Welands Overview


Data and Reports


MACWA Program



The Mid-Atlantic Coastal Wetlands Assessment (MACWA) is the first wetland program to study tidal wetland health in our region. MACWA is a joint effort of two National Estuary Programs (The Partnership for the Delaware Estuary and Barnegat Bay Partnership) with other federal, state and academic institutions. MACWA aims to supply coastal managers with data to help plan wetland recovery and protection.

MACWA is a 4-tiered method designed to provide rigorous, comparable data across the Mid-Atlantic region with monitoring and research studies that seek to resolve unanswered questions about relationships within these systems which allow for more informed decisions.

4-Tier Approach

Tier 1: Landscape census surveys of extent and condition of tidal wetlands using satellite imagery and models
Tier 2: On-the-ground random sampling across the study region to assess condition and ensure the validity of Tier 1 studies—this is achieved through the Random Assessment Method (RAM; see below)
Tier 3: Intensive studies to examine relationships among condition, function, and stressor impacts in order to resolve unanswered questions
Tier 4: Intensive monitoring of condition and function at fixed stations to study changes over time—this is achieved through Site Specific Intensive Monitoring (SSIM; see below)

MACWA is currently focused on Tier 2 and Tier 4 analysis. Below are short descriptions of each. For further details, please refer to the Data & Reports tab.


Landscape data and models, which are based on the analysis of satellite imagery, conclude that there is alarming loss and degradation of tidal marshes in the Mid Atlantic. In order to ensure the accuracy or validity of these conclusions, it is important to ground-truth, or verify by visiting locations in person (see Tier 2). It borders impossible to examine every square meter of both Mid-Atlantic estuaries. In order to make the process feasible, a Random Assessment Method (RAM) was adopted, which allows researchers to sample a reasonable number of locations to get a snapshot of the larger wetland complex. This method has been used in New England (NERAM) as well as California (CRAM). Both of these region-specific protocols were used as templates to create the Mid-Atlantic Tidal Rapid Assessment Method or MidTRAM, which caters to the tidal wetlands of the Mid Atlantic. To find out more information about the MidTRAM and Delaware’s Department of Natural Resources and Environmental Control development and use in the state of Delaware please click this link.


MidTRAM protocol uses high resolution variables that help to predict stress responses and relationships. The suite of variables collected represent four categories important for the maintenance of a wetland:

i. Habitat and biotics: the composition of the plants and animals within the wetland provide insight on the services they potentially provide. Variables assessed include above and below ground biomass, plant community (or the type and abundance of plant species), and the presence of invasive plants.

ii. Hydrology: Changes to the natural flow of water, such as ditching or filling, which could be detrimental to wetland viability

iii. Buffers: Wetlands migrate naturally, so impediments to landward migration or expansion affect the wetland’s ability to evolve, especially with regards to climate change.

iv. Shorelines:  Ultimately the driver of wetland migration, dynamics at the water-wetland interface lead to erosion or accretion (deposition) of sediment.


Surveying the same locations for several years allows researchers to track and compare changes over time. Monitoring stations for Site Specific Intensive Monitoring (SSIM) were selected covering a range of marsh types, conditions, and in different health states. Monitoring consists of a variety of biological, chemical and physical parameters and metrics. Principal core metrics include biological integrity and biomass, and surface elevations and physical conditions. Monitoring for geomorphology, biota, and water quality was designed to describe both structural and functional properties and overall integrity. All of these SSIM stations are subject to potential shifts in base forcing functions of the estuary such as sea level rise, sediment budgets, and temperature. There is considerable variation among SSIM stations in local stressors (e.g. nutrient loadings, mosquito ditch practices, impoundments).

The main focus of SSIM is to monitor elevation changes in the chosen wetlands over time, and to find relationships between those rates and the vegetation community. SSIM studies incorporate permanent plots and transects that are surveyed for the characteristics of the plant communities they contain, as well as their respective elevations. Surface Elevation Tables (SETs) were constructed in order to track elevation changes; these consist of permanent rods that are inserted deep into the sediment of the wetland. In order to maintain a high degree of accuracy, precision leveling devices and real time kinetic GPS (RTK GPS) are used, which are accurate to the millimeter or centimeter. This accuracy allows researchers to find and compare subtle changes in elevation, as these changes are often quite small.