In April, Steve Rogers, a.k.a. Captain America, will be gunned down on the steps of a courthouse after being convicted of crimes against the government. News of the sudden end of the 66-year-old figure has captured headlines across the world. The story has already run on all major media outlets and even Variety had the decency to run an obituary.

The death of Cap is not simply the demise of a fictional character. He was an American icon—thanks to an experimental Super Soldier serum, he became a “perfect” human who technically did not have any super powers, but was just an ordinary guy who lived up to his full potential —and it’s always traumatic when an icon bites the dust. People cried when the “Old Man of the Mountain” became the “Rubble Formerly Known as the Old Man of the Mountain.” And some are already reaching for the tissues because of the danger posed to another American icon: the salt marsh. Though salt marshes are not nearly as well known as Captain America, there are unexpected and eerie parallels between their fates.

Like Captain America, healthy wild places are the embodiment of the American spirit. But the beautiful fields of tall grasses that line New England’s coastal waterways are being plagued by a new ailment. Termed “sudden wetland dieback,” the condition results in the relatively rapid death of salt marsh plants in one or two growing seasons. SWD affects primarily smooth cordgrass (Spartina alterniflora) and suddenly appeared in New England during the last five years. The condition makes a formerly healthy salt marsh look like Ron Howard’s receding hairline. Large bare patches appear in the marsh, marked by dead or dying grass stubble. The phenomenon causes salt marsh ecologists to shiver—there is no clear cause for the dieback and the implications on the salt marsh ecology are unknown.

The primary concern is that the underlying peat, a rich organic “meatloaf” for a multitude of creatures, will quickly erode against the onslaught of tidal currents and sheets of ice without the anchoring effect of the cordgrass roots. The soil may erode so much that the height of the marsh will drop and the sea will gain a deeper foothold on the land. The change in the diverse and important salt marsh ecology may spell trouble for species dependant on this habitat, like the saltmarsh sharp-tailed sparrow (Ammodramus caudacutus).

Despite seemingly normal conditions, the plants affected by SWD simply cease to grow. Stephen Smith, plant ecologist for the Cape Cod National Seashore, has noted that soil taken from an affected marsh can produce healthy cordgrass in a greenhouse, and plants transplanted into affected areas will grow, too. For now, it seems the reason for SWD, like the reason for Captain America’s murder, is a mystery.

According to Captain America’s publishing company, Marvel, Cap’s assassin was the villain Crossbones. He was hired by Cap’s arch enemy, the Red Skull. It is suspected that Cap’s death is part of a bigger plot by the Red Skull, rather than a simple case of “kill the nemesis.” Crossbones’ bullet only hit Cap in the shoulder. The deadly blow came from Cap’s friend Agent 13, who pumped three bullets into his gut after the sniper’s shot. But she was under a hypnotic spell at the time, so she really can’t be held accountable for her part in his death. The overall plot behind Cap’s death will likely be revealed soon, but for now fans can only guess.

Salt marsh ecologists have only guesses at this stage, too. A few leads on the cause of SWD sound like capers carried out by super villains. One suggestion is that it might be death by acid. Chemical changes that occur when the salt marsh soil is exposed to oxygen may be allowing a type of bacteria to create sulfuric acid, which in turn weakens the cordgrass. This makes it susceptible to other diseases. Another thought is that the super-villain “The Purple Crab” (sesarma reticulatum ) may be terrorizing the cordgrass at its weakest moments. But perhaps the best villainous theory is fungus from Africa. In the past three decades, coral reefs in the Caribbean have been dying and the suspected culprits are pathogens from African dust storms. Some salt marsh ecologists believe that the African dust may be distributing pollutants or microorganisms to New England salt marshes, too. The dust has been shown to contain fusarium, a fungus known to harm plants. However, there is too little evidence to convict the evil African dust. Currently, super sleuthing scientists are checking its alibi.

In the end, it will likely be determined that it is a multitude of “villains” that are quickly taking down the salt marshes. A combination of ecological factors may be creating an inhospitable environment. It is sort of like a plot crafted by “Masters of Evil,” the super villain group that often goes up against The Avengers, the all-star super hero group of which Captain America was a founding member.

All is not lost, though. Marvel chat rooms concur that Captain America will return—it’s clear that Steve Rogers is dead, but the Captain America suit can be worn by anyone. The leading contender is Frank Castle, a super vigillanti called “The Punisher.” Salt marshes may recover as well. Some places in New England have recovered, although tidal wetlands in some parts of the Cape are still struggling. SWD has not been around long enough to know if it is a permanent condition. It is important to monitor the problem and avoid loosing the iconic New England salt marshes.

To see an example of SWD in the Seacoast, you can take a walk to the salt marshes of North Mill Pond in Portsmouth. To see Captain America in action, you could rent the 1970s movie “Captain America” starring Reb Brown. It was created in the spirit of Linda Carter’s “Wonder Woman” and Lou Ferrigno’s “Incredible Hulk.”