Coastal Louisiana is currently experiencing high rates of wetland loss and large-scale ecosystem restoration is being implemented. One of the largest and most novel restoration projects is a controlled sediment diversion, proposed to rebuild and sustain wetlands by diverting sediment- and nutrient-rich water from the Mississippi River. However, the impact of this proposed sediment diversion on the nutrient budget of the receiving basin is largely unknown. A water quality model was developed to investigate the impact of the planned Mid-Barataria Sediment Diversion on the nutrient budget of the Barataria Basin (herein referred to as ‘the Basin’). The model results indicate that the planned diversion will increase TN and TP pools by about 38% and 17%, respectively, even with TN and TP loadings that increase by >300%. Water quality model results suggest that the increase of nutrients in the basin will be mitigated by increased advection transport (i.e., decreased residence time from ~170 days to ~40 days, leading to greater flushing) and increased removal via assimilation, denitrification, and settling within the Basin. Advection transport resulted in higher TN removal in the Basin than other processes, such as uptake or denitrification. Approximately 25% of the additional TN loading and 30% of the additional TP loading were processed within the Basin through the assimilation of phytoplankton and wetland vegetation, denitrification, and burial in the sediment/soils. These nutrient budgets help to better understand how the planned large-scale sediment diversion project may change the future ecological conditions within the estuaries of coastal Louisiana and near-shore northern Gulf of Mexico.

The process of developing a socioenvironmental report card through transdisciplinary collaboration can be used in any system and can provide the foundation for collaborative solutions for sustainable resource management by creating a holistic assessment that balances environmental, economic, and social concerns that incorporates multiple perspectives from multisectoral actors. We demonstrated this in the Mississippi River watershed, USA with the ultimate goal of promoting holistic management of the region's natural resources. But working at the scale of the Mississippi River watershed presents the challenge of working across geographical, organizational, and disciplinary boundaries. The development of a socioenvironmental report card served as the focus for efforts to foster a shared vision among diverse stakeholders in the watershed and to promote transdisciplinary collaboration. The process engaged more than 700 participants from environment, flood control, transportation, water supply, economy, and recreation sectors, from more than 400 organizations representing local, state, and federal government agencies, businesses and trade associations, and private, nonprofit, and academic institutions. This broad engagement in the selection of important themes, indicators, measures, and assessment methods as part of the cocreation of boundary objects aimed to foster social and mutual learning and to develop common understanding and shared visioning among stakeholders with differing perspectives. The process was facilitated by boundary-spanning organizations, creating an atmosphere of trust by utilizing "third places" for knowledge exchange and integration. This transdisciplinary process also led to collective action through collaboration and selection of restoration and management activities that could improve conditions for multiple sectors simultaneously and/or recognize potential tradeoffs for informed decision making. Integr Environ Assess Manag 2020;16:494-507. © 2020 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Resource managers in South Florida are aware that coastal and marine ecosystems provide food, recreation, and a quality of life that are highly-valued by humans. Estimates of economic values in Florida, such as willingness-to-pay for a day of coral reef snorkeling or the change in this value from a change in coral cover, are not updated in a timely manner or are not available at all. Usually these studies are "baseline studies" that provide a snapshot of economic values under existing economic and environmental conditions. Therefore, to be useful to ecosystems management, human dimension (HD) economic indicators that are relatively easy to measure each year must be identified. In addition, they must be combined with a conceptual model that links these indicators to the ecosystem services; their relevant economic values; the HD non-economic metrics of well-being; and the quality and/or quantity of the environmental and ecologic attributes associated with the ecosystem service. Carefully selected HD economic indicators together with ecological, environmental, and non-economic human dimensions indicators can provide a rich source of information for managing the long term conservation and use of coastal and marine ecosystems.In this paper, we specify criteria for selecting HD economic indicators that measure the change in demand for ecosystem services resulting from changes in the quality or quantity of the environmental attributes that comprise the service. We assessed a suite of candidate metrics and arrived at a final set of HD economic indicators for further evaluation. These HD economic indicators are the percentage change from year to year in: (1) coastal park visitation; (2) number of registered recreational boats; (3) pounds of commercial seafood landed; (4) number of live marine organisms landed; and (5) dollar value of insured flood damage claims paid.We illustrated the use of these HD economic indicators with an empirical example for the Florida Keys and Dry Tortugas where the indicators are measured over a one year period. The changes were then scored and the scores were assigned a stop light rating of: green for good (or increasing), yellow for fair (or stable), and red for poor (or decreasing). Our empirical illustration of HD economic indicators offers a first step in developing metrics to rate the status of Florida's coastal and marine ecosystem services. The next steps are to propose a full suite of candidate HD economic indicators and metrics; final selection of HD economic indicators and their integration into the conceptual model; annual calculation of these indicators and their evaluation; and environmental/ecosystem assessment. (C) 2014 Elsevier Ltd. All rights reserved.

Commercial and recreational fisheries target hundreds of fish and shellfish species across the seascape of southern Florida including inshore coastal bays, the flats of barrier islands, coral reefs and offshore pelagic waters. The ecological dynamics and economic sustainability of these valuable fishery resources are key conservation concerns. This study examined two ecological indicators of fishing impacts on exploited populations: (1) the more traditional metric catch per unit of fishing effort (CPUE); and (2) the non-traditional metric average length (L¯) in the exploited life stage of a population. We show that both indicators were closely related to stock productivity via fisheries population dynamics theory, and that either indicator could be used to estimate fishing mortality rates (F). Data requirements are much less stringent for estimating F from the L¯ indicator than CPUE, making it more practical for data-poor situations common to tropical marine fisheries. Using indicator-based estimates of Fˆ within a population dynamic modeling framework enabled an evaluation of fishing impacts on sustainability at both the species and community levels, an important step toward ecosystem-based fisheries assessment and management. A comparison of these approaches applied to the assessment of southern Florida coral reef fisheries suggested that fishing has fundamentally altered the ecological structure of the fish community by depleting the biomass of higher-trophic level carnivores to the extent that the stocks are unsustainable.

Most economic activity in coastal Louisiana depends, either directly or indirectly, on the Mississippi River, its delta and the coastal wetlands of the Chenier plain. Maintaining the economic vitality of the region requires taking action to restore these essential elements of the coastal landscape. The economic value of the jobs and assets that will be lost without restoration can be estimated from standard indices of economic activity in the region such as gross domestic product and jobs, and from the value of ecosystem goods and services. The economic health of the United States also depends on sustaining the navigation, flood control Flood control , energy production, tourism, and seafood and other natural resource production functions of the Mississippi Delta and river system, making Mississippi River Delta restoration critically important. These systems are at risk due to the degradation of coastal wetlands. The Mississippi River Delta ecosystems provide at least $ 12–47 billion in ecosystem goods and services benefits to the people of the United States every year and a natural capital asset value between $ 330 billion and $ 1.3 trillion. Unless the delta is restored and maintained, the entry to the Lower Mississippi navigation system, the lynchpin in the entire Mississippi navigation and freight transportation system, is likely to collapse. The economic value of the MRD is $ 1.3 trillion when the natural capital is included as a valued economic asset. The economics are clear, an investment in costs to modernize the Mississippi River Delta in ways that allow it to gain ground, and to sustain critical infrastructure far into the future is justified and critical to the economic health of both the state and the nation. Economic collapse on a large scale looms in the near future unless dramatic steps are taken to reverse the deterioration of the Mississippi River Delta.

Ecosystem-based management is widely regarded as a method to improve the way we manage our coastal marine resources and ecosystems. Effective ecosystem-based management relies upon synthesizing our scientific knowledge and transferring this knowledge into management actions. Integrated ecosystem assessment is a framework to conduct this scientific synthesis and transfer information to resource managers. Portions of the framework were applied to build consensus on the focal ecosystem components and processes that are characteristic of a sustainable South Florida coastal ecosystem that is producing ecosystem services at the level society desires. Consensus was developed through facilitated meetings that aimed to conceptualize the ecosystem, develop ecosystem indicators, and conduct risk analysis. Resource managers, researchers, academics, and non-governmental organizations participated in these meetings and contributed to the synthesis of science and a myriad of science communications to transfer information to decision makers and the public. A proof of concept Bayesian Belief Network was developed to explore integrating the results of this assessment into an interactive management scenario evaluation tool. The four year effort resulted in the development of a research and management coordination network in South Florida that should provide the foundation for implementing ecosystem-based resource management across multiple agencies. (C) 2014 Elsevier Ltd. All rights reserved.

There is a pressing need to integrate biophysical and human dimensions science to better inform holistic ecosystem management supporting the transition from single species or single-sector management to multi-sector ecosystem-based management. Ecosystem-based management should focus upon ecosystem services, since they reflect societal goals, values, desires, and benefits. The inclusion of ecosystem services into holistic management strategies improves management by better capturing the diversity of positive and negative human-natural interactions and making explicit the benefits to society. To facilitate this inclusion, we propose a conceptual model that merges the broadly applied Driver, Pressure, State, Impact, and Response (DPSIR) conceptual model with ecosystem services yielding a Driver, Pressure, State, Ecosystem service, and Response (EBM-DPSER) conceptual model. The impact module in traditional DPSIR models focuses attention upon negative anthropomorphic impacts on the ecosystem; by replacing impacts with ecosystem services the EBM-DPSER model incorporates not only negative, but also positive changes in the ecosystem. Responses occur as a result of changes in ecosystem services and include inter alia management actions directed at proactively altering human population or individual behavior and infrastructure to meet societal goals. The EBM-DPSER conceptual model was applied to the Florida Keys and Dry Tortugas marine ecosystem as a case study to illustrate how it can inform management decisions. This case study captures our system-level understanding and results in a more holistic representation of ecosystem and human society interactions, thus improving our ability to identify trade-offs. The EBM-DPSER model should be a useful operational tool for implementing EBM, in that it fully integrates our knowledge of all ecosystem components while focusing management attention upon those aspects of the ecosystem most important to human society and does so within a framework already familiar to resource managers.

The overall goal of the MARine and Estuarine goal Setting (MARES) project for South Florida is “to reach a science-based consensus about the defining characteristics and fundamental regulating processes of a South Florida coastal marine ecosystem that is both sustainable and capable of providing the diverse ecosystem services upon which our society depends.” Through participation in a systematic process of reaching such a consensus, science can contribute more directly and effectively to the critical decisions being made by both policy makers and by natural resource and environmental management agencies. The document that follows briefly describes the MARES project and this systematic process. It then describes in considerable detail the resulting output from the first two steps in the process, the development of conceptual diagrams and an Integrated Conceptual Ecosystem Model (ICEM) for the second subregion to be addressed by MARES, the Southwest Florida Shelf (SWFS). What follows with regard to the SWFS is the input received from more than 60 scientists, agency resource managers, and representatives of environmental organizations beginning with a workshop held August 19-20, 2010 at Florida Gulf Coast University in Fort Myers, Florida.

Hydrologic conditions are critical to the nesting behavior and reproductive success of crocodilians. In South Florida, USA, growing human settlement has led to extensive surface water management and modification of historical water flows in the wetlands, which have affected regional nesting of the American alligator (Alligator mississippiensis). Although both natural and anthropogenic factors are considered to determine hydrologic conditions, the aspects of hydrological patterns that affect alligator nest effort, flooding (partial and complete), and failure (no hatchling) are unclear. We deconstructed annual hydrological patterns using harmonic models that estimated hydrological matrices including mean, amplitude, timing of peak, and periodicity of surface water depth and discharge and examined their effects on alligator nesting using survey data from Shark Slough, Everglades National Park, from 1985 to 2005. Nest effort increased in years with higher mean and lesser periodicity of water depth. A greater proportion of nests were flooded and failed when peak discharge occurred earlier in the year. Also, nest flooding rates were greater in years with greater periodicity of water depth, and nest failure rate was greater when mean discharge was higher. This study guides future water management decisions to mitigate negative impacts on reproduction of alligators and provides wildlife managers with a tool for assessing and modifying annual water management plans to conserve crocodilians and other wetland species. © 2012 The Wildlife Society.

This whitepaper defines the terms Driver and Pressure and identifies the sets of Drivers and Pressures used by the MARES project to describe the South Florida coastal marine ecosystem. This set may change during the course of the project and if so updates to this whitepaper will track these changes. This update incorporates the results of review and comments received beginning with the All PIs meeting in August 2011 and continued through a poll of the project membership conducted in September 2011.

The authors summarize the main findings of the Florida Coastal Everglades Long-Term Ecological Research (FCE-LTER) program in the EMER, within the context of the Comprehensive Everglades Restoration Plan (CERP), to understand how regional processes, mediated by water flow, control population and ecosystem dynamics across the EMER landscape. Tree canopies with maximum height 3 m cover 49% of the EMER, particularly in the SE region. These scrub/dwarf mangroves are the result of a combination of low soil phosphorus (P 59 g P g dw-1) in the calcareous marl substrate and long hydroperiod. Phosphorus limits the EMER and its freshwater watersheds due to the lack of terrigenous sediment input and the phosphorus-limited nature of the freshwater Everglades. Reduced freshwater delivery over the past 50years, combined with Everglades compartmentalization and a 10 cm rise in coastal sea level, has led to the landward transgression (1.5 km in 54 years) of the mangrove ecotone. Seasonal variation in freshwater input strongly controls the temporal variation of nitrogen and P exports (99%) from the Everglades to Florida Bay. Rapid changes in nutrient availability and vegetation distribution during the last 50years show that future ecosystem restoration actions and land use decisions can exert a major influence, similar to sea level rise over the short term, on nutrient cycling and wetland productivity in the EMER.

By transforming fixed nitrogen (N) into nitrogen gas, the biochemical processes that support denitrification provide a function critical to maintaining the integrity of ecosystems subjected to increased loading of N from anthropogenic sources. The Louisiana coastal region receives high nitrate (NO3−) concentrations (>100µM) from the Mississippi–Ohio–Missouri River Basin and is also an area undergoing high rates of wetland loss. Ongoing and anticipated changes in the Louisiana coastal region promise to alter biogeochemical cycles including the net rate of denitrification by ecosystems. Projecting what these changes could mean for coastal water quality and natural resources requires an understanding of the magnitude and patterns of variation in denitrification rates and their connection to estuarine water quality at large temporal and spatial scales under current conditions. We compile and review denitrification rates reported in 32 studies conducted in a variety of habitats across coastal Louisiana during the period 1981– 2008. The acetylene inhibition and 15N flux were the preferred techniques (95%); most of the studies used sediment slurries rather than intact sediment cores. There are no estimates of denitrification rates using the N2/Ar ratio and isotope pairing techniques, which address some of the problems and limitations of the acetylene inhibition and 15N flux techniques. These studies have shown that sediments from estuaries, lakes, marshes, forested wetlands, and the coastal shelf region are capable of high potential denitrification rates when exposed to high NO3− concentrations (>100µM). Maximum potential denitrification rates in experimental and natural settings can reach values >2500µmolm2h−1. The lack of contemporary studies to understand the interactions among critical nitrogen transformations (e.g., organic matter mineralization, immobilization, aquatic plant assimilation, nitrification, nitrogen fixation, dissimilatory nitrate reduction to ammonium (DNRA) and anaerobic ammonium oxidation (annamox) limits our understanding of nitrogen cycling in coastal Louisiana, particularly the role of respiratory and chemolithoautotrophic denitrification in areas undergoing wetland restoration.

Reliable and accurate forecasts of salinity changes are essential for the success of current and future management scenarios aimed at restoring and sustaining natural resources of coastal and estuarine ecosystems. Because of the physical complexity of such ecosystems, information on uncertainty associated with salinity forecasts should be assessed and incorporated into management and restoration decisions. This study focuses on the impact of spatial variability and limited sampling of rainfall on salinity prediction in an estuarine system. The analysis is conducted on the Barataria basin, which is a wetland-dominated estuarine system located directly west of the Mississippi Delta complex on the United States coast of south Louisiana. The basin has been experiencing significant losses of wetland at a rate of nearly 23km2/year. Radar-rainfall data with high spatial resolution are used to simulate various scenarios of hypothetical rain gauge sampling densities over the basin. A mass-balance hydrologic salinity model is used to assess the effect of reduced rainfall sampling on salinity prediction in the basin. The results indicated that, due to the critical role played by rainfall in determining the overall balance of the basin freshwater budget, a high degree of uncertainty exists in salinity predictions when using typical average rain gauge densities (e.g., 1.3gauges/1000km2 in the US). These uncertainties decline sharply as the number of available gauges is increased beyond the typically available density. Uncertainties in salinity predictions in the Barataria basin are larger in inland locations and smaller near the mouth of the basin, where salinity conditions in the coastal waters of the Gulf of Mexico exert a large influence. Rainfall uncertainties also affected parameter estimation during model calibration, where the estimation of some parameters exhibited significant levels of bias and random scatter. The study highlights the necessity of improving rainfall monitoring especially in estuarine systems that are controlled by rainfall as a main source of freshwater and where the management of freshwater supply is a viable option.

Variation and uncertainty in estimated evaporation was determined over time and between two locations in Florida Bay, a subtropical estuary. Meteorological data were collected from September 2001 to August 2002 at Rabbit Key and Butternut Key within the Bay. Evaporation was estimated using both vapor flux and energy budget methods. The results were placed into a long-term context using 33 years of temperature and rainfall data collected in south Florida. Evaporation also was estimated from this long-term data using an empirical formula relating evaporation to clear sky solar radiation and air temperature. Evaporation estimates for the 12-mo period ranged from 144 to 175 cm yr−1, depending on location and method, with an average of 163 cm yr−1 (±9%). Monthly values ranged from 9.2 to 18.5 cm, with the highest value observed in May, corresponding with the maximum in measured net radiation. Uncertainty estimates derived from measurement errors in the data were as much as 10%, and were large enough to obscure differences in evaporation between the two sites. Differences among all estimates for any month indicate the overall uncertainty in monthly evaporation, and ranged from 9% to 26%. Over a 33-yr period (1970–2002), estimated annual evaporation from Florida Bay ranged from 148 to 181 cm yr−1, with an average of 166 cm yr−1. Rainfall was consistently lower in Florida Bay than evaporation, with a long-term average of 106 cm yr−1. Rainfall considered alone was uncorrelated with evaporation at both monthly and annual time scales; when the seasonal variation in clear sky radiation was also taken into account both net radiation and evaporation were significantly suppressed in months with high rainfall.