Monitoring:
The Measure of Success in Saving Louisiana’s Coastal Wetlands
The partnership that was formed in 1990 when Congress passed the Coastal Wetlands Planning, Protection and Restoration Act (CWPPRA) has been working on multiple fronts to protect and restore Louisiana’s coastal wetlands—developing and implementing ecological and engineering solutions and testing new restoration techniques. CWPPRA authorized 147 projects on 13 annual priority project lists during the first 13 years of the program. However, the current loss rate of 24 square miles a year is still significant, and represents 90 percent of the coastal marsh loss in the contiguous 48 states.
Monitoring can take a variety of forms,
depending on the nature of the restoration project. Here, a wetlands ecologist with the Louisiana Department of Natural Resources uses a rake to sample submerged aquatic
vegetation in an open water pond.
The Breaux Act, as CWPPRA is commonly known, recognized the importance of learning from each project to improve the selection, engineering and design, and construction of new projects. To accomplish this, it would be critical to gain knowledge and experience about each project’s environmental impacts. The act mandated, in addition to project selection and construction, that a monitoring program be developed to provide “…an evaluation of the effectiveness of each coastal wetlands restoration project in achieving long-term solutions to arresting coastal wetlands loss in Louisiana.” Second, it called for “…a scientific evaluation of the effectiveness of the coastal wetlands restoration projects carried out under the plan in creating, restoring, protecting and enhancing coastal wetlands in Louisiana.”—that is, evaluation of all the projects as a whole. These mandates were accompanied by a long-term (20-year) funding commitment for monitoring in habitats that may be slow to respond to project features; in contrast, most other wetlands restoration projects typically feature significantly shorter periods of monitoring.
Tackling the complex challenges of making sure restoration solutions succeed and learning which solutions work best in various situations, scientists turned to the fundamentals that have guided science for hundreds of years, the scientific method: stating questions, developing hypotheses, and collecting and analyzing data to test the hypotheses.
To ensure that data collected were scientifically valid, the Louisiana Department of Natural Resources, Coastal Restoration Division, teamed with the U.S. Geological Survey National Wetlands Research Center to develop standard procedures, or protocols. These protocols were developed in collaboration with coastal wetland scientists from federal and state agencies, and from academia experienced in collecting and analyzing wetland data. The protocols have become the backbone of the project-specific monitoring. USGS performs spatial monitoring and assessment, such as aerial photography and interpretation, while primarily DNR collects other data for project monitoring.
Biological monitoring at CWPPRA projects includes the collection of a wide range of data that vary according to the type of restoration project and its specific goals. DNR uses continuous recorders for hourly measurements of water depth, salinity and temperature for projects such as river diversions and hydrologic restoration. These projects often also require samplings of fisheries, vegetation, water discharge and suspended sediments. Other types of projects, such as sediment and nutrient trapping, marsh creation and vegetative plantings, require measurements of vegetative health, sediment buildup and shoreline change.
Scientists use monitoring data to better understand complex interactions in the wetlands. This chart presents data collected on salinity and water level over the course of a year at one monitoring station. Too much salinity causes marsh to erode into the ocean.
The CWPPRA monitoring program was initially developed to evaluate individual projects, case-by-case. Each project-specific monitoring plan was developed through a Technical Advisory Group review process that included representation from DNR, USGS, the federal sponsor building the project, any interested CWPPRA agency, and an independent ecologist and statistician. USGS met the spatial data needs, while DNR provided all other data collection needs. CWPPRA currently continues to conduct project-specific monitoring, although the program is preparing to shift to a monitoring strategy that will provide a much broader analysis of the effects of restoration projects.
Wetland Loss: A Significant Trend
The rate of wetland loss peaked almost 30 years ago at over 40 square miles per year. A staggering 1,900 square miles of Louisiana’s coastal wetlands have been lost since 1932 due to human and natural causes—an area larger than the state of Delaware. The stakes at risk include significant cultural, ecological and economic resources whose losses could severely impact the entire nation. The Breaux Act provides federal funds to slow the rate of land loss in a cost-sharing arrangement (85 percent federal/15 percent state) among the state of Louisiana and five federal agencies.
Adaptive Management:
A System for Continuous Improvement
In 2002, CWPPRA scientists conducted an adaptive management review of constructed projects to (1) improve the linkages among planning, engineering and monitoring, (2) document changes made to projects during development and implementation, (3) recommend improvements for specific projects, and (4) learn from implemented projects so that future projects can be improved.
In CWPPRA’s first large-scale attempt of this kind, engineers, environmental scientists, hydrologists and others worked to institutionalize the feedback and use of project monitoring information to benefit all projects, existing and future ones. Constructed projects were studied as they evolved from the concept stage through construction and several years of monitoring. This review identified 51 project-specific recommendations and 94 lessons learned for individual projects, and made 25 recommendations by project type. The review demonstrated the value of comprehensive information at multiple scales, from project-specific, to project-type, to ecosystem-wide.
In addition to collecting data on the variety of vegetation in certain projects, ecologists also gather data on the height of the dominant species in a given site to gauge the health of the vegetation.
Louisiana Department of Natural Resources
Gauging the Value of Monitoring
Monitoring provides more than a means to assess individual projects’ effectiveness. Monitoring data can also be aggregated from multiple projects of the same type, allowing analysts to measure the success of that type of project and recommend ways to improve the implementation of similar projects. For example, the majority of rock shoreline protection projects have decreased, and in some cases reversed, shoreline erosion. Monitoring data have also provided guidance on operating freshwater diversions and water control structures.
Monitoring is also essential to the practice of adaptive management—the use of procedures to ensure that “lessons learned” are employed to improve the effectiveness of future work. This approach is critical to CWPPRA’s continued success, says John Foret, wetland ecologist at NOAA Fisheries. “Restoration of systems at the scale we’re attempting is unprecedented,” says Foret. “It’s a huge challenge to get a handle on what’s going on across the landscape. We have a great deal of engineering and science theory to back up our decisions, but we’re still learning.”
The CRMS-Wetlands program will feature 700 monitoring stations located throughout coastal Louisiana.
R. Greg Linscombe, Louisiana Department of Wildlife and Fisheries
The Need for Broader Analysis
Yet, while project-specific monitoring has been very effective for small-scale programs, it was recognized as early as 1995 that a more comprehensive approach was needed to evaluate cumulative effects on a larger, basin, or coast-wide scale.
In addition, project-specific monitoring required that data be collected both within each project area as well as in an adjacent reference or control area—that is, a site sharing the same condition of the project area prior to (or in absence of) some restoration action. Reference areas were also intended to distinguish natural system variability from the actual effects of restoration.
However, adequate reference areas were difficult to find, and in many cases unavailable. This project-reference monitoring approach also prohibited the assessment of cumulative, indirect influences on processes that impact the entire landscape, hydrologic basin, or coastal ecosystem. Data collection stations were distributed within and adjacent to project areas, while no information was collected from vast areas unaffected by restoration activity. The need to characterize habitats across their full range of conditions in coastal Louisiana and establish reference standards and targets prompted the development of a new ecosystem-scale monitoring approach—one that would come to be known as the Coast-wide Reference Monitoring System–Wetlands.
Monitoring and Modeling: Two Keys to Success
In 2003, a U.S. General Accounting Office report on ecosystem restoration in southern Florida highlighted two key tools needed for effective adaptive management: a comprehensive plan for monitoring key indicators of ecosystem health, and mathematical models to simulate aspects of the ecosystem. The GAO concluded that without these tools, the ability to understand how an ecosystem responds to restoration actions would be severely limited. GAO’s report reaffirms CWPPRA’s direction towards adaptive management and CRMS-Wetlands.