The effect of habitat change on nutrient removal in the Atchafalaya River Basin, Louisiana

The Mississippi and Atchafalaya rivers are the major sources of freshwater and nutrients to the Gulf of Mexico. Increased nutrient loads from these rivers exacerbate eutrophication in coastal receiving waters and contribute to the large area of hypoxia that develops seasonally in the Gulf. Levees along the Mississippi River have reduced contact between the river and the historic floodplain; this limits the ability of floodplain wetlands to naturally mitigate excess nutrients. However, the Atchafalaya River diverges from the Mississippi 217 km from the Gulf and enters a large river floodplain with a widely spaced levee system. This enhances the ability of the Atchafalaya River Basin to remove and sequester nutrients, potentially reducing downstream eutrophication. Overbank flow spreads river-water and sediment across the floodplain. Over time, sedimentation has filled in many of the open water areas on the floodplain, such that lakes are transitioning to baldcypress swamps and bottomland hardwood forests. These habitats differ in their available nutrient reservoirs and the rates at which they transform and store nutrients. This dissertation investigated the major retention and removal mechanisms for carbon, nitrogen, and phosphorus within bottomland hardwood forests, baldcypress swamps, and lakes of the Atchafalaya River Basin. These reservoirs include denitrification, sedimentation, and assimilation by aboveground biomass. Results estimate that nutrient retention and removal within bottomland hardwood forests ranges from 1,177,605—1,561,805 t C yr-1, 46,049—47,603 t N yr-1 and 20,040—20,175 t P yr-1. Within baldcypress swamps, rates range from 493,953—600,180 t C yr-1, 21,821—22,364t N yr-1 and 2,168—2,202 t P yr-1. Rates in the lakes were 57,490 t C yr-1, 5,140—5,390 t N yr-1 and 2,550 t P yr-1. Total retention and removal for the entire basin is on the order of 1,177,605—1,561,805 t C yr-1, 46,049—47,603 t N yr-1, and 20,040—20,175 t P yr-1. Rates varied by habitat, highlighting the need to consider habitat change when developing management strategies to improve water quality. Data from this dissertation can be used to parameterize nutrient models for the Atchafalaya River Basin, as well as for river diversions and floodplains with similar habitat types

Gauging Residential Knowledge and Behavior to Inform Stormwater Outreach Efforts across South Carolina

Public outreach and education are important components of local stormwater management efforts aimed at protecting water quality and reducing pollutants of concern. Increasingly, educators recognize that creating effective outreach material depends on an understanding of the target audience, their current behavior, and their barriers and motivations to adopting pro-environmental behaviors. Clemson Extension’s Carolina Clear program partners with 39 communities across South Carolina to provide compliance-based stormwater education and outreach. On behalf of these community partners, Carolina Clear conducted the third iteration of a telephone survey to gauge local knowledge, perceptions, and behaviors of residents related to stormwater and watershed health. Results presented here will highlight key knowledge gaps (e.g., the misconception that stormwater runoff is treated) and behaviors (e.g., dumping down storm drains) that could potentially be targeted through education and removal of barriers (e.g., storm drain markings). Survey results showed ongoing misperceptions about the major sources of stormwater pollution, whether stormwater is treated, and what behaviors generate pollution. However, results also show a high level of concern about water quality, as well as a desire to practice pro-environmental behavior. Highlighting the connection between potential sources of pollution, such as pet waste and septic systems, and impacts, such as shellfish bed closures and swimming restrictions, could provide stronger awareness and motivation, particularly among the large number of residents who enjoy visiting beaches and who swim, fish, and boat in local waterways. Ultimately, the survey results can be used by a variety of educators and practitioners statewide to better understand and identify target audiences and to guide the development of stormwater programming that addresses these knowledge gaps. Conducting focus groups with subpopulations of residents is recommended as a next step to further identify specific motivations within subpopulations of residents. Combining the survey results with focus-group data can help educators remove barriers to taking action and further motivate behavior change

Managing Bay and Estuarine Ecosystems for Multiple Services

Abstract Managers are moving from a model of managing individual sectors, human activities, or ecosystem services to an ecosystem-based management (EBM) approach which attempts to balance the range of services provided by ecosystems. Applying EBM is often difficult due to inherent tradeoffs in managing for different services. This challenge particularly holds for estuarine systems, which have been heavily altered in most regions and are often subject to intense management interventions. Estuarine managers can often choose among a range of management tactics to enhance a particular service; although some management actions will result in strong tradeoffs, others may enhance multiple services simultaneously. Management of estuarine ecosystems could be improved by distinguishing between optimal management actions for enhancing multiple services and those that have severe tradeoffs. This requires a framework that evaluates tradeoff scenarios and identifies management actions likely to benefit multiple services. We created a management action-services matrix as a first step towards assessing tradeoffs and providing managers with a DOI 10.1007/s12237-013-9602-7 decision support tool. We found that management actions that restored or enhanced natural vegetation (e.g., salt marsh and mangroves) and some shellfish (particularly oysters and oyster reef habitat) benefited multiple services. In contrast, management actions such as desalination, salt pond creation, sand mining, and large container shipping had large net negative effects on several of the other services considered in the matrix. Our framework provides resource managers a simple way to inform EBM decisions and can also be used as a first step in more sophisticated approaches that model service delivery

An Introduction to Wetlands of South Carolina

This article describes the importance of wetlands through a discussion of the ecology, ecosystem services, history, and policy of wetland ecosystems. With a particular focus on South Carolina wetlands, this article targets landowners, land managers, and conservation professionals

Watershed-Based Planning to Protect and Improve Surface Water Quality

Watershed-based plans are a tool to restore impaired waterways through community education and voluntary best management practice implementation. By establishing a framework for improving water quality, plans can assist with a more cohesive approach to watershed restoration. This publication outlines the goals, required elements, data sources, and potential funding opportunities involved in creating a successful watershed-based plan

Funding Stormwater Management: An Introduction to Stormwater Utility Fees in South Carolina

Stormwater utility fee (SUF) is crucial for sustaining efforts to protect water resources. Having a dedicated fund source for stormwater ensures the sustainability of stormwater management programs. While the inception of SUFs can be traced back to the Water Quality Act of 1987, their implementation and revenue allocation are subject to local ordinances, resulting in significant variations across the United States. This article provides examples of how SUFs are administered in South Carolina

An Introduction to Stormwater Ponds in South Carolina

Stormwater ponds are a widely used practice to manage stormwater runoff and treat water quality. This article summarizes the use, design, function, and management of stormwater ponds in South Carolina

Ponds in South Carolina

Four types of ponds are common in South Carolina, these include: aquaculture, irrigation, recreational, and stormwater ponds. Pond type influences the practices used to manage both water quality and aquatic biodiversity. This article provides introductory information to farmers, producers, landowners, municipalities, and pond managers related to pond type, design, regulations, and pond health

Managing Bay and Estuarine Ecosystems for Multiple Services

Managers are moving from a model of managing individual sectors, human activities, or ecosystem services to an ecosystem-based management (EBM) approach which attempts to balance the range of services provided by ecosystems. Applying EBM is often difficult due to inherent tradeoffs in managing for different services. This challenge particularly holds for estuarine systems, which have been heavily altered in most regions and are often subject to intense management interventions. Estuarine managers can often choose among a range of management tactics to enhance a particular service; although some management actions will result in strong tradeoffs, others may enhance multiple services simultaneously. Management of estuarine ecosystems could be improved by distinguishing between optimal management actions for enhancing multiple services and those that have severe tradeoffs. This requires a framework that evaluates tradeoff scenarios and identifies management actions likely to benefit multiple services. We created a management action-services matrix as a first step towards assessing tradeoffs and providing managers with a decision support tool. We found that management actions that restored or enhanced natural vegetation (e.g., salt marsh and mangroves) and some shellfish (particularly oysters and oyster reef habitat) benefited multiple services. In contrast, management actions such as desalination, salt pond creation, sand mining, and large container shipping had large net negative effects on several of the other services considered in the matrix. Our framework provides resource managers a simple way to inform EBM decisions and can also be used as a first step in more sophisticated approaches that model service delivery