Earth & Sky

Our thanks to the following individuals and institutions who assisted in the preparation of this script:

J.R. Shute
Conservation Fisheries, Inc.

Jim Herrig
Forest Fisheries Biologist
Cherokee National Forest, TN

To learn more about the captive propagation of endangered and threatened native North American fish, please visit the Conservation Fisheries Website here.

Author’s Notes:
Notes from an interview with J.R. Shute,
co-director, Conservation Fisheries

Can you describe one of your reintroduction projects?

The anchor project, the longest one, has been to reestablish four federally listed fish in Abrams Creek, in the Great Smoky Mountains National Park. Most of the source population for these reintroduced fish are from the Citigo creek in the Cherokee National Forest.

Citigo and Abrams Creeks are about 20 miles away. Both are tributaries of the Little Tennessee River. Historically, these waterways were connected. Fish from both creeks had access to the same gene pool. But they are now separated by dams.

Why did these fish disappear from Abrams creek?

In 1957, officials decided to introduce trout for fishing. In order to get rid of competing fish species, they poisoned the stream at Abrams Falls. From there, the poison was carried to the entire lower section of the stream, killing most fish. At the time, no one knew about the four rare fish species that lived there. One of them was discovered later, by someone who found a preserved specimen of a Smoky Madtom from Abrams Creek, that had been caught before the poisoning. The fish was scientifically described from that specimen, and the fish was presumed to be extinct. But in 1983, a student found the Smoky Madtom in Citigo creek.

There was a unique situation here; Abrams and Citigo Creeks had similar conditions. Except during the poisoning incident in 1957, Abrams Creek was in good shape. The ecosystem had bounced back over time. Some fish were able to reestablish themselves. But the four rare fish species did not survive the poison.

The Abrams Creek habitat was now healthy and it was possible to reintroduce these four fish species back to their natural habitat. But it wasn?t that simple; just catching fish from Citigo and placing them at Abrams was not possible because there simply weren’t enough fish in Citigo necessary to start a founding population in another creek. Around 1986, the U.S. Fish and Wildlife Service wanted to know if these fish could be propagated in captivity, and their offspring introduced to Abrams Creek.

How are the introduced fish in Abrams Creek doing?

After 12 to 14 years of work, we’re seeing successes in the reintroduction efforts. The Smoky Madtom and Yellowfin Madtom are doing well, and we’re hopeful about the Duskytail Darter and Spotfin Chub.

The Smoky Madtom is doing real well in Abrams Creek. It was initially described from a preserved specimen from Abrams Creek, and had been presumed extinct till its discovery at Citigo Creek. The Smoky Madtom is only known from these two streams. It?s listed as an endangered species. Currently, within its small range, it?s doing well.

The Yellow-fin Madtom, a federally threatened species, is doing OK. It used to be found in the Abrams Creek before the poisoning, and was mentioned in the poisoning survey. However, no specimens were kept. The fish introduced back to Abrams Creek came from Citigo Creek. Some fish are also known from Copper Creek in Virginia but that will probably turn out to be a different species. Some have been found in the Powell river as well, but are similar to the fish from Copper Creek. Historically, this fish was found in the Upper Tennessee River but has been extirpated due to impoundments (from dams) and poor water quality.

The Duskytail Darter is federally endangered. It is known to have once lived in Abrams Creek from a preserved specimen that was collected before the poisoning. The fish being used to populate Abrams Creek are from the Citigo Creek stock. These fish are also found in the Little River, which is the next drainage up, and quite close-by. The fish is also found in Copper Creek in Virginia. All these rivers used to be connected before dams were built. This darter tolerates big rivers and were able to move around quite a bit before dams were built. A specimen was known in the Holston River, a Tennessee river tributary, from the 1930s.

The Spotfin Chub, federally threatened, is found throughout the upper Tennessee drainage. But it is now restricted to a few populations. The source population introduced to Abrams Creek is from the Little Tennessee River in North Carolina. It?s on the same system as Abrams Creek so the fish are from the same gene pool as the previous residents of Abrams Creek. Until reservoirs arrived, these fish were able to intermingle. The spotfin chub is able to reproduce in large numbers in captivity. Although the project started 5 years ago, it?s only within the last 2 years that fish have been introduced to Abrams Creek. Surveys have indicated that the fish are reproducing naturally.

What does the success of this project mean for future reintroduction efforts?

The Southeast U.S. – Tennessee, Arkansas, Virginia, and Georgia – have the largest diversity of temperate freshwater fish in the world. Dams built along rivers have fragmented the range of many of those fish, their corridors of dispersal have been removed. Captive propagation of some fish species is needed to get these fish into restored areas that these fish no longer have access to, places where they once existed but were extirpated due to environmental degradation. This project can serve as a model for future reintroductions.

How do you determine which species are reintroduced to a habitat, and what guidelines do you follow?

Fish should only be reintroduced in their historic range. Never put fish in areas where they have not occurred naturally – there could be other closely-related fish to the ones being introduced, and they could hybridize, that’s something that should be avoided.

The ecosystem where the fish will be reintroduced should be able to sustain them. Many of these places were once degraded in the past, but have now recovered. Take for instance, the Teleco River in the Cherokee National Forest. Ten to twenty years ago, a cannery on the river caused pollution, and there was a poorly-run sewage treatment plant. The plant has now been upgraded and the cannery is gone. Improvements in logging practices more in tune with good land use practice – no more clear cutting – has also helped to improve water quality.

Another issue is genetic diversity. Eggs and breeder fish are collected from diverse locations from one year to the next, across the fish’s current range. In the case of introductions to Abrams Creek, the genetic population is from a wide cross-section of the genome from Citigo Creek, not from a small founder group of fishes. Abrams Creek once had access to the same fish gene pool as Citigo Creek, and that’s what’s being done in these reintroductions.

Also, all reintroduction projects are done by committee. A recovery team, consisting of scientists from the U.S. Fish and Wildlife Service, Forest Service, Park Service, local and state wildlife agencies, and private groups, meet to discuss what’s going on in current projects, decide on reasonable future projects, and brainstorm on various issues affecting captive propagations and reintroductions. CFI is currently working with these agencies to establish working guidelines for such reintroduction efforts.

How are the sites monitored and surveyed, to determine if it’s a suitable habitat for reintroduction, or to monitor progress of introduced fish?

Reintroduction sites are evaluated for food source availability, determining the presence and abundance of snails, mussels, and worms. Conditions are studied, such as the amount of siltation in the stream. Habitat structure is also important, for instance, rocks are needed in spawning sites for some fish species. In streams like Citigo and Abrams Creeks, these surveys are done by snorkeling.

Other methods are also used depending on the type of habitat and fish species. For instance, Pat Rakes monitors the Barrens topminnow, a small killifish confined to small springs, using binoculars to observe the fish. In other places, where water is murky and visibility bad, seines and dipnets are used in fish surveys. Methods that are potentially harmful to fish, like electrofishing, are avoided.