Impacts of Sea Level Rise on Tidal Wetlands

Tidal wetlands perform functions that are crucial to the health of the Bay and provide services that benefit ourselves and our communities. Tidal wetland ecosystems improve water quality, recycle nutrients, draw down and store atmospheric carbon (carbon sequestration) thus helping us to slowdown climate change. They serve as nurseries and habitat for many fisheries (70% of commercial fisheries depend on wetlands habitats) and help reduce flooding caused by storm surges and wind driven waves, and they can provide flood accommodation space (they can absorb bay water as it rises during storms thus reducing flooding potential).

Tidal wetlands are resilient habitats. As sea levels rise, tidal wetlands capture suspended sediment which helps these wetlands increase in vertical height. And if adjacent upland areas have gradual slopes, tidal wetlands can migrate inland. However, sediment supplies to the Bay are decreasing due to things like channelization and damming of rivers, limiting the ability of tidal wetlands to grow vertically. And in many places, we have developed to the edges of the Bay, limiting the ability of wetlands to migrate inland.

Just like our communities, tidal wetlands are vulnerable to sea level rise. These habitats cannot survive prolonged periods of inundation. As sea levels continue to rise our Bay’s tidal wetlands may drown unless we take actions to help preserve them and their essential functions.