Continued large-scale public investment in declining ecosystems depends on demonstrations of “success”. While the public conception of “success” often focuses on restoration to a pre-disturbance condition, the scientific community is more likely to measure success in terms of improved ecosystem health. Using a combination of literature review, workshops and expert solicitation we propose a generalized framework to improve ecosystem health in highly altered river basins by reducing ecosystem stressors, enhancing ecosystem processes and increasing ecosystem resilience. We illustrate the use of this framework in the Mississippi-Atchafalaya River Basin (MARB) of the central United States (U.S.), by (i) identifying key stressors related to human activities, and (ii) creating a conceptual ecosystem model relating those stressors to effects on ecosystem structure and processes. As a result of our analysis, we identify a set of landscape-level indicators of ecosystem health, emphasizing leading indicators of stressor removal (e.g., reduced anthropogenic nutrient inputs), increased ecosystem function (e.g., increased water storage in the landscape) and increased resilience (e.g., changes in the percentage of perennial vegetative cover). We suggest that by including these indicators, along with lagging indicators such as direct measurements of water quality, stakeholders will be better able to assess the effectiveness of management actions. For example, if both leading and lagging indicators show improvement over time, then management actions are on track to attain desired ecosystem condition. If, however, leading indicators are not improving or even declining, then fundamental challenges to ecosystem health remain to be addressed and failure to address these will ultimately lead to declines in lagging indicators such as water quality. Although our model and indicators are specific to the MARB, we believe that the generalized framework and the process of model and indicator development will be valuable in an array of altered river basins.

Like pine trees bending in a strong wind or a river meandering over the landscape, the most energy-efficient way to deal with physical opposition may be to shift in shape or position. It is by this manner of response to physical stress, seeking the path of least resistance while still advancing, that flowing water exemplifies the concept of ecological resilience. Here, we discuss the Lower Mississippi River ecosystem (LMRS) with respect to relationships of its hydrology and floodplain to ecological resilience and ecosystem services. Following an introduction to basic features, we look backwards to when the river could still meander freely and flood expansively. Next, we discuss some impacts of 20th century engineering on contemporary system properties. We argue that despite extensive alterations, the LMRS remains resilient in provision of a multitude of valuable services. This is possible largely because the system retains a dynamic hydrograph with a more-or-less predictable pattern of strong connection to a relatively substantial floodplain mosaic of diverse natural habitats. Still, in the face of various, intense stressors, including continuing adjustments to engineered channel cut-offs, steady infilling of floodplain habitats, impacts of climate change and invasive species, there is much to learn and do to manage the system to sustain desired ends. We conclude by discussing restoration options to enhance and protect resilient services in the context of sometimes conflicting social interests.

Coastal ecosystems are complex and often support a broad spectrum of functions with competing objectives. In addition to their ecological value, they offer socio-economic benefits (i.e., ecosystem services) to coastal com-munities. One potential way to help address this complexity is to use decision support systems to help natural resources managers understand system dynamics and evaluate strategies to maintain the health and integrity of these ecosystems. This paper presents a roadmap and detailed application of co-production strategies where managers and researchers are fully engaged in a collaborative manner in the design of a decision support tool for coastal ecosystems. It also emphasizes the importance of capturing end-users' (i.e., natural resource managers) priorities to refine the conceptual design of the decision support tool, while maintaining a sound scientific and modeling framework. The case study presented here centers on the Northern Gulf of Mexico, but the concept can be exported globally to other systems. This effort highlights foundational co-production strategies, including transdisciplinary team assembly, a knowledge sharing workshop, Toolbox Dialogue Initiative workshops to facilitate working across disciplines, core team and focus group meetings, and design charrettes. Further, this paper articulates the benefits and difficulties of executing a co-production process through virtual collaborations.

The Mississippi River channel from New Orleans to the Gulf of Mexico (GOM) is a key deep draft navigation channel and an active deltaic lobe. Natural and engineered lateral exits from this reach into adjacent receiving basins historically has provided mineral sediment for wetland accretion in the face of rising relative sea level and supported estuarine-coastal food webs. However, our analysis indicates water losses from the channel have increased by 25% since 2004 due to (1) bank failures during large floods since 2012 that have created several large exit channels downriver of the flood protection levee, and (2) the opening of an engineered diversion at West Bay in 2004. This has resulted in a 60-80% loss in stream power in the lowermost navigation channel that is accompanied by net shoaling between 2012 and 2022 and an increased dredging need. Our 2022 survey in the GOM exit passes indicates that only 20% of the freshwater, 5% of the total suspended sediment (2% of the sand) at New Orleans now reaches the GOM: this supports previous research indicating the delta front is retreating after centuries of progradation. Together these results indicate that (1) river containment and the sustainability of the navigation channel is threatened, (2) sediment load reaching the seaward end of the delta may be insufficient to avoid major degradation, and (3) the increased freshwater flux into adjacent shallow coastal water bodies has unknown implications for coastal hypoxia and food webs, including commercial species (e.g., oysters) and marine mammals. Future acceleration in sea level rise rates and tropical storm frequency/intensity likely will worsen these trends.

Microbial communities are found throughout the biosphere, from human guts to glaciers, from soil to activated sludge. Understanding the statistical properties of such diverse communities can pave the way to elucidate the common mechanisms ...Multiple ecological forces act together to shape the composition of microbial communities. Phyloecology approaches—which combine phylogenetic relationships between species with community ecology—have the potential to disentangle such forces but are often ...

A recent National Academies consensus report addresses monitoring and assessment of cumulative effects of large-scale and multiple restoration projects within the context of long-term environmental change. Fines and penalties from the Deepwater Horizon oil spill in the Gulf of Mexico (GoM) have supported hundreds of restoration projects at spatial scales not often possible in the past. Here, the report committee members and staff provide personal reflections from our time working on the study. We found that gaps in data collection, issues with data accessibility, and a lack of synthesis and analysis are hindering the ability to answer a basic question: What are the impacts of these many restoration efforts on improving ecosystem health and productivity in the GoM at the regional and Gulf wide scale? Restoration efforts are occurring in environments where many trends are changing and exhibiting higher variability than in the past, suggesting that previously successful restoration practices may no longer be adequate to compensate for the effects of environmental changes and variability. Our proposed approach to these challenges includes employing emerging monitoring technologies; using conceptual models; devising an adaptive management framework; rethinking restoration outcome goals; assessing cumulative effects; and undertaking rigorous synthesis and analysis of existing information on long-term environmental trends and restoration efforts. Restoration scientists and practitioners working in the GoM have an unprecedented opportunity to demonstrate large-scale environmental recovery if advances in monitoring, synthesis, assessment, and action are taken quickly. We are cautiously optimistic that, with mid-course adjustments, continued progress toward large-scale environmental recovery is possible.

A description of historical and ambient water quality conditions is often required as part of navigational studies. This paper describes a series of tools developed by the USGS that can aid navigation managers in developing water quality assessments. The tools use R, a statistical software program, and provide methods to retrieve historical streamflow and water quality data, summarize observations, model concentrations and fluxes, and estimate seasonal, annual, and decadal trends. The utility of these tools is demonstrated by providing an analysis of the seasonal variability and long-term trends of nitrate plus nitrite, orthophosphate, and suspended sediment concentrations and fluxes at nine sites in the Mississippi River Basin. Trends in annual mean concentration and flux showed fairly stable nitrate plus nitrite at most of the nine sites, with increases in the Upper Mississippi and Missouri Rivers and decreases on the Illinois River over a 40-year period beginning in 1980. Orthophosphate concentration or flux increased at almost all sites over a similar time period. Conversely, a concurrent steady decline in suspended sediment concentrations and fluxes was noted at sites throughout the basin.

Water-quality functions associated with bottomland hardwood ecosystems include 1) control of sediment detachment and transport, 2) sediment detention, and 3) nutrient and contaminant detention and transformation. Human activities that modify the various physical characteristics of bottomland hardwood ecosystems correspondingly affect the influence of these ecosystems on water quality. In general, water-quality functions associated with bottomland hardwoods are 412adversely affected by all human developmental activities because undeveloped stands provide optimal physical characteristics for improving water quality. Any activity resulting in flood control or conversion of bottomland hardwoods will have a negative effect on water-quality functions, particularly if best management practices or other mitigation measures are not included in the activity.

The Mississippi River and its delta and plume provide insights into research-informed approaches to managing river-dominated coastal zones.

The Mississippi River & Tributaries (MR&T) Project was authorized by Congress in the 1928 Flood Control Act following the disastrous 1927 flood and has thus far prevented a repeat of such catastrophic flooding while providing adequate conveyance to safely pass flood events. Despite the magnitude of the 2011 flood event, flooding was limited to the conveyance areas intended for safe passage of major floods as designed by the MR&T system. As with most major floods, public and media interest focused on the areas that were flooded, but provided only limited acknowledgement of the areas that would have flooded without the project. Despite the success of the MR&T Project, some interests have raised concerns that the flood risk reduction system has overly constricted or constrained the river and its floodplain and have suggested that more of the historic floodplain should be made available for major floods, habitat and water quality concerns. The Netherlands' "Room for the River" program consists of measures and projects designed to reopen its Rhine River floodplains to address similar concerns within their river basin. The MR&T project will be compared and contrasted to the Netherlands' program with an emphasis on the differences in scale between the two programs, with respect to the overall area and volume of water that must be conveyed by the systems. Using the 2011 Flood results, this paper compares how the MR&T project system was designed and how it functioned to provide "Room for the River" while limiting flooding impacts to the four million residents of the Lower Mississippi River basin.

The Mississippi is the largest riverine system in North America and one of the most engineered rivers in the world. The challenges of studying the Mississippi River are due to its complex sediment-water dynamics and the multi (and often competing) uses for its resources. Flood control and navigation are primary factors that control how the river is managed. A third factor is the use of river resources, namely water and sediment, for nourishing the degrading coastal wetlands of the states of Louisiana and Mississippi. As such, these factors must be fully considered and coordinated while investigating and developing techniques to harness the sediment resources of the River for coastal restoration. This paper presents a detailed suspended sediment budget analysis for the lowermost Mississippi and Atchafalaya River systems for the flood years of 2008, 2009, and 2010. Data were derived mainly from Federal and State of Louisiana measurements of water discharge and suspended sediment load at (1) monitoring stations along the river channel and (2) boat-based measurements made during specific project studies at natural passes and man-made channel diversions. The present study was focused on flood years 2008-2010 to (1) minimize the influence on the budgets of a historical decline in sediment loads carried by the river as observed by previous investigators and (2) take advantage of recent improvements in the monitoring network. The results show that both the Mississippi and Atchafalaya distributary pathways were efficient at sequestering suspended sediments, particularly the larger (sand) size fraction. Approximately 44% of the total Mississippi + Red River suspended load (80% of the sand) reaching Old River Control structures split between the distributaries was sequestered upstream of the Gulf of Mexico by overbank storage and channel bed aggradation. Increases in bed aggradation in the Mississippi distributary are linked to a loss of stream power associated with man-made and natural exits upstream of the Gulf of Mexico. This further decreased the water and suspended sediment load reaching the deep water Gulf distributary exits in FY08-10 to 46% (water), 19% (total suspended load), and 1.4% (suspended sand). These patterns of sediment storage and delivery have major implications for channel dredging and river sediment diversions planned for Louisiana coastal restoration. (C) 2012 Elsevier B.V. All rights reserved.

: This report describes the development and application of an updated version of the Multi-Scale Assessment of Watershed Integrity (MAWI) approach for watershed assessment. This work demonstrated the approach's capabilities as an assessment and planning tool using parts of the MAWI model developed for the Russian River watershed in northern California. The report also discusses the possibility of adapting the Russian River MAWI model for use in watersheds nationally.

PURPOSE: This technical note announces the availability of a tool developed by the U.S. Army Engineer Research and Development Center (ERDC). The tool and accompanying user's guide can be used to create an ArcGIS-based wetland restoration spatial decision support system (SDSS) tool. An SDSS is useful for evaluating and comparing multiple areas across a large study area, and works by scaling and combining multiple, spatially explicit data layers within a geographic information system (GIS). The purpose of this tool and user's guide is to help those involved in wetland restoration planning create their own area-specific, GIS-based wetland restoration SDSS, which can be used to identify and evaluate potential wetland restoration sites at a landscape or watershed scale. The tool and user's guide are available for download at http://el.erdc.usace.army.mil/emrrp/gis.html. BACKGROUND: The tool was designed and is applied using ESRI's ArcGIS Desktop® ModelBuilder application. Use of the tool requires at minimum the ArcGIS/ArcView Desktop v.9.x software and Spatial Analyst extension, although using the core area ratio model requires the higher end ArcInfo license. With the user's guide, those with only minimal GIS experience should be able to utilize the tool. The background for the creation and application of this tool and the ecological or functional basis of the variables used in it is documented in a technical note by Lin et al. (2006). For a real-world example of how an SDSS can be used, see Lin and Kleiss (2007). This report describes how an SDSS (created using a preliminary version of this tool) was applied for the selection and evaluation of potential wetland restoration areas along the Mississippi Gulf Coast following Hurricane Katrina. DESCRIPTION OF THE TOOL: The SDSS tool consists of a toolbox containing several individual ModelBuilder models. Several of these models create raster layers, which can be used in an SDSS. The raster layers that can be created using these models are: • Distance to seed source • Distance to protected areas • Distance to roads • Wetness index • Depressions • Block size • Core area ratio (requires an ArcInfo level license)

This technical note is a product of the Ecosystem Management and Restoration Research Program (EMRRP) work unit titled “Development of a Spatially Explicit Decision Support System for Prioritizing Wetland Restoration Areas.” This technical note discusses the potential development and application of a generalized, GIS-based wetland restoration decision support system (DSS) using ArcView ® ModelBuilder. The discussion includes the general steps needed in creating a wetland restoration DSS, the types of digital data that can be useful in performing these types of evaluations, and an example of a specific restoration DSS created using ModelBuilder.

: U.S. Army Corps of Engineers (USACE) Vicksburg District has the task of mitigating functions of bottomland hardwood (BLH) wetland forests in Mississippi lost as a result of the construction of various water resource projects. To date, the Vicksburg District has reforested almost 20,000 acres of BLH forest. This technical note reports on early functional recovery and monitoring at several of these sites, utilizing methodology based on The Regional Guidebook for Conducting Functional Assessments Based on Hydrogeomorphic (HGM) Classification and Reference Wetlands for Selected Wetland Subclasses in the Yazoo Basin, Lower Mississippi River Alluvial Valley, USA (Smith and Klimas 2002).