Aquatic Ecosystems

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Aquatic Ecosystems

• Freshwater
• Ponds Lakes
• Streams Rivers
• Wetlands

• Marine
• Oceans
• Coral Reefs
• Estuaries

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Freshwater

• Ponds Lakes
• Streams Rivers
• Wetlands

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Freshwater

• Freshwater is defined as having a low salt
  concentrationusually less than 1
• Plants and animals in freshwater regions are
  adjusted to the low salt content and would not be
  able to survive in areas of high salt
  concentration (i.e, ocean)

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Ponds and Lakes

• range in size from just a few square meters to
  thousands of square kilometers
• ponds may be seasonal, lasting just a couple of
  months (such as sessile pools)
• lakes may exist for hundreds of years or more
• may have limited species diversity since they
  are often isolated from one another and from
  other water sources like rivers and oceans

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Ponds and Lakes

• divided into three different zones determined
  by depth and distance from the shoreline
• littoral zone
• limnetic zone
• profundal zone

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Littoral Zone

• warmest since it is shallow and can absorb more
  of the Suns heat
• sustains a fairly diverse community, which can
  include several species of algae (like diatoms),
  rooted and floating aquatic plants, grazing
  snails, clams, insects, crustaceans, fishes, and
  amphibians
• the egg and larvae stages of some insects are
  found in this zone
• vegetation and animals living in the littoral
  zone are food for other creatures such as
  turtles, snakes, and ducks

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Limnetic Zone

• near-surface open water surrounded by the
  littoral zone
• well-lighted (like the littoral zone) and is
  dominated by plankton, both phytoplankton and
  zooplankton
• plankton are small organisms that play a crucial
  role in the food chain most life would not be
  possible without them
• variety of freshwater fish also occupy this zone

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Profundal Zone

• Plankton have short life spanswhen they die,
  they fall into the deep-water part of the
  lake/pond
• much colder and denser than the other two
• little light penetrates all the way through the
  limnetic zone into the profundal zone
• animals are decomposers

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Ponds and Lakes

• Temperature
• varies seasonally.
• Summer
• from 4 C near the bottom to 22 C at the top
• Winter
• from 4 C while the top is 0 C (ice)
• between the two layers is a narrow zone called
  the thermocline where the temperature of the
  water changes rapidly with depth

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Ponds and Lakes

• during the spring and fall seasons is a mixing of
  the top and bottom layers resulting in a uniform
  water temperature of around 4 C
• mixing also circulates oxygen throughout the lake
• many lakes and ponds do not freeze during the
  winter resulting in the top layer being a little
  warmer

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Ponds and Lakes

• ice can develop on the top of lakes during winter
• blocks out sunlight and can prevent
  photosynthesis
• oxygen levels drop and some plants and animals
  may die
• called "winterkill."

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Ponds and Lakes
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Streams Rivers

• bodies of flowing water moving in one direction
• found everywherethey get their start at
  headwaters, which may be springs, snowmelt or
  even lakes
• travel all the way to their mouths, usually
  another water channel or the ocean

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Watershed

• describes an area of land that contains a common
  set of streams and rivers
• drains into a single larger body of water, such
  as a larger river, a lake or an ocean

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Streams Rivers

• characteristics change during the journey from
  the source to the mouth
• temperature is cooler at the source than it is at
  the mouth
• water is also clearer, has higher oxygen levels,
  and freshwater fish such as trout and
  heterotrophs can be found there

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Streams Rivers

• Towards the middle part of the stream/river, the
  width increases, as does species
  diversitynumerous aquatic green plants and algae
  can be found

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Streams Rivers

• toward the mouth the water becomes murky from all
  the sediments that it has picked up upstream
• decreasing the amount of light that can penetrate
  through the water
• less light
• less diversity of flora
• lower oxygen levels
• fish that require less oxygen, such as catfish
  and carp, can be found

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Streams Rivers
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Wetlands

• Wetlands are areas of standing water that support
  aquatic plants
• Marshes, swamps, and bogs are all considered
  wetlands

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Wetlands

• Plants
• adapted to the very moist and humid conditions
  are called hydrophytes
• Pond lilies Cattails
  Sedges
• Tamarack
  Black Spruce
• Gum
  Cypress

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Wetlands

• highest species diversity of all ecosystems
• many species of amphibians, reptiles, birds (such
  as ducks and waders), and furbearers can be found
  in the wetlands
• not considered freshwater ecosystems as there are
  some, such as salt marshes, that have high salt
  concentrationsthese support different species of
  animals, such as shrimp, shellfish, and various
  grasses

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Wetlands

• River Otter
• 
  Damselfly Dragonfly Mayfly
• Crayfish Snails Leech
  Bluegill Bass
• Catfish Sculpin Minnow
  Snakes
• 
  Frog Turtle
• Great Blue Heron Canadian Goose

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Aquatic Ecosystems

• Marine
• Oceans
• Coral Reefs
• Estuaries

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Marine

• cover about three-fourths of the Earths surface
  and include oceans, coral reefs, and estuaries
• algae supply much of the worlds oxygen supply
  and take in a huge amount of atmospheric carbon
  dioxide
• evaporation of the seawater provides rainwater
  for the land

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Oceans

• largest of all the ecosystems
• dominate the Earths surface
• separate zones
• Intertidal
• Pelagic
• Abyssal
• Benthic
• great diversity of species
• richest diversity of species even though it
  contains fewer species than there are on land

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Oceans
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Intertidal Zone

• where the ocean meets the land
• sometimes submerged and at other times exposed
• waves and tides come in and out
• communities are constantly changing

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Intertidal Zone

• rocky coasts
• stratified vertically
• Where only highest tides reach
• a few species of algae and mollusks
• submerged during high tide
• more diverse array of algae and small animals,
  such as herbivorous snails, crabs, sea stars, and
  small fishes
• bottom of the intertidal zone
• only exposed during the lowest tides, many
  invertebrates, fishes, and seaweed can be found

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Intertidal Zone

• sandier shores
• not as stratified
• waves keep mud and sand constantly moving
• very few algae and plants can establish
  themselvesthe fauna include worms, clams,
  predatory crustaceans, crabs, and shorebirds.

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Wave Regions

• much stronger than wind
• decide what grows where
• shores classified by amount of wave action
• Exposed shores receive full brunt of the ocean
  for most or at least some of the time
• Semi-exposed shores sheltered by barrier
  islands but still have to cope with waves
• Sheltered shores shelter of peninsulas and
  inshore islands
• Enclosed shores
• river mouths and estuaries
• completely sheltered by either a protective rocks
  or a sand bar

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Pelagic Open Ocean

• waters further from the land, basically the open
  ocean
• generally cold though it is hard to give a
  general temperature range since, just like ponds
  and lakes, there is thermal stratification with a
  constant mixing of warm and cold ocean currents

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Epipelagic Open Ocean

• extends down to around 200m
• lowest depth that light can penetrate
• flora in the epipelagic zone include surface
  seaweeds
• fauna include many species of fish and some
  mammals, such as whales and dolphins
• many feed on the abundant plankton

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Mesopelagic Zone
http//oceanlink.island.net/oinfo/deepsea/meso.htm
l

• "twilight zone" of the ocean
• photic zone above
• darkness below
• food becomes scarce some animals
• migrate up to the surface at night to feed
• rely on food that falls down from above
• eat each other
• sometimes the only things to eat may be bigger
  than the hunter
• developed long sharp teeth,
• expandable jaws and stomachs

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ctenophore related to
jellyfish Big Scale - ambush predator
cilia can be illuminated


Firefly squid


three kinds of
photophores Hatchet Fish only a few
inches long
Viperfish
specially adapted
hinged skull Dragonfish - stomachs hold
big meals Snipeel up to 1.2m

Siphonophores are colonies of animals

related to jellyfish

best known is Portugese Man of War
http//oceanlink.island.net/oinfo/deepsea/meso.htm
l
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Bathypelagic Zone

• extends down from 1000 to 4000m
• only light is from bioluminescent organisms
• only food is what trickles down from above, or
  from eating other animals
• water pressure at this depth is considerable
  (100 400 atmospheres)
• most animals are either black or red in color
• very little blue/green light penetrates this deep
  red is not reflected and looks black

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Narcomedusa Vampire Squid Snake
Dragon Angler Fish
Amphi - crustacean
Ctenophore
voracious predator

Deepstaria very slow swimmers,
no tentacles, close flexible bells
(up to a meter across) around
their prey
Big Red
grows to over
a meter across
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Abyssopelagic Zone - the Abyss

• 4000m to the sea floor
• only zone deeper than this is the hadal zone
• areas found in deep sea trenches and canyons
• home to pretty inhospitable living conditions
• near- freezing temperatures
• crushing pressures

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• Deep Water Squid
• 
  Basketstar
• 
  Sea Pig
  Sea Spider
  
• Shrimp
• 
  Winged Sea Cucumber
• 
  
  
  Medussa
• 
  
  
• Deep Sea Smoker - 648F
• 
  Deep-sea Anemone
  Hydrothermal Vent

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• Ballina Angelfish
• Beaked Salmon
• A deepsea anglerfish (no common name)
• Duckbilled Eel
• A fanfin anglerfish
• Fangtooth
• Gilbert's Halosaur
• Gulper Eel
• Hammerjaw
• Largescale New Laternfish
• Longray Spiderfish
• Portuguese Dogfish
• Sharpnose Sevengill Shark
• Short-tail Torpedo Ray
• Silver Lighthouse Fish
• A snaggletooth (no common name)
• Snubnosed Eel
• Southern Spineback
• Sparkling Slickhead

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The Coral Reef Biome

• A Look at a Marine Biome
• Created by
• Terri Street

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What Is a Coral Reef?

• A structure formed by coral polyps, tiny animals
  that live in colonies.
• Coral polyps form a hard, stony, branching
  structure made of limestone.
• New polyps attach to old coral and gradually
  build the reef.

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Types of Coral Reefs

• Fringing reefs
• Submerged platforms of living coral extending
  from the shore into the sea
• Barrier reefs
• Follow the shore but are separated from it by
  water
• Great Barrier Reef is worlds largest

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Types of Coral Reefs

• Atolls
• Ring-shaped islands of coral in open sea
• Form on submerged mud banks or volcano craters
• Surround a seawater lagoon
• Channels connect lagoon to the sea

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A World of Coral Reefs
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Coral Reef Climate

• Usually found near land in shallow, warm salt
  water
• Lots of light
• Tropical temperatures, averaging 70-85 F
• Most coral cannot survive below 65 F

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Coral Reef Plants

• Phytoplankton
• Microscopic
• Basis for all ocean food chains

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Coral Reef Plants

• Algae
• Green
• Red
• Brown algaetakes many forms

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Coral Reef Plants

• Seaweed and Sea grasses
• Brown seaweed
• Sea grass
• Shoal grass
• Turtle grass

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Fascinating Fact The Great Barrier Reef

• Worlds largest coral reef
• Over 1257 mileslong
• Off the northeast coast of Australia
• Only grows about one inch per year

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The Great Barrier Reef Home to

• 1500 species of fish
• 400 different types of coral
• 4,000 mollusks
• 500 species of seaweed
• 215 species of birds
• 16 species of sea snake
• 6 species of sea turtle
• Whales visit during winter

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Coral Reef Creatures

• Coral polyps
• Tentacles
• Digestivesac
• Connectingfilaments
• Skeletal body

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Coral Reef Creatures

• Symbiotic relationships
• Coral with algae
• Clown fish with sea anemones

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Coral Reef Creatures

• Tropical fish
• Angel fish
• John Dory
• Butterfly fish

• Sea horse
• Octopus
• Reef shark

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Fascinating FactThe Sea Horse

• Very weak swimmers
• Female lays eggs, male carries them in pouch till
  birth
• Only animal in which the father gives birth
• Body covered with armored plates

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Sample Food Chain
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Endangered Coral Reefs

• Major threats to coral reefs include
• Ocean pollution
• Dredging off the coast

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Endangered Coral Reefs

• Other dangers
• Careless collection of coral specimens
• Sedimentation
• Inhibits growth of coral polyps
• Inhibits algae growth
• Upsets balance of the biome

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Estuaries
http//www.epa.gov/owow/estuaries/about1.htm

• enclosed body of water formed where freshwater
  from rivers and streams flows into the ocean,
  mixing with the salty sea water
• estuaries and the lands surrounding them are
  places of transition from land to sea, and from
  fresh to salt water
• although influenced by the tides, estuaries are
  protected from the full force of ocean waves,
  winds, and storms by the reefs, barrier islands,
  or fingers of land, mud, or sand that define an
  estuary's seaward boundary

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Estuaries are semi-enclosed bodies of water where
fresh water from the land mixes with sea water.

• Estuaries originate as drowned river valleys,
  fjords, bar-built estuaries, and tectonic
  estuaries.
• Salinity typically grades from normal marine
  salinity at the tidal inlet to fresh water at the
  mouth of the river.

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Estuaries can be subdivided into three types
based upon the relative importance of river
inflow and tidal mixing.

• Salt-wedge estuaries are dominated by the outflow
  from rivers.
• Partially-mixed estuaries are dominated by
  neither river inflow nor tidal mixing.
• In well-mixed estuaries tidal turbulence destroys
  the halocline and water stratification.
• Because river discharge and tidal flow vary,
  conditions within an estuary can also change,
  being well-mixed when river flow decreases
  relative to tidal mixing, to becoming a
  salt-wedge estuary at times of maximum river
  discharge.

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The widely fluctuating environmental conditions
in estuaries make life stressful for organisms.

• Estuaries are extremely fertile because nutrients
  are brought in by rivers and recycled from the
  bottom because of the turbulence.
• Stressful conditions and abundant nutrients
  result in low species diversity, but great
  abundance of the species present.
• Despite abundance of nutrients, phytoplankton
  blooms are irregular and the base of the food
  chain is detritus washed in from adjacent salt
  marshes.
• The benthonic fauna strongly reflects the nature
  of the substrate and most fishes are juvenile
  forms living within the estuary until they mature
  and migrate to the ocean.

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Estuaries
http//www.epa.gov/owow/estuaries/about1.htm

• Estuaries are sometimes called marine nurseries
  
• habitats for many juvenile organisms, especially
  for fishes
• many fish are born and grow up in estuaries
• migrate to the open ocean

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Lagoons are isolated to semi-enclosed, shallow,
coastal bodies of water that receive little if
any fresh water inflow.

• Lagoons can occur at any latitude and their
  salinities vary from brackish to hypersaline
  depending upon climate and local hydrology.
• Bottom sediments are usually sand or mud eroded
  which was from the shoreline or swept in through
  the tidal inlet.
• In the tropics, the water column is typically
  isothermal.
• In the subtropics, salinity generally increases
  away from the inlet and the lagoon may display
  inverse flow.

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Salt marshes are intertidal flats covered by
grassy vegetation.

• Marshes are most commonly found in protected
  areas with a moderate tidal range, such as the
  landward side of barrier islands.
• Marshes flood daily at high tide and then drain
  through a series of channels with the ebb tide.
• They are one of the most productive environments.
• Marshes can be divided into two parts Low salt
  marshes and High salt marshes.
• Distribution and density of organisms in salt
  marshes strongly reflects availability of food,
  need for protection, and frequency of flooding.

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Mangroves are large woody trees with a dense,
complex root system that grows downward from the
branches

• Mangroves are the dominant plant of the tropical
  and subtropical intertidal area
• Distribution of the trees is largely controlled
  by air temperature, exposure to wave and current
  attack, tidal range, substrate and sea water
  chemistry
• Detritus from the mangrove forms the base of the
  food chain

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Bibliography

• http//www.ucmp.berkeley.edu/glossary/gloss5/biome
  /index.html
• http//www.enchantedlearning.com/biomes/marsh/fres
  hwater.shtml 
• http//mbgnet.mobot.org/ 
• http//www.runet.edu/swoodwar/CLASSES/GEOG235/bio
  mes/intro.html
• http//archive.globe.gov/sda-bin/wt/ghp/tgL(en)P
  (seasons/Miniinvestigation)
• http//www.panda.org/about_wwf/where_we_work/ecore
  gions/global200/pages/home.htm
• Coral Reefs. World Book. Chicago World Book,
  1998. Vol. 4, p. 257.
• Coral Reefs. http//kidscience.about.com/kids/ki
  dscience/cs/coralreefs/