System Wide Monitoring Program
A primary focus of the NIWB NERR Research and Monitoring Program is participation in the National Estuarine Research Reserve’s System-Wide Monitoring Program (SWMP). SWMP is a national initiative among all NERRs, developed and initiated in 1995, that is designed to develop quantitative measurements of short-term variability and long-term changes in the water quality, biotic diversity, and land-use ⁄ land -cover characteristics of estuaries and estuarine ecosystems for the purposes of contributing to effective coastal zone management.
Long-term monitoring conducted within the national network of NERR sites is intended to improve our fundamental understanding of the temporal and spatial dynamics of estuarine ecological processes. It provides the baseline data necessary to evaluate changes in estuarine ecosystems in response to natural perturbations and anthropogenic disturbance. Continued operation of the long-term monitoring efforts within the NERRs network further provides valuable data for assessments and models on the cumulative effects of environmental stressors in estuarine ecosystems at the local, regional and national scales.
Current Components of SWMP
Monitoring Stations
The NIWB NERR has four long-term monitoring sites established as part of SWMP:
The Oyster Landing meteorological and water quality monitoring site is located near the western, upland edge of the North Inlet basin, at the confluence of two 1st order tidal creeks: the upper reaches of Crabhaul Creek and a much smaller un-named creek that directly drains pine forested uplands and wetlands. The sampling site is approximately 2.8 km from the terminus of Crabhaul Creek. The vegetation of the Crabhaul Creek sub-basin is dominated by Spartina alterniflora that transitions into salt pan, Juncus roemerianus and mixed vegetation communities along its upland edge. At the monitoring site the creek has an average depth of ≈ 2m at MHW and an average width of ≈ 150m at MHW. The average tidal range is ≈ 1.4 m. Salinity has ranged from 0-40, with a long-term average of 32.0. The creek bottom is comprised mostly of oyster shell hash with some fine sediment and detritus. The site is considered to represent relatively pristine conditions due to the absence of significant disturbance in its drainage area. Water quality, nutrient and chlorophyll monitoring was initiated at this site in 1993. Oyster Landing is also the site of a NOAA NOS tide gauge, established in 2001.
The Debidue Creek monitoring site is located in an ocean-dominated Spartina alterniflora marsh that forms the northern most drainage of the North Inlet basin. The monitoring site is approximately 1 km south of the DeBordieu Colony. The Colony is a large residential development, the only developed land presently in the watershed of North Inlet, which is built around wetlands, stormwater retention ponds and constructed canals that directly drain into the northern portion of Debidue Creek. The average tidal range is ≈ 2 m. Salinity has ranged from 0.8 to 38.9, with a long-term average of 32.3. The approximate depth and width of the creek at the monitoring location at MHW is 2.2 m and 70 m, respectively. The bottom is mostly comprised of oyster shell hash with some fine sediment and detritus. The site is considered impacted due to the presence of the development upstream. Water quality, nutrient and chlorophyll monitoring was initiated at this site in 1998.
The Clambank Creek monitoring site is located roughly in the center of the reserve boundary. This site is surrounded by a Spartina alterniflora marsh and does not drain a defined sub-basin of the North Inlet estuary (as is the case for Crabhaul and Debidue Creeks). It is predominantly influenced by oceanic waters due to its close proximity to North Inlet, but is occasionally influenced by water entering from Winyah Bay at the creek’s southern end. Salinity has ranged from 5.1 to 39.1, with a long-term average of 33.3. The bottom is mostly comprised of oyster shell hash and some fine sediment. Water quality, nutrient and chlorophyll monitoring was initiated at this site in 2001.
The Thousand Acre monitoring site is located ≈ 15 m from the mouth of creek that drains a tidal brackish marsh emptying into the northeastern side of the mid portion of Winyah Bay. The marsh, which is now dominated by brackish plants such as Spartina cynosuroides was formerly impounded for rice cultivation. Rice cultivation was abandoned prior to the Civil War. The upland drainage consists of undeveloped pine forest and forested wetlands. At the monitoring site, the creek depth is ≈ 2 m at MHW and creek width is ≈ 10 m. The average tidal range is ≈ 1 m. Salinity has ranged from 0 to 33.4, with a long-term average of 8.5. The bottom is mostly composed of fine sediments and detritus. The city of Georgetown, 5 km upstream from the Thousand Acre site and on the southern side of Winyah Bay, is the home to a number of heavy industries including a steel plant, paper mill, chemical plant, and a coal fired power plant. A public sewage treatment plant, which discharges into the bay, is also located in Georgetown. Water quality, nutrient and chlorophyll monitoring was initiated at this site in 1993.
