September Habitat Highlight: Estuaries

In September we will be exploring Estuaries – the somewhat enclosed water bodies where rivers and streams meet the ocean!





Estuaries consist of nutrient-rich freshwater blending into saltwater. This blend gives a rich environment of nutrients for the marine-life within the estuary to thrive. In fact, according to the Environmental Protection Agency (EPA), estuaries create more organic matter each year than similar sized areas of grassland, forests, or even agricultural land.


Estuaries tend to be calm bodies of water, so they provide safety for a large variety of wildlife as mentioned. This variety includes shellfish, shore animals and migrating birds.







There are four common types of estuaries which all arise in different ways. Coastal plain estuaries arise when rising sea levels in a particular area begin to fill in an existing river valley.

Tectonic estuaries are formed by the shifting and drifting (tectonic) mechanisms taking place in Earth’s crust.

Bar-built estuaries are formed by a sand bar or barrier island which close off a lagoon or bay from the ocean.

And finally, Fjord estuaries are caused by valleys created by glaciers, and the subsequent ocean flooding into these valleys.





{Written by Orla Troup}