ML20083Q070

Forwards Addl Comments Re Fish Kill in Response to 730131 Telcon

ML20083Q070
Person / Time
Site:	Oyster Creek
Issue date:	02/02/1973
From:	Reintjes J COMMERCE, DEPT. OF, NATIONAL MARINE FISHERIES SERVICE
To:	Stohr J US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20083Q056	List: ML20083Q066 ML20083Q070 ML20083Q088
References
NUDOCS 8302230066
Download: ML20083Q070 (4)

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/ U S, EEPARTM CF CZMMERTE

, se.  ; N:ti:nal Ocozia cnd Atm::pheric Admini:tration

\ "O ,/ . NATIONAL MARINE FISHERIES SERVICE *

• " # Atlantic Estuarine Fisheries Center Beaufort, North Carolina 28516 i

. February 2, 1973 - -

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Mr. J. P. Stohr, Sr. -

Environmental Protection and Special Programs Section U.S. Atomic Energy Commission Directorate of Regulatory Operations Region I 970 Broad Street Newark, NJ 07102

Dear Mr. Stohr:

In response to your telephone call cf January 31, attachra are

' Additional Comments Relative to the Oyster Crock Menhaden Kill, January 1973." I have includad more information on the esti-mates of menhaden killed with scxnc statistical confidence limits as to what these estimates might mean. 'Because relatively unscientific methods were used ,in sampling, it is questionable that a Atatistical treatment is appropriate. I hope these addi-tional remarks are helpful.

If I do not see you and discuss these reports at the Johns "Hopkins University Workshop in Baltimore, I would appreciate some further discussion on the type and c-ontent of reports you would like res arding any future consulting.

Also enclosed are copies of Dr. Wurtz' reports of January 11 and 17.

Sincerely, W 9E c,. .,

• J hn W. Reintjos Fishery Biologist Attachments O

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'125/1 Additional Comments Relative to Oyster Creek Menhaden Kill, January 1973. ,

e In my report of January 19, I summarized information received from three sources: 1. Charles B. Wurtz, Biological Consultant.

2. Paul E. Hamer, Director, N.J. Nacote Creek Research Station,

3. John Mahoney, Fishery Biologist, Middle Atlantic Coastal Fisheries Center, Sandy Hook From the information received, I compiled 3 estimates of.the number of dead menhaden in the surface ice of Oyster Creek and 1 estimate of the total kill including those out of sight on the bottom.

3 1. Dr. Wurtz estimated 900 dead in 20,000 ft 2 of surface ice in the 4 finger lagoons.- This number was arrived at by counting the dead fish in the terminal 50 feet of each lagoon. He mentioned that the dead seemed concentrated in the closed end of each lagoon. However,

.if the number were extrapolated to the total area of the 4 lagoons (I estimated each lagoon was 1,000 by 100 feet), it would give an estimate of 18,000 dead menhaden. For comparison, if th,e dimensions used by NCRS were used the extrapblated figure would be 24,468 dead in the surface ice of the 4 lagoons.

2. Paul E. Hamer and staff biologists estimated 23,000 dead menhaden in the surface ice of the 4 finger lagoons. This was done by counting the number of dead while walking on the ice. The area covered was approximately 1/4 of the lagoon starting from the closed end. They cut holes in the ice and used an Ekman grab dredge (36 in2 ) to sample the fish on the bottom. They made 9 grabs towards the closed ends of the lagoons and obtained 5 menhaden, 4-5 in. long. From these sampics they calculated the number of dead menhaden in the bottom of the lagoons. The lagoon dimensions used were 1,050 by 125 ft. for the 3 western and 1,200 by 125 feet for the easternmost.

3. I called John Mahoney because'I heard that Sandy Hook Laboratory had investigated the kill. He had not been involved but would inquire and call me back. He reported that someone from the Laboratory had called Mr. Mallie, a yacht basin operator at Forked River. Mr. Mallic estimated 6 dead menhaden per 2yd frozen in the ice along the bulkheads and 1 per yd2 in the central areas of the lagoons. By interpreting and extrapolating this observation, an estimated total.of 58,000 fish

! was obtained for the 4 lagoons, 1000 X 100 ft. For comparison, if the l

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dimensionsusedbyNCRSwereusedtheextrapolatedfigurewouldbk[

74,718 dead in the surface. ice of the 4 lagoons.

The estimates of 23,000, 24,468, Land 74,718 when treated statis- '

tically give confidence limits of 7,409 and 74,048, unless a 1/20 error occurred in the sampling counts. I extrapolated the catimates without any information on the uniformity of the actual values for-the total lagoon area. Dr. Wurtz reported the dead were concentrated near the closed ends of the lagoons and,Mr. Mallie's estimate of 6 per yd2may have been the maximum in one lagoon or. in a small area.'

Extr5polated estimates from counts made in restricted areas tend to be larger than total area counts.

2 The estimate of 1,208,321 dead menhaden on 543,750 ft .of bottom in the 4 lagoons would have wide confidence limits. The results of the 9 grabs resemble a negative binomial distribution and were so treated .

. with a Poisson generation to obtain 95% confidence-limits *. The nudber of dead fish on the bottom of the 4 lagoons calculated from the sample of 5 fish obtained in 9 grabs is between 386,665 and 2,827,492 unless a 1/20 chance of error occurred in sampling. '

The Ekman grab dredge used was too small to adequately sample.the dead menhaden on the bottom. It is unlikely that the grab would take.

fish larger than 6 inches long. Wurtz' gillnet catch of 205 menhaden with a'mean length of 8.6 inches-on December 29 and the reported size to 14 inches among those in the ice means that menhaden over 6 inches were present that would not be taken by the grab. Also, the gillnet Wurtz used will not catch menhaden 3-inches or less, fork length.

Wurtz' estimates in the following table showed that lagoons 1 and 3 (numbered from the west) had fewer dead fishJ in the ice than did lagoons 2 and 4 and this is also indicated in the Ekman grab samples:

.Wurtz'1 NCRS ,

Estimated estimate in grab Lagoon size ft2 5,000 ft 2 samples

1. Venice 131,250 50 0,0,0

2. Sanabel 131,250 400 .1,1

. 3. Buccaneer 131,250 50 0,0

4. Privateer 150,000 400 1,2 1 in surface ice at closed end of lagoon.

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• 95% confi'dence limits: Poisson .

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It is reasonable to assume'that more dead menhaden would be oni.

the bottom than in the surface ice.. Menha' den have a relatively small-

. swim bladder so that recently dead menhaden usually sink.- Decomposition.

and bloating will bring them to the surface but with ambient temperatures near freezing this process would, occur very slowly or not at all.

In conclusion, the methods used to estimate the number of dead fish lacked the precision required to evaluate the situation adequately.

Undoubtedly, the number frozen in.the ice represented some fraction of the total dead. . Any assum'ption that the number counted in part of a lagoon or in part of each lagoon could be used to calculate the number in the total area leaves room for doubt. The number of bottom samples and the type and size of grab dredge raises many questions about the. reliability of the estimated number of dead on the bottom.

Suggestions to ameliorate or prevent a cold-shock kill in a heated effluent area when the generating station is closed down:

1. If dilution pumps are available, operate for a period proceding the' shutdown to decrease the effluent temperature.

2.. Shut down gradually so that a shallow' declining' gradient is developed towards ambient.

3. Select or adjust the date for a planned shutdown to coincide

- with a warm meterological forecast.

4. If feasible avoid planned shut downs during the colder months of the year.

At present, the best way to avoid cold-shock kills is to utilize discharge areas that distribute and circulate the heated effluent so that a very small area has a high a t and a large area has a small o t.

Basins, embayments, and other relatively closed bodies of water, such as Oyster Creek, are profoundly influenced by the effluent creating an.

If this environment that is maintained 15' or more above winter emblent.

habitat is large, proportionally large cold-shock kills may occur. .

John W. Reintjes Fishery Biologist

- ~ Atlantic Estuarine Fisheries Center.

! Beaufort, N.C.

February 2,1973 l

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