Last week, before Hurricane Alex fully unleashed itself along the Gulf coast, the news seemed better than many had expected. Oil didn’t appear to have penetrated the coastal marshlands to as great an extent as some coastal observers had feared. Alex pushed it farther toward beaches into wetlands in some areas; it’s unclear what effect future storms might have, because depending on their direction they might propel oil inland or move it away from the coast.
The marshes act as a buffer during storms—which is why it’s so alarming that they’re shrinking at a rate of 40 square miles or more each year—and now it appears they’re serving as a buffer against the oil as well. Scientists from the National Audubon Society’s Louisiana Coastal Initiative, Louisiana State University, Tulane University, and elsewhere are studying the oil’s progress, including surveying the marshes and wetlands from the air.
Wetlands, a Tulane scientists points out, effectively filter pollutants, and so far the outer edges of the coastal wetlands appear to be doing just that—but, he adds, it’s “a sacrificial sort of filtering” because the affected plants will likely die. Researchers will be watching in the coming months to see just what the widespread effect will be on the wetland plants and, since the plants anchor the ecosystem, on the continuing erosion of the coastal marshlands.