DNERR: Spotlight on Tidal Marshes
The Delaware National Estuarine Research Reserve (DNERR) recently collaborated with 15 other National Estuarine Research Reserves in 13 coastal states on a research study that examined the capabilities of tidal marshes to keep pace with sea level rise.
Results of the pioneering study, “Rising to the Challenge: Will Tidal Marshes Survive Rising Seas?” were recently published.
The study included a tidal marsh resiliency assessment of DNERR’s St. Jones Reserve in Dover.
“As a low-lying state, Delaware is highly vulnerable to the effects of sea level rise. Our tidal marshes provide the first line of defense for nearby communities – protecting people and property against storm surges and flooding and improving water quality,” said DNREC Secretary David Small.
“This study provides a national comparison of marsh resilience to sea level rise, and provides critically-needed information that will help shape coastal policy and management decisions on protecting Delaware’s tidal marshes and the valuable benefits they provide.”
The study evaluated five categories that determine resiliency of a tidal marsh – marsh elevation, changes to marsh elevation, sediment supply, tidal range and the local rate of sea level rise.
Most tidal marshes kept pace with rising seas through accretion, the buildup of sediments on the surface of the marsh, or by migrating inland, the gradual movement of a marsh toward dry land as it becomes flooded by sea level rise.
Sea level rise is projected to increase in the future leaving the fate of tidal marshes around the country uncertain.
The study suggests that accretion at the St. Jones Reserve is helping to curb marsh loss due to rising seas, however, continuous monitoring is needed to determine whether vulnerabilities will arise.