National Estuaries Day

Not all estuaries are created equal. Or at least there are different types of estuaries. Most scientists classify estuaries geomorphologically—that is, how were they formed and what is the end result of those geological processes. Most American estuaries are one of four types:

  • A coastal plain estuary, formed when the sea level rises into an existing river valley (Chesapeake Bay is a prime example, as are Tampa Bay and Galveston Bay);
  • A tectonic estuary is caused by folding and faulting of the earth (San Francisco Bay);
  • There’s the lagoon (or bar-built) estuary, where a shallow lagoon forms behind the shelter of a barrier island or sand bar (Albemarle Sound-Pamlico Bay is the largest lagoon estuary in the United States);
  • And then there are the “fjords,” deep u-shaped gashes formed by glaciers. Most of these are in Washington state and Alaska. Puget Sound is an outstanding example of a fjord estuary.

Viewer Tip: Whatever kind of estuary is near you, get out on the water this year! Restore America’s Estuaries will be celebrating National Estuaries Day on Saturday, September 24. This year’s theme is “Day on the Bay.’ Check our website—www.estuaries.org—for more information on National Estuaries Day activities and events.

This information is provided by Restore America’s Estuaries. Learn more at www.estuaries.org.

What Kind of Estuary?

 

Not all estuaries are created equal. Or at least there are different types of estuaries. Most scientists classify estuaries geomorphologically—that is, how were they formed and what is the end result of those geological processes. Most American estuaries are one of four types: A coastal plain estuary, formed when the sea level rises into an existing river valley (Chesapeake Bay is a prime example, as are Tampa Bay and Galveston Bay). A tectonic estuary is caused by folding and faulting of the earth (San Francisco Bay). There’s the lagoon (or bar-built) estuary, where a shallow lagoon forms behind the shelter of a barrier island or sand bar (Albemarle Sound-Pamlico Bay is the largest lagoon estuary in the United States). And then there are the “fjords,” deep u-shaped gashes formed by glaciers. Most of these are in Washington state and Alaska. Puget Sound is an outstanding example of a fjord estuary.

 

Viewer tip: Whatever kind of estuary is near you, get out on the water this summer! Restore America’s Estuaries will be celebrating National Estuaries Day on Saturday, September 24. This year’s theme is “Day on the Bay.’ Check our website—www.estuaries.org—later this summer for more information on National Estuaries Day activities and events.

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