For episode 30, Caleb Moses shares his work on reintroducing native freshwater mussels to Abrams Creek in the Great Smoky Mountains National Park. You can watch the full interview on our YouTube channel or in the video below.

What are we doing out here?

Well, we came out. We’re trying to do a survey site, and that kind of fell through, but we came out to check my silos and cages that are holding mussels in Abrams Creek for a long survey on how they do with reintroduction here.

What made you want to do this project?

This is actually the third project I’ve done on Abrams Creek, so I love it here. This is one of my favorite rivers in the Southeast in general, and I started getting interested in mussels a year or so after I graduated from my undergrad, and then this opportunity came along with helping the park service to restore the mussel community here.

Could you talk about the history of Abrams Creek?

Abrams Creek flows through Cades Cove. That’s where the area where its headwaters originate, and it flows through several limestone layers there, so it’s a very diverse stream. Lots of algae, lots of macrophytes, lots of insects. That makes a lot of fish diversity, produces a lot of fish diversity here. In the 1950s, Abrams Creek was chosen to become a trophy trout stream, and to accomplish that they decided to remove all the native fish species here. So, they rotenoned from Abrams Falls to what was in the Tennessee River, killed all the native fish off, and then later that same year, Chilhowee Dam was completed, which prevented any natural recolonization of the native fish species here. So, mussels require fish to complete their life cycle. So, when the fish went, the mussels pretty soon after followed and were pretty effectively removed from Abrams Creek as well. So, the fish fortunately have been restored. Several populations that were thought to have been made extinct by that treatment were found in several sister streams nearby and have been restored here, so now, we can start looking at putting mussels back now that part of their life cycle has been restored.

What role does a fish play in a mussel’s life cycle?

Mussels require a fish host to reproduce, so at the start of the cycle, female mussels will either make a lure or something that looks like a food packet or really anything to just entice their preferred fish host. That usually entices the fish to come up close to the mussel or to eat her packet of glochidia, and the end goal is for the mussel glochidia, or juvenile, young, to attach to the fish’s gills and fins and other areas that carry blood through the fish. They attach and affix onto the fish, ride it for about three weeks or so. It depends on the species. There’s a wide range of how long they’ll stay on, but they’ll feed on the fish’s blood at that time, draw on the nutrition from the fish to grow, and then fall off and begin to grow in the substrate filter feed, and then the cycle starts all over. Once they’re big enough, they’ll attract another preferred host fish, and it starts all over from there.

Are you hoping to continue this research after you graduate?

Yes! I love working with mussels, so I really am aiming to continue to work with mussels in the future whether that be as a malacologist or just as someone who is helping manage mussel populations somewhere. That’s all I’m aiming for is for my next position to work with mussels in some capacity.

If you had to tell someone why mussels are important, what would you say?

There’s a lot of directions I could go with that, and I’m kind of biased because I love mussels, but I mean mussels are a really intrinsic part of our ecosystem here. They’re a vital part of what makes up our biodiversity here in the Southeast, and they’re something that not a lot of people expect to be here you know. When you start digging around and showing people mussels from the river, that just looks like a rock. That doesn’t really look like a living thing, but they’re very much alive, and they have this crazy unique life cycle that they go through. Tennessee has around 139 species, which you really wouldn’t expect, but you know there’s an insane amount of diversity.

From a management aspect, they’re an invaluable indicator species because whereas species of fish, crayfish, and even other mollusks can move out of the way, mussels are pretty sedentary. They’re pretty well stuck in place, so they can’t move out of the way of pulse pollutants or a wide range of things affect them, but they will reliably indicate if something’s wrong in a stream whereas other species could just move out of the way of the pollutants.

Culturally, if you look back, they’ve been important to people for a really long time. They appear in spiritual art. They were money at one point, so you know, there’s a whole long history to them, but now, they’re just important kind of because they’re there, and aquatic biodiversity is worth preserving.

Is there anything else you want to say about your research or plans after you graduate?

This is the kind of work that needs to be done for a broad range of organisms. Mussels are not the only ones that need help, so that’s something I like to tell people. Even if you’re not interested in mussels, this needs to happen, this type of work needs to happen for crayfish, for snails, for birds, for lizards, for you know. If it’s something you’re interested in, there’s projects like this that are there to be done, so it’s important work regardless of what you’re dealing with. It’s meaningful and valuable and worth doing.