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• 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.

Pic: Salt Marsh & Food WebSalt marsh

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

• 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

Red Tide Formation

SumaryChoose 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.