Aquatic Ecology by 4jT883xf

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									Aquatic Ecology
              Aquatic Biomes
 There are two types of aquatic biomes:
Marine biomes include
  estuaries, coastal
  wetlands, coral
  reefs, the oceanic
  zone, and polar
  ecosystems
Freshwater biomes
  include lakes/ponds,
  rivers/streams, and
  inland wetlands
              Aquatic Organisms
 Both freshwater and marine ecosystems share major
  types of organisms:
   – plankton are free-floating organisms which have
     such weak swimming ability that they are at the
     mercy of the prevailing water movement
      • phytoplankton are capable of photosynthesis
        while zooplankton are animals
   – nekton are organisms capable of sustained
     locomotion against the prevailing water movement
   – benthos are bottom-dwelling organisms without the
     need for swimming
             Limiting Factors
 The types and numbers
 of organisms in aquatic
 environments depend on
 temperature, access to
 sunlight, dissolved
 oxygen, and availability
 of nutrients such as
 carbon (CO2), nitrogen
 (NO3-), and phosphorus
 (PO43-)
                               Marine Biomes
  Saltwater oceans cover about 71% of the earth’s
      surface. The oceans are essential for regulating
      global temperature and climate. There are about
      250,000 known species of marine plants and
      animals.                   There are two major
                                      marine zones:
                                      – the neritic zone
                                        extends to the edge of
                                        the continental shelf
                                        and contains 90% of
                                        all marine species
                                      – the oceanic zone
                                        includes all waters
Bluefin Tuna Thunnus thynnus
                                        beyond the continental
                                        shelf.
Estuaries            An estuary is a partially enclosed
                      area of coastal water where
                      seawater mixes with freshwater.
                       – Constant water movement from tides
                         and currents provide for a nutrient-
                         rich environment with a wide range of
                         temperature and salinity

                             Coastal Wetlands
 Coastal wetlands are areas of coastal land that are
   covered with saltwater all or part of the year
 Wetlands are incredibly important because they
  filter water, protect shorelines from erosion, and
  provide feeding and breeding grounds for many
  organisms
            Types of Coastal Wetlands
 marshes are freshwater or estuarine wetlands
  dominated by grasses
 bogs are inland freshwater wetlands dominated by
  mosses                        swamps are
                                  freshwater,
                                  estuarine, or marine
                                  wetlands dominated
                                  by trees
                                mangrove swamps
                                  are tropical
                                  communities
                                  dominated by
                                  halophytic (adapted
                                  to grow in saline
                                  conditions) trees
                   Coral Reefs
 Coral reefs are massive colonies
 of coral polyps living in a
 secreted skeleton of calcium
 carbonate (limestone - CaCO3).
  – most coral (phylum Cnidaria) is in
    a mutualistic symbiosis with
    zooxanthellae, which are single-
    cell algae.
 Coral reefs are among the oldest
 and most productive ecosystems
 in the world, but grow at only
 one-half centimeter per year.
                     Coral Reefs
 The biggest threat to coral reefs is the deposition of
  eroded soil. This is the primary cause of bleaching,
  in which the coral becomes stressed and expels the
  zooxanthellae.
                                Other stresses to
                                  coral include
                                  increased UV
                                  radiation, global
                                  warming, and
                                  runoff of pesticides,
                                  fertilizers, and
                                  industrial chemicals
                    The Oceanic Zone
 Divisions of the oceanic zone:
   – epipelagic: 0-200 m, this
     the photic zone (lighted)
   – mesopelagic: 200-1,000m
   – bathypelagic: 1,000-2,000
     to 4,000 m, 10oC to 4oC
     (benthic zone is the
     bathyal zone)

    – abyssalpelagic: to a depth of 6,000 m, overlying the plains
      of the major ocean basins (benthic zone is the abyssal
      zone)
    – hadalpelagic: 6,000-10,000 m, includes the open water of
      deep trenches (benthic zone is the hadal zone)
                                    While polar bears, Ursus maritimus, do not eat plankton, the largest
The Oceanic Zone                    part of their diet is fish which do



 The Oceanic Zone is one
     of the least productive of
     all ecosystems, because
     light penetrates only the
     surface waters.


                                              Polar Ecosystems
                                  Polar Caps are considered marine
                                    ecosystems because the primary
                                    food source is plankton
                                     – the Arctic Ocean is rich in
                                       nutrients from surrounding
                                       land masses
                                     – the Antarctic is not as rich in
                                       nutrients, lacking the
Whale Shark, Tiburon ballena
                                       surrounding land masses
              Freshwater Biomes
                                 Freshwater life zones
                                   occur where water
                                   with a salinity of less
                                   than 1 ppt
                                   accumulates on or
                                   flows through the
                                   surfaces of terrestrial
                                   biomes.


– lentic systems are standing, such as lakes, ponds, and
  inland wetlands
– flowing systems are moving, such as streams and rivers.
                 Lakes and Ponds
 Lakes are large bodies of standing fresh water,
  formed when precipitation, runoff, or groundwater
  seepage fills depressions in the earth’s surface.
 Lakes normally consist of four major zones:
   – the littoral zone is the shallow area near the shore
     to the depth at which rooted plants stop growing
   – the limnetic zone is the open, sunlit water surface
     layer away from the shore that extends to the
     depth penetrated by sunlight
   – the profundal zone is the deep, open water where
     it is too dark for photosynthesis
   – the benthic zone is the bottom of the lake
               Lakes and Ponds
 Seasonal changes occur in temperate lakes, causing
  an overturn of the water column.
                          During the summer and
                            winter, the water
                            becomes stratified into
                            different temperature
                            layers, separated by a
                            thermocline. In the fall
                            and spring, the waters at
                            all layers mix in
                            overturns that equalize
                            the temperatures at all
                            depths.
                 Streams and Rivers
  The entire land area, which delivers water,
   sediment, and dissolved substances to a stream or
   river is called a watershed, or a drainage basin.
 A river system is a series of different ecosystems
  because of different environmental conditions in each
  of three zones:
  – The source zone contains the headwaters of the river. This
    zone typically has cold, clear, highly oxygenated water.
  – In the transition zone, the headwater streams merge to form
    wider, deeper streams. The warmer and slower moving
    water supports more biodiversity, particularly
    phytoplankton.
  – The flood plain zone joins streams into wider and deeper
    rivers that meander across broad, flat valleys. This area
    supports the greatest number of both plant and animal
    species.
                  Inland Wetlands
 Inland wetlands include
  marshes, swamps and bogs
  along with seasonal
  wetlands (ex.floodplain
  wetlands, prairie
  potholes). These are
  important for three main
  reasons:
   – provide food and habitat for fish, migratory waterfowl,
     and other wildlife
   – filter, dilute, and degrade toxic wastes, excess nutrients,
     sediments, and other pollutants from runoff
   – reduce flooding and erosion by absorbing overflows of
     streams and lakes
                Water Cycle
 The overall amount of water on the Earth stays about
  the same.
 The water cycle is a process of water movement
  between the Earth’s surface and the atmosphere.
 The sun provides the energy that drives the water
  cycle.
 Heat from the sun evaporates water from the ocean,
  lakes, rivers, soil, plant leaves, and body of
  organisms.
 Water vapor cools in the atmosphere it condenses
  and forms droplets in clouds.
 When clouds meet cold air the water returns to the
  Earth as precipitation.
 Precipitation is rain, sleet, and snow.
Where does most precipitation fall?
Ocean – Earth is 71% Ocean.
Water which falls on land and
 soaks into the soil and rocks until it
 reaches a layer of rock or clay
 where it can’t go down any further.
This layer of water is called
 groundwater.
 How much water is on the Earth?
71% of the Earth is covered with water.
The problem is 97% of the water on
 Earth is salt water and only 3% is fresh
 water.
Of the 3% fresh water about 77% is
 frozen in the polar icecaps.
Water we use for our everyday needs
 comes from surface water and
 groundwater.
       Surface Water
All fresh water that is above ground is
 called surface water like ponds, lakes,
 streams, and rivers.
The area of land that is drained by a
 river is called its watershed.
                         Groundwater
 The water that seeps underground is called groundwater.
 Water percolates through the soil and to the rock below.
 Large areas of groundwater found in underground rock
  formations called aquifers.
 It takes millions of years to form an aquifer.

                           Porosity
Porosity is the amount of space between the particles that make
up a rock.
Rocks which allow water to flow through it are called
permeable.
The recharge zone is the area of land where the groundwater
originates to form an aquifer.
The problem is people are pumping water out of the aquifer
faster than it can be replaced naturally.
Ogallala Aquifer

The largest aquifer in the United
 States is the Ogallala Aquifer which
 is losing water very quickly and
 some communities which have used
 this water are now using other
 sources.
A hole which is drilled or dug to
 reach groundwater is a well.
     Water Use and Management
 Most water must be treated to make it safe to drink or potable.
 Pathogens are disease causing organisms which can be found
  in water.
 Chlorine is added to drinking water to prevent bacteria from
  growing.
 Industry uses 19% of water in the world. To manufacture
  goods, dispose of waste, and generate power.

              Who uses the water?
Highest % of industrial water use occurs in Europe and North
America.
Agriculture uses 67% of the water in the world. by irrigation.
Water management projects bring water to dry habitats for
recreation, drinking, or for electricity.
Conflicts over control of water has been a problem all over the world and as
our need for fresh water increases so will the problem of water rights.
          Solutions to Water Shortages
 We need to develop new sources of fresh water.
 We need to practice conservation.
 Low flow shower heads and toilets.
 Xeriscaping is landscape designing that requires
   minimal water use.
                        Problems
 The problem with desalinization today it is very expensive.
 Another possible solution is the towing of water from one place
  to another.
 Saudi Arabia is conducting experiments on towing icebergs.
 Problem with towing icebergs they are hard to tow, melt rapidly,
  and are difficult to transport on land.
 The removal of large amounts of ice will disrupt the polar
  ecosystem.

								
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