Coastal Habitats and Sea Level Rise

Since 2009, the Chesapeake & Coastal Program (CCP) has been working on a project entitled, “Coastal Land Conservation in Maryland: Targeting Tools and Techniques for Sea Level Rise Adaptation and Response.” The purpose of the project is to develop new conservation criteria to identify coastal habitats that may help Maryland proactively adapt to sea level rise and increased storm events associated with climate change. Climate change targeting criteria resulting from this project will be used to review land acquisition projects, such as Coastal Estuarine and Land Conservation Program (CELCP), and will be added to the State’s current land conservation targeting program, “GreenPrint.”

Background

In the Chesapeake Bay, relative sea level rise is impacting low-lying coastal lands at twice the global average rate. Over the past 100 years, Maryland has seen a foot of relative sea level rise. Rising waters have caused the disappearance of 13 Bay islands. This is due, in part, to local isostatic rebound or land subsidence from the last glaciation period and to sea level rise. Many of the islands lost played a role in Maryland’s maritime culture as year-round residences for our watermen communities. Like our island communities, many coastal communities in today’s landscape are being threatened by encroaching waters. In order to address these impacts, the Maryland Department of Natural Resources has been developing new land conservation strategies to help preserve the long-term survival of coastal wetlands that provide storm surge buffering to communities as well as critical habitat for aquatic and terrestrial species.

Identifying long-term planning options to increase resiliency against coastal storm surge, flooding, and erosion is an important step in protecting Maryland’s coastal zone. Coastal wetlands provide a natural buffer against the impacts of these coastal hazards. Targeting lands that may enable the inland retreat of our coastal and nearshore wetlands can help the State maintain the long-term ecological functions of storm surge buffering, carbon sequestration, water filtration, wildlife habitat, recreation and others that wetlands provide.

In order to better understand the potential impacts sea level rise may have on the Maryland’s coastal wetland system, the Sea-Level Affecting Marshes Model (SLAMM) version 6.0.1 was run for all 16 coastal counties and Baltimore City. SLAMM uses elevation, accumulation of sediments, wetland accretion and erosion rates, and sea level rise to predicatively model long-term wetland and shoreline change. In Maryland, SLAMM was run using the best available science, including 3.4 feet of sea level rise by year 2100, as recommended by the Maryland Commission on Climate Change. Wetlands were grouped into descriptive classes for this analysis. For more information on the wetland classes used for SLAMM, click here to download the wetland descriptions.

Predictive Shoreline Change Using SLAMM in Dorchester County, Maryland.

Initial Wetland Conditions	Year 2050	Year 2100, 3.4’ Sea Level Rise

The product from this model allows the user to visualize resulting changes to coastal wetlands and shorelines in their current state, 2050 and 2100 year scenarios on the Coastal Atlas’ Shorelines mapping tool. The predictive modeling results will be used to help frame new landscape level conservation targeting in Maryland’s coastal zone. While these results will help Maryland identify potential strategies for maintaining coastal habitats, there are identified and limiting caveats of SLAMM that should be mentioned. SLAMM is a predictive model that has built in limitations and margins of error that increase with the quality and resolution of spatial data input into the model. To visualize the SLAMM data please visit the Coastal Atlas’ Shorelines mapping tool.

Trainings and Workshops

Coastal Land Conservation Training: Incorporating Blue Infrastructure and Climate Change into Project Decision-Making (June 30, 2011)

In June, the Maryland Environmental Trust, Defenders of Wildlife, and CCP delivered a training for land trusts to demonstrate the importance of incorporating tidal and nearshore ecological data – the Blue Infrastructure – and climate change adaptation benefits into parcel-level conservation evaluations and project decisions. The goals of the training were to inform local land conservation planners about the availability of new data and its benefit in evaluating coastal zone properties; provide tools for incorporating climate change into conservation easements; and to facilitate a dialogue on the challenges land trusts are facing.

Coastal land trusts and managers have an important role in climate change adaption in Maryland. Program staff provided a demonstration on how to incorporate coastal zone conservation targeting datasets into parcel-level conservation assessments using the Coastal Atlas and a climate change evaluation form. The combination of identifying Blue Infrastructure and climate change effects of sea level rise will help inform decision-makers about the properties' aquatic ecological value and climate resiliency and adaptability. Attendees and training partners discussed the challenges of drafting conservation easements that consider the potential impacts of climate change while at the same time protecting conservation values and purposes of the property.

Coastal Land Conservation Training materials:

Coastal Land Conservation and Climate Change Workshop (December 2, 2009)

In December 2009, 50 experts from federal and state agencies and non-governmental organizations gathered at the Patuxent Research Refuge National Visitors Center in Laurel, MD. The focus was to develop new criteria for adapting current land conservation practices in response to sea level rise. Land conservation expert, Andy Pitz of Natural Lands Trust set the stage for the day as the key note speaker. Through focus groups, experts evaluated sector-based adaptation strategies used to brainstorm land conservation criteria under projected sea level rise scenarios. The sector-based adaptation strategies were pulled from the recommendations found in Maryland’s Phase I Adaptation & Response Working Group and a literature review.

The criteria that came out of the workshop will continue to be refined and developed to help frame Maryland’s plan for land conservation under the projected climate change impacts of sea level rise. Participants from the workshop and additional local regional experts will continue to provide feedback as the project moves towards developing land conservation criteria into a GIS based model.

Coastal Land Conservation and Climate Change Workshop materials:

In Focus

New Data Launched on the Coastal Atlas!

Visit the Coastal Atlas to visualize and analyze how wetlands may respond to sea level rise in the coastal zone. ‘New Wetland Areas’ layers for years 2050 and 2100 provide insight into potential future wetland migration zones. These projections are based on Maryland’s SLAMM study.