Still too early to assess effects of Gulf oil spill.

• Position: The Environment

The doom-and-gloom predictions for the Gulf oil spill's effects on coastal wetlands are premature, asserts one researcher whose work focuses on wetland restoration, nutrient enrichment and eutrophication, carbon sequestration, and the effects of climate change.

"At this point, the effects of the oil probably are limited to the aboveground vegetation," contends Christopher Craft, former president of the Society of Wetland Scientists, Washington, D.C. "The roots that contain food reserves that enable the shoots to resprout seem to be unaffected. With chronic and repeated exposure to oil, though, the roots could die and the marsh surface collapse, since the roots hold the marsh and soil together. This could lead to disintegration of the marsh as it will convert to open water."

Moreover, Craft explains, the wetlands, which are home to a wide variety of birds, reptiles, amphibians, and insects--key components to the food web--have been disintegrating for many years. "Coastal Louisiana's wetlands have been under siege for a century or more. The Mississippi River delta is sinking as a result of natural and human-caused activities. Delta regions naturally sink over time as the soft sediments that are deposited by river flooding consolidate and compact. The landscape is stable as long as fresh sediment is deposited by the annual river floods.

"However, human activities, such as construction of dikes and...