2. Estuaries Place where freshwater from a river or stream mixes with salt water from the ocean Embayment- Coastal area that is partially cut off from the rest of the ocean

3. Geological Types Coastal Plain (Drowned river valley) Chesapeake Bay and Long Island Sound Once land that was flooded due to glacial melting Tectonic Earthquakes caused land to sink creating flooding Tidal Flats When sediment carried by rivers deposits high enough to be exposed at low tide Bar-built When Barrier islands are built that cut off the estuary Fjord Flooded glacier valleys

4. Salinity and Mixing Positive estuary Less dense freshwater flows out to sea on top More dense salt water flows inland on bottom More common Negative Estuary Rapid evaporation causes surface water to become more saline and therefore more dense Surface water flows inland Bottom water flows out to sea

5. Mixing Patterns A- Salt Wedge Common at the mouths of rivers River outflow pushes top water Sea inflow moves in and gets stopped by outflow B- Partially Mixed Stronger influx of seawater Mixes in sections C- Well Mixed Low river flow causes tides to mix the estuary D- Fjord Little mixing between surface fresh water and bottom sea water

6. Estuarine Productivity Freshwater brings nutrients from land runoff Mixing of those nutrients with saltwater nutrients creates well balanced pools Excess nutrients stored in clay and silt Shallow waters provides constant sunlight Psuedofeces- Excess balls of undigested phytoplankton produced by many bivalves in estuaries

7. Life in an Estuary Osmotic balance The constant, rapid changes in salinity mean organisms in a salt marsh must be able to either deal with the changes in fluid or actively control their salt/fluid concentrations Osmoregulators Change the salinity of their body fluids by actively taking in or releasing salts. Osmoconformers Able to deal with the changing fluids concentrations in their bodies

8. Estuaries as Nurseries High amount of nutrients Low number of predators Examples: Bluefish Striped Bass Croaker