NCCOS Project Explorer (NPE)

Assessments of Ecosystem Condition and Stressor Impacts at NERRs sites(2010)

Project Description:
Under its FY05-09 Strategic Plan (Goals 1.1, 1.2), NCCOS is directed to produce baseline assessments of ecological resources and to quantify impacts of ecosystem stressors in NOAA protected areas, including the National Estuarine Research Reserve System (NERRS). The NERRS is an especially important network of NOAA protected areas characterized by high ecological and societal value. An integrated system-wide approach for monitoring ecological condition of NERRS resources and potential threats from multiple stressors currently does not exist (except for water-quality parameters). The present effort is the initiation of a partnership with NERRS to develop approaches for characterizing the ecosystem condition and public-health status of NERRS sites and providing a framework for forecasting future condition of these important protected waters. This work is intended to complement system-wide water-quality monitoring (SWMP) and other site-specific research activities currently underway in the NERRS program. There are two components of the project: (1) a tidal creek study to develop a framework for evaluating impacts of land use and associated stressors on tidal creeks in the NERRS; and (2) a probabilistic monitoring component to assess the spatial extent of ecological condition throughout sub-tidal estuarine waters of NERRS sites, and to provide this information as a quantitative benchmark for tracking future changes due to either natural or human disturbances. Field work for both components was initiated in summer 2006. The tidal creek component is focusing on the Sapelo Island site in GA and Masonboro Island site in NC, and is being coordinated with results of prior/ongoing tidal creek work in SC. For each NERRS site, three creek networks were sampled, including ones in degraded to non-degraded watersheds. Up to three creek orders (portions of creek networks with similar environmental attributes) were randomly sampled within each network. The sub-tidal probabilistic component is focusing on the four NERRS locations in NC (Currituck Sound, Rachel Carson, Masonboro Island, and Zeke’s Island). Sampling was conducted at a total of 30 stations stratified by site location and the size of sub-tidal segments therein. For both components, stations were sampled for multiple indicators of ecological condition, including water quality (D0, salinity, temperature, pH, depth); chemical contaminants in sediments and biota (metals, PAHs, PCBs, pesticides, PBDEs and other emerging chemicals of concern); diversity and abundances of benthic fauna; sediment toxicity; and water-column nutrients/chlorophyll. Additional sampling of fish assemblages and human pathogens (fecal coliform and viral indicators) also was included in the tidal creek work. Hopefully, results of this initial pilot work will serve as a useful framework to consider for the implementation of systematic ecological monitoring across other reserves.

Expected Outcome:
There are two primary goals of this project: (1) To provide a framework for determining impacts of land use and associated stressors on tidal creeks in the NERRS; and (2) to initiate complementary assessments of the spatial extent of ecological condition of individual NERR sites, based on the status of various measured ecological indicators relative to desired management thresholds, and to provide this information as a quantitative benchmark for tracking any future changes due to either natural or human disturbances. This first goal is being addressed by evaluating the applicability of a preliminary hierarchical tidal-creek classification framework developed and tested recently in SC estuaries by NCCOS/HML scientists. This ongoing research suggests that creek networks are a major source of non-point source pollution inputs to shallow estuarine ecosystems and are the primary hydrologic link to land-based activities. The levels of microbial and chemical contamination in headwater creeks are frequently an order of magnitude greater than in adjacent deeper open waters. As a result of this prior work, a conceptual model of linkages between watersheds and estuarine condition also has been developed and verified for the two SC NERRS sites (ACE Basin, North Inlet/Winyah Bay). If this model can be validated for other reserves and regions, including freshwater environs and tidal ranges from micro- to deeper macro-tidal open waters, it may provide an invaluable conceptual framework for conducting system-wide interdisciplinary monitoring activities at NERRS and addressing related coastal management needs. The second goal listed above is being addressed with a stratified-random sampling design consisting of synoptic measurement of multiple ecological indicators, including stressor levels and measures of biological response, at a series of random probabilistic sampling stations within sub-tidal portions of the four NC NERRS sites. Such a probabilistic sampling framework is a powerful assessment tool in that it provides a basis for making unbiased statistical estimates of the spatial extent of a study area having degraded versus non-degraded condition, based on the status of the various measured ecological indicators relative to desired management thresholds. A similar approach is being applied in estuaries nationwide by EPA, NOAA, and partnering coastal States as part of the EMAP and related National Coastal Assessment (NCA) programs. Also, the incorporation of multiple ecological indicators provides a basis for evaluating relative contributions of various stressor sources to potential biological risks and identifying which may be the most problematic for a given reserve. Together, the two project components should provide a demonstration of the utility of two complementary assessment tools, one serving as a sentinel of environmental signals in areas of estuaries where signals are likely to occur, and the other providing a means for assessing the spatial extent of condition throughout a targeted resource category (e.g., sub-tidal estuarine waters of a reserve) and how the relative proportions of healthy vs. degraded areas may be changing with time. This pilot project is focusing on work in the NC and GA NERRS and builds upon earlier work in SC. If successful, a related outcome would be a prototype framework of such assessment strategies that could be applied systematically across other reserves to support national comparisons. The current effort involves four NCCOS Centers (HML, CCEHBR, CCMA, CCFHR) working in close collaboration with the NERRS program to address common research and coastal management goals. Results support NCCOS FY05-09 Strategic Plan Goals 1.1, 1.2 and 4.4. A Final Report is expected by March 2008.