Preserving Aquatic Biodiversity

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Preserving Aquatic Biodiversity

• Chapter 12

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Lake Victoria

• The second largest freshwater lake in the world
• How have humans changed it?
• Introduced Nile perch killed other fish
• Added nutrients eutrophication
• Introduce water hyacinth blocks light

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Aquatic biodiversity

• Greatest marine diversity in coral reefs and
  deep-sea floor
• Higher near coasts than open ocean
• Higher in benthic layer than near the surface
• Higher near tropics

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How do humans benefit

• Food
• Seaweed (cosmetics)
• Chemicals
• Antibiotics
• Anticancer
• Hypertension
• Bone replacement

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Destroying freshwater habitats

• Draining wetlands lost over 50 of wetlands
• Introduction of non-native species
• Dams, diversions, canals, flood control levees
• Ruin existing habitat or changing flow rate,
  sediment deposits, spawning beds, migration
  patterns, plant life, nutrient cycles

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Major loss of aquatic biodiversity by humans

• Overfishing
• Habitat destruction
• Coastal development
• Rising sea level
• Trawler boats
• Pollution
• Introduction of alien species

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Nonnative examples

• Asian swamp eel Florida, eats everything, can
  breath air, cross to new waterways
• Purple loosestrife wetlands, perennial plant in
  Eurasia, spreads rapidly, no native predators,
  displaces native plants, reduces biodiversity
• Zebra mussels Great Lakes, from ship ballasts,
  no natural predators, displaced other mussels,
  interrupted food chain, clogged pipes, grows in
  large masses on everything

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Major pollution threats

• Oil especially from runoff
• Acid deposition
• Plant nutrients and oxygen demanding wastes
• Toxic chemicals
• Sedimentation from development

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Protection of Marine Species

• CITES
• 1979 Global Treaty on Migratory Species
• U.S. Marine Mammal Protection Act of 1972
• Endangered Species Act 1973
• Whale conservation and protection act 1976
• Changing fishing nets and fishing practice

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Whaling

• International Convention for the Regulation of
  Whaling formed the IWC to set quotas (often
  ignored)
• IWC set moratorium on commercial whaling since
  1986 (Inuits still allowed to hunt whale) many
  populations recovered
• US banned whaling and importing goods
• Japan and Norway still are large whaling countries

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Restoring Wetlands

• US requires a federal permit to drain/alter a
  wetland over 3 acres
• Mitigation banking allows development of
  wetlands if an equal area elsewhere is created or
  restored
• Use proper planning to keep development/Ag away
• Prevent introduction of alien species

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Floridas Mistake

• Army Corps of Engineers diverted much of the
  Everglades natural flow with levees and canals
• Wetlands dried and were converted to farmland
• Runoff from fields introduced excess nutrients
• Disrupted entire ecosystem
• Now largest ecological restoration project (at
  least 7.8 billion)

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Columbia River Basin

• Located in Pacific Northwest 1,200 miles of
  river
• Largest hydroelectric power system
• Provides jobs, electricity, flood control,
  stimulate industry/agriculture
• Hurts habitats especially migratory fish (salmon)
• Northwest Power Act 1980 find way to generate
  power and rebuild wild salmon and other fish
  populations

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Protecting Rivers

• National Wild and Scenic Rivers Act 1968
  waterways kept free from development, no motors,
  no alterations
• A river can be designated by congress based on
  outstanding scenic, recreational, geological,
  wildlife, historical, or cultural value

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The Great Lakes

• Faces several threats
• Alien species, like the zebra mussel, is the
  greatest, but also is encountering
• Thermal pollution from power plants
• Commercial fishing
• Human sewage (mostly processed)
• Acid rain (but there is more to the east)

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Act Now

• Approximately 50 of the worlds original coastal
  wetlands have been lost
• Main reasons
• Agriculture
• Housing/building development

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Commercial fishing techniques

• While many systems are bad for the environment,
  these appear to be the worst
• Trawling - nets destroy ocean floor habitat
• Drift nets (more than 2 miles long) - kill many
  mammals, turtles and birds
• Longlining - creates a lot of bycatch such as
  dolphin, shark, pilot whales, birds, and turtles

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What can you do?

• Use comsumer power to buy products that do not
  threaten aquatic species
• Use environmentally friendly cleaners in the home
• Prevent soil erosion
• Vote against wetland development
• Eat less fish and seafood (more organic veggies)