HomeMy WebLinkAboutNC0000396_Biological Studies_19850201 •.
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Ashevji•{,
tAjj1\ State of North Carolina
Department of Natural Resources and Community Development
512 North Salisbury Street • Raleigh, North Carolina 27611
James G. Martin, Governor S. Thomas Rhodes, Secretary
Division of Environmental Management
February 1, 1985
Mr. R. B. Starkey, Jr.
Manager, Environmental Services
Carolina Power and Light Company
Shearon Harris Energy and Environmental Center
Route 1, Box 327
Jew Hill , North Carolina 27562
Subject: Biological Studies
Carolina Power and Light Co.
Asheville Steam Electric Plant
Buncombe County, "1.OV
Dear F1r. Starkey:
Your letter of December 17, 1984, detailing the results of biological
studies in the cooling water impoundment of Asheville Steam Electric
Plant (Lake Julian) , has been reviewed by staff members of this Division.
As you are aware, conduct of these studies was a condition of NPDES
Permit No. NC0000396 issued June 30, 1981, and were to demonstrate that
Lake Julian remains a reasonable fishing resource in consideration of
the Company's thermal discharge.
In review of your recent report and previous results, it appears
that the cooling water discharge to Lake Julian from the CP&L Asheville
Steam Electric Plant has caused no drastic changes to the biota of
these waters , and that a reasonable recreational fishery continues to
be present. Therefore, no additional biological studies are necessary
at this time. We will , however, reinstate the requirement if there
is a clear indication of its need.
If you have any questions, please contact Mr. Forrest R. Westall
of our Asheville Regional Office at telephone number (704) 253-3341.
Sincerely,
ORf !NAL S(,_.;N:D BY
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R. Paul Wilms
Acting Director
��� RPW:dm P.O.Box.7687,Raleigh,North Carolina 27611-7687 Telephone 919-733-4984
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An Equal Opportunity.attirmativeAction Employer
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CP&L — BUNCOMBE COUNTY
rv` Carolina Power & Lig ht Company
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�/ Shearon Harris Energy & Environmental Center
/ Route 1. Box 327
New Hill. North Carolina 27562
DEC 17 1984
Serial: ESS-84-924
Mr. Roy Davis �•..a''1
N.C. DNR&CD
Division of Environmental Management '
Interchange Building
159 Woodfin Street
P.O. Box 370 !c, '-
Asheville, North Ca' ILLItt D-4-1
Dear Mr. Westall: c4
Biolof 1 7= 1dant
Biological st ctric Plant cooling
impoundment) we �`' � with the program
approved by the { ' lent. Sampling has
been completed E I �
anticipated for the
remainder of the
Samples cc ;, and data are being
analyzed. Preli ins in the lake were
physically and c :nthos, and zooplank-
ton population , and it appears at this
time that popultt,..,,__ 7-to-year variation.
Discrete depth zooplankton sampling appe . indicate that during
summer months, microcrustaceans migrate down through the water column to
the vicinity of the thermocline (and exhibit diel vertical migrations) rather
than disappear from the lake. Macroinvertebrate data do not indicate ele-
vated concentrations in the deep 'bottom areas during summer but do indicate
that populations of oligochaetes and tolerant chironomids are present. Food
habit studies of tilapia indicate that the fish feed predominantly on diatoms
and filamentous green and blue-green algae (during the winter collection
period). Some benthic organisms and sediment were found in stomachs, but
occurrence was irregular. No ichthyofauna were found in tilapia stomachs.
Standing crop estimates from two coves in Lake Julian ranged from
4,565 to 32,020 fish per hectare. Weight varied from 59.8 to 203.9
kg/hectare. The average standing crop (table enclosed) was greater than
many other reservoirs and species composition is similar to that reported in
past years. The greatest changes in fish populations, as indicated by the
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Mr. Roy Davis 2 DEC 17 1984
standing crop estimates, were declines in blue tilapia and increases in
threadfin shad. The decline in blue tilapia is probably the result of cold water
temperatures in January that killed thousands of tilapia. The number and size
of tilapia collected, however, indicate that they remain a dominant species in
the lake and abundance is probably increasing. Largemouth bass averaged 120
fish weighing 5.8 kg/hectare, while bluegill averaged 3526 fish weighing 31.4
kg/hectare. These values indicate good populations relative to most other
mountain lakes. The data necessary to make population estimates for large-
mouth bass has been entered on the computer system, but no estimates are
available yet.
The preliminary creel survey data indicate that fishing pressure during
spring was very high and that good catches of largemouth bass, bluegill, and
channel catfish were made. There were catches of tilapia made during sum-
mer indicating some fisherman utilization. Until all data are received, how-
ever, no estimates can be made of fishing pressure or exploitation of the
various fish species on an annual basis.
With this information, it appears that no drastic changes have occurred
to the biota of Lake Julian and that a reasonable recreational fishery con-
tinues to exist. It will take several months following completion of sampling
(December 1984) to completely analyze the data and produce a report. It is
anticipated that such a report will be completed in early 1985 and submitted
to you by May 1, 1985.
Since biotic conditions are similar to previous years and specific anal-
yses will not be available until 1985, CP&L plans no field studies to be con-
ducted at Lake Julian next year. This will allow thorough analysis of the data
and recommendation and review of management and/or monitoring activities
for future years.
We would be glad to discuss this proposal at your convenience or respond
to any questions you may have.
Yours very truly,
R. B. Starkey, Jr
Manager
Environmental Services
W H T/sbk
Enclosure
cc: Mr. R. B. Hamilton
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Table 1 Density and standing crop estimates of fish collected by cove
rotenone sampling at Lake Julian during 1984 (Coves A and 0
combined).
Species Number/hectare Weight (kg)/hectare
Threadfin shad 12,842 26.5
Unidentified bullhead 2 < 0.1
Brown bullhead 17 < 0.1
Channel catfish 64 4.8
Unidentified sunfish 31 0.1
Sunfish (hybrid) 7 0.1
Redbreast sunfish 1,068 8.5
Warmouth 176 0.4
Bluegill 3,526 31.4
Redear sunfish 7 0.8
Largemouth bass 120 5.8
Blue tilapia 431 53.4
Total 18,292 131.9