almost impossible to slow their spread. Figure 11-13 Overharvesting Loss of fish species due to overfishing - ¾ of commercially valuable marine fish species are overfished or fished near limits Commercial Extinctiondepletion of a commercially valuable resource (ie. Specific species of fish like N. Atlantic cod) to a level at which it is no longer valuable to harvest it and the pop. may never recover. Bycatch- non-targeted species caught on fishing hooks and nets (ie. Long lining and sharks or turtles) 1989: US enforces law that all shrimp trawlers must include turtle exclusion devices (TED’s) Overharvesting/ Overexploitation Some protected species are killed for their valuable parts or are sold live to collectors. Killing predators and pests that bother us or cause economic losses threatens some species with premature extinction. Legal and illegal trade in wildlife species used as pets or for decorative purposes threatens some species with extinction. OVEREXPLOITATION Rhinoceros are often killed for their horns and sold illegally on the black market for decorative and medicinal purposes. Case Study: Rising Demand for Bushmeat in Africa Bushmeat hunting has caused the local extinction of many animals in West Africa. Can spread disease such as HIV/AIDS and ebola virus. Endangered Species Because of scarcity of inspectors, probably no more than 1/10th of the illegal wildlife trade in the U.S. is discovered. “Gorillas in the Mist” The Story of Dian Fossey POPULATION GROWTH, POLLUTION, AND CLIMATE CHANGE Population growth, affluenza, and pollution have promoted the premature extinction of some species. Projected climate change threatens a number of species with premature extinction. Pollution Each year pesticides: Example of biomagnification of DDT in an aquatic food chain. Kill about 1/5th of the U.S. honeybee colonies. 67 million birds. 6 -14 million fish. Threaten 1/5th of the U.S.’s endangered and threatened species. Biomagnification video OBJ 12.9 PROTECTING WILD SPECIES: Solutions??? LEGAL AND ECONOMIC APPROACHES CITES. International treaties have helped reduce the international trade of endangered and threatened species, but enforcement is difficult. One of the most powerful is the 1975 Convention on International Trade of Endangered Species (CITES). • Signed by 169 countries, lists 900 species that cannot be commercially traded. OBJ 12.10 The U.S. Endangered Species Act One of the world’s most far-reaching and controversial environmental laws is the 1973 U.S. Endangered Species Act (ESA). ESA forbids federal agencies (besides defense department) to carry out / fund projects that would jeopardize an endangered species. ESA makes it illegal for Americans to engage in commerce associated with or hunt / kill / collect endangered or threatened species. The U.S. Endangered Species Act Biodiversity hotspots in relation to the largest concentrations of rare and potentially endangered species in the U.S. Lacey Act 1900 Prohibits transporting live or dead animals or their parts across state lines without a federal permit. (US law) PROTECTING WILD SPECIES: THE SANCTUARY APPROACH The U.S. has set aside 544 federal refuges for wildlife, but many refuges are suffering from environmental degradation. Pelican Island was the nation’s first wildlife refuge. THE SANCTUARY APPROACH Gene banks, botanical gardens and using farms to raise threatened species can help prevent extinction, but these options lack funding and storage space. Zoos and aquariums can help protect endangered animal species by preserving some individuals with the long-term goal of reintroduction, but suffer from lack of space and money. Protecting and Sustaining Marine Biodiversity Problems: Jurisdiction in regulation of open seas? Tragedy of the Commons- much of the damage is not noticeable to most people; ocean is an inexhaustible resource Solutions: Establish laws and international treaties • CITES, EPA, US Marine Mammal Protection Act, US Whale Conservation and Protection Act, etc. Education U.S. Coastal Waters Pew Oceans Commission conducted a 3 year study which determined our coastal waters were in deep trouble and laws needed to be reformed in order to protect them. Recommendations included: 1) Pass a Natl. Ocean Policy Act that commits the country to sustain, protect, and restore oceans. 2) Double fed. Budget for ocean research 3) Fishery management based on preserving aquatic ecosystems rather than catch limits for certain fish species. 4) set up a network of marine reserves (like terrestrial biophere reserves) with protected corridors linking reserves to help protect fish breeding and nursery grounds. Commercial Whaling Cetaceans (marine mammals ranging from 3-100 ft; toothed and baleen whales) Intl. Whaling Commission (IWC- 1946) – 49 nations to regulate the whaling quotas to prevent overharvesting 1970 : US banned whaling and imports of whale products 1986: IWC imposed moratorium on commercial whaling; some countries like Japan, Norway, and Iceland still hunt specific species claiming they are used for “scientific research” purposes. Commercial Whaling industry Info on Japanese whaling (IWC and scientific permits) International Agreements Coastal countries control up to 12 miles offshore, fishing allowed up to 230 miles (beyond any country jurisdiction is known as High Seas) Marine Protected Areas (MPA’s)- areas of the ocean protected by some or all human activities (1300 MPA’s provide protection for 0.2% of earth’s total oceans) Marine Reserves- fully protected areas and no extraction of any living or nonliving resource is allowed. (90 of 350 biosphere reserves are coastal or marine habitats) Marine Protected Areas Marine Reserves Integrated Coastal Management Community effort to develop and use coastal resources more sustainably. Goal is to increase zoning of marine reserves and protected areas; Hard to enforce Integrated Coastal Management and Reconciliation Ecology Red Sea Star Restaurant, Israel: restored coral reef and tourist attraction! ($ and environmental purpose!) Protecting, Sustaining and Restoring Wetlands CERP (Comprehensive Everglades Restoration Plan)one of the world’s largest ecological restoration project Flow maps Surface Water Storage Reservoirs Water Preserve Areas Management of Lake Okeechobee as an Ecological Resource Improved Water Deliveries to the Estuaries Underground Water Storage Treatment Wetlands Improved Water Deliveries to the Everglades Removal of Barriers to Sheetflow Storage of Water in Existing Quarries Reuse of Wastewater Improved Water Conservation Additional Feasibility Studies 13-6 Protecting, Sustaining, and Restoring Lakes & Rivers Pacific Salmon – construction of dams (Great animation of similar human impacts on Atlantic salmon!) Fish ladder- help reestablish salmon migration path for breeding Sustainability of Aquatic Ecosystems Increase research of aquatic life Expand efforts to protect and restore (US National Wild and Scenic Rivers System) Incorporate more integrated ecological management between terrestrial and aquatic ecosystems RECONCILIATION ECOLOGY Reconciliation ecology involves finding ways to share places we dominate with other species. Replacing monoculture grasses with native species. Maintaining habitats for insect eating bats can keep down unwanted insects. Reduction and elimination of pesticides to protect non-target organisms (such as vital insect pollinators). Using Reconciliation Ecology to Protect Bluebirds Putting up bluebird boxes with holes too small for (nonnative) competitors in areas where trees have been cut down have helped reestablish populations.