# Presentation: 899036

## Present distribution of the threatened snail darter (Percina tanasi)

- Matt Ashton and James B. Layzer
- Tennessee Cooperative Fishery Research Unit
- Department of Biology
- Tennessee Tech University, Cookeville, TN

## Objectives of study

- Present distribution of tributary populations

**Notes:**
The objectives of this study were to document the present distribution of the snail darter. 
This data is to provide the USFWS Cookeville Field Office with a scientific basis to determine whether or not objectives in the recovery plan may or may not have been met

## Study area

**Notes:**
The study area of this project included nine tributaries of the TN River, which are marked with the red dots, where snail darters have previously been found.
These included the French Broad, Holston, Little, Hiwassee, Ocoee, Sequatchie, and Paint Rock rivers, as well as Sewee and South Chickamauga Creek.
Nolichucky and Elk excluded transplants considered failed.

## Slide 4

**Notes:**
From top left to bottom right, these are pictures of sites where snail darters have been historically found, and were part of this past years survey.  They include a site on the Paint Rock River, Sequatchie River, South Chickamauga Creek, and the Holston River.  Of these specific sites, snail darters were only found at the Holston River location.

## Sampling methods

- Electrofishing - Scott 2003
- Snorkeling

**Notes:**
Two methods of sampling were used during the survey.
The primary method was backpack electrofishing following methods used by TVA/Scott 2003 – Snail Darter Monitoring Program of Douglas Tailwater.
One unit of effort = completed by shocking downstream a 300 sq ft area into a stationary seine w/ 1⁄4” mesh.
Snorkeling was used to verify the absence of darters if none were encountered during electrofishing and conditions permitted.
Also used in FBR and Holston River to cover large shoals

## Summary table – 2005 snail darter survey

**Notes:**
This table summarizes the findings of this past years survey.  Within it you can see the stream sampled, the distribution sampled, the number of samples taken, the number of snail darters collected electrofishing, and the number of snail darters observed while snorkeling if snorkeling was done.

## French Broad River

**Notes:**
Further summarizing data collected on the French Broad River -
113 Snail darters were collected electrofishing – all but 4 were at RM 8.0-Campbell Is.
Total of 121 measured (TL – mm) over the course of multiple sampling events.
Snorkel survey
8 sites, 11 events, 7.5 river miles
210 counted – all at RM 8.0

## Slide 8

**Notes:**
This table shows the length frequency distribution of P. tanasi collected on 5/18/05 by TVA, TDEC, TTU, UT, etc. @ Campbell Is. French Broad River – TDEC specimens were not used in my summary data because no records of # of samples were reported. N=117.

## Survey says?

- Prescence/Abscence
- French Broad River
- Other tributaries
- Young-of-year

**Notes:**
Conclusions from this past years survey.
Snail darters were present in seven of nine tributary streams sampled – they were NOT present in the Ocoee and Paint Rock rivers.
Of the 9 tributary populations these have the lowest historical occurrences of snail darters, the Ocoee only having one ever recorded.
When compared with recent data at least three year classes and later YOY were present in the French Broad River.
Nearly all fish were (~96%) present at Campbell Island - RM 8.0
Sample size was too low in other tributaries to develop length frequency analysis.
   Could be assigned to classes based on previous data.
YOY present after August in FBR and HITW - Most tributaries sampled prior

## Future work

- Microhabitat use
- YOY and adult fish
- French Broad and Hiwassee rivers

**Notes:**
Further work scheduled for this year includes a study of the microhabitat use of YOY and adult snail darters in the French Broad and Hiwassee rivers.

## Acknowledgements

- Private land owners, graduate students, and undergraduate students providing assistance.

**Notes:**
I would like to thank the USFWS and the Water Center at TTU for funding this project, Ed Scott and the TVA for sampling and logistical support, the TTU Co-operative Fishery Unit, private land owners for providing access to nearly all of my sites, and the graduate and undergraduate students who provided me assistance in conducting field work.

## Questions?