Our Estuary

Many people have heard of or visited the slender ribbon of islands known as the Outer Banks. Unspoiled, sandy beaches summon a steady tide of visitors. Fishing villages, national park lands, and historical lighthouses lure millions of outdoor adventurers. Yet these islands comprise only the eastern edge of a much bigger coastal system with significant ecological connections. Behind the barrier islands are shallow, sprawling sounds, and beyond these waters are freshwater rivers and streams that shape the landscape. 

The entire watershed, or drainage area, of the Albemarle-Pamlico region includes approximately 28,000 square miles of northeastern North Carolina and southeastern Virginia. Nearly 10,000 miles of streams and rivers carve the landscape and pour into an incredibly productive 2-million-acre estuary that is the second largest estuary system in the country. The eastern boundary of the Albemarle-Pamlico region reaches from the southern portion of Virginia Beach to Bogue Inlet near the mouth of the White Oak River. The westernmost edge encompasses most of the Raleigh-Durham metropolitan area. Working according to the ecological boundaries of this watershed, instead of stopping our work at state lines, is part of what makes APNEP unique. The Albemarle-Pamlico estuary was designated as "an estuary of national significance" in 1987, and it continues to be recognized as a nationally important resource through its more recent listing as one of "America's Great Waters." Due to the mixing of nutrients from land and sea, estuaries produce more food per acre than even the richest farmland. Estuaries provide habitat for 75 percent of America's commercial fish catch and between 80 and 90 percent of America's recreational fishing catch. The overall region supports abundant plant and animal life, and is home to nearly 4 million people. It provides generous economic opportunities - farmers cultivate the soils, fishermen ply the waters, loggers harvest forests, and miners unearth minerals. The area also offers residents and visitors alike a wealth of outdoor recreation, from hiking and swimming to hunting, fishing, and boating.

What is an Estuary?

An estuary is a place where fresh water from rivers mixes with saltwater from the ocean. Estuaries are partially enclosed and thus protected from ocean waves and storm surges. The waters are an ideal environment for a rich assortment of fish and shellfish, while the margins of marshes, swamps, and wetlands attract a vast assortment of shorebirds and waterfowl. 

The Albemarle-Pamlico estuary is named for the expansive Pamlico Sound and the Albemarle Sound north of it, but it also includes five smaller sounds - Currituck, Croatan, Bogue, Core, and Roanoke. The sounds are shallow, relatively sheltered embayments that are fed by large volumes of fresh water from the rivers draining into them.

The Albemarle-Pamlico system is mostly enclosed by barrier islands, but small amounts of saltwater push in from the ocean through several inlets. As a result, these estuaries have relatively low salinity. The influence of lunar tides in the sounds is minimal because gaps between the barrier islands are few. Wind is the primary influence on movement and mixing of water. Salinity in the estuaries ranges from as low as 3 parts per thousand (ppt) in Currituck Sound to about 20 ppt in the portions of Pamlico Sound closest to inlets. By comparison, the salinity of seawater is 33 to 35 ppt.

Although estuary is the term given to the entire ecosystem, there are many different habitats and environments within it. These are wide-ranging, and include open waters, saltwater and freshwater marshes, forested swamp, oyster reefs, submerged seagrass beds and tidal flats. Estuarine habitats are defined by constant change - be it fluctuations in salinity, temperature, wind and wave action, or water levels.