Scientists are peering into the future, and the fate of the Great Marsh and other coastal salt marshes is coming into focus. The U.S. Geological Survey (USGS) predicts that by 2100, rising sea level – driven primarily by a warming climate – may submerge North Shore’s Great Marsh to such an extent that it will more resemble the mud flats and open water of Plum Island Sound than the iconic salt-hay landscape famously painted by Martin Johnson Heade.
So what’s at stake if the Great Marsh can’t keep up with sea level rise? As a self-described marsh rat, who grew up jumping ditches that crisscross the 20,000 acre marsh and still relishes weekends at a family duck hunting camp on Shad Creek in Rowley, the loss is difficult to fathom.
Take the commuter line from Ipswich to Newburyport and the grandeur of the Great Marsh is on full display. The train bisects the heart of the marsh, skipping from oak island to oak island, elevated just a few feet from the grass tips. Through the Lexan windows it’s not uncommon to see flocks of birds (greater yellowlegs, snowy egrets, least sandpipers, etc.) alight on the marsh surface or to glimpse a lone snowy owl perched on the pitch of a clam shack. Will these species move on or perhaps adapt to the anticipated changed landscape? Marshes are incredibly nutrient rich, processing and filtering organic material like a fine-tuned, backyard composter – giving back these nutrients to a range of other forms of life. If this enormous energy processor is gone, what will be the ripple effect?
Setting aside the profound ecological impacts there will be other losses; with the potential disappearance of the marsh a distinct cultural landscape disappears, like losing a priceless heirloom. I asked my friend, Geof Walker, a carver of beautiful marsh bird decoys who put it simply, “The Great Marsh holds a person's heart in its hands. It was a gift from my father, Hank Walker, the famous wildlife artist, to me. I have gifted it to my wife and sons, Nathan and Joshua. It’s hard to believe that this ritual will be lost forever and a place of such ecological importance will disappear.”
The 20,000-acre question is what can people and communities do to help these marshes keep up with rising seas and migrate inland? We are developing and implementing climate change adaptation strategies, but with especially-vulnerable wetlands like the Great Marsh, we may only have a generation or two to make sure we get it right.