Conservation Fisheries, Inc.

Newsletter #23 April 2004

Summer 2004 Happenings

Well, I always plan to do a better job getting the Newsletter published on a regular basis. Like so many things, it tends to fall farther and farther down my "to do" list! I did want to get out a brief update and hope to put together something more substantial in the near future.

Once again, springtime field work has been made more difficult by the weather. Small stream work has not been too bad, but getting into the larger rivers has been difficult. We have had just enough rain to keep levels up and the water murky. And, as I look out the window, looks like more is on the way! Springtime in the southeast! 

We have been able to get into Citico Creek to do our madtom nest collecting. Both smoky and yellowfin madtoms seem to be doing great, based on the ease of finding nests this year. Yellowfins seem to be continuing to move downstream in the creek. We still have no idea why this species was never seen in the lower reaches of Citico until recently.

We have also been into Abrams Creek this spring to check on the reintroduced fishes there. Most of you are familiar with this work. We have been stocking propagated smoky and yellowfin madtoms along with duskytail darters (all from Citico Creek stock) for some years now. This project continues to look promising! Duskytail darters can be found nesting throughout several stream miles. In fact, we have not stocked any additional duskytails into Abrams in the past couple of years, and still see good numbers (including nests) whenever we survey! At this point, all duskytail darters seen in Abrams Creek were spawned there as these guys only live a year or two.

We also discovered a smoky madtom male with nest just above the Abrams Creek campground in June. This is a site that initially showed considerable promise and had, arguably, some of the best smoky madtom habitat in the stream. This area, however, became a favorite site for campground users to construct rock dams. In fact, the dam grew, at one time, to be over two feet tall! 

This dam not only incorporated most of the slab rocks that would normally serve as nesting sites for the madtoms and duskytail darters, but its presence altered the nature of the pool/riffle transition zone that constitutes the primary habitat of the smoky madtom. Since the construction of this dam (and it seemed to be an ongoing project for several seasons), we had been unable to document any smoky madtoms at this site (prior to the dam, this had been one of the sites where we could almost always find them). 

In early spring 2003, we completely dismantled this dam. Amazingly, with no preexisting dam there, the Park users have yet to reconstruct it! By last fall, the site was looking much better and the pool/riffle transition zone had returned to something resembling its former condition. This is where we found the male nesting this spring! It is encouraging to see these fish moving back into this improved habitat and we hope the campers don't decide to get back into the dam building business! 

In hatchery news, quite a bit is going on right now. We are in the midst of our best year ever for Barrens topminnow production. We have also been working on techniques to better harvest and rear pelagic darter larvae.

Basically, eggs that have either been spawned into a tank located above this tub, or have been moved into a tank above the tub, hatch; the larvae swim up into the water column, and are eventually captured by the overflow which empties into this tub. That is a greatly oversimplified description, but will, hopefully give you some idea of the nature of the set up. This was a great success when used with the Warrior darters! We have since used it with boulder darters, yellowcheek darters, and Etowah darters. All of these have small, pelagic larvae that are probably easily damaged in their handling (removing eggs from substrate etc...). Larvae are easily concentrated in these tubs and are more easily fed the necessary fine foods needed to rear them. Since these tubs are on line with the rest of the system, water quality is not often an issue. We will present more complete details of this system in upcoming newsletters.

On another matter relating to the hatchery..... CFI recently received funding from the Duke Energy Corporation that is earmarked to go toward the purchase and installation of a dedicated back up generator for our facility! This money, coupled with funds from the Fish and Wildlife Service and others brings us closer to being able to complete this project. We are now trying to raise the remaining funds so, hopefully we can finish this project this summer. We will certainly rest easier when the generator is in place!