APES-Chapter-11-PPT-16th-Edition by cuiliqing

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									Sustaining Aquatic Biodiversity


           Chapter 11
 Core Case Study: A Biological Roller Coaster
            Ride in Lake Victoria

 Loss of biodiversity and cichlids
 Nile perch: deliberately
  introduced in 1950s and 1960s
  to stimulate exports of the fish
 Frequent algal blooms due to
    Nutrient runoff
    Spills of untreated sewage
    Less algae-eating cichlids
     Natural Capital Degradation:
           The Nile Perch

Nile perch
population is
decreasing due to
reduced food
supply of smaller
fishes (cichlids)
and being
overfished.
  What Are the Major Threats to Aquatic
              Biodiversity?


 Aquatic species are threatened by habitat loss,
 invasive species, pollution, climate change, and
 overexploitation, all made worse by the growth of
 the human population. (HIPPCO)
         We Have Much to Learn about
             Aquatic Biodiversity

 Greatest marine biodiversity occurs in
   Coral reefs
   Estuaries
   Deep-sea ocean floor
 Biodiversity is higher
   Near the coasts because of great variety of producers,
    habitats, and nursery areas than in the open sea
   In the bottom region than in the surface region of the
    ocean due to a greater variety of habitats
Human Activities are Destroying and
Degrading Aquatic Habitats
  Habitat loss and degradation – the “H”
   in HIPPCO – the greatest threat to
   the biodiversity of oceans
     Marine – only 4% of the world’s
      oceans are NOT affected by
      pollution
       Coastal – coral reefs, mangrove
        forests, and coastal wetlands
       Ocean floor – effect of trawlers
        which drag huge nets weighted
        with heavy chains and steel
        plates, reduce coral reefs to
        rubble
     Freshwater Habitats
       Dams
       Excessive water withdrawal
  Invasive Species are Degrading Biodiversity
 Invasive species - the “I” in HIPPCO
    Threaten native species
    Disrupt and degrade whole
    ecosystems
 Three Examples:
   Water hyacinth: Lake Victoria (East
    Africa)
   Asian swamp eel: waterways of
    south Florida
   Purple loosestrife: indigenous to
    Europe                                 Invasive Water Hyacinth
      Treating with natural predators—a
       weevil species and a leaf-eating
       beetle—Will it work?
   Science Focus: How Carp Have Muddied
               Some Waters
 Lake Wingra, Wisconsin (U.S.):
  eutrophic, excessive nutrient inputs
  from run off with fertilizers from
  farms/lawns
   Contains invasive species
      Purple loosestrife and the common
       carp, which devour the algae
 Dr. Richard Lathrop
   Removed carp from an area of the
    lake
      This area appeared to recover
Population Growth and Pollution Can Reduce
            Aquatic Biodiversity
 The two “P’s” in HIPPCO
 By 2020, 80% of the world’s
  population will live near coasts
 Population growth and pollution
  have drastic effects on ocean
  systems
 Nitrates and phosphates mainly
  from fertilizers enter water
    Leads to algal bloom and
     eventual eutrophication, fish               Hawaiian Monk Seal
     die offs
 Toxic pollutants from industrial    Plastic items from ships and litter on
  and urban areas kill some forms     beaches kill seabirds, mammals, and sea
  of aquatic life by poisoning them   turtles – POLLUTION
 Climate Change Is a Growing Threat
 The “C” in HIPPCO
 Global Warming: sea levels will rise and aquatic biodiversity is
  threatened – during the past 100 years, average sea levels have
  risen an average of 10-20 cm and scientists estimate they will rise
  another 18-59 cm, and perhaps as high as 1-1.6 m between 2050
  and 2100
  ◦ Destroy coral reefs
  ◦ Swamp some low-lying islands
  ◦ Drown many highly productive coastal wetlands including New
    Orleans, Louisiana
          Overfishing and Extinction
 Overfishing – the “O” in HIPPCO
 Marine and Freshwater Fish
    Threatened with extinction by human activities more than any other
    group of species.
 Commercial Extinction – due to overfishing which occurs when it is
  no longer profitable to continue fishing the affected species.
  Industrialized fishing fleets can deplete marine life at a much faster rate.
  Can deplete 80% of target fish species in 10-15 years.
    Collapse of the cod fishery off the coast of Newfoundland and its domino
     effect leading to collapse of other species.
 Bycatch – seals, dolphins (non-target species, 1/3 of annual fish catch)
 Biological Extinction – 34% of marine and 71% of fresh water species
  face extinction within your life time.
                       900,000


                       800,000

                       700,000


                       600,000
Fish landings (tons)




                       500,000


                       400,000
                                                                1992
                       300,000


                       200,000

                       100,000

                            0
                            1900   1920   1940    1960   1980      2000
                                             Year                         Fig. 11-6, p. 254
Science Focus: Protecting and Restoring
              Mangroves
  Protect and restore mangroves because they provide
   important ecological services.
     Reduce the impact of rising sea levels
     Protect against tropical storms and tsunamis
     Cheaper than building concrete sea walls
  Due to coastal development in Indonesia, about 70% of
   mangroves have been degraded or destroyed. Now
   efforts to protect those areas.
      Case Study: Industrial Fish Harvesting
        Methods are Vacuuming the Seas
 Trawler fishing – fish
  and shellfish
 Purse-seine fishing –
  surface dwelling species
  like tuna, mackerel
 Long-lining – open
  ocean fish species like
  tuna, swordfish, sharks
 Drift-net fishing –
  1992 ban on the use of
  drift nets longer than
  2.5 km in international
  waters
How Can We Protect and Sustain Marine
           Biodiversity?
     We can help to sustain marine biodiversity by using laws
     and economic incentives to protect species, setting aside
     marine reserves to protect ecosystems, and using
     community-based integrated coastal management.
Legal Protection of Some Endangered and
       Threatened Marine Species
  Why is it hard to protect marine biodiversity?
    Human ecological footprint and fishprint are expanding.
    Much of the damage in the ocean is not visible.
    The oceans are incorrectly viewed as an inexhaustible
     resource that can absorb an almost infinite amount of
     waste.
    Most of the ocean lies outside the legal jurisdiction of
     any country.
    Treaties - CITES, Marine Mammal Protection Act,
     Endangered Species Act, Whale Conservation and
     Protection Act, International Convention on Biological
     Diversity.
   Protecting Whales:
A Success Story… So Far
 Cetaceans: two groups – toothed whales
  and baleen whales
 Overharvesting has driven some valuable
  species to almost extinction.
 1946: International Whaling
  Commission (IWC) – set annual quotas
 1970: U.S.
   Stopped all commercial whaling
   Banned all imports of whale products
 1986: IWC imposed a moratorium on
  commercial whaling – this worked
   Japan ,Norway, Iceland, Russia do not
    support the IWC ban.
Norwegian Whalers Harpooning a
        Sperm Whale
Economic Incentives Can Be Used to
    Sustain Aquatic Biodiversity

  Tourism – example: sea turtles, worth more to local
   communities alive than dead (WWF); brings in almost
   three times more money than does the sale of turtle
   products such as meat, leather, and eggs.
  Economic Rewards
    Reconciliation Ecology – science of inventing, establishing, and
     maintaining habitats to conserve species diversity in places
     where people live, work, and play. Example: artificial coral
     reef created in Israel.
 Case Study: Holding Out Hope for Marine
Turtles (6 of the 7 species are endangered)
  Carl Safina, Voyage of the Turtle
   ◦ Studies of the leatherback turtle
  Threats to the leatherbacks
   ◦ Trawlers destroy coral reefs which is their feeding grounds
   ◦ Entangled in fishing nets and lines
   ◦ Pollution—discarded plastic bags
   ◦ Climate change—rising sea levels will flood nesting and feeding
     areas
  Communities protecting the turtles
  Turtle Excluder Devices required on trawlers (shrimp boats) by
   the U.S. government
An Endangered Leatherback Turtle is
     Entangled in a Fishing Net
  Marine Sanctuaries Protect Ecosystems
              and Species
 Offshore Fishing Zone – extends to 370 kilometers from its
  shores
   Exclusive Economic Zones – foreign fishing vessels can take certain
    quotas of fish within these zones with a government’s permission.
   High Seas – ocean area’s beyond the legal jurisdiction of any country.
    Laws and treaties pertaining to the high seas are difficult to monitor
    and enforce.
 Law of the Sea Treaty – world’s coastal nations have jurisdiction
  over 36% of the ocean surface and 90% of the world’s fish stocks.
 Marine Protected Areas (MPAs) – 4000 world wide, 200 in US
  waters. Most MPAs allow ecologically harmful activities like
  trawling, dredging, and resource extraction.
 Establishing a Global Network of Marine Reserves:
     An Ecosystem Approach to Sustainability
 Primary Objective – protect and sustain whole marine ecosystems for current and
  future generations instead of focusing primarily on protecting individual species.
 Marine Reserves closed to extractive activities such as
      Commercial fishing
      Dredging reserves
      Mining and waste disposal
      Core zone – No human activity allowed
      Less harmful activities allowed – recreational boating and shipping
 Fully protected marine reserves work and work fast
    Fish populations double
    Fish size grows by almost one-third
    Reproduction triples
    Species diversity increase by almost one-fourth
 But, less than 1% of the world’s ocean area is closed to fishing in marine reserves.
          Protecting Marine Biodiversity:
      Individuals and Communities Together
 Integrated Coastal
 Management
   Community-based effort to
    develop and use coastal
    resources more sustainably
   Community-based group to
    prevent further degradation
    of the ocean
   More that 100 such groups
   Seek reasonable short term
    trade offs that can lead to
    long term ecological and
                                  An atoll of Australia’s Great Barrier Reef
    economic benefits
   How Should We Manage and Sustain
           Marine Fisheries?


 Sustaining marine fisheries will require improved
  monitoring of fish populations, cooperative fisheries
  management among communities and nations, reduction of
  fishing subsidies, and careful consumer choices in seafood
  markets.
Estimating and Monitoring Fishery Populations
               Is the First Step

   Maximum Sustained Yield (MSY)—mathematical model where
      the maximum number of fish that can be harvested annually without
      causing a population drop is calculated. Traditional approach.
     Optimum Sustained Yield (OSY)—takes into account
      interactions with other species and allows more room for error.
     Multispecies Management—of a number of interaction species,
      which accounts for competition and predator-prey interactions.
     Large Marine Systems—using large complex computer models.
     Precautionary Principle—use this method because of the
      uncertainty of all the above methods.
Some Communities Cooperate to Regulate
          Fish Harvests


 Community Management of the Fisheries – allotment and
 enforcement systems. Norway’s Lofoten fishery (cod) is
 self-regulated with no participation by the Norwegian
 government.

 Co-management of the Fisheries with the Government –
 sets quotas for various species and divide the quotas among
 communities.
   Government Subsidies Can Encourage
Overfishing: $30-34 Billion Around the World
  2007: World Trade Organization, U.S.
    Proposed a ban on fishing subsidies.


  Reduce illegal fishing on the high seas and in coastal waters.
    Close ports and markets to such fishers.
    Check authenticity of ship flags.
    Prosecution of offenders.
   Some Countries Use the Marketplace
         to Control Overfishing
 Individual Transfer Rights (ITRs) – assigned to each
  fisherman – can be bought, sold, or leased like private property.
    Use to control access to fisheries
      New Zealand – 1986 and Iceland - 1990
      Difficult to enforce
      U.S. - 1995 introduced tradable quotas to regulate Alaska’s
       halibut fishery
 Problems with the ITR approach
    Transfers public ownership of fisheries in publically owned
     waters to private fishers
    Squeezes out small fishing companies
    Fishing quotas are often set too high
  Consumer Choices Can Help to Sustain
    Fisheries and Aquatic Biodiversity
 1997: Marine Stewardship Council (MSC), London –
  operates in more than 20 nations
   Support sustainable fishing and certifies that fish are
    caught using sustainable practices.

 Manage global fisheries more sustainably.
   Individuals
   Organizations
   Governments
            SOLUTIONS

                  Managing Fisheries
Fishery Regulations                    Bycatch
Set catch limits well below the        Use wide-meshed nets to
maximum sustainable yield              allow escape of smaller fish
Improve monitoring and                 Use net escape devices for
enforcement of regulations             seabirds and sea turtles
Economic Approaches                    Ban throwing edible and
Sharply reduce or eliminate            marketable fish back into the
fishing subsidies                      sea
Charge fees for harvesting fish        Aquaculture
and shellfish from publicly            Restrict coastal locations for
owned offshore waters                  fish farms
Protect Areas                          Control pollution more strictly
                                       Depend more on herbivorous
Certify sustainable fisheries
                                       fish species
Establish no-fishing areas
Establish more marine protected        Nonnative Invasions
areas                                  Kill organisms in ship ballast
Rely more on integrated coastal        water
management                             Filter organisms from ship
Consumer Information                   ballast water
Label sustainably harvested fish       Dump ballast water far at sea
Publicize overfished and               and replace with deep- sea
threatened species                     water
                                                                        Fig. 11-12, p. 265
      How Should We Protect and Sustain
                 Wetlands?


    To maintain the ecological and economic services of
    wetlands, we must maximize preservation of
    remaining wetlands and restoration of degraded and
    destroyed wetlands.
      Coastal and Inland Wetlands are
       Disappearing around the World
 U.S. has lost more than half of its coastal and inland
  wetlands since 1900.
 Ecological Value:
   Highly productive wetlands
   Provide natural flood and erosion control
   Maintain high water quality; natural filters
   Effected by rising sea levels due to global warming
   which will degrade aquatic biodiversity
We Can Preserve and Restore Wetlands
   Laws for protection


   Mitigation Banking
     Allows destruction of existing wetlands as long as
     an equal area of the same type of wetland is created
     or restored.
     Ecologists argue this should be used only as a
     last resort.
Individuals Matter: Restoring a Wetland
  Jim Callender: 1982


  Scientific knowledge + hard work =
   a restored wetland in California, U.S.

  Marsh used again by migratory fowl
 Natural Capital Restoration:
Wetland Restoration in Canada
 Case Study: Can We Restore the Florida
              Everglades?
 “River of Grass”:   South Florida, U.S.

 Since 1948: damages
   Drained
   Diverted
   Paved over
   Nutrient pollution from agriculture
   Invasive plant species

 1947: Everglades National Park unsuccessful protection
  project
Can We Restore the Florida Everglades?

    1970s: political haggling for 20 years


    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
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?
    Cannot undue 120 years of ecological damage done by
     agriculture and urban development
    Will take at least 50 years and too expensive
The World’s Largest Restoration Project
    How Can We Protect and Sustain
Freshwater Lakes, Rivers, and Fisheries?


 Freshwater ecosystems are strongly affected by human
  activities on adjacent lands, and protecting these ecosystems
  must include protection of their watersheds.
      Freshwater Ecosystems are Under
               Major Threats

 HIPPCO – major threats
 40% of the world’s rivers have been dammed or otherwise
  engineered.
 Invasive species, pollution, climate change
  Case Study: Can the Great Lakes Survive
   Repeated Invasions by Alien Species?

 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



                                       Zebra Mussels Attached to a Water Current
                                       Meter in Lake Michigan, U.S.
               Managing River Basins is
              Complex and Controversial
 Columbia River: U.S. and Canada
   Dam System: 119 dams, 19 of which are hydroelectric power
    plants.
   Pro–electricity; Con–salmon affected


 Snake River: Washington State, U.S.
   Hydroelectric dams removed
   Pro–salmon saved ; Con–economy affected
Natural Capital: Ecological Services of Rivers
     We Can Protect Freshwater Ecosystems
          by Protecting Watersheds
 Freshwater ecosystems protected through
   Laws
   Economic Incentives
   Restoration Efforts
 National Wild and Scenic Rivers Act—passed in 1968 to protect
  rivers and river segments with outstanding scenic, recreational,
  geological, wildlife, historical, or cultural values.
 Sustainable management of freshwater fishes involves encouraging
  populations of commercial/sport species, prevents overfishing, and
  reduces or eliminates less desirable fish populations.
What Should Be Our Priorities for Sustaining
  Biodiversity and Ecosystem Services?

   Sustaining the world’s biodiversity and ecosystem
    services will require mapping terrestrial and
    aquatic biodiversity, maximizing protection of
    undeveloped terrestrial and aquatic areas, and
    carrying out ecological restoration projects
    worldwide.
What Should Be Our Priorities for Sustaining
  Biodiversity and Ecosystem Services?

  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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