Tracking the sicklefin: Understanding rare fish’s lifestyle important for conservation
The sicklefin redhorse is a sneaky kind of fish. It wasn’t discovered as a species until 1992, and even with its existence known, the fish is difficult to tag and track, avoiding radio detection at the bottom of deep river pools. But will the bottom-feeding suckerfish also be able to avoid getting listed as a threatened or endangered species?
Mike LaVoie, biologist for the Eastern Band of Cherokee Indians, is hoping to answer that question with a negative. The sicklefin has been a candidate for listing since the early 2000s — candidate species are those for whom listing is recommended but funds aren’t available to follow through — but it’s likely the U.S. Fish and Wildlife Service will make a decision by the end of 2015. Listing can help vulnerable species make a comeback, but it can also make things more difficult for people who use the river.
“Our goal when we began this initiative with our partners with the Fish and Wildlife Service and the [N.C.] Wildlife Resources Commission and the Conservation Fisheries was to actively work together to restore this fish without the need for it to be listed under the Endangered Species Act,” LaVoie said.
The initiative LaVoie refers to is a restocking effort that has, over the last two years, released about 12,000 sicklefin into the upper Oconaluftee and 16,000 into the Tuckasegee River, of which the Oconaluftee is a tributary.
That’s a lot of fish, but it’s hard to say what those release numbers mean for the total population. Some wild fish already lived in the rivers, adding to the number, but young fish like the 28,000 released tend to have a high mortality rate. It’s likely that many of them died before reaching adulthood.
LaVoie needed some more information about how well the creatures were doing after release — whether they were reproducing in the wild, which locations provided the best habitat and what other species they were associating with.
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Tagging and tracking
This August, LaVoie’s department teamed up with the Fish and Wildlife Service and University of North Carolina Asheville to gather some of that information, releasing 10 tagged adult sicklefin into the upper Oconaluftee. The core question: are the sicklefin happy in the upper Luftee?
“The upper Oconaluftee is more of a natural system with the park protecting a larger portion of the headwaters,” LaVoie explained.
Which might sound like a pure positive, but earlier studies had shown that young sicklefin tend to drift downstream in search of pool habitat. Often, they’d fall over Ela Dam into the lower Luftee and were then unable to make it back to the upper part of the river. This year’s study aimed to find out if there was enough habitat upstream of the dam to make stocking efforts worthwhile there.
“Tagging them and seeing where they go and where they move and if they are in suitable habitat, it’s important to see that if they are able to survive and if they are able to assimilate with native populations, and hopefully breed,” said Jessica Davis, an intern from UNCA who’s been working on the project.
Initially, the researchers tried to answer that question by tagging 11 juvenile fish, but that effort didn’t meet much success. Of the 11, only four survived the surgery to implant the tag, and only two of the tags activated properly. After one week, the fish essentially disappeared.
“We spent about three weeks going along the riverbank using a handheld device, then we floated the river the whole way,” Davis said while presenting her results at the 2014 Southeastern Fishes Council meeting in Asheville.
When the fish were eventually found, they were hanging out in the same pool where they’d initially been released.
Researchers followed that effort up with an August translocation of 10 adult fish, which were taken from the Tuckesegee in Swain County, tagged and then released into the upper Oconaluftee. Though five of the 10 eluded radio detection still, this tracking project was a good bit more successful than the one with juveniles. The five detectable fish were located a total of 56 times, allowing the scientists to find some patterns.
“We’ve seen some movement on about half the fish, but there’s also been evidence of site fidelity where the fish are staying in one place,” LaVoie said. “So it appears that some of this habitat available in the upper Oconaluftee may be suitable for these fish.”
In other words, most of the fish seemed to find a place they liked well enough to stay.
“Hopefully, that means that they’re happy, healthy and eating a whole lot of food,” Davis said.
For the five fish researchers were able to locate, the evidence seemed to indicate a happy, healthy and food-full life. Fish stayed within about 1.5 miles of their release site, for the most part settling in one place.
“Scientifically and statistically, it’s too early to say if they’ve integrated into a suitable habitat, but considering other past projects that are similar to this, they have assimilated pretty well into the Oconaluftee,” Davis said.
Dealing with the dam
The upper and lower Luftee are separated by the Ela Dam, so part of the point of tagging and tracking the fish was to figure out whether it’s worth it to release fish above the dam or if they end up just moving down through the spillway anyway, into the lower Luftee and maybe the Tuck eventually.
To date, LaVoie said, researchers had not found any adult sicklefin above the dam, and in a juvenile tagging study done two years ago with researchers from Western Carolina University, the majority of the fish ended up washing downriver.
“Our initial thoughts are that the reach of river above Ela Dam may not be long enough to support juvenile recruitment due to the fact that these fish naturally drift downstream in their early stages of life to smaller pool-like habitat,” LaVoie said.
This latest adult tagging study also showed that the fish overwhelmingly preferred downstream movement. And while the five located fish were found to have settled down into pool above the dam, it’s hard to say what happened to the other five.
“At this point we’re still looking for five of the other fish, and it’s possible that some of these adult fish may have gone through the dam as well,” LaVoie said. “They may have moved down into the main stem of the Tuck or even down into Fontana [Lake].”
Because sicklefin redhorse stick to the bottom of the deep pools in the river, it can be hard for radio telemetry equipment to pick up the signals. The five missing fish could just be living in extremely deep holes, or their tags could have stopped working.
Data analysis for the project goes through Oct. 21 fro now, but monitoring will continue through 2015 to see what happens to movement through the winter and spring spawning season. Davis says she plans to stay on the project for as long as there is funding and knows she’ll be there at least through February.
Culture and ecology
Hopefully, the data will reveal some good news for the sicklefin redhorse. Most anglers don’t seek to hook the bony bottomfeeder, but for the Cherokee people, the fish represents a historical staple of food and culture.
“The fish would move through these streams in pretty regular patterns during spawning runs, so they would provide a regular, large source of protein for Cherokee fishermen during certain times of the year,” LaVoie said.
The large-bodied sucker can reach 5 pounds and 24 inches, so nabbing a few of those during spawning times could go a long way toward feeding a family.
Today, Cherokee don’t fish for the sicklefin in the large numbers they used to, but some people carry on the tradition. If the fish were listed as threatened or endangered, there would be more regulation involved with continuing that practice. It’s likely some sort of compromise could be worked out to allow Cherokee to continue the culturally related practice in some capacity, though rules would be tighter with an endangered listing than with a threatened listing.
But it will be in everybody’s best interest for the sicklefin to thrive, avoiding listing and continuing to fill its niche in both environment and culture.
“We’re interested in preserving a culturally important species but also conserving a rare species that also needs a lot of focused effort to conserve,” LaVoie said.
