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Sustaining Aquatic Biodiversity Chapter 11
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Core Case Study: A Biological Roller Coaster Ride in Lake Victoria Loss of biodiversity and cichlids Nile perch: deliberately introduced Frequent algal blooms Nutrient runoff Spills of untreated sewage Less algae-eating cichlids
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11-1 What Are the Major Threats to Aquatic Biodiversity? 1) We have Much to learn a) Only explore about 5% of oceans b) Have little knowledge of oceans and limited for Freshwater c) 3 Patterns of marine biodiversity 1. greatest in coral reefs 2. Higher near coasts 3. Higher at the bottom d) Remember they provide important services
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We Have Much to Learn about Aquatic Biodiversity 2) We are degrading aquatic habitats (HIPPCO) 3) Invasive species: a) 84% of coastal waters are being colonized by invasive species b) Ex. Asian swamp eel and purple loosestrife 4) Population Growth & Pollution a) By 2020, 80% of people will be living along or near the coasts b) Only 4% of oceans are NOT affected by pollution
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Fig. 11-5, p. 255 Hyacinths in Lake Victoria 1997
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Human Activities Are Destroying and Degrading Aquatic Habitats c) 80% of ocean pollution comes from the land d) Fertilizers increase nitrogen Algal blooms fish kills e) Toxic pollutants kill some forms of aquatic life 5) Climate change a) Causes sea levels to rise b) Destroys coral reefs, swamps land, drown many wetlands
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Science Focus: How Carp Have Muddied Some Waters pg. 252 Lake Wingra, Wisconsin (U.S.): eutrophic Contains invasive species Purple loosestrife and the common carp Dr. Richard Lathrop Removed carp from an area of the lake This area appeared to recover
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Degrading Aquatic Biodiversity 6) Overfishing a) Not a new problem, but it is faster with industrialized fishing b) Can cause 80% depletion in 10-15 years c) Demand is outgrowing sustainable yield d) Fishprint: amount of ocean needed to sustain an ave. person, nation, or the world e) Commerical extinction: no longer profitable to catch
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Fig. 11-7, p. 257
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Overfishing and Extinction: Gone Fishing, Fish Gone f) Almost 1/3 of fish catch by weight are nontarget species g) Seals, dolphins and other marine mammal are also caught h) 34% of marine & 71% of FW species face extinction within your lifetime
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Science Focus: Protecting and Restoring Mangroves PG 255 Protect and restore mangroves Reduce the impact of rising sea levels Protect against tropical storms and tsunamis Cheaper than building concrete sea walls Mangrove forests in Indonesia
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Case Study: Industrial Fish Harvesting Methods Pg 256 (know this picture) Trawler fishing Purse-seine fishing Longlining Drift-net fishing
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11-2 How Can We Protect and Sustain Marine Biodiversity? 1) Laws and Treaties a) Why is it hard to protect marine biodiversity 1. Ecological footprint/fishprint is growing 2. Most damage is not visible 3. Many think it is inexhaustible resource 2) CITES, Global treaty on Migratory species, US Marine Mammal Protection ACT, ESA, UT Whale conservation & Protection act & International Convention on biological diversity
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Case Study: Protecting Whales: A Success Story… So Far (pg 257) Cetaceans: Toothed whales and baleen whales 1946: International Whaling Commission (IWC) 1970: U.S. Stopped all commercial whaling Banned all imports of whale products 1986: moratorium on commercial whaling Pros Cons
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Fig. 11-1, p. 250
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3) Economic Incentives Can Be Used to Sustain Aquatic Biodiversity a) Tourism: Example sea turtles b) Rewards for restoring and sustaining aquatic systems 4) Marine Sanctuaries a) High seas: beyond fishing zone (370 km) b) Law of the Sea treaty: 1) nations have jurisdiction over 36% of ocean & 90% of fish stocks 2. Many have promoted over fishing
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c) MPA’s (marine protected areas): area of the ocean partially protected from human activities 5) Global network of marine reserves: a) Main objective is to protect & sustain whole marine ecosystems b) Trying to establish a global network of fully protected reserves off-limits to destructive human activities c) Would include large areas on high seas and a mixture of small areas in coastal zones
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d) Most would contain core zones e) These work fast: within 2-4 years 1. fish populations double 2. size grow by about 1/3 3. reproduction triples 4. diversity increases by ¼ f) Kiribati created the world’s largest, the 2 nd is in the US off of Hawaii 6) Protection requires community and individual commitment
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Case Study: Holding Out Hope for Marine Turtles ( pg 259) Carl Safina, Voyage of the Turtle Studies of the leatherback turtle Threats to the leatherbacks Trawlers Pollution Climate change Communities protecting the turtles
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Fig. 11-9, p. 262
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Individuals Matter: Creating an Artificial Coral Reef in Israel (pg 261 Reuven Yosef, Red Sea Star Restaurant Coral reef restoration Reconciliation ecology Treatment of broken coral with antibiotics
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11-3 How Should We Manage and Sustain Marine Fisheries? 1) Estimating & Monitoring Fish populations a) Max. sustained yield (MSY): projects the max number of fish that can be harvested without causing a population drop (hasn’t worked) b) Optimum sustained yield (OSY) : takes into account interactions among species & provides more room for error c) Multispecies management: includes a large number of interacting species. d) Large marine systems: used computer models e) Push to use precautionary principle
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2) Some Communities Cooperate to Regulate Fish Harvests a) Coastal fishing communities have developed allotment and enforcement systems b) With modern fishing boats & international fishing fleets these systems no longer work as well c) Comanagement: communities & the government work together to manage fishing 3) Subsidies encourage overfishing a) Governments give about $30-40 billion per year to help keep fishing businesses running
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b) $20 billion buys ships, fuel & equipment, the rest pays for research & management c) Some think this money encourages overfishing and expansion of the industry 4) Marketplace control a) Individual transfer rights (ITRs) government gives each vessel owner a percentage fo the total allowable catch (TAC) in a year b) These can be sold or leased c) it has helped in some areas (page 264) & ended subsidies, but enforcement is difficult
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d) 3 problems 1. transfers ownership in public waters to private business 2. ITR can squeeze out small companies 3. TAC’s are often too high to prevent overfishing 5) Consumer choices can help a) Demand sustainable seafood b) Better labeling c) Certification of sustainable caught seafood d) MSCs- Fish forever eco-label e) Fig 11-12
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Fig. 11-11, p. 267
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11-4 How Should We Protect and Sustain Wetlands? 1) Coastal & Inland wetlands are disappearing: a) US has lost more than ½ since 1900 b) Drained, filled in or covered to create rice fields, farmland, cities, roads, removal of minerals, eliminate insect breeding grounds c) Global warming will cause many to be under sea water 2) We can preserve & restore wetlands a) Laws have been passed to protect existing areas b) US law requires a federal permit to fill in wetlands covering 3 acres
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c) Mitigation banking: allows destruction of existing wetland if equal areas of same type wetland is created or restored d) Creating wetlands can be profitable by saving credits to sell to developers ($3 billion a year)
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Individuals Matter: Restoring a Wetland (pg 266) Jim Callender: 1982 Scientific knowledge + hard work = a restored wetland in California, U.S. Marsh used again by migratory fowl
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Case Study: Can We Restore the Florida Everglades? (pg 267-268) “River of Grass”: south Florida, U.S. Since 1948: damaged Drained, Diverted, Paved over, Nutrient pollution from agriculture, Invasive plant species 1947: Everglades National Park unsuccessful protection project 1970s: political haggling 1990: Comprehensive Everglades Restoration Plan (CERP) Restore the curving flow of most of the Kissimmee River Remove canals and levees in strategic locations Flood 240 sq. km farmland to create artificial marshes Goal?
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Case Study: Can We Restore the Florida Everglades? Comprehensive Everglades Restoration Plan (CERP) cont… Create reservoirs and underground water storage areas Build new canals, reservoirs and efficient pumping systems Why isn’t this plan working?
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11-5 How Can Protect and Sustain Freshwater Lakes, Rivers, and Fisheries? 1) FW ecosystems are under major threats a) FW services are threatened by human activities b) HIPPCO again c) 40% of rivers have been dammed or engineered d) Wetland have been destroyed e) Sustaining and restoring the biodiversity & services is complex and challenging
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Case Study: Can the Great Lakes Survive Repeated Invasions by Alien Species? (pg 269) Collectively, world’s largest body of freshwater Invaded by at least 162 nonnative species Sea lamprey Zebra mussel Good and bad Quagga mussel Asian carp
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Fig. 11-16, p. 272
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2) Managing River Basins Is Complex and Controversial a) Rivers & streams provide important services b) Many help humans, but disrupt natural ecosystems ex: Columbia River & Snake River and salmon 3) Protecting FW by protecting the watershed a) What we do on land can end up in the water b) Runoff of fertilizers and pollutants c) National Wild & Scenic Rivers Act: protects “wild rivers” from widening, straightening, dredging, filling & damming (only 2%) d) Fishing is usually regulated by season, size & number
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11-6 We Need to Set Priorities for Protecting Biodiversity, Ecosystem Services (pg 271-272) 2002: Edward O. Wilson Complete the mapping of the world’s terrestrial and aquatic biodiversity Keep old-growth forests intact; cease their logging Identify and preserve hotspots and deteriorating ecosystem services that threaten life Ecological restoration projects Make conservation financially rewarding
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