NPS photo / SECN staff
NPS photo / SECN staff
Overview
Cumberland Island is the largest barrier island along Georgia’s coast, measuring 28.2 kilometers (17.5 miles) long and between 0.8–9.7 kilometers (0.5–6.0 miles) wide. The island is 6.4 kilometers (4 miles) east of St. Marys, Camden County, Georgia. The boundary of the National Seashore is 14,709 hectares (36,347 acres) and includes the main Cumberland Island, Little Cumberland Island to the north, and Drum Point Island in Cumberland River; over half of this area is owned and managed by the National Park Service. The majority of the island was formed during the Pleistocene (50,000 to 5,000 years ago) and is part of a chain of barrier islands along Georgia’s coast known as the Silver Bluff formation. Conversely, the eastern edge, southern tip, and Little Cumberland Island were formed during the Holocene (5,000 years ago to present). Elevation ranges on Cumberland Island are from sea level to over 15 meters (50 feet) on the northwestern corner of the island (Terrapin Point) and 12 meters (40 feet) within the central portion of the island. Relatively little of the island is developed, despite a history of human habitation dating back hundreds of years.
The Southeast Coast Network conducts the following monitoring at Cumberland Island National Seashore:
- Water-quality monitoring is conducted in the estuarine waters near Cumberland Island National Seashore. To effectively monitor a diverse and dynamic set of estuarine water resources, the network implements a two-pronged monitoring approach consisting of a fixed-monitoring stations and parkwide assessments. This gives a more complete picture of physical processes, diurnal and seasonal variations, and spatial patterns during critical portions of the year. The fixed station, located at the Sea Camp ferry dock, is equipped with a sonde that measures depth, dissolved oxygen, pH, salinity, turbidity, and water temperature every 30 minutes. In addition, monthly samples are collected to evaluate nutrient levels and water clarity. These data help determine if there are excess nutrients in the estuary that are harmful to fish, oysters, and other animals. Water-quality data from the sonde are available on the Aquarius web portal and nutrient data are available from the Water Quality Portal. Parkwide water quality assessments are conducted every five years at 30 randomly selected estuarine sites and evaluate the same parameters monitored at fixed stations. In addition, sediment samples are collected every ten years and analyzed for metals and organic contaminates. Water-quality monitoring at Cumberland Island National Seashore has been ongoing since 2005.
- Coastal shoreline change monitoring is conducted on an annual basis and frequently after major storm events. Change in shoreline position drives the alteration and replacement of established natural habitats, and shoreline retreat may destroy cultural resources, facilities, and other infrastructure. Shoreline monitoring has been ongoing at Cumberland Island National Seashore since 2017 and an open-data geo package containing all shoreline data collected by the Southeast Coast Network from 2017–2023 has been recently published.
- Salt marsh elevation monitoring sites are surveyed twice annually during spring and fall. Salt marshes and coastal wetlands habitats host a wide diversity of wildlife and are important to many aquatic species but are threatened by sea-level rise. The marshes must grow at a rate equal to or greater than the rate of sea level rise, or they will eventually disappear. The network measures salt marsh elevation and investigates the rate of accretion or subsidence (growth or reduction) in these areas. Salt marsh elevation monitoring at Cumberland Island National Seashore has been ongoing since 2015 and a cumulative data package was recently updated and published. This data package includes data from 1998 through 2024 and includes data for five I&M networks.
- Landbird community monitoring and Vocal anuran community monitoring is conducted on a rotating schedule every three years. These wildlife communities play critical roles in park ecosystems and interact with several trophic levels of food webs. The network uses automated recording devices (ARDs) to collect vocalization data during mornings and evenings in the spring, which are analyzed by bioacoustics specialists. Data collected from these vital sign monitoring efforts help assess the ecological integrity and diversity of park areas and how communities and park conditions may change over time. The landbird and vocal anuran monitoring efforts in network parks began in 2012.
- Vegetation community monitoring is conducted on a rotating schedule. Monitoring vegetation is important because it’s key indicator of overall ecosystem health. Changes in vegetation reflect the effects of stressors like extreme weather, disease, invasive species, fire, and land use change. Plant communities also provide structured habitat and food resources for other species. Vegetation monitoring data provides managers with information about the degree of change in their park’s natural communities. Vegetation plots have been established across the following habitats: Coastal Plain Upland Open Woodlands, Maritime Open Upland Grasslands, Maritime Upland Forests and Shrublands, Tidal Wetlands, and Non-tidal Wetlands. Data reports include information about new occurrences and rare plants, species richness and abundance, tree health and regeneration, disturbance observations, soil nutrients, landform/geomorphology, and downed woody debris.
| Vital Sign | Examples of Measurement |
|---|---|
| Estuarine Water Quality | pH, temperature, dissolved oxygen, conductivity |
| Terrestrial Vegetation Communities | Plant community diversity, relative species/guild abundance, structure/age class, incidence of disease |
| Landbird and Vocal Anuran Communities | Species occurrence, distribution |
| Salt Marsh Elevation | Magnitude, rate and within-site variability of surface elevation, sediment accretion or erosion, different drivers |
| Shoreline Change | Net shoreline movement and end-point rate |
Source: Data Store Collection 9580. To search for additional information, visit the Data Store.
Source: Data Store Collection 3965 (results presented are a subset). To search for additional information, visit the Data Store.
Source: Data Store Collection 3967 (results presented are a subset). To search for additional information, visit the Data Store.
Source: Data Store Collection 3966 (results presented are a subset). To search for additional information, visit the Data Store.
Source: Data Store Collection 3970 (results presented are a subset). To search for additional information, visit the Data Store.
Source: Data Store Collection 3969 (results presented are a subset). To search for additional information, visit the Data Store.
Source: Data Store Collection 3968 (results presented are a subset). To search for additional information, visit the Data Store.
Last updated: November 11, 2024