DURHAM, N.C. -- Tidal marshes, which nurture marine life and reduce storm damage along many coastlines, should be able to adjust to rising sea levels and avoid being inundated and lost, if their vegetation isn't damaged and their supplies of upstream sediment aren't reduced, a new Duke University study suggests.

Such marshes "offer great value as buffers of coastal storms in cities such as New Orleans, which is separated from the Gulf of Mexico by marshlands," Matthew Kirwan and A. Brad Murray said in a report published online on Monday, March 26, in the journal "Proceedings of the National Academy of Sciences."

The researchers built a 3-D computer model that agrees with other recent work in suggesting that marshlands have some potential for adapting to environmental change. However, the Duke modeling also suggests that substantially disturbing the wetlands' plants or starving them of sediment could disrupt that equilibrium.

These coastal systems of water-tolerant plants and tidal channels also "provide highly productive habitat and serve as nursery grounds for a large number of commercially important fin and shellfish," according to the researchers. Murray is an associate professor of geomorphology and coastal processes at Duke's Nicholas School of the Environment and Earth Sciences. Kirwan, the report's first author, is a doctoral student working with Murray.

Despite those benefits, a variety of environmental changes often linked to humans -- including sea-level rise, sinking land and alterations to sand and silt supplies that anchor the wetland plants -- are "affecting coastal marshes worldwide," the scientists said.

The research was funded by the National Science Foundation and the Andrew W. Mellon Foundation.

The team's model, which was based partly on field studies done in South Carolina, and compared with observations in Louisiana, Massachusetts and British Columbia marshlands, uses computerized m
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Contact: Monte Basgall
monte.basgall@duke.edu
919-681-8057
Duke University
28-Mar-2007