Sentinel Monitoring of Salt Marshes in the Chesapeake Bay National Estuarine Research Reserve in Virginia

Rachel M. Gregg
Posted on: 3/29/2010 - Updated on: 10/28/2021

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Rachel Gregg

Project Summary

The Chesapeake Bay National Estuarine Research Reserve in Virginia (CBNERR-VA), along with four other National Estuarine Research Reserves, is acting as a sentinel site to monitor climate change impacts on salt marsh habitat. This project involves creating a long-term ecological monitoring program to determine the effects of sea level rise, saltwater intrusion, warmer temperatures, shoreline erosion, and coastal storms on salt marshes.


The Chesapeake Bay is the nation’s largest estuary. CBNERR-VA covers the southern portion of the bay, and the reserve established a component system along the York River estuary salinity gradient; reserve components include Sweet Hall Marsh, Taskinas Creek, Catlett Islands, and Goodwin Islands. Key issues to the reserve include water quality degradation from sedimentation, excess nutrients, and toxins; loss and degradation of habitats such as wetlands, oyster reefs, and marshes; and declining fish populations due to overfishing and disease.

CBNERR-VA is also part of a national effort, created in 2007, to establish salt marshes as long-term reference sites at five reserves (Narragansett; Wells, Maine; Chesapeake Bay, Virginia; North Carolina; South Slough, Oregon). In addition, the reserve, along with other NERRs, participates in the System Wide Monitoring Program (SWMP), tracking changes in water quality, plants, animals, and habitats within the reserve over time.

Salt marshes provide valuable habitat for fish, crabs, and other wildlife, and important ecosystem services by filtering water and protecting shorelines during strong coastal storms. Salt marshes in the reserve area have been subject to human alteration (e.g., dredging, filling, development), which has resulted in restricted flow, increased sedimentation, and habitat degradation. This habitat is also threatened by climate change; impacts of concern include sea level rise, warmer temperatures, coastal storms, salinity intrusion, and erosion.


This project is funded through the National Oceanic and Atmospheric Association and has two goals: 1) use natural marshes as references to understand what is happening at restored marshes, and 2) use these natural reference sites to understand how marshes across the United States are responding to the impacts of climate change.

The reserve is monitoring salt marsh characteristics (e.g., salinity, vegetation cover, flow patterns, peat soils) at natural marsh reference sites and recently restored marsh sites every year to track water levels and marsh height in order to determine if and how salt marshes can respond to sea level rise and other climate impacts. The reserve is examining the effects of shoreline erosion and habitat loss at Goodwin Islands and marsh subsidence and saltwater intrusion at Sweet Hall Marsh.

Outcomes and Conclusions

This project will provide a long-term data set on salt marsh response to climate change impacts and inform a broader national effort. This information can be used in other restoration efforts.


Gregg, R. M. (2010). Sentinel Monitoring of Salt Marshes in the Chesapeake Bay National Estuarine Research Reserve in Virginia [Case study on a project of the Chesapeake Bay National Estuarine Research Reserve in Virginia]. Product of EcoAdapt's State of Adaptation Program. Retrieved from CAKE:… (Last updated March 2010)

Affiliated Organizations

The Chesapeake Bay National Estuarine Research Reserve is one of 27 reserves in the National Estuarine Research Reserve System (NERRS). Currently, NERRS protects over one million acres of estuarine waters and adjacent upland habitats. The Reserve is managed on a daily basis by the Virginia Institute of Marine Science (VIMS). The Reserve’s and Institute’s missions are closely aligned through interdisciplinary research in coastal ocean and estuarine science, education of students and citizens, and by providing advisory service to policy makers, industry, and the public.

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Adaptation Phase
Sharing Lessons
Sector Addressed
Climate Justice
Conservation / Restoration
Culture / Communities
Disaster Risk Management
Education / Outreach
Land Use Planning
Rural / Indigenous Livelihoods
Transportation / Infrastructure
Water Resources
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