Dramatic change doesn’t always start dramatically. It can often take a lifetime to see the extraordinary which is unfolding, imperceptibly, day-by-day. At Blackwater National Wildlife Refuge (NWR), located on the eastern shore of the Chesapeake Bay in Maryland, the slow breakup and conversion of tidal marsh to open water was observed and documented for six decades by my colleague and friend Guy Willey. Guy began his 33-year career at Blackwater NWR right out of high school, and remained active in protecting our local ecosystem and wildlife after his official retirement 1985. Guy was an astute observer of the natural world with an incredible memory, so I took every opportunity to talk with him about the history and landscape at Blackwater when I was assigned here in 2008.

Guy Willey (10/3/1930 – 1/16/2017). Guy’s career was dedicated to protecting the marsh and its ecosystems at Blackwater NWR. After his retirement, Guy helped to restore the Delmarva Fox Squirrel population in his home state of Maryland. Photo by Barbara Haddock Taylor, Baltimore Sun.

Guy spoke of the slow changes that took place in the marshes of the Blackwater River. When he started at the Refuge, the marshes were dotted with little ponds, only flooded with saltwater on the highest tides. Some of the larger ponds bore names like “Quinn Pond” and “Cold Creek.” Over the years, these isolated ponds merged as the marsh between them broke apart and converted to open water. Quinn Pond and Cold Creek are now lost to history, now part of what we know as “Lake Blackwater.”

Blackwater NWR. Photo by Whitney Flanagan.

The loss of tidal marsh means different things to different people. To some, it might mean loss of nursery areas for recreationally and commercially valuable finfish and shellfish. To others, it might mean the loss of breeding habitat for specialized marsh birds like the black rail or saltmarsh sparrow. Everyone can agree that the benefits of wetlands to water quality and flood protection are critical. Bottom line—the loss of wetlands affects most everyone.

Using aerial imagery we are able to quantify some of what Guy observed over the years from the tiller handle of a johnboat. Since Blackwater was established in 1933, more than 5000 acres of tidal marsh have been lost to open water. The combination of rising sea level, subsidence (sinking land), and destructive effects of nutria (invasive rodents that feed on the roots and leaves of marsh plants) is responsible for the vast majority of this marsh loss. The Chesapeake Bay Nutria Eradication Project has made phenomenal progress towards eradicating nutria from the area. This is a critical step towards slowing the rate of marsh loss and allows us to think about restoration and building marsh resiliency.

Blackwater NWR. Photo by USFWS.

To that end, The Conservation Fund and Audubon Maryland-DC helped us develop a Sea Level Rise Adaptation Plan for the Refuge. Completed in 2012, this plan spells out the changes that have been observed on the refuge over the years, looks at all of the scientific research into the cause of these changes, and uses predictive models developed by Maryland Department of Natural Resources to help understand what the future may look like.

In 2016 we were able to implement one aspect of the plan by building 30 acres of resilient tidal marsh on the refuge. With federal Superstorm Sandy relief funding, The Conservation Fund worked with Audubon Maryland-DC and the Refuge to pump mud from the bottom of the Blackwater River and place it in a thin layer across the marsh. This built up the elevation of the marsh, increasing plant vigor and increasing the longevity of the marsh. This project should be a big benefit to salt marsh obligate species like the saltmarsh sparrow.

Dredged material is applied to the wetlands at Blackwater NWR to elevate the marsh and compensate for rising sea level and sinking land mass. Photo by Middleton Evans.

Most importantly, this plan recognizes the dynamic nature of the Refuge’s natural systems. We need to think not only about managing the current condition of these natural resources, but also their future status. The original boundary of Blackwater NWR was drawn to protect a vast system of highly productive tidal marsh that existed in 1933. With sea level rise and land subsidence we have lost much of that historic marsh, while new marsh is forming in the adjacent uplands. Dying trees at the marsh edge and the presence of old tree stumps in tidal marsh habitats provide evidence that these tidal wetlands have been migrating upslope and will continue to expand beyond Blackwater Refuge’s original boundaries. Planning for where the largest tidal marshes will likely be in 2050 or 2100 is critical for the long-term viability of tidal marshes in the area.

This represents an important shift in the way we think about habitat conservation at Blackwater. Maintaining historic conditions is the benchmark for many natural resource managers. While this is clearly an important standard, recognizing the dynamic nature of these systems is becoming more important as we come to understand the impacts of climate change. Maintaining critical habitats and ecosystem services on the landscape—even if not in the exact historic location—is an important way in which we are redefining conservation.

Guy’s observations, made over a lifetime of living and working in the marshes and forests of the Chesapeake Bay, provide an important lesson on the dynamic nature of these systems. In the years following his retirement from Blackwater, Guy was awarded the Distinguished Service Award (the highest honorary recognition an employee can receive within the Department of the Interior) for his exceptional contributions, and his dedication to wildlife conservation continued in many forms until his death in January 2017. My conversations with Guy about changes to this treasured landscape during his lifetime are forever imprinted in my memory, and he will be missed. Recognizing that these systems are changing and explicitly planning for these changes is essential as we move forward, and will honor Guy’s legacy of protecting the unique Blackwater ecosystem.

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For more information:

Superstorm Sandy relief funding was appropriated by the U.S. Congress through the Disaster Relief Appropriations Act of 2013, including the Congressional delegation representing Blackwater National Wildlife Refuge: U.S. Senators Ben Cardin and Chris Van Hollen and U.S. Representative Andy Harris, MD. Resilience efforts at Blackwater also are supported by a grant through the Department of the Interior's Hurricane Sandy Coastal Resiliency Competitive Grant Program administered by the National Fish and Wildlife Foundation.

Check out our project page to learn more about Blackwater NWR.

Matt Whitbeck and The Conservation Fund’s Erik Meyers have contributed to several recent articles about the changing conditions at Blackwater NWR:

Path to Improving Atlantic Flyway at Blackwater Is Filled With Mud

At Blackwater Refuge, Rising Sea Levels Drown Habitat