Do Now: What happens to water when
salt and fresh water mix?
Aim: What type of biomes form
when fresh and salt water mix?
Estuary
• Where the “arm” of a sea extends inland to meet the
mouth of a river
– Sea water moves inward mixing with fresh river water
resulting in brackish water
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•
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High in nutrients and sediments
Shallow water, high sunlight
Rich in both plant and animal life
Commercially important marine life use estuaries as a
nursery for their eggs
• Types: Salt water marsh, Mangrove forest, Inlets, &
Bays
Estuary
Salt Marsh
• Transition zone from ocean to land, where salt
water and freshwater mix.
• Water level fluctuates do to tides.
• Plants are salt and tide tolerant.
• One of the most productive ecosystems.
Salt marsh
Pic: Salt Marsh & Food Web
Mangrove Forest
• Trees that grow in saline water in the tropics.
• Characterized by deposition of fine sediment
that protects the area from high energy wave
action.
• Can tolerate brackish water-pure salt water.
Pic: Mangrove Forest
Mangrove forest
Wetlands
• Among the most diverse ecosystems
• Area saturated with water permanently or
seasonally
• Found along the shores of fresh bodies of water
• Types:
– Marshes
– Swamps
– Bogs
– Prairies potholes (seasonal)
– Flood plains (occur when excess water flows out of
the banks of river into a flat valley)
BOG
SWAMP
PRARIE POTHOLE
FLOOD PLAIN
Saltwater Ecosystem: Barrier islands
• Important source of biodiversity
• Land form off coastal shores created by the
build up of deposited sediments
• Boundaries are constantly shifting as water
moves around them
• Important buffer for the shoreline behind
them when offshore storms hit
• How did the barrier island protect NJ
during Hurricane Sandy?
Pic: Island Barrier
Tropical Waters Barrier Island: Coral
Reef
• Formed by cnidarians that secrete a hard,
calciferous (calcium carbonate) shell skeleton
– providing homes for a diversity of marine life
species
• Not formed by depositing of sediment
• Vulnerable to physical stresses, change of light
intensity, and water temperature
FW & SW Upwelling
- Seasonal movement water from the cold, nutrient
rich bottom to the surface
- Provides nutrients to organisms living in the
photic zone causing exponential growth
Red Tide Formation
• After upwellings, fisheries boom
• Organisms like single-celled algae
grow exponentially
– Algal blooms can lead to red tide
– Deadly toxins released into water from
dinoflagellate wastes
– Result massive fish and marine life die
off
Sumary
Choose 1 of the following:
1. Explain how the atmosphere effects the
hydrosphere.
2. Compare & contrast sea water salinity to
fresh water salinity.
3. Create a story about the life of a river
starring you as a drop of rain.
4. Explain vertical stratification in fresh water
biomes.