Salt marsh degradation and restoration
Since 1991, the Wells Reserve has been studying the impact of tidal restrictions on salt marsh functions and values, and the response of salt marshes to tidal restoration. Salt marsh ecosystems in the Gulf of Maine sustained themselves in the face of sea-level rise and other natural disturbances for nearly 5,000 years. Since colonial times large areas of salt marsh have been lost through diking, draining, and filling. Today, the remaining marshland is fairly well protected from outright destruction, but during the past 100 years, and especially since the 1950's, salt marshes have been divided into fragments by roads, causeways, culverts, and tide gates. Tidal flow to most of these fragments is severely restricted, leading to chronic habitat degradation and greatly reduced access for fish and other marine species. Under the umbrella of the Global Programme of Action Coalition for the Gulf of Maine, the Reserve evaluates monitoring results from marsh restoration projects throughout the gulf to assess their performance and to identify data gaps and future monitoring needs.
For ten years, scientists at the Wells Reserve have surveyed and studied fish fauna of southern Maine estuaries and coastal watersheds. Their current emphases are on the York River and Casco Bay. Collaborators: York Land Trust, York Rivers Association, University of New England
Casco Bay is the largest oil port in northern New England, handling over 20-million tons of crude oil and oil products annually. Oil spills could cause extensive damage to the Bay's ecosystem. Because the Casco Bay marshes are predominantly fringing marshes that serve as nursery grounds for finfish and shellfish, more information is needed about their ecological role in the estuaries of New England. To measure these functions, the researchers will map marshes, survey fish and invertebrate populations, assess plant communities, and investigate sediment accretion rates. This information will help guide oil spill management and improve the baseline knowlege for assessing natural resource damage if a spill affects the marshes. Collaborators: University of New England
Salt Marsh Assessment and Restoration Tool (SMART): An evaluation of
hyperspectral, LIDAR and SWMM for producing accurate habitat restoration predictions
Salt marshes are among the most productive ecosystems on earth. Unfortunately, ecological value has not always protected marshes from damage. It is estimated that over half of the original salt marshes in the United States have been destroyed, most often to create more land area for development and agriculture. Over the last three decades, increased knowledge of the importance of healthy salt marshes has brought about state and federal laws to protect them. Salt marsh restoration efforts are now underway across the country. New tools like Self-Regulating Tide Gates (SRTG) have made it possible to restore large tracts of degraded marsh. But restoration planning is limited by a lack of high-resolution data and predictive modeling, especially regarding SRTGs. The goal of this project is to develop both a method to evaluate restoration goals and a tool to visualize the likely impact of management decisions.
Spatial modeling and visualization of salt marsh habitat change in the Great Bay NERR
Degradation of salt marsh habitat due to tidal restrictions is a significant issue in New England. Restoration efforts often produce unintended and less than optimal results due to lack of synthesized information concerning key ecological interactions. This project will develop a general spatial model integrating biologic, hydrologic and geologic salt marsh processes. Two historic restoration marshes will be used to build the model and to conduct sensitivity analyses. Finally, output from the spatial model will be combined with new animation software to create photorealistic visualizations of habitat change. Project deliverables will enhance future restoration planning as well as management-stakeholder communications.
Enhancement of salt marsh reestablishment to improve water quality
There has been tremendous interest and investment in recent years to restore salt marshes, however restoration efforts are often compromised by sediment erosion before the restored plant communities can become established. This project is developing and evaluating low-cost, biodegradable devices called FEDS (Filtration Enhancement Devices) that can be placed at the seaward edge of restored marshes to reduce sediment erosion caused by wind waves, boat wakes and ice scour.
Spatial modeling of eelgrass habitat change in Great Bay National Estuarine Research Reserve
Eelgrass meadows provide important habitat for many species of commercially and recreationally important finfish and shellfish. Unfortunately, eelgrass is susceptible to many natural and human-induced disturbances and many acres of eelgrass habitat have been lost in recent years. While some of the factors that impact eelgrass are known, the combined effects of natural and man-made disturbances are poorly understood. This project is using a unique coupling of physical and biological numerical models to predict changes and impacts to eelgrass habitat under a variety of circumstances. The results of the modeling efforts will allow coastal resource managers to implement strategies to protect this valuable resource.
Restoring an oyster reef for mitigation of estuarine water quality
Oyster populations in the Mid-Atlantic and the Northeast U. S. have declined dramatically in the past four decades as a result of disease and over-harvesting. In addition to the economic loss associated with this decline, a drastic reduction in filtration capacity has resulted in increased turbidity and degraded water quality that has impacted other plants and animal communities. This project is employing innovative techniques to restore an oyster reef and to determine if water quality improvements can be achieved by the oysters' filtering activity.