A Place Where They Live(d)
Dustin Hicks | May 2018
As I drag dwindling fragments of blue and red chalk across the deeply fractured pavement, marking the path of Boone Creek where it flows for nearly half a mile buried under a parking lot, I think about what it used to be: a gentle, clear, cold, forested mountain stream.
Boone Creek is a small headwater stream originating and flowing through Boone, North Carolina, until it eventually finds its way to the South Fork of the New River. I and others are here in an art-exploration of the creek’s past, and the past of those who have lived, played, and fished in its waters. I hope, in doing so, we are also imagining it a different future.
Inextricably, irrevocably attached to the story of human lives by our streams, is the story of the life that lives within them. In researching this life, I discovered that my home in the southern Appalachians is home to a third of the world’s freshwater mussel species. Like the local salamanders, mussels here benefited from getting off relatively easy in the ice age. The glaciers didn’t extend far south enough to have a huge impact on them, so they lived on, while other mussels in North America weren't so lucky.
For most of their lives, freshwater mussels are anchored to the stream bed. They're filter feeders, feasting on various broken-down plant matter and bacteria. They depend on a small siphon to catch the food in the current. That means it has to flow right past them, since they can’t move to reach for it. A great deal of this plant matter falls from the forest above. As a major prey species, they are a food source for many other animals including fish, crayfish, amphibians, reptiles, birds and mammals. Moreover, their sustenance purifies streams. They play a big role in making Appalachian streams the crystal-clear waters other species in the area depend on.
When the colonists arrived, the mussels coated the bottoms of streams across the area, and they named them accordingly. One popular name is various versions of the “heelsplitter,” a name that speaks for itself. There’s one such endangered mussel found only in the river system I call home: Carolina heelsplitter. Other names describe them by their appearance like purple wartyback, found upstream from Boone Creek in the New River Basin, or Appalachian elktoe, a species that finds its home in the French Broad and Tennessee river basins.
Unlike the Native Americans, freshwater mussels never became a significant food source for the colonists, but they did become wrapped up in an odd trade where their shells were voraciously hunted to be turned into buttons. This decimated many populations. The mussels were also found to be producers of pearls, yet another economic reason to hunt these creatures. North American mussels found a role in marine pearl production too. Their shells are used as seeds to start the formation of pearls in marine clams. This industry is still ongoing.
However, most of the threat today comes from more indirect sources. Chief among these is a ubiquitous substance all over earth: sediment. That might come as a surprise, but many freshwater creatures evolved in clear, pure streams, and can’t deal with dirty water. Freshwater mussels are a prime example. You remember that siphon they eat through? Well, if a sediment particle finds its way into that siphon, it chokes off their food supply, which can, of course, lead to death.
Although they are edible, I wouldn’t suggest it in an unclean stream. As filter feeders, freshwater mussels concentrate many toxins, including metals, which can kill them, or if they survive, gives all those contaminants to the unfortunate creature that eats them, potentially leading to higher and higher concentrations of toxins in animals that rely on them.
Other threats have to do with their unique reproductive strategy. Since they can’t move, freshwater mussels have developed a strategy to take advantage of more mobile aquatic lifeforms. It begins with the male mussel dispersing sperm into the water, which a female downstream then catches through that same siphon, and then the fertilized eggs are moved into the gills where they develop into the first larval stage. Then they are expelled, and, if lucky, find their way onto one of specific set of fish or salamander, where they latch on until they develop further. For some mussels, this is a parasitic relationship, but for them it’s commensal, as they don't cause the host any harm, they just use them to hitchhike a bit. Once they’ve reached the final stage, they fall off, and hopefully land in a place they can set up shop and start filtering away like their parents. In this way, they’ve been able to spread much further than they would otherwise be able. But, this comes with many vulnerabilities, as too much sediment often means the landed young want be able to breathe, or, if the river has been dammed, they won’t be able spread outside of that range, isolating populations from one another.
The Appalachian elktoe has suffered from a number of these in its short, fragmented range. It is endemic only to the Tennessee and French Broad rivers, both rivers the Cherokee considered sacred, and treated as such. Though it thrived under their watch, under colonial rule the elktoe is not doing so well. With isolated populations that can’t reach one another to breed, the numbers don’t look good, and in recent reading, it seems it may have already been extirpated from the French Broad.
Learning about all this, I come back to the creek. As a small mountain stream, it would have once been the perfect habitat for the elktoe (though they, in particular, may have never lived here). But now, the creek floods madly in storms, and the salt used to keep our roads ice-free pours in. With it partially buried, and partially exposed with little native plant coverage, I fear this isn’t a place where freshwater mussels might live anymore.
Dustin Hicks | May 2018
As I drag dwindling fragments of blue and red chalk across the deeply fractured pavement, marking the path of Boone Creek where it flows for nearly half a mile buried under a parking lot, I think about what it used to be: a gentle, clear, cold, forested mountain stream.
Boone Creek is a small headwater stream originating and flowing through Boone, North Carolina, until it eventually finds its way to the South Fork of the New River. I and others are here in an art-exploration of the creek’s past, and the past of those who have lived, played, and fished in its waters. I hope, in doing so, we are also imagining it a different future.
Inextricably, irrevocably attached to the story of human lives by our streams, is the story of the life that lives within them. In researching this life, I discovered that my home in the southern Appalachians is home to a third of the world’s freshwater mussel species. Like the local salamanders, mussels here benefited from getting off relatively easy in the ice age. The glaciers didn’t extend far south enough to have a huge impact on them, so they lived on, while other mussels in North America weren't so lucky.
For most of their lives, freshwater mussels are anchored to the stream bed. They're filter feeders, feasting on various broken-down plant matter and bacteria. They depend on a small siphon to catch the food in the current. That means it has to flow right past them, since they can’t move to reach for it. A great deal of this plant matter falls from the forest above. As a major prey species, they are a food source for many other animals including fish, crayfish, amphibians, reptiles, birds and mammals. Moreover, their sustenance purifies streams. They play a big role in making Appalachian streams the crystal-clear waters other species in the area depend on.
When the colonists arrived, the mussels coated the bottoms of streams across the area, and they named them accordingly. One popular name is various versions of the “heelsplitter,” a name that speaks for itself. There’s one such endangered mussel found only in the river system I call home: Carolina heelsplitter. Other names describe them by their appearance like purple wartyback, found upstream from Boone Creek in the New River Basin, or Appalachian elktoe, a species that finds its home in the French Broad and Tennessee river basins.
Unlike the Native Americans, freshwater mussels never became a significant food source for the colonists, but they did become wrapped up in an odd trade where their shells were voraciously hunted to be turned into buttons. This decimated many populations. The mussels were also found to be producers of pearls, yet another economic reason to hunt these creatures. North American mussels found a role in marine pearl production too. Their shells are used as seeds to start the formation of pearls in marine clams. This industry is still ongoing.
However, most of the threat today comes from more indirect sources. Chief among these is a ubiquitous substance all over earth: sediment. That might come as a surprise, but many freshwater creatures evolved in clear, pure streams, and can’t deal with dirty water. Freshwater mussels are a prime example. You remember that siphon they eat through? Well, if a sediment particle finds its way into that siphon, it chokes off their food supply, which can, of course, lead to death.
Although they are edible, I wouldn’t suggest it in an unclean stream. As filter feeders, freshwater mussels concentrate many toxins, including metals, which can kill them, or if they survive, gives all those contaminants to the unfortunate creature that eats them, potentially leading to higher and higher concentrations of toxins in animals that rely on them.
Other threats have to do with their unique reproductive strategy. Since they can’t move, freshwater mussels have developed a strategy to take advantage of more mobile aquatic lifeforms. It begins with the male mussel dispersing sperm into the water, which a female downstream then catches through that same siphon, and then the fertilized eggs are moved into the gills where they develop into the first larval stage. Then they are expelled, and, if lucky, find their way onto one of specific set of fish or salamander, where they latch on until they develop further. For some mussels, this is a parasitic relationship, but for them it’s commensal, as they don't cause the host any harm, they just use them to hitchhike a bit. Once they’ve reached the final stage, they fall off, and hopefully land in a place they can set up shop and start filtering away like their parents. In this way, they’ve been able to spread much further than they would otherwise be able. But, this comes with many vulnerabilities, as too much sediment often means the landed young want be able to breathe, or, if the river has been dammed, they won’t be able spread outside of that range, isolating populations from one another.
The Appalachian elktoe has suffered from a number of these in its short, fragmented range. It is endemic only to the Tennessee and French Broad rivers, both rivers the Cherokee considered sacred, and treated as such. Though it thrived under their watch, under colonial rule the elktoe is not doing so well. With isolated populations that can’t reach one another to breed, the numbers don’t look good, and in recent reading, it seems it may have already been extirpated from the French Broad.
Learning about all this, I come back to the creek. As a small mountain stream, it would have once been the perfect habitat for the elktoe (though they, in particular, may have never lived here). But now, the creek floods madly in storms, and the salt used to keep our roads ice-free pours in. With it partially buried, and partially exposed with little native plant coverage, I fear this isn’t a place where freshwater mussels might live anymore.