Coastal Marsh Loss and Sea Level Rise

Michael Kearney, Eric Kasischke, Stephen Prince, Kyle Pitman

Widespread losses of coastal marshes from rising sea levels have been identified by the IPCC as one of the major impacts from global climatic change on coastal systems. Much of the research on coastal marsh loss has focused on field studies investigating marsh vertical accretion rates in conjunction with analyses of and local regional changes in marsh coverage using maps and aerial photographs. However, these approaches not only lack timeliness, but they generally do address the landscape processes that actually comprise the phenomenon of marsh loss.

With support from NASA, synoptic investigations of marsh loss have been undertaken in the US middle Atlantic Coast using Landsat TM data and ERS radar imagery to assess changes in the condition of coastal marshes in response to the rapid rates of sea level rise that have characterized the last decade. The results show that high rates of marsh degradation continue, particularly in the Chesapeake Bay, reinforcing earlier work using Landsat TM data and field investigations, which found that over half the marshes in the Bay were too degraded, with 20% of these systems being severely degraded. The continuing decline of coastal marshes in the largest estuary in the US is a major concern, further impacting fundamental ecological and biogeochemical cycles that are already at risk.

Example Publication: Kearney, M. S., A. S. Rogers, J. R. G. Townshend, J. C. Stevenson, J. Stevens, E. Rizzo, and K Sundberg. 2002. Landsat imagery shows decline of coastal marshes in Chesapeake and Delaware Bays. EOS, Transactions American Geophysical Union 83 (16): 173, 177-78.