National Estuarine Research Reserve System Research Articles

Using Podcasts to Bring National Estuarine Research Reserves into the Classroom

In secondary and undergraduate classroom settings, there are significant challenges to exposing students to concepts related to Earth sciences and the environment. These challenges are exacerbated when conveying lessons about geographic areas with limited access, such as the ocean and coastlines. It is now more important than ever for environmental education to improve and adapt to our changing world. Educators may have the opportunity to bring these subjects to life by using media content such as podcasts to introduce students to new places and the scientists, managers, and educators who work in those spaces. Although education and public information sharing are part of the mission of the National Estuarine Research Reserve System (NERRS), there are few pathways for bringing reserves and the research, monitoring, and conservation associated with them into schools that are distant from NERRS sites. To address this educational gap, an instructor survey was conducted, and 43 responses were analyzed to identify best practices for secondary school and higher education lesson formats and assessment strategies. Based on this feedback, an introductory podcast series called “NERR or Far: The Reserves Are Where You Are” was created. This educational series is designed to increase access to regional conservation information and foster stewardship of our coastal resources.

Bivalve Shellfish Aquaculture in the National Estuarine Research Reserves: Assessing Current Activities, Relevant Policy, and Engagement Approaches

Expansion of shellfish aquaculture in the U.S. is currently being promoted for its demonstrated potential as an environmentally friendly and sustainable food production system. The National Estuarine Research Reserve System (NERRS), through its network of protected estuarine sites and research, education, and interpretation mandates, may provide an effective means for enhancing public awareness and management of shellfish aquaculture within the nation’s estuarine areas. However, the NERRS’s role regarding the presence of aquaculture within Reserve boundaries, for research or non-research purposes, is not broadly understood by NERRS stakeholders. The goals of this study were to broadly review and highlight the current activities, regulatory framework, and engagement approaches to aquaculture within the NERRS, and more specifically, to focus on the suitability and role(s) the NERRS may choose to seek or strengthen with respect to shellfish aquaculture. To accomplish this, a survey questionnaire was disseminated within the NERRS community. Twelve of the 29 Reserves within the NERRS held some type of aquaculture activity, while 17 Reserves believed their Reserve was suitable or potentially suitable for shellfish aquaculture. Reserve suitability was driven by a range of factors, including: water quality, NERRS regulations, character of Reserve land-managing entities, scope of protected areas, and preexisting or historical shellfish aquaculture and/or wild harvest activities. Overall, the Reserves’ approach to shellfish aquaculture was locally focused, but with patterns that reflected a regional influence. Additionally, Reserves displayed key roles as coordinating entities and a trusted source of science. Particularly with establishing commercial aquaculture, it is critical to couple the goals of an aquaculture activity with the net positive and negative impacts to a specific geographic area. We recommend that the NERRS would benefit from developing best management practices for approaching shellfish aquaculture within Reserve boundaries, and educating and engaging with shellfish aquaculture stakeholders. One approach might be to develop a decision-support model for approaching and allowing each use of aquaculture (research, restoration, conservation, recreation, and commercial), in collaboration with regulatory agencies and other stakeholders.

Graduate fellowships for the National Estuarine Research Reserve System (DOC)

Graduate fellowships for the National Estuarine Research Reserve System (DOC)

Economic Contribution Analysis of National Estuarine Research Reserves

Increased attention to the value of protected natural areas has led to the proliferation of ecosystem service valuations for coastal habitats. However, these studies do not provide a full representation of the economic value of these habitats. Protected coastal environments, such as the National Estuarine Research Reserve System (NERRS), add jobs and revenue to their local communities. Institutions such as NERRS provide economic contributions that extend beyond their operational spending and jobs they provide. Spending by reserves and their partners ripples throughout the economy. We performed an economic contribution analysis at four pilot sites using input-output modeling through IMPLAN. Sites contributed millions in revenue and tens to hundreds of jobs in their respective regions. Each of the four sites had a different category of spending that was the largest contributor of revenue and jobs, which is likely due to the community context and location of the reserves. Understanding these contributions is helpful in validating funding for NERRS. Communicating these contributions along with ecosystem service values may increase support from community members who otherwise do not use or rely on NERRS as much as traditional reserve supporters.

Co-producing science for sustainability: Can funding change knowledge use?

There is widespread belief that meaningful interaction between scientists and practitioners, or co-production, increases use of scientific knowledge about sustainability and environmental change. Although funders are increasingly encouraging co-production, there have been few empirical studies assessing the outcomes of these efforts in shaping knowledge use. In this study, we systematically analyze research project reports (n = 120) and interview project participants (n = 40) funded by the U.S. National Estuarine Research Reserve System from 1998 to 2014 to support coastal management. Our analysis shows that escalating funding requirements for collaboration with users change research practice and strengthen connections between research outcomes and knowledge use. In consequence, a new model for science funding emerges, where sponsor, researcher, and user are more interactive with one another.

Who Benefits from National Estuaries? Applying the FEGS Classification System to Identify Ecosystem Services and their Beneficiaries.

In spite of their perceived value, the widespread implementation of ecosystem services assessments has been limited because of perceptions of being too technical, too expensive, or requiring special expertise. For example, federal estuary management programs have widely used ecosystem services concepts to frame management issues and communicate with stakeholders. Yet, indicators assessed, monitored, and reported in estuarine management still have traditionally focused on ecological conditions, with weak connections, if any, to social or economic outcomes. Approaches are needed which expand the range of ecosystem services that can be considered, link ecosystem services explicitly to different stakeholder groups, facilitate effective communication with economists and other social scientists, and expand the array of available valuation techniques. We applied the concept of final ecosystem goods and services to review the broad suite of ecosystem services and their beneficiaries relevant to the management of two federal programs for estuary management, the National Estuary Program (NEP) and the National Estuarine Research Reserve System (NERRS). The Final Ecosystem Goods and Services Classification System provided a structured framework for connecting ecosystem services to their beneficiaries and the environments providing them. Document analysis of management plans assessed the degree to which these programs consider ecosystem services, their beneficiaries, and habitats within the estuarine watershed. The hierarchical list of final ecosystem goods and services generated from document analysis serves as a tool for defining management goals, identifying stakeholders, developing meaningful indicators, and conducting valuation studies in estuarine management planning efforts. Though developed here for estuarine management, the keyword hierarchy and final ecosystem goods and services approach have broad applicability and transferability to other environmental management scenarios.

Advancing Knowledge for Use in Coastal and Estuarine Management: Competitive Research in the National Estuarine Research Reserve System

Decades of research has generated new scientific understanding and technologies aimed at better managing environmental change in estuarine and coastal regions. Yet many across the communities of coastal and estuarine research, management, and funding believe that progress has been too slow in applying this research in practice. This essay reviews how the National Estuarine Research Reserve System’s funding program evolved over the past two decades to improve how researchers and users of research work together to increase the uptake of science to achieve resource management and conservation goals. Incremental innovation in the design of the NERRS funding program enabled more intensive and multiway engagement between funders, researchers, and users, which created new pathways for applying science in practice. Furthermore, these interactions stimulate reflection and adaptation within each separate institutional setting, supporting changes that may science to better support environmental problem solving.

The National Estuarine Research Reserve System: A Review of Research and Monitoring Initiatives

The National Estuarine Research Reserve System (NERRS) is an integrated network of 29 protected and coordinated estuarine reserve sites in 23 states and one territory (Puerto Rico) covering more than 525,000 ha of estuarine habitat, adjoining wetlands, and uplands that encompass 19 biogeographical regions along the Atlantic, Gulf of Mexico, and Pacific coasts, as well as the Caribbean Sea and Great Lakes. NERRS is an ecosystem-based research and monitoring network of sites serving as platforms to develop quantitative databases of value to coastal management programs in identifying and tracking short-term variability and long-term changes in the integrity and biodiversity of estuarine systems nationwide due to natural perturbations and anthropogenic disturbances. The reserve sites also play a vital role in assessing coastal issues of local, regional, and national significance for the purpose of sustaining estuarine systems and coastal lands, such as evaluating their responses to climate change and other major stressors to inform coastal decision-making and public awareness for the protection and resilience of natural resources and coastal communities. Over the past four decades, NERRS sites have collected large volumes of research and monitoring data of great utility in characterizing estuarine environments and addressing an array of resource-management concerns, including degraded water quality, loss and alteration of essential habitat, impacted fisheries, invasive species, and conservation.

Quantifying Metabolically Driven pH and Oxygen Fluctuations in US Nearshore Habitats at Diel to Interannual Time Scales

We compiled and examined 15 years (2002–2016) of high-frequency monitoring data from the National Estuarine Research Reserve System (NERRS) to characterize diel to interannual variability of pH and dissolved oxygen (DO, % saturation) across 16 diverse, shallow-water habitats along the US Atlantic, Gulf of Mexico, Caribbean, and Pacific coasts. We asked whether these systems exhibit a common pH/DO relationship, whether there were detectable interannual trends in temperature, pH, and DO within and across systems, and how pH/DO dynamics would relate to measured levels of nutrients and chlorophyll. Our analyses confirmed that large, metabolically driven, and thus concurrent fluctuations of pH and DO are a unifying feature of nearshore habitats. Moreover, we derived well-constrained relationships that predict (i) monthly mean pH or (ii) mean diel pH fluctuations across systems based on habitat mean salinity and (i) mean DO or (ii) mean diel DO fluctuations. This suggests that common metabolic principles drive diel to seasonal pH/DO variations within as well as across a diversity of estuarine environments. Yearly pH and DO anomalies did not show monotonous trends over the study period and differed considerably between sites and regions. However, weekly anomalies of means, diel minima, and diel ranges of pH and DO changed significantly over time and were strongly correlated to temperature anomalies. These general patterns lend strong empirical support to the notion that coastal acidification—in addition to being driven by eutrophication and atmospheric CO2 increases—is exacerbated simply by warming, likely via increasing community respiration. Nutrient and chlorophyll dynamics were inversely related in these shallow, well-mixed systems, but higher nutrient levels were still associated with lower pH and lower DO levels in most, but not all, systems. Our analyses emphasize the particular dynamics of nearshore habitats and the critical importance of NERRS and its system-wide monitoring program.

Evaluating Tidal Wetland Restoration Performance Using National Estuarine Research Reserve System Reference Sites and the Restoration Performance Index (RPI)

Evaluations of tidal wetland restoration efforts suffer from a lack of appropriate reference sites and standardized methods among projects. To help address these issues, the National Estuarine Research Reserve System (NERRS) and the NOAA Restoration Center engaged in a partnership to monitor ecological responses and evaluate 17 tidal wetland restoration projects associated with five reserves. The goals of this study were to (1) determine the level of restoration achieved at each project using the restoration performance index (RPI), which compares change in parameters over time between reference and restoration sites, (2) compare hydrologic and excavation restoration projects using the RPI, (3) identify key indicator parameters for assessing restoration effectiveness, and (4) evaluate the value of the NERRS as reference sites for local restoration projects. We found that the RPI, modified for this study, was an effective tool for evaluating relative differences in restoration performance; most projects achieved an intermediate level of restoration from 2008 to 2010, and two sites became very similar to their paired reference sites, indicating that the restoration efforts were highly effective. There were no differences in RPI scores between hydrologic and excavation restoration project types. Two abiotic parameters (marsh platform elevation and groundwater level) were significantly correlated with vegetation community structure and thus can potentially influence restoration performance. Our results highlight the value of the NERRS as reference sites for assessing tidal wetland restoration projects and provide improved guidance for scientists and restoration practitioners by highlighting the RPI as a trajectory analysis tool and identifying key monitoring parameters.

Density-dependent role of an invasive marsh grass, Phragmites australis, on ecosystem service provision.

Invasive species can positively, neutrally, or negatively affect the provision of ecosystem services. The direction and magnitude of this effect can be a function of the invaders’ density and the service(s) of interest. We assessed the density-dependent effect of an invasive marsh grass, Phragmites australis, on three ecosystem services (plant diversity and community structure, shoreline stabilization, and carbon storage) in two oligohaline marshes within the North Carolina Coastal Reserve and National Estuarine Research Reserve System (NCNERR), USA. Plant species richness was equivalent among low, medium and high Phragmites density plots, and overall plant community composition did not vary significantly by Phragmites density. Shoreline change was most negative (landward retreat) where Phragmites density was highest (-0.40 ± 0.19 m yr-1 vs. -0.31 ± 0.10 for low density Phragmites) in the high energy marsh of Kitty Hawk Woods Reserve and most positive (soundward advance) where Phragmites density was highest (0.19 ± 0.05 m yr-1 vs. 0.12 ± 0.07 for low density Phragmites) in the lower energy marsh of Currituck Banks Reserve, although there was no significant effect of Phragmites density on shoreline change. In Currituck Banks, mean soil carbon content was approximately equivalent in cores extracted from low and high Phragmites density plots (23.23 ± 2.0 kg C m-3 vs. 22.81 ± 3.8). In Kitty Hawk Woods, mean soil carbon content was greater in low Phragmites density plots (36.63 ± 10.22 kg C m-3) than those with medium (13.99 ± 1.23 kg C m-3) or high density (21.61 ± 4.53 kg C m-3), but differences were not significant. These findings suggest an overall neutral density-dependent effect of Phragmites on three ecosystem services within two oligohaline marshes in different environmental settings within a protected reserve system. Moreover, the conceptual framework of this study can broadly inform an ecosystem services-based approach to invasive species management.

Improving estimates of ecosystem metabolism by reducing effects of tidal advection on dissolved oxygen time series

AbstractIn aquatic systems, time series of dissolved oxygen (DO) have been used to compute estimates of ecosystem metabolism. Central to this open‐water method is the assumption that the DO time series is a Lagrangian specification of the flow field. However, most DO time series are collected at fixed locations, such that changes in DO are assumed to reflect metabolism and that effects of advection or mixing are negligible. A weighted regression model was applied to remove variability in DO time series from tides, thereby helping to partially relax this assumption and improve metabolism estimates. The method offers a distinct advantage over traditional deconvulution methods by targeting the periodicity of the tidal component while preserving the true biological signal. The model was first applied to simulated DO time series with specified biological and physical characteristics, and then applied to 1 yr of continuous monitoring data from four stations within the National Estuarine Research Reserve System. The correlation of DO and metabolism estimates with tides was greatly reduced after using weighted regression. The model was especially effective when the magnitude of tidal influence was high and correlations between tidal change and the solar cycle were low at the time scales of interest. The model was less robust when tides and the solar cycle were correlated for protracted periods. By reducing the effects of physical transport on metabolism estimates, there may be increased potential to empirically relate metabolic rates to causal factors on timescales of several days to several weeks.

A spatial assessment of baseline nutrient and water quality values in the Ashepoo–Combahee–Edisto (ACE) Basin, South Carolina, USA

The Ashepoo–Combahee–Edisto (ACE) Basin (South Carolina, USA) National Estuarine Research Reserve System (NERRS) encompasses some of the least developed USA coastline. Yet, periodic sampling showed that certain regions have higher nutrient, fecal coliform, and chlorophyll a levels, often with lower dissolved oxygen, than other South Carolina estuaries. To evaluate the spatial extent of these issues, a summer (2008) baseline study was conducted. Physical water quality, total nitrogen and phosphorus, chlorophyll a, dissolved organic carbon, and suspended solids were measured from surface waters of 67 stations (30 tidal creek, 37 open water). Nutrient and chlorophyll a levels were significantly (p<0.01) and negatively correlated with the extent of open water (% land cover), and chlorophyll a and nitrogen levels were, at times, elevated relative to concentrations typical of other estuaries in the state, reinforcing previous findings. This survey also identified several creeks not previously monitored that exhibited elevated nutrients.

An integrated assessment of habitat quality of national estuarine research reserves in the southeastern United States.

Multiple indicators of water quality, sediment quality, and biological condition were used to assess the status of ecological condition of National Estuarine Research Reserve System (NERRS) sites in North Carolina, South Carolina, and Georgia relative to a suite of corresponding scoring criteria. All measurements were made in subtidal aquatic habitats. Calculated scores were integrated into an overall index of habitat quality and used to make comparisons among the various NERR and nonNERR estuaries throughout the region. Sediment quality scores varied considerably among NERR sites, but in most cases were similar between individual NERR and non-NERR sites in corresponding states. Water quality and biological condition indicators scored consistently higher for NERRs versus non-NERR sites. Overall habitat quality scores also were consistently higher for NERRS sites, suggesting that these areas are on par with if not in slightly better condition ecologically than neighboring nonNERR estuaries. Portions of individual NERR sites rated as poor with respect to overall habitat quality were limited to relatively small areas (<13% of a reserve's total sampling area).

Seasonal and Inter-annual Patterns in Primary Production, Respiration, and Net Ecosystem Metabolism in Three Estuaries in the Northeast Gulf of Mexico

Measurements of primary production and respiration provide fundamental information about the trophic status of aquatic ecosystems, yet such measurements are logistically difficult and expensive to sustain as part of long-term monitoring programs. However, ecosystem metabolism parameters can be inferred from high frequency water quality data collections using autonomous logging instruments. For this study, we analyzed such time series datasets from three Gulf of Mexico estuaries: Grand Bay, MS; Weeks Bay, AL; and Apalachicola Bay, FL. Data were acquired from NOAA's National Estuarine Research Reserve System Wide Monitoring Program and used to calculate gross primary production (GPP), ecosystem respiration (ER), and net ecosystem metabolism (NEM) using Odum's open water method. The three systems represent a diversity of estuaries typical of the Gulf of Mexico region, varying by as much as two orders of magnitude in key physical characteristics, such as estuarine area, watershed area, freshwater flow, and nutrient loading. In all three systems, GPP and ER displayed strong seasonality, peaking in summer and being lowest during winter. Peak rates of GPP and ER exceeded 200 mmol O2 m−2 day−1 in all three estuaries. To our knowledge, this is the first study examining long-term trends in rates of GPP, ER, and NEM in estuaries. Variability in metabolism tended to be small among sites within each estuary. Nitrogen loading was highest in Weeks Bay, almost two times greater than that in Apalachicola Bay and 35 times greater than to Grand Bay. These differences in nitrogen loading were reflected in average annual GPP rates, which ranged from 825 g C m−2 year−1 in Weeks Bay to 401 g C m−2 year−1 for Apalachicola Bay and 377 g C m−2 year−1 in Grand Bay. Despite the strong inter-annual patterns in freshwater flow and salinity, variability in metabolic rates was low, perhaps reflecting shifts in the relative importance of benthic and phytoplankton productivity, during different flow regimes. The advantage of the open water method is that it uses readily available and cost-effective sonde monitoring technology to estimate these fundamental estuarine processes, thus providing a potential means for examining long-term trends in net carbon balance. It also provides a historical benchmark for comparison to ongoing and future monitoring focused on documenting the effect of human activities on the coastal zone.

Barriers and Opportunities for Integrating Social Science into Natural Resource Management: Lessons from National Estuarine Research Reserves

The need for cross-disciplinary scientific inquiries that facilitate improved natural resource management outcomes through increased understanding of both the biophysical and human dimensions of management issues has been widely recognized. Despite this broad recognition, a number of obstacles and barriers still sometimes challenge the successful implementation of cross-disciplinary approaches. Improving understanding of these challenges and barriers will help address them and thereby foster appropriate and effective utilization of cross-disciplinary approaches to solve natural resource management challenges. This research uses a case study analysis of the United States National Estuarine Research Reserve System to improve understanding of the critical factors that influence practitioners' decisions related to incorporating social science into their natural resource management work. The case study research is analyzed and evaluated within a Theory of Planned Behavior framework to (1) determine and describe the factors that predict practitioners' intent to incorporate social science into their natural resource related activities and (2) recommend potential strategies for encouraging and enabling cross-disciplinary approaches to natural resource management. The results indicate that National Estuarine Research Reserve practitioners' decisions related to incorporating social science are primarily influenced by (1) confidence in their own capability to incorporate social science into their work and (2) beliefs about whether the outcomes of incorporating social science into their work would be valuable or beneficial.

Research and Monitoring Components of the National Estuarine Research Reserve System

The National Estuarine Research Reserve System (NERRS) consists of an integrated network of 27 reserve sites in 19 biogeographical subregions. These estuarine reserves are protected sites where comprehensive databases are compiled to characterize the natural and anthropogenic processes governing ecosystem stability and change. Data collected by research and monitoring programs of the NERRS provide the foundation for sound coastal management decision-making. Three principal areas of research and monitoring are targeted by the NERRS: (1) abiotic factors, including meteorological, water quality, and physical conditions; (2) biotic features, including both flora and fauna; and (3) land use and habitat change characterizations. Baseline conditions and trends in physical, chemical, and biological parameters are vital for evaluating changes that occur in response to various environmental stressors and long-term climate change throughout the network of estuarine ecosystems. The NERRS is a particularly effective program because its research and monitoring activities occur in all geographical regions of the United States and almost every recognized climatic zone. Because of the geographic expanse of the NERRS and its intensive and extensive research and monitoring initiatives, an ideal platform exists to characterize both the short-term variability and long-term changes in estuarine systems nationwide and to make these results available to support informed decision-making and increased public awareness of coastal systems.

Concurrent Assessment of Eelgrass Beds (Zostera marina) and Salt Marsh Communities along the Estuarine Gradient of the South Slough, Oregon

Abstract Salt marshes, eelgrass beds (Zostera marina), and benthic macroalgae frequently occur in close proximity along the steep tidal channels of Pacific Northwest estuaries, where they constitute distinct patches of transitional land-margin habitat. The eelgrass beds and adjacent salt marshes within the South Slough National Estuarine Research Reserve, Oregon, provide an opportunity to investigate commonalities and differences between two ecological-indicator communities that are often separated by only a few meters. The principal objectives of this study are to establish a series of adjacent eelgrass and salt marsh assessment and monitoring sites within different hydrographic regions of the South Slough estuary and to characterize initial temporal and spatial changes in the composition of the plant communities in accordance with new field protocols developed by the National Estuarine Research Reserve System (NERRS) and by SeagrassNet. Eelgrass beds and emergent salt marsh communities were sampled at t...

Temperature, Salinity, Nutrients, and the Covariation of Bacterial Production and Chlorophyll-ain Estuarine Ecosystems

Abstract The National Estuarine Research Reserve System represents a diverse collection of ecosystems among which environmental conditions differ dramatically, making it inherently difficult to determine the extent to which patterns and properties identified in one estuary are transferable to those of any other. The primary objective of our study was to develop a multivariate classification framework for comparison of these estuaries and identify the primary sources of environmental variability in each. Using a 4-year dataset from the National Estuarine Research Reserve System-Wide Monitoring Program, combined with principal components analysis, we identified distinct patterns among 21 reserves that allowed grouping based on the primary factors shaping physicochemical variability. Salinity and temperature were the primary factors shaping variability in the reserves, an observation that was corroborated by similar multivariate analysis of data from 33 published studies of non–National Estuarine Research Re...

Land Cover Change within the Grand Bay National Estuarine Research Reserve: 1974–2001

Estuarine water bodies provide a land to sea (freshwater to saltwater) transition zone. Protected from the full force of waves, winds, and storms by topographic features, e.g., reefs and barrier islands, estuaries provide habitats for countless numbers of plant and animal species. An estuary's wetlands, including salt marshes, naturally improve water quality by acting as filters. Thus, there are societal benefits to preserving estuaries. The U.S. government, in fact, passed the Coastal Zone Management Act of 1972, creating the National Estuarine Research Reserve (NERR) System. The present study documents temporal land cover change occurring during the period 1974–2001 within the Grand Bay National Estuarine Research Reserve (GBNERR)—the 24th NERR, designated in 1999. Occupying an area of 7284 hectares, it is one of the largest relatively undisturbed estuarine marsh–pine savanna habitats remaining on the northern coast of the Gulf of Mexico. Results were obtained by applying both unsupervised classification and change detection techniques to data derived from Landsat satellite imagery acquired in 1974, 1991, and 2001, respectively. Land cover classes included open water, herbaceous wetland, forest, and barren land. For change detection analysis, change matrices were derived from postclassified pairs of successive image dates, yielding two change matrices. A map of overall cover change between 1974 and 2001 was also produced. Submersion of wetlands by water, attributed to a combination of factors, including rising sea levels, land subsidence, and historical geomorphologic changes that increased wave action and decreased sedimentation, caused a majority of the observed changes. Such a broad land cover analysis provides resource managers with information regarding the estuary's land cover types and spatial distributions, allowing for more informed decisions with regard to preserving biodiversity and planning restoration efforts.