ML20042A895

Summarizes Striped Bass (Monroe Saxatilis) Situation Near Facility in Response to 811214 Telcon.Facility Is Cool Thermal Refuge for Adult Bass.Greatest Abundance Appear Along Steep Banks.Rept Re Fish Habitat Encl

ML20042A895
Person / Time
Site:	Clinch River
Issue date:	12/16/1981
From:	Coutant C OAK RIDGE NATIONAL LABORATORY
To:	Masnik M NRC
Shared Package
ML20042A896	List: ML20042A895 ML20042A902
References
NUDOCS 8203240251
Download: ML20042A895 (2)

Text

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OAK RIDGE NATIONAL LABORATORY OPERATED SV UNION CARBIDE CORPORATION NUCLEAR DIV1310N O

POST OFFICE 80X X M '

OAK RIDGE. TENNES$CE 37830 //

December 16, 1981 f.Ef40,Tn 3

5G, " D 2d1982a. h

@gfygga 4 Dr. Michael Masnik D "o AR-5200 rN O' US Nuclear Regulatory Commission Washington, D.C. 20555

Dear Mike:

In reply to your telephone call of December 14, here is a summary of the striped bass (Morone saxatilis) situation near the Clinch River Breeder Reactor Plant site. I have also enclosed a draft copy (without appendices) of the M.S. thesis by my graduate student, Terry Cheek, who studied the distribution and movements of stripers in Watts Bar Reservoir betwen July 1979 and December 1980 using telemetry techniques. Most of what we know about stripers near the breeder site has come from our study of the last 2-3 years.

As I mentioned over the phone, the Clinch R. below Melton Hill Dam and above Gallaher Bridge appears to be a cool thermal refuge for adults of this species in summer. In 1980, the summer temperatures were sufficiently high in the main body of the resrvoir (higher than about 25'C) that none of our tagged fish could be found there. All tagged fish and all fish collected by electroshocking for purposes of tagging or other research were found in the cool waters of the Clinch and in a cool spring area of the main Tennessee arm. The greatest abundance of fish appeared to be along steep banks on the outside of river bends in the vicinity of the breeder site. In contrast, the spring, fall and winter distributions covered most of the reservoir, with fish traveling widely and rapidly throughout the available reservoir volume. A secondary accumulation of stripers near the breeder bend occurred in June during a presumed spawning run. In 1979 there was also an accumulation of stripers in the cool water below the Tellico dam site, a location not available after November of that year.

Detailed data on the locations of fish in the breeder area are not available because of the reservoir-wide emphasis of our studies to date.

When we discovered the predominance of summer sightings near the breeder site, we notified Henry Piper in the Project Management Corporation. A proposal was offered for a detailed examination of the movements and habitat 8203240251 811213 29 DR ADOCK 05000537 PDR h\

2 preferences of adult striped bass in that area during summer 1981. That would h6ve been timely, for transmitters applied to fish in the winter of 1980 were still functioning, and costs would have been minimized. The response was one of concern but no funds were available.

It appears that the cool water of the Clinch is essential for maintaining adult striped bass in Watts Bar Reservoir. Although the reservoir is generally excellent habitat for this species in terms of space and food, the temperature appears to be too high in mid and late summer.

The enclosed manuscript of mine gives some of the general thermal requirements of this species, which are corroborated by the Watts Bar study. The Clinch refuge is, however, large enough to avoid severe overcrowding of habitat with attendant disease problems and die-offs tl'at have been observed in Cherokee Reservoir. If the striped bass fishery remains as a management objective for Watts Bar Reservoir by the Tennessee Wildlife Resources Agency, then the integrity of the Clinch thermal refuge should be maintained.

I personally believe that additional, detailed study of the distribution of striped bass in the vicinity of the breeder site will show that intake, discharge, loading dock, etc. can be placed so that conflicts with these fish are minimized. At the moment, however, we are in a shaky position to say that the breeder and the striped bass are compatible, and it is clear that the whole of the Watts Bar population of adults is potentially at risk (not just a localized subset).

As I noted on the phone, the same thermal refuge concept may be important for explaining the abundance of sauger (another cool-water species) in the lower Clinch River. We have little summertime data on this species, though. Our work for NRC concentrated on the winter shad kills at Kingston Steam Plant and the relationships to sauger populations. Some telemetry studies of distribution of sauger in the breeder area would be valuable for sorting out that problem.

I hope that these brief comments, our phone conversation, and the enclosed materials prove useful to you in evaluating the Clinch River Breeder Reactor license application. If I can be of further assistance, please do not hesitate to call upon me.

Sincer y, fL, Charles C. Coutant Environmental Sciences Division CCC:csa Enclosures (2) cc: S. I. Auerbach A. Myhr (TWRA)

H. Piper (CRBRP) (w/ enclosures)

W. Van Winkle