Environmental Geochemistry- Managed Wetlands

Science Center Objects

The challenge of wetland persistence is complicated by widespread management and alteration of wetland hydrology, and built infrastructure within migration corridors. Human development and utilization of coastal landscapes in the U.S. during the past several centuries has resulted in loss of approximately half of tidal wetland area, largely due to 1) restriction of tidal flows, through intentional diking and drainage or impoundment, 2) construction of levees, or road and railroad construction leading to varying degrees of impoundment, and 3) development on drained/filled wetlands with critical portions of our developed and urbanized coasts are built on drained and filled former tidal wetland. We have estimated that ~40% of remaining wetlands are landward of tidal restrictions.

All of these hydrological changes and alterations in tidal wetlands have well-known ecological consequences, including disruption of fish migrations and mobility of other fauna, alteration of vegetation assemblages, and promotion of biological invasions.  Less well-understood or predicted are the consequences for wetland stability, elevation change, persistence, and migration in the context of rising sea level and other environmental change.  In general, alterations of wetland hydrology result in changes in water level, period and frequency of soil inundation, water salinity and chemistry, and extent of water exchange.  Those physical changes cascade through the ecological, biological and chemical processes that control the production, retention, and preservation of organic matter in wetland soils. The cascade of changes further affects the rates of deposition and erosion of sediment within wetlands.  Together with our federal, state, and local partners, research in the Environmental Geochemistry group is focused on understanding these unique systems and providing the best data and products to those tasked with managing wetlands for future resilience.

Trunk River is an example of a tidally restricted impounded wetland (Cape Cod, MA).

Trunk River is an example of a tidally restricted impounded wetland (Cape Cod, MA).