December 9, 2008

Ike’s effects back Texas eco-research

Hurricane Ike reconfirmed one Texas researcher's idea: Interfering with Galveston Island's natural elevation hurts the island's sand dunes and marsh flora.

Ike reconfirmed the basic idea I've had for several years, Rusty Feagin, ecosystem scientist with Texas AgriLife Research at Texas A&M University, said in a news release. The plants on sand dunes and in marshes build an island's elevation, so we shouldn't compromise that.

When comparing pre- and post-Ike marshes, Feagin said he found they lost elevation.

Feagin said four things are affected as a hurricane rolls over a barrier island such as Galveston Island -- beaches erode, sand dunes blow out, houses and buildings are damaged and marshes receive sediment deposits from the three other activities.

Feagin said sand dunes in the disaster area were eroding already when Ike hit, adding that natural mending may not be possible because structures and non-native landscapes are blocking dune re-establishment.

Feagin said marshes also help build new land because plants slow down rising tides, causing suspended sediment to settle.

However, when studying post-Ike surface erosion, Feagin said, we found the plants did not prevent sediment erosion by waves during Ike and in fact enhanced erosion because their roots wiggled, stirring up sediment to be washed out to sea.