Chapter 24 Lecture

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Chapter 24 Lecture

• Sustaining Aquatic Biodiversity

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Aquatic Biodiversity

• Less than 5 of the ocean has been explored and
  mapped -- a poorly funded research frontier
• Represents 71 of the planets surface
• Represents 99 of the earths biosphere.
• Most biodiverse habitats
• Coral Reefs
• Estuaries
• Deep Ocean Floor
• Remember, Aquatic includes freshwater
  environments as well!

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Patterns of Marine Biodiversity

• Biodiversity
• Most in coral reefs and deep sea floor
• Higher near the coasts (more producers, habitats,
  and nursery areas)
• Higher at the bottom than the top
• Lowest in the middle depths of the open ocean
• Keystone predators dominate the biodiversity and
  ecological dynamics

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What is the Importance of Aquatic Biodiversity

• Food Source 6 of total protein and 16 of
  animal protein comes from fish and shellfish (30
  in Asia)
• Cosmetics and Pharmaceuticals
• Antibiotic and anticancer chemicals
• Hypertension medicine
• Bone reconstruction (from coral)
• Binding adhesive for tooths fillings (from
  barnacles)
• Chemicals agains viral encephalitis and herpes
  (from sponges)

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How Have Humans Impacted Aquatic Biodiversity

• Species Loss and Endangerment
• Marine Habitat Loss and Degradation
• Freshwater Habitat Loss and Degradation
• Overfishing
• Nonnative Species
• Pollution and Global Warming

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Species Loss and Endangerment

• 1,200 species have become extinct in the past few
  hundred years
• Freshwater species are more at risk than
  land-based species
• 20 of the worlds fish species are threatened
• U.S. has the worlds highest diversity of
  freshwater species -- many are at risk of
  extinction

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Marine Habitat Loss and Degradation

• 1/2 of the worlds wetlands have disappeared
  since 1800 due to agriculture and coastal
  development
• 58 of the coral reefs are threatened
• 2/3 of the US estuaries and bays are at risk from
  runoff pollution
• 35 of the mangroves have disappeared
• 70 of the beaches are eroding
• Bottom habitats are being degraded
• Deep sea mining
• Dredging
• Trawler Boats

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Freshwater Habitat Loss and Degradation

• Loss of wetlands
• 60 of the worlds 237 large rivers are
  fragmented by dams, diversions, canals
• Reduces water flow
• Flood control levees and dikes alter and destroy
  aquatic habitats, disconnect rivers from
  floodplains, eliminate wetlands and backwaters

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Overfishing

• 75 of the worlds commercially valuable marine
  species are either overfished or fished to the
  limit.
• Commercial Extinction - a temporary depletion of
  fish stocks
• Can unravel food webs
• Disrupt ecosystem
• Hinder recovery of fish at higher trophic levels

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Nonnative Species

• Can disrupt native species and ecosystem
• Blamed for 68 of fish extinction between 1900
  and 2000
• Asian Swamp Eel
• Eats almost everything
• Can elude cold water, drought, fires, predators
  by burrowing into mud banks
• Resistant to poisons because it can breathe air
• Invades waterways, ditches, canals

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Pollution and Global Warming

• Common Pollutions
• Oil
• Acid
• Excess Plant Nutrients and Oxygen Demanding
  Wastes
• Toxic Chemicals - cyanide, DDT
• Coastal Development
• Sedimentation from erosion
• 44 comes from runoff, 33 from the atmosphere,
  23 from shipping, offshore oil, and gas
  production, and ocean dumping
• Global Warming Can
• Alter migration and feeding patterns
• Increase average ocean temperature
• Raise average sea levels

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Why Is It Difficult to Protect Marine
Biodiversity?

• Coastal development harms shore-hugging species
  and threaten biologically diverse coastal
  ecosystem
• Most damage is not visible to most people
• Most believe that the seas are inexhaustible
• Most of the oceans lie outside the legal
  jurisdiction of any country and are an open
  access resource subject to exploitation
• There are no effective international agreements
  to protect biodiversity

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How Can We Protect and Sustain Marine
Biodiversity?

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

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How Can We Protect Endangered and Threatened
Marine Species

• Identify them
• Example Sea Turtles
• Loss of beach habitat
• Legal and illegal taking of their eggs
• Used as a source of food, medicine, jewelry, and
  leather
• Unintentional capture and drowning by fishing
  boats
• Use Turtle Exclusion Devices!
• Examples of Laws
• CITES, ESA, U.S. Marine Mammal Protection Act of
  1972, 1979 Global Treaty on Migratory Species,
  U.S. Whale Conservation Act, 1995 International
  CBD
• Use Aquariums to educate, but not effective gene
  banks
• Two problems
• There is a lack of knowledge abour marine species
• It is difficult to monitor and enforce treaties
  in the open ocean.

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Case Study Commercial Whaling

• Cetaceans - two types - toothed whales and
  baleen whales
• Followed a classic tragedy of the commons pattern
  - 8 of the 11 were at commercial extinction
• 1946 Regulation of Whaling Established the
  International Whaling Commisions (IWC) to
  regulate the industry
• Currently the IWC quotas on whales are based on
  inaccurate data or ignored by whaling countries
• Some countries are trying to overthrow the ban
• CITES also has a ban on buying and selling whale
  products
• 1970 - the U.S. stopped all commercial whaling
  and banned all imports of whale products
• Some believe they should be saved for ethical
  reasons
• Estimates of numbesr arent inaccurate
• Some whaling would open the door to other whales
• What about DNA tests!

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What is the Role of Marine Sanctuaries

• Coastal nations have soverignty over the waters
  and seabed up to 12 miles offshore and total
  jurisdiction over their exclusive economic zone
  (EEZ) which extends 200 miles offshore
• 36 of the ocean surface and 90 of the worlds
  fish stocks
• Coast areas can disrupt marine reserves
• 12 regional agreements to protect large marine
  areas
• 90 of the worlds 350 biosphere reserves include
  coastal or marine habitats - less than .1 of the
  ocean are fully protected marine reserves
• 12 marine sanctuaries have been designated by the
  US - allow some activities that can be harmful
• World Conservation Union - designates a global
  system of marine protected areas (MPAs) - most
  are too small

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What is the Role of Integrated Coastal Management

• Integrated Coastal Management - a community based
  attempt to develop and use coastal resources
  sustainably
• Identify shared problems and goals
• Agrees to good, cost effective solutions
• Overall goal zone the land and sea portions into
  some protected areas and some multi-use areas.
• Example Great Barrier Reef Marine Park

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Case Study Beach Erosion

• 70 of the worlds beaches are eroding
• Sea level has been rising
• Due to ice age melting
• Extracting groundwater
• Redirecting rivers
• Draining wetlands
• Diverting more water into the oceans
• Possible Solutions
• Ban or limit sea walls, breakwater, groints, and
  jetties
• Move inlets
• Prohibit development on remaining undeveloped
  areas.
• 25 of the homes within 500 feet of the US will
  be damaged or fall into the sea as a result of
  erosion between 2000 and 2060.

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How To Protect Populations of Marine Fisheries

• Preventing Overfishing
• Develop better measurements for protecting fish
  populations
• Control fishing methods and access to fisheries
• Methods to Project Populations
• Maximum Sustained Yield
• Optimum Sustained Yield
• Multispecies Managment
• Large Marine System Management
• Precautionary Principle

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Maximum Sustained Yield (MSY)

• Uses a mathematical model to project the number
  of fish that can be harvested annually from a
  fish stock without driving it into decline
• Has hastened the collapse of most commercially
  valuable stocks
• Populations are difficult to measure
• Most estimates are based on people reporting
  their catch
• Harvesting at the maximum leaves little room for
  error
• Fishing quotas are difficult to enforce
• Many groups ignored MSYs for political or
  economic reasons
• Can affect the populations of other organisms

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Optimum Sustained Yield (OSY)

• Takes into account interactions with other
  species and provides more room for error
• It still depends on poorly understood biology of
  fish and changing ocean conditions
• Many ignore OSY estimates

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Multispecies Management

• Takes into account organisms competitive and
  predator-prey interactions
• There are free computer modeling programs which
  can monitor the interaction of 50 different
  species or groups of species involved in a food
  web.

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Large Marine Species Management

• More complex computer models
• Has been success for
• Mediterranean Sea
• Great Barrier Reef
• Managing the Yellow Sea

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Precautionary Principle

• Where significant risk of damage to the
  environment and scientific evidence is
  inconclusive, we should take precautionary action
  to limit the potential risk of damage.

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International and National Laws to Control
Fisheries

• International and National Laws
• Offshore fishing zone vs. High Seas
• Community-based Comanagement - coastal
  communities and government work together to
  manage fisheries sustainably
• Has illustrated that the T.O.T.C is not
  inevitable.
• Individual Transfer Quotas (ITQs)
• Goverment gives each fishing vessel a specified
  percentage of the Total Allowable Catch

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In What Ways Can We Manage Fisheries to Sustain
Stocks and Protect Biodiversity?

• Fishery Regulations
• Economic Approachs
• Bycatch
• Protected Areas
• Nonnative Invasions
• Consumer Information
• Aquaculture (Fish farming)

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Protecting Wetlands in the US

• Only 8 are protected - federal, state, and
  local wetland protection is weak
• A federal permit is required to fill or to
  deposit dredged or fill material into wetlands
• Mitigation banking - does not work!
• Being created to serve as sewage treatment plants
  

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Sustaining and Restoring Wetlands

• Save the existing wetlands
• Use comprehensive land planning to steer
  developers, farmers, and resource extractors away
• Use mitigation banking as a last resort
• Require the creation and evaluation of a new
  wetland before destroying any existing wetlands
• Restore any degraded wetlands
• Try to prevent and control the invasions of
  wetlands by nonnative species

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Restoring the Florida Everglades

• 56 Endangered and Threatened Species
• Shrunk to half its size
• Vulnerable to wildfires
• Water has been diverted and disrupted by canals,
  levees, spillways, and pumping stations
• Runoff of phosphorus and other plant materials
  has stimulated cattail growth
• Creation of Everglades National Park - 1947
• Plumbing has cut off water flow to sustain the
  parks wildlife
• 90 of the parks birds have vanished
• Invertebrates down 75 - 95
• Saltier and warmer water
• Large algae blooms
• Worlds Largest Ecological Restoration Project

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Environmental Threats To Lakes

• Pollution
• From cultural eutrophication and toxic wastes
• Invasions from nonnative species
• Dropping water levels by diversion of water for
  irrigation

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Nonnative Invaders in Lakes

• Invaded by 145 nonnative species
• Zebra Mussel
• Round Gody
• Euraisan Ruffe
• Hydrilla
• Nonnative Microorganisms - disease causing!

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Greatest Environmental Threats to Rivers

• Pollution
• Disruption of Water Flow by Dams and
  Channelization
• The Diversion of Water from Rivers for Irrigation
  and Urban Areas
• Overfishing

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Case Study The Columbia River Basin

• Worlds largest hydroelectic power system
• Harms the salmon population because of dams,
  overfishing, disruption of spawing groups,
  withdraw of water
• Solutions
• Salmon ranching
• 1980 - Northwest Power Act - develop and meet
  the electricity needs while rebuilding wild and
  hatchery-raised salmon.

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Managing Freshwater Fisheries

• Regulations
• Time and length of fishing season
• The number and size of fish that can be taken
• Building reservoirs and farm ponds
• Fertilizing nutrient poor lakes and ponds
• Protecting and creating spawning sites
• Protecting habitats
• Removing debris
• Preventing excessive growth of aquatic plans
• Buidling small dams
• Controlling predators, parasites, and diseases
• Improving habitats
• Breeding genetically resistant fish varieties
• Using antibiotics and disinfectants

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Protecting Wild and Scenic Rivers

• National Wild and Scenic Rivers Act - 1968
• Created the National Wild and Scenic Rivers
  System to Protect Rivers and River Segments -
  only .2 protected.
• Keep the area free of development
• Cannot be widened, straightened, dredged, filled,
  or damned
• Recreational activities allowed

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Yay for Sustaining....

• Wild Species
• Terrestrial Biodiversity
• Aquatic Biodversity!
• 11 Chapters Down...17 To Go.