1. Estuaries

3. Estuaries Where rivers meet the sea Constant environmental change
Estuaries
Where rivers meet the sea
mixing of fresh and saltwater
Dependent on the tides
Constant environmental change
Temperature
Salinity
Nutrients
Important ecosystem – for animals and humans
“nursery” for juvenile fish, mollusks, etc.
Shallow – so lots of primary producers
Commercial fishing - economy & food source
Some estuaries filters and cleans the water

4. Estuarine Communities
Mud Flats
Salt Marsh
Mangrove swamp

5. http://oceanservice. noaa
_estuar06a_saltmarsh.html

6. Mud Flats
Found in bays and around the mouths of rivers wherever the land is protected from wave action
Bacteria and microorganisms thrive in the nutrient rich mud
Home to filter feeding, juvenile, and burrowing organisms
producers
macroscopic and microscopic algae living on the surface, sulphur bacteria, detritus food chain
grazers
Snails
suspension feeders
clams, worms, crustaceans
detritus feeders
clams, worms
carnivores
rays, flatfish and birds

7. Salt Marsh Tidal wetlands Found higher than Mudflats
Salt Marsh
Tidal wetlands
Found higher than Mudflats
Dominated by Halophytes (Salt-Tolerant Plants)
Hypoxic (Low Level of Oxygen because of the high amount of decomposition.)

8. Mangrove Forests found along tropical seacoasts
Mangrove Forests
found along tropical seacoasts
They are named for the Mangrove trees that grow there.
found along muddy estuaries of large rivers, and in sheltered intertidal coastal settings that include lagoons, bays, tidal creeks and inlets.

9. Mangrove Trees What stressors do they have?
Hypoxic soil
Brackish Water/changing water salinity
How do they deal with the stressors?
Aerial Roots (above ground roots) help them obtain oxygen from the air
Salt Glands concentrate the salt into a solution and release it through their leaves

10. Estuary Organism Adaptations
Pickleweed
Accumulates salts in the tips of certain leaves (aka “sacrificial leaves”)
Sacrificial leaves will fall off, leaving the rest of the plant safe from the salt

11. Estuary Organism Adaptations
Bull Sharks “Highest level of testosterone”
Have the ability to osmoregulate
Osmoregulation: the ability to be able to regulate the water and the salt content Can either retain salt or release salt
Their Kidneys can regulate the amount of salt that is released through urine. Other sharks are unable to do this.
What Does this mean?
*Bull Sharks can swim in both freshwater and the ocean.
*According to Texas Wildlife, Bull sharks have been found many miles up rivers connected to the gulf.
*Example: 5-6ft Bull Sharks have been found in the Trinity River

12. Environmental Issues Agricultural Runoff Dams Overfishing Dredging
Construction
Removal of Vegetation