AQUATIC ECOSYSTEMS.ppt - AQUATIC ECOSYSTEMS

					  AQUATIC ECOSYSTEMS
  LANDSCAPE ECOLOGY
 RESTORATION ECOLOGY
ECOSYSTEM MANAGEMENT

     Chapters 8 and 10
       What are the basic needs of
             aquatic biota?
•   CO2
•   O2
•   Sunlight
•   Nutrients- food &
    minerals
     What factors influence the
  availability of those basic needs?
• Substances dissolved in water-
  Nitrates, phosphates,
  potassium, O2
• Suspended matter- (silt, algae)
  can affect light penetration
• Depth
• Temperature
• Rate of flow
• Bottom characteristics (muddy,
  sandy, or rocky)
• Internal convection currents
• Connection to or isolation from
  other aquatic ecosystems.
  Types of Aquatic Ecosystems
• Freshwater Ecosystems
   – Standing Water- lakes &
     ponds
   – Moving Water- rivers &
     streams
• Transitional Communities
   – Estuaries
   – Wetlands- bogs/fens,
     swamps, marshes
• Marine Ecosystems
   –   Shorelines
   –   Barrier Islands
   –   Coral Reefs
   –   Open Ocean
       Freshwater Ecosystems
• Usually 0.005% salt
   – Some exceptions:
      • Great Salt Lakes-
              5-27% salt
      • Dead Sea- 30% salt
• Moving water- high
  elevations; cold; high O2;
  trout; streamlined plants
• Standing water- lower
  elevations; warmer; less
  O2; bass, amphibians;
  cattails, rushes
   How is a lake stratified and what
         lives in each level?
• Epilimnion- upper layer of
  warm water; high light & O2;
  ex: water striders, phyto- &
  zooplankton, fish
• Thermocline (mesolimnion);
  middle layer; medium light &
  O2; ex: phyto- & zooplankton,
  fish
• Hypolimnion- lower layer of
  cold water; lower light & O2;
  ex: fish
• Benthos- bottom level; no light
  & little O2; ex: anaerobic
  bacteria, leeches; insect larvae
• Littoral- near the shoreline;
  cattails, rushes, amphibians,
  etc.
     Transitional Communities
• ESTUARIES
• Where freshwater dumps
  into ocean
• Brackish (less salty than
  seawater)
• Has rich sediments that
  often form deltas
• Productive & biodiverse
• Organisms adapted to
  varying levels of salinity
  as tide ebbs & flows
• “Nursery” for larval forms
  of many aquatic species
  of commercial fish &
  shellfish
       Transitional Communities
• WETLANDS
• Land saturated at least part of
  the year                          Swamp
• Swamps- have trees like bald
  cypress; high productivity
• Marshes- no trees; tall
  grasses; high productivity
• Bogs/Fens- may or may not                 Marsh
  have trees; waterlogged soil
  with lots of peat; low
  productivity
    – Fens- fed by groundwater &
      surface runoff
    – Bogs- fed by precipitation
                                                Bog
                            Fen
                Importance of Wetlands
•   Highly productive- get lots of
    sunlight, ↑ plants =
    ↑ animals
•   Nesting, breeding ground for
    migratory birds
•   Slows flooding by absorbing runoff
•   Silt settles, making water clearer &
    nutrient rich
•   Trap & filter water
•   Natural chemical rxns neutralize
    and detoxify pollutants
•   Gives H2O time to percolate thru
    soil & replenish underground
    aquifers.
•   Threats- artificial eutrophication
    (see slide 13), draining,
    sedimentation via construction
•   “Nature’s Septic Tank”
             Marine Ecosystems
• SHORELINES
• Rocky coasts- great density &
  diversity attached to solid rock
  surface
• Sandy beaches- burrowing
  animals
• Threats- due to hotels,
  restaurants, homes on beach,
  more plant life destroyed,
  destabilizing soil, susceptible
  to wind & water erosion
• Insurance high; danger of
  hurricanes, erosion
• Build sea walls to protect
  people but changes &
  endangers shoreline habitat
          Marine Ecosystems
• BARRIER ISLANDS
• Low, narrow offshore
  islands
• Protect inland shores
  from storms
• Beauty attracts
  developers = developers
  destroy land
• New coastal zoning laws
  protect future
  development
        MARINE ECOSYSTEMS
• CORAL REEFS
• Clear, warm shallow seas
• Made up of accumulated
  calcareous (made of calcium)
  skeletons of coral animals
• Formation depends on light
  penetration.
• Have a symbiotic relationship
  with algae
• Very diverse, abundant
  (rainforests of sea)
• Threats- destructive fishing
  (cyanide & dynamite to stun
  fish), pet trade; about 3/4ths
  have been destroyed
    What factors can alter aquatic
           ecosystems?
• Natural Succession-
  normal cycle of pond
  becoming forest
• Artificial Succession-
  humans add N & P to
  water via fertilizer &
  sewage causing
  succession to happen
  faster =
  EUTROPHICATION
      What factors can alter aquatic
             ecosystems?
• Humans!
  – Find food
  – Recreation
  – Waste disposal
  – Cooling of power
    plants
  – Transportation
  – Dams, canals
                  Biomes
• Which biome has the largest total area? The
  smallest total area?
• Which biome has the highest % of undisturbed
  habitat?
• Which biome has the lowest % of undisturbed
  habitat?
• Which biome has the highest % human
  dominated habitat?
• Which biome has the lowest % human
  dominated habitat?
LANDSCAPE ECOLOGY
        LANDSCAPE ECOLOGY
• Landscape- geographic
  unit with a history that
  shapes the features of
  the land and organisms
  in it.
• Landscape ecology- the
  study of how landscape
  structure affects the
  abundance and
  distribution of organisms.
• Does not just focus on
  “untouched nature”
     LANDSCAPE ECOLOGY
• Uses geographical
  information systems
  (GIS) to map patch
  size, type and
  configuration to
  create 3-D maps
• These maps assist
  land planners in
  analyzing land use
  patterns
    LANDSCAPE ECOLOGY
• Focus on how neighboring communities of
  a landscape interact
RESTORATION ECOLOGY

      Chapter 10
    RESTORATION ECOLOGY
• Repair or reconstruct        Before
  ecosystems damaged by
  humans or natural forces
• Growing field of science
• People are now being
  held responsible for their
  actions- restoring
  wetlands & habitat for
  endangered species

                                After
The 5 “R’s” of Restoration Ecology
                         Before
1. Restoration-
   manipulation of
   nature to re-create
   species composition
   & ecosystem
   processes as close
   as possible to the
   state they were in
   before humans
   interfered.           After
The 5 “R’s” of Restoration Ecology
2. Rehabilitation- to
   bring an area back
   to a useful state for
   human purposes
   rather than a truly
   natural state.
   - reverse
   deterioration if can’t   These people in Africa are trying to
                            use rocks to create a sort of wind
   be restored fully        break to prevent wind erosion of their
                            soil. The soil will never be like it was
                            but it will hopefully be usable.
 The 5 “R’s” of Restoration Ecology
3. Remediation- process
   of cleaning chemical
   contamination from a
   polluted area by
   physical or biological
   methods to protect
   human & ecosystem
   health
   - Incinerate soil
   contaminated with oil
   - use special bacteria to
   clean up oil spills in
   water (bioremediation)
                               This is like an artificial wetland-
                               wastewater comes in, settles,
                               roots cleanse the water
 The 5 “R’s” of Restoration Ecology
4. Reclamation-
   techniques used to       Before
   restore the shape,
   original contour and
   vegetation of a
   disturbed site
   - Surface Mining Control
   & Reclamation Act
   (SMCRA) requires
   mining operations to
                              After
   restore the open pit
   mines they create to
   natural state.
    The 5 “R’s” of Restoration Ecology
5. Re-creation- attempts to
   construct a new biological
   community on a site so
   severely disturbed that
   there is virtually nothing left
   to restore.
   - often must build a wetland
   elsewhere to make up for
   the one destroyed by
   developer
   - Read story of Army Corp
   of Engineers & Florida
   Everglades restoration
Preservationists vs. Restorationists
• Preservationist- don’t start
  destructive projects in the first
  place. Preserve nature- “you
  can’t always fix what you
  broke”
• Restorationists- you are never
  going to be able to save every
  bit of land. Who says changes
  we make in restoring
  ecosystems is unnatural?
• Are we members of the
  community or separate from it?
• Should we use our creative
  energies to try to improve
  nature, or should we leave well
  enough alone?
          Tools of Restoration
• Prairies- collect native
  prairie grasses from
  graveyards and plant in
  abandoned farm fields to
  reestablish native
  grasslands
• Remove alien species-
  like privet @ nature
  center; hunting goats on
  Galapagos
• Walk away from
  ecosystem & let recover
  naturally- N. & S. Korea
  after the Korean War
                       Restoration Ethics
•   If habitat was filled with diseased, ugly
    organisms, should you return it to that     Canal
    state? Should you reintroduce               in
    mosquitoes, black flies, leeches, ticks,    China
    poisonous snakes?                           Before
•   Should you improve on nature?
•   Where do you find plants for
    restoration? Do you take from small
    population nearby or find larger
    population farther away?
•   Is there more than one natural state?
    What is the history of the area?            Canal
•   Since humans are part of nature,            in
    whatever changes we make to                 China
    landscape also are natural. Is that         After
    true?
•   Can we use nature to solve human            Notice
    problems? Read story on page 121            plants
    about Arcata, California’s artificial
    wetland project.                            used as
                                                filtering
                                                system
        Ecosystem Management
• How can we have progress
  and still maintain the
  environment?
• Aldo Leopold was one of the
  pioneers on his Sand County
  farm
• US Forest Services, Bureau of
  Land Management, National
  Park Service all adopted
  versions of ecosystem
  management
• Previously, these agencies
  used their lands for
  commercial or recreational
  uses & did not focus on wildlife
  habitats, endangered species,
  etc.