Westspit Braddock Bay

Tuesday, April 28, 2015

What is an Estuary? How do estuarial bays stay healthy? Oxygenated water!

What is an estuary according to NOAA?  Could Braddock Bay receive designation as an estuary like Old Woman Creek on L. Erie and St. Louis River on L. Superior?
aerial view of Wells National Estuarine Research Reserve (Image credit: Wells National Estuarine Research Reserve)

According to NOAA, the National Ocean Service, the Estuary is generally where fresh and saltwater mix. Estuaries and their surrounding wetlands are bodies of water usually found where rivers meet the sea. Estuaries are home to unique plant and animal communities that have adapted to brackish water—a mixture of fresh water draining from the land and salty seawater. However, there are also several types of entirely freshwater ecosystems that have many similar characteristics to the traditional brackish estuaries.  FRESHWATER ESTUARIES ON GREAT LAKES:  Old Woman Creek Estuary . . . . . St. Louis River Estuary

For example, along the Great Lakes, river water with very different chemical and physical characteristics mixes with lake water in coastal wetlands that are affected by tides and storms just like estuaries along the oceanic coasts. These freshwater estuaries also provide many of the ecosystem services and functions that brackish estuaries do, such as serving as natural filters for runoff and providing nursery grounds for many species of birds, fish, and other animals.

Estuaries are among the most productive ecosystems in the world. Many animals rely on estuaries for food, places to breed, and migration stopovers. 

Estuaries are delicate ecosystems. Congress created the National Estuarine Research Reserve System to protect more than one million acres of estuarine land and water. These estuarine reserves provide essential habitat for wildlife, offer educational opportunities for students, and serve as living laboratories for scientists.   
http://oceanservice.noaa.gov/facts/estuary.html


NOTE:  Bays, estuaries, marshes stay healthy as long as streams/rivers provide intermittent flows and incoming water mixes purging excess nutrients often during storm events.  How to encourage aeration: oxygen in water is very beneficial to its overall health. The value to fish is obvious. Less obvious, but of great importance, is the ability of the marsh to get rid of waste. The waste that occurs includes “deposits” from its animal life - fish and geese, waste material that enter with storm water runoff, as well as plant and animals that die in the pond. Aerobic bacteria work about twenty times faster than anaerobic bacteria in breaking this waste down and putting it into solution. Once in solution it can be flushed out or is available to grow new life.
Oxygenation happens in two major ways: plants and algae do photosynthesis during the day and wind adds oxygen at night. The oxygen plants produce is released into the water and maintains high levels of oxygen;  oxygen exchange with the atmosphere at the surface of the water. The rougher the surface the more rapid the exchange. Also the more deficient the oxygen content of the water the faster the exchange occurs. This process is important at night and is critical for water with a heavy load of plants and animals. At night the plants do respiration instead of photosynthesis the same as the animals.

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