APES Chapter 24 Sustaining Aquatic Biodiversity

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APES Chapter 24 Sustaining Aquatic Biodiversity
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Aquatic Systems

• According to aquatic scientists, the scientific
  investigation of poorly understood aquatic
  systems is a poorly funded research frontier
  whose study could result in immense ecological
  and economic benefits.
• Oceans cover 71 of the planets surface and 99
  of the living space or volume of the earths
  biosphere
• The 3 most biologically diverse habitats found in
  the worlds oceans are
• coral reefs
• estuaries
• deep ocean floor

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Ecological and Economic Importance of Aquatic
Biodiversity

• People get 16 of their animal protein form fish
  and shellfish and 30 in Asia
• Chemicals from sea life provide antibiotic and
  anticancer properties
• Chemicals to treat hypertension from seaweed and
  octopuses
• Natures superglue from barnacles
• Chemicals effective against viral encephalitis
  and herpes from sponges
• Freshwater systems provide trillions of dollars
  in economic services per year

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Human Impacts on Aquatic Biodiversity

• Overfishing
• Habitat destruction
• Pollution
• World Wildlife Fund says 20 of the worlds
  10,000 freshwater fish species are threatened
  with extinction
• in the US
• 69 of freshwater mussels species
• 51 of crayfish
• 36 of amphibians and 37 of fish
• are at risk of extinction in the lower 48
  states

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Marine Habitat Loss

• ½ of the worlds wetlands mostly from development
• 58 of the worlds coral reefs are threatened and
  27 gone from warmer waters, overfishing,
  pollution, and development
• 2/3 of US bays and estuaries are at risk from
  land runoff
• 35 of the worlds mangroves have disappeared
  mostly from coastal development, shrimp farms,
  and growing crops
• 70 of worlds beaches have eroded from coastal
  development and rising sea levels
• bottom habitats have been degraded from dredging,
  net fishing with large heavy nets scraping the
  ocean bottom
• deep sea mining

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Freshwater Habitat Loss

• the world has lost more than ½ of its wetlands
  since 1800 mostly from draining and filling in
  for ag and urban development
• 60 of the worlds large rivers are fragmented
  from dams, diversions, or canals
• flood control levees destroy aquatic habitats and
  eliminate wetlands

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Overfishing

• 75 of the worlds commercial fish is overfished
  or to the limit
• disrupts ocean food webs
• overfishing is leading to serious depletion and
  extinction of sea turtles, dolphins, and other
  marine mammals

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Nonnative Species

• 100s of nonnative species have been deliberately
  or accidentally introduced into coastal waters,
  lakes, and wetlands
• Example Asian Swamp Eel eats anything, burrows
  in mud to avoid being caught, can wiggle across
  dry land to invade new waterways, eventually will
  take over much of the southeastern US waterways
• 68 of fish extinctions are blamed on invaders

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Major Pollution threats to aquatic systems and
species

• oil
• acid deposition
• excess plant nutrients and Oxygen demanding
  wastes
• toxic chemicals
• coastal development
• sediments from soil erosion

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Global Warming Threats

• alter migration and feeding patterns
• destroy coral reefs from warmer water
• raise sea levels causing flooding of coastal
  areas

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Protecting Marine Biodiversity is Difficult

• much of the damage is not visible
• many people see ocean as inexhaustible resource
  that can absorb waste and pollution
• most of the oceans lie outside the legal
  jurisdiction of any country, thus subject to
  overexploitation
• no effective international agreements protect
  biodiversity in the open seas

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Protect and Sustain Marine Biodiversity

• Protect threatened and endangered species
• Establish protected areas
• Use integrated coastal management
• Regulate and prevent ocean pollution
• Sustainably manage marine fisheries

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Good News

• United nations law of the Sea the nations of the
  world have jurisdiction over 36 of oceans
  surface and 90 of the worlds fish stock
• United Nations Environment Programme has
  spearheaded effort to protect large marine areas
• 90 biosphere reserves include marine habitats
• The US has designated 12 marine sanctuaries
• The World Conservation Union has established
  global system of marine protected areas (MPA)

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Bad News

• Less than .01 of the worlds oceans consist of
  fully protected marine reserves
• Most MPAs too small to fully protect the species
  within them
• Many existing marine sanctuaries allow extractive
  activities
• Stresses from coastal areas surrounding a reserve
  can disrupt the wildlife

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Integrated Coastal Management

• Is a community attempt to develop and use coastal
  resources sustainably
• Overall goal is to zone the coastal areas and
  leave portions completely protected
• Computer models predict that an increase in
  beach erosion and flooding of coastal areas will
  cause 25 of homes and structures (500ft) from
  the shore to be severely damaged or fall into the
  sea between 2000 and 2060.

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Managing and Sustaining the Worlds Marine
Fisheries

• Change Maximum sustained yield (MSY) to optimum
  sustained yield (OSY) concept
• Multispecies management takes into account
  predator-prey relationships
• Use Precautionary Principle to prevent harm to
  large systems and humans

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Should we control access to fisheries?

• By international law a countrys offshore fishing
  zone is 230 miles from shore. Beyond that is the
  high seas. International maritime treaties and
  laws have set some limits but they are hard to
  monitor and enforce
• Comanagement of coastal fisheries between local
  communities and the central government is working
  well in Japan, Norway and the US but has mixed
  success in Canada and the United Kingdom

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How are Wetlands Managed in the US?

• Good News
• Federal permit required to fill in wetlands
• Law has helped cut average annual loss by
  80
• Bad News
• Attempts to weaken law have continued
• Only 8 of inland wetlands are under federal
  protection
• Federal, state, and local wetland protection
  is weak

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Protecting Lakes and Rivers

• Threats to Lakes
• Pollution
• Nonnative species
• Diversion of water for irrigation
• Cultural eutrophication
• See Case Study on the Great Lakes Page 655

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Protecting Lakes and Rivers

• Threats to Rivers
• Pollution
• Dams
• Diversion of water for irrigation and urban
  areas
• Overfishing
• See Case Study on Columbia River page 656

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THE END