Sudden Wetland Dieback

Researchers are investigating whether a pathogenic fungus may be partly responsible for the rapid death of wetland grasses in New England.

Sudden Wetland Dieback has been recorded in several Gulf Coast and southeastern states as well as all New England states, and researchers suspect the latest outbreaks may be in the Mid-Atlantic, at Prime Hook National Wildlife Refuge in Delaware, said Susan Adamowicz, salt marsh researcher at Rachel Carson National Wildlife Refuge in Maine.

Although no one has determined the cause of the dieback in New England, researchers are looking into whether a strain of the fungus Fusarium is spreading disease on the common wetland grass Spartina, causing the vegetation to turn brown, wilt and wash away in a matter of weeks to months.

In Louisiana, where hundreds of thousands of wetland acres were lost to dieback, researchers believe the stressor was a severe drought beginning in 1999, possibly unleashing a strain of the disease-causing Fusarium that is slightly different than the one found in New England, said Irv Mendelssohn, a researcher with Louisiana State University’s Department of Oceanography. Mendelssohn said he believes the water shortage during the drought increased the acidity of the soil, releasing aluminum, iron and other metals that are toxic to the plants. Fusarium could have been a contributing problem, he said.

With the drought now over, recovery in the Gulf has been “appreciable,” he said.

New England has lost substantially less acreage to dieback, but the problem hasn’t subsided and last summer was among the wettest in recent years.

Contact: Susan Adamowicz, (207) 646-9226.