State officials are asking volunteers to help identify areas where Delaware marshes are dying, a phenomenon not unique to the area but one identified here last year.
Chris Bason, a scientist with the Center for the Inland Bays, and others noticed the occurrence, dubbed “marsh dieback” or “brown marsh,” late last year after normally-lush salt marshes around Sussex County’s Inland Bays turned brown.
Officials have noticed dieback across the watershed, threatening of the area’s most precious and valuable resources. The Delaware Department of Natural Resources and Environmental Control plans to monitor the situation in this area — and likely statewide, as more situations arise. But officials do not yet have funding to study its causes and initiate potential solutions.
“It’s definitely a big concern,” Bason said. “It’s essentially a new disturbance to the marsh, a new stressor to the marsh. We don’t now if the cause is a natural cause or if it’s triggered by a number of stressors out there.”
Marsh dieback could lead the loss of the salt marshes it has invaded in this area, resulting in potentially dire consequences for pollution control and for wildlife populations. Salt marshes serve as habitats to numerous species, protect uplands from water surges and capture carbon dioxide pollutants and nutrients, such as nitrogen and phosphorous, that run into the Inland Bays daily, polluting the water and wreaking havoc on underwater habitat.
Unwanted nutrients lead to low oxygen levels underwater and fish kills and carbon is believed to be a major contributor to global warming. Global warming, the predicted sea rise that comes with it and human encroachment are already said to be dangers to salt marshes in the Inland Bays.
Anyone who notices dieback along marshes — mainly noticeable by a formerly green marsh turning brown — is being urged to contact Andy Howard, a DNREC scientist, through the Internet at www.dnrec.delaware.gov or at (302) 739-9939.
“We are just looking for people that are out in the boat or out in the field and see dieback,” Howard said. “We’d like for them to report where they have been seeing it. No one really knows,” the cause of the dieback in Delaware’s Inland Bays, he added. “That’s one of the biggest problems.”
Bason said that, late last year, areas around the bays that are normally lush only showed roughly 6 percent to 25 percent vegetative coverage. The dieback essentially transforms vegetated marshes into mudflats.
The phenomenon has occurred in other spots along the East Coast and in the Gulf Coast, where it affected more than 100,000 acres in Louisiana in the late 1990’s and early 2000’s. Experts say that fungi and small parasites living within and feeding on the marshes can cause the problem, as can drought.
Greg Grandy, a project manager with the Louisiana Department of Natural Resources, said last fall that his state’s problem was mainly caused by severe drought in the late ’90s. Snails and other animals living within the marsh then expanded the damaged areas by feeding on the vegetation that had survived.
Nearly 90 percent of the marshes there recovered when supportive weather returned — something Bason expects to happen in Delaware.
Grandy said he and his department also used re-planting techniques to revive marshes in Louisiana. Because of a lack of funding, no such measures are currently planned for the portion of Sussex County marshes that, according to Bason, will not recover.
“On a positive note, we will see recovery,” Bason said, adding that he expects the problem to also arise in the Delaware and Chesapeake Bay systems. “The bad side of it is that we might be losing marshes to this. This might tip the scale for a number of different marshes, and we could lose the functions of those marshes we rely on.”