7 Estuarine Sediment Dynamics

Sunday, 14 March 2010
10:25 AM - 12:05 PM
Hopkins

SEABED AND SHORELINE DYNAMICS OF THE ALBEMARLE-PAMLICO ESTUARINE SYSTEM

Paper number: 7-1
Program: Theme Sessions
Time: 10:25 AM – 10:45 AM

Authors

Abstract

Estuaries are critical habitats as well as places where people live, recreate, and make their livelihood. Additionally, they are sites where land and sea interact, and sediments, and associated pollutants and carbon, are deposited, remobilized and accumulated. Many processes, such as river discharge, waves, tides, and sea-level rise, are operating in estuaries to cause sediment dynamics, impacting humans and organisms as a result. Recent research we have been engaged in across the Albemarle-Pamlico Estuarine System (APES) has investigated the seabed and shoreline dynamics of this important estuary.

The APES is the second largest estuary in the continental United States, consisting of the Albemarle and Pamlico sounds and the Pamlico River and Neuse River sub-estuaries. Although expansive in size, the system is shallow with minimal tidal range. Water and sediment discharge into the APES is modest, and the existence of few inlets along the Outer Banks limits mixing with the Atlantic Ocean. Human impact on the drainage basin and estuarine system is moderate and increasing over time.

Over the last five years, a considerable volume of sedimentary process data has been collected over various timescales and locations in the APES. More specifically, work has included: deployments of instrumented tripods to examine seabed dynamics; collection and analysis of shallow cores and GIS investigation of aerial photographs and other data. This wealth of data highlights several insights: 1) shoreline change although variable is generally eroding at the average rate of ~0.25 m/y; 2) seabed erosion and deposition is inconsistent, but net accumulation of 2-4 mm/y is widespread; and 3) storm-wave activity and river sediment discharge are important to this shallow but large estuarine system.