Ecology Chapters 10-11
Freshwater and Marine Biomes
Voc. List: Aquatic Biomes, Freshwater Biomes, Standing-Water Ecosystem, Flowing-Water
Ecosystem, Wetlands, Sediments, Estuary, Marine Biome, Hypersaline Lakes, Salt Marshes, Photic
zone, Disphotic zones, Aphotic zones, Eurythermal zone, Disthermal zone, Sunlit Layer, Thermocline
Layer, Deep Thick Layer, Salinity, Pelagic zone, Neritic zone, Oceanic zone, Intertidal Littoral zone,
Supralittoral zone, Sublittoral zone, Bathyal zone, Benthic zone, Phytoplankton, Zooplankton, Nekton
zone, Detritus, zooxanthellae, Filter feeders, Eutrophication
Aquatic Biomes
Nearly 75% of the Earth’s surface is covered by water. It is the largest part of the biosphere and
without water most life could not exist. There is a large diversity of aquatic plants and animals
large and small in size some even microscopic in nature. There are two basic forms of aquatic
biomes:
 Freshwater (wetlands, ponds, lake, rivers, and streams)
 Divided into two main types-standing and flowing-water ecosystems
 Lakes, ponds and wetlands (marsh, swamp, bogs): standing –water
 Wetlands-in general are ecosystems in which the roots of plants are submerged
under water at least part of the year
◊ Very important for the biosphere because they act as filters, detoxifying
chemicals in the water that passes through them.
◊ Important in breeding, feeding, and resting grounds for migratory water fowl,
such as ducks, and geese.
◊ Wetlands along the banks of rivers act as flood protection regions
◊ Wetlands are being destroyed by man
 Rivers, streams, creeks, and brooks: flowing-water ecosystems
◊ Organisms include many types of fish such as salmon and catfish
◊ Stream-flow causes erosion
*Sediments are small particles that settle on the bottom of these bodies
of water from erosion
◊ An estuary is a region where a freshwater source, usually the mouth of a
river, meets the salt water of the ocean.
*It functions as buffer zones, filtering sediments and pollutants from the
water
*It also eases the effects of storms and floods by slowing the flow of
water.
*Estuaries often are spawning grounds for commercial fish


The amount of dissolved salts in a sample of water is called salinity
 Measured in parts per thousand
 There is salt in fresh water but only a little
o 0.5 parts per thousand
Marine (oceans, coral reefs, and estuaries)
 In the ocean water the salinity is about 30 parts per thousand
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Most lakes, rivers, ponds are freshwater but there are exceptions
 Great Salt Lake in Utah and Mono Lake in California
 They are saltier than the oceans: 40 parts per thousands
 Called hypersaline lakes
There are salt marshes as well as fresh-water marshes
 Salt Marshes are flat, muddy wetlands that often surround estuaries, bays, and
lagoons
o Most are influenced by tides
o Very common in the east coast of the United States and the
shores of the Gulf of Mexico
o Role: Supporting migratory bird populations
Ocean Zonation
Classification by Light
1. Photic zone- Sunlit top layer of the ocean that extends in the tropics about 200 meters in depth
(660 ft.) and in productive mid-latitude water about 100 meters (330 ft.)
o Upper ½ is where most of biological productivity occurs called euphotic zone
2. Disphotic zone- very small amounts of light penetrates
3. Aphotic zone- lowest zone
o Dark
o 90% of the space
o extends to the bottom
Classification by Temperature
1. Uppermost layer where temperature changes with seasons
o Eurythermal zone-usually missing in high latitudes
2. Most stable temperatures below the thermocline is the disthermal zone
Layers by Temperature
1. Sunlit-Layer with sunlight and the warmest
2. Thermocline-Only a little light and temperature varies and salinity increases
3. Deep thick layer-usually the coldest (except in underwater volcanic and hydrothermal vent
areas) and greatest salinity
Classification by Location
Pelagic Zone-The Open Ocean
2 subdivisions:
o Neritic zone(shallow) near the shoreline over the Continental Shelf (<600 ft. deep)
a. Continental Shelf is the area between the shore and about 200 meters below the
surface of the water.
o Oceanic zone (deep water) beyond the Continental Shelf
Further division by Light
o Epipelagic zone-Lit photic zone where photosynthesis occurs
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o
o
o
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Mesopelagic zone-top of aphotic area little to not light
Bathypelagic zone-deep and no light
Abyssopelagic zone –water in trenches
Hadalopelagic zone-deepest
Division from the Shoreline to the bottom
1. Intertidal littoral zone- Starts at the Shoreline and is the band of coast alternately
covered and uncovered by tides.
 This area is constantly being pounded by the surf so organisms that live here
adapt by either burrowing themselves in the sand (like clams and crabs) or
attaching themselves to the rocks (like barnacles)
2. Supralittoral zone-Splash zone
3. Sublittoral zone-Below splash zone and has further divisions
 Inner sublittoral-Ocean bottom near the shore
 Outer sublittoral-Ocean floor out to the edge of the Continental Shelf
4. Bathyal zone-Covers the sea bed on the slopes and down to great depths.
o Abyssal zone-The beginning where Abyssal plains are found
o Hadal zone-Where trench walls and ocean floors lie
5. Benthic zone-Deepest (floor bottom)
o The organisms seen depends on the depth
o In shallow water, sunlight reaches the benthic zone so plants can grow.
 Common freshwater benthic animals include zooplankton, snails,
catfish, and turtles
o In deep ocean water there is no sunlight
 Animals can present special features like bioluminescence
 Some animals are so unique that they can live over a hundred
years-Giant tubeworms
Types of Standing-Water Ecosystems
Body of water
Lake
Pond
Abiotic Factors
Deepest; may have an aphotic zone; may be fed
by groundwater aquifers.
Light reaches benthic zone; fed mostly by
rainfall; may be seasonal.
Marsh
Very shallow water with land occasionally
exposed; soil is saturated, water often lacks
oxygen; may be freshwater, saltwater, or
brackish; often tidal; Florida Everglades is the
largest freshwater marsh in the United States.
Swamp
Land is soaked with water because of poor
drainage; usually along low streambeds and flat
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Biotic Factors
Main producers are floating
algae in the photic zone and
benthic plants along the
shoreline; complex food webs.
Main producers are plants and
algae that grow on the bottom;
food web usually simpler than in
lakes.
Plants have roots under water,
but leaves are above the water
(emergent); mostly grasses,
cattails, and rushes; ducks,
waterfowl, and benthic animals
are common.
Dominated by large trees and
shrubs; plants are adapted to
Bog
land; mangrove swamps are salty and found along grow in muddy, oxygen-poor
coastlines.
soil; cypress trees common in
the south, willow and dogwood
common in the northern United
States.
Inland wetland with little inflow or outflow; soil
Sphagnum moss is the dominant
is acidic; decay is slow; carbon is stored in dead
organism; partly decayed moss
plants.
accumulated as peat.
Ocean Life: 3 categories
Plankton are marine algae and animals that drift with the currents. Most are microscopic like
Diatoms but some are as big a Portuguese man-of-war
Two types:
 Phytoplankton: plant-like plankton (producers)
 Zooplankton: animal-like plankton (consumers)
Nekton are animals that actively swim. Example: Blue whale
Benthos are algae, animals, and plants living on the ocean floor or near the ocean floor. Example:
Coral
 Detritus are tiny pieces of dead organic matter that are food for organisms at the base of
an aquatic food web such as coral and sponges
CORAL
o There are hard and soft coral.
o Only hard coral colonies form reefs.
◊ A reef is a natural structure built on a continental shelf.
o Form in water that is high in salt (salinity), no more than 30 meters from the surface, and warm
water near the equator.
o Coral habitats contain the most diverse creatures and without the coral reefs millions of species
of fish and other organisms would be extinct.
◊ Rough 1/3 of all bony-fish live on or depend on coral reefs
o The ecology of the coral reef is unique and fragile.
◊ The reef itself is made of the Calcium Carbonate skeletons of millions of
tiny corals
◊ Only the top layer of the reef is alive.
o Corals depend on a symbiotic relationship with a form lf alga,
called zooxanthellae that live inside the tissue of the coral. The
algae carry out photosynthesis and provide the coral with food.
o Human activities are harming the coral reefs-water pollution and
reef structural damage
MANGROVE SWAMP
In the United States are for three of the 50 species of Mangrove trees abundant in Florida and the
Florida Keys.
o The species found in these areas are Red, Black, and White.
o They form a unique ecosystem essential for certain organisms to live.
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o Each species has its unique way to protect itself and the environment for excess
salt, provide a save haven for organisms, and to reproduce.
The Mangrove Swamp provides a food chain resource and storm protection.
o The leaves on the trees last roughly a year before falling.
o The bacteria and fungus cause the leaves to decompose once in the water
causing these leaves to form the base of the food chain.
o After decomposing, this material provides food for the marine organism like
crabs and shrimp.
o From there larger organisms eat the crabs and other smaller creatures.
o These trees also provide protection from waves and winds produced by storms.
o This buffer system reduces winds and harmful waves that would erode the area.
The structures of the Mangroves provide everything it needs to balance it ecosystem.
o The Mangroves all have leathery evergreen leaves, some type of root system,
and fruit.
o For a Mangrove swamp ecosystem to work the falling leaves from the trees and
their roots themselves have to create a barrier between the land and water.
o This system allows small organisms the protection they need from larger
organism that can’t get through the barrier and it also allows the mangrove trees
to filter out the salt so the salinity levels will not get too high.
o In addition, the fruit from the mangroves also has the ability to germinate and
form roots quickly.
Chesapeake Bay Estuary
The Chesapeake Bay is the largest and most productive marine ecosystem in the United States.
 It receives fresh water from many tributaries ranging from large rivers to thousands of smaller
creeks.
 All the land that drains water into the Bay is the estuary’s watershed.
o The Chesapeake watershed includes six states and the District of Columbia: Virginia,
Pennsylvania, Maryland, West Virginia, and New York
o 50 % of the fresh water that flows into the Bay comes from the Susquehanna River at
the Bay’s northern end
 The bay is home to nearly 300 species of fish including important commercial species such as
striped bass, bluefish, summer flounder, American eel, and Atlantic menhaden.
 This bay is famous for its blue crab and oysters.
Estuaries across the globe have similar characteristics and threats. Below is a list of characteristics and
organisms:
1. SAV-Submerged Aquatic Vegetation: These plants are sources of food for shellfish, finfish,
birds, amphibians, reptiles, invertebrates, and mammals.
a. SAV provide nurseries for young fish.
b. The plants trap sediment by slowing water currents. This causes the suspended particles
(sediments) to drop to the bottom
2. Wetlands: The high primary productivity in the wetlands fuels food webs.
a. Wetlands are a source of food and shelter for juvenile aquatic organisms and filter
sediment, nutrients, and contaminates.
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4.
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b. They are important to the carbon and nitrogen cycles.
c. Wetlands are important habitats for birds, reptiles, mammals, and invertebrates and
protect the land from eroding and flooding,
Filter feeders: These organisms filter suspended particles to obtain food by straining the water.
a. Anything not eaten is bound with mucus and discarded.
b. The heavier waste pellets fall to the bottom.
c. If not consumed by decomposers, sediment covers the organic material, becoming a
natural sink.
Pit-Stops for Migratory Birds: The North American migratory flyways describe the routes
followed by migratory birds.
a. Though the routes vary with each species, they often intersect at estuaries.
b. Estuaries are important stop-overs for the birds to rest and eat so they can refuel from
their long journeys.
Habitat for Endangered Species: Estuaries and their tributaries often sheltered habitats for
species now endangered of becoming extinct like sea turtles and manatees.
Natural, Economic, and Aesthetic Values: The sheltered access to the sea offers people
commercial and recreational fishing, boating, tourism, and other coastal industries.
a. Estuaries provide spawning and nursery grounds for commercial fisheries.
The Role of Aquatic Plants
There are three types of aquatic plants in the Chesapeake Bay: floating plants, emergent plants, and
submerged aquatic vegetation
1. Floating plants have roots that dangle in the water or anchor in the bottom sediment.
a. Long stems allow the leaves to float on the water’s surface.
b. Water lilies and water hyacinths are commonly seen
2. Emergent plants are rooted at the water’s edge, but their stems and leaves grow above the
surface of the water.
a. Cattails, cord grass, and rushes are examples.
3. Submerged aquatic vegetation are critical for maintaining the cycle of gases in the water
through t he process of photosynthesis.
a. There are more than 15 dominant species of SAV in the Chesapeake Bay such as
Eelgrass, Horned Pondweed, Muskgrass, and Wild Celery.
b. SAV are important food source to ducks, fish, muskrats, beavers, turtles, and a large
number of invertebrates.
c. SAV slows the movement of water and that causes suspended particles to fall to the
bottom.
d. Roots hold the particles in place.
Challenges to Estuaries
Dead Zones: Animals can suffocate in the water without the proper dissolved Oxygen levels.
 As water flows over the gills of an aquatic animal, dissolved oxygen is absorbed and enters its
bloodstream.
o The blood carries the oxygen to every cell of its body for the process of cellular
respiration.
o This is how the animal uses the energy obtained from eating.
 Eutrophication increases the amount of nitrogen and phosphates in the water.
o Chemical compounds containing these elements act as nutrients for algae and are found
in fertilizers and sewage.
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o SAV depend on small amounts of these but large amounts are pollutants.
o This pollution changes the chemistry of the water and fertilizes the algae.
o This explosive growth leads to algae bloom.
 The algae take all of the dissolved oxygen and none is left for the other
organisms especially fish-killing the fish.
Restoration efforts
 Fisheries
 Managing Lands: Laws are being passed to limit or restrict wetland construction
 Replanting SAV
 Reducing Runoff of farming chemicals
 Comprehensive Monitoring of chemicals in the water
 Aquaculture farming aquatic organisms underwater.
o Provides seafood for the human market and reduces the need to catch wild specimens.
Power points
Creatures of the Deep
Mangrove Swamp
Our Seashores
Ocean Environments
Marine Life
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