Estuaries: Gateway to the Sea

Estuaries come in all shapes and sizes

October 5, 1998
Web posted at: 3:50 PM EDT

(ENN) -- October 3 was the 10th annual National Estuaries Day, and the theme was Gateways to our Oceans. You may not realize how important estuaries are to us -- or possibly even what exactly an estuary is and does. Here's what you need to know.

What are they?

Estuaries come in all shapes and sizes and go by many different names -- bays, marshes, swamps, lagoons, harbors, inlets, sounds or sloughs, depending on where you live. They are the meeting place of the river and the sea, are tidally-influenced and are protected from the full force of ocean waves, winds and storms by the reefs, barrier islands, or fingers of land, mud or sand that define an estuary's seaward boundary.

How important are they?

On a scale of one to ten, we're looking at a ten here. Estuaries are some of the most important and complex links in the Earth's entire ecosystem. What do they do?

• Nurseries of the sea --Estuaries are nursery grounds for two-third's of the fish and shellfish we eat and provide habitat, resting and feeding sites for tens of thousands of birds and other wildlife.

• Productivity -- A healthy, untended estuary produces from four to ten times the weight of organic matter produced by a cultivated corn field of the same size.

• Water filtration -- Estuaries provide important water filtration services. Water draining from the land into the river carries a load of sediments and nutrients. As the water flows through salt marsh peat and the dense mesh of marsh grass blades, much of the sediment and nutrient load is filtered out, creating cleaner and clearer water.

• Flood control -- Porous, resilient salt marsh soils and grasses absorb flood waters and dissipate storm surges. Salt marsh dominated estuaries provide natural buffers between the land and the ocean. They also protect billions of dollars of real estate.

How have we treated them?

Badly. Long considered junk land, they've been dredged, filled, built on and generally mistreated. They continue to be threatened by urban growth and development, nutrient over-enrichment and habitat loss.

Random factoids

Nearly 50 percent of Americans live in coastal areas, and approximately 180 million tourists travel to these communities each year. By the year 2010, it is estimated that the coastal population will increase to 127 million.

The average American spends 10 recreational days on the coast each year. Americans annually spend about $75 billion on coastal recreational activities each year.

Who's watching out for them?

Estuaries are the focus of two government programs; the National Oceanic and Atmospheric Administration's National Estuarine Research Reserve system, and the Environmental Protection Agency's National Estuary Program. Together the two programs include over 50 estuaries that have been specially designated by the federal government to protect living resources, improve water quality, restore estuarine habitats, and provide opportunities for research, education, and public use.

The celebration

Narragansett Bay, R.I., will serve as the site for a national celebration.

A new reserve will be dedicated at Kachemak Bay, Alaska on Oct. 3. The reserve was developed with nearly $500,000 from the criminal settlement of the Exxon Valdez oil spill.

For information about activities in your neighborhood, call EPA's Coastal Management Branch, (202)260-6502 or visit one of the web sites below.