ML061880215
| ML061880215 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee  |
| Issue date: | 01/15/1998 |
| From: | Normandeau Associates |
| To: | NRC Region 1 |
| References | |
| %dam200611 | |
| Download: ML061880215 (13) | |
Text
AQUATIC ECOLOGY IV.M.(e). Normandeau Associates, Inc. 1998a
DRAFW VERMONT YANKEE/CONNECTICUT RIVER SYSTEM ANALYTICAL BULLETIN 70 Composition of Adult American Shad at the Vernon Hydroelectric Dam Fishway During Spring 1997 NORMANDEAU ASSOCIATES, INC.
224 OLD FERRY ROAD BRATTLEBORO, VT &
25 NASHUA ROAD BEDFORD, NIH BULLETIN PREPARED JANUARY 1998
DRAFT ABSTRACT Eighty-five adult American shad were collected from the Vernon Dam Fishway on 10, 12, 17, and 20 June 1997. Males dominated the first two of the samples collected, and overall, constituted 63.1% of the fish sampled. Eighty-five percent of the adults sampled at the Vernon Fishway were age IV and V (52% and 33%, respectively). Male shad composition was dominated (62%) by age IV fish, and females at age V were more abundant (58%) than other age classes in the sample. Repeat spawning was evident in 18% of the age V adults and 14% of the age IV adults. In general, the sexual condition of sampled shad was mostly green on the first sampling date, and steadily increased to mostly ripe by the last sample. The 1997 results are consistent with surveys conducted at the Vernon Fishway between 1990 and 1995. There were no adult shad sampled at Vernon in 1996. The slight annual differences seen in age and sex ratios are typical of the characteristics of natural fish populations.
INTRODUCTION One of the stated objectives by the Shad Studies Subcommittee of the Connecticut River Atlantic Salmon Commission in "A Management Plan for American Shad in the Connecticut River Basin" (prepared February 1992) is that population monitoring is required to support the achievement of the management goal of sustaining 1.5 to 2 million shad in the Connecticut River system. Vermont Yankee has participated in the long-term population monitoring in past years (e.g., Vermont Yankee Analytical Bulletin Nos. 40 & 42), and agreed to continue monitoring adult American shad during the 1997 spawning migration.
As part of the 1997 objective specific studies of the Vermont Yankee Nuclear Power Corporation's NPDES Permit (NPDES No. VT0000264), life history data were collected on a sample of adult American shad (Alosa sapidissima)that utilized the Vernon Dam Fishway during the Spring 1997 spawning run. The objective of this study was to examine American shad size, sex ratios, sexual condition, and age structure for a sample of fish over the course of the spawning run, and compare those data with previous years.
METHODS The Fishway at Vernon Dam (river km 230, Vernon, Vermont) (Figure 1) is located less than one mile downstream of the Vermont Yankee Nuclear Power Plant. The Fishway operated between 27 May and 7 July 1997, typically between 0600 and 1900 hours0.022 days <br />0.528 hours <br />0.00314 weeks <br />7.2295e-4 months <br />. American shad were sampled on June 10, 12, 17, and 20, 1997 at the Fishway. After 20 June 1997, the number of shad utilizing the Fishway was too sporadic to effectively trap more than a few at a time. Beginning on 10 June, shad were randomly trapped by Vermont Division of Fish and Wildlife employees and processed by Normandeau Associates, Inc. (NAI) biologists. Captured shad were weighed to the nearest gram (g) using a calibrated Pesola precision spring scale, and total length was measured to the nearest millimeter (mm). The sex of each shad was determined by applying pressure ventrally and posterior to the pelvic fins and observing the release of eggs or milt from the vent. Sexual condition was estimated by the quantity and appearance of the milt or eggs extruded. Water temperature in the C:\VTYANKEE\.EPORTS\1997\97ASHAD.WPD 1/29/98 I
DRAFT Fishway was recorded at the time of sampling. Scales were taken from each processed shad from above the lateral line near the insertion of the dorsal fin. After processing, those individuals that were stressed beyond recovery were sacrificed. All others were released back into the Fishway.
Shad scales were prepared for age determination in the laboratory. Age and repeat spawning status was determined following the method outlined by Cating (1953). Each scale was soaked in water and gently scrubbed with a soft bristled brush. Three to five scales from each fish were mounted between two microscope slides. Annuli enumeration was conducted by two NAI biologists. One biologist examined scales under 30X magnification utilizing a Swift dissecting microscope. Another biologist independently examined the scales with a Nikon microprojector with 10 - 20X magnification. In instances where the first two investigators disagreed on fish age, a third biologist examined the scales in disagreement, utilizing a Bausch and Lomb microprojector with 20 - 40X magnification. Repeat spawning shad were identified by "spawning checks" on scales.
RESULTS Eighty-five adult American shad were sampled and processed over the four sampling events (Table 1). This represents 1.2% of the total shad passed at Vernon. Vernon passed 80.1% of the total American shad known to have passed the Turner's Falls fish ladder. Water temperature in the Fishway ranged from 20 - 22°C over the four sampling events. Flow through the Fishway was maintained at 135 cubic feet per second (cfs) during Fishway operation. Total river flow at Vernon Dam ranged from 4,470 - 11,600 cfs over the four sampling dates.
Males dominated the first two samples, constituting 76% and 64% of shad sexed (Figure 2).
Approximately equal numbers of male and female fish were processed in the last two samples with males constituting 50% and 55% of those sexed. Overall, 63.1% of the processed shad were males.
The sex of one of the adult shad processed at the Vernon Fishway was not determined. The sexual condition of the males sampled over the four dates, was 68% ripe and 32% green (Table 2). Male shad ranged in weight from 500 - 1200 g, and in length from 305 - 680 mm (Figure 3). The percentages of green (48%) and ripe (45%) females were similar. The remaining 7% of the females were partially spent (Table 2). The sexual condition of the sampled fish showed "green" individuals dominating on the first sample date (23%) which steadily decreased to zero on the last sampling date, while the number of "ripe" individuals increased over the four sampling dates, reaching 21% on the last day (Table 2).
Fifty-two percent of the adult shad processed at the Vernon Fishway were age IV, followed by 33%
that were age V. Age III and VI constituted 11% and 4% of the fish sampled, respectively (Table 3).
Fourteen percent of sampled shad were repeat spawners. The age composition of males processed at the Vernon Fishway was dominated (62%) by four-year olds (Table 3). Three and five-year old males contributed 17% and 19% of the total, respectively (Table 3). There was one male shad aged at six years old. Female American shad age composition was dominated (58%) by five-year olds; 36% of the female shad were age IV (Table 3). Two female shad were determined to be age VI.
Female shad ranged in weight from 800 - 1700 g, and in length from 449 - 535 mm (Figure 3).
C:\VTYANKEEqEPORTS\1997\97ASHAD.WPD 1/29198 2
DRAFr Repeat spawning was evident in 21% of the age V adults and 14% of the age IV adults (Table 3).
Repeat spawning was evident in 18% of age IV females and 11% of age V females (Table 3). Repeat spawning was evident in 12% of age IV males and 30% of age V males (Table 3). There was no evidence of spawning checks on the scales of any of the age III and VI adults.
DISCUSSION Historically, the sex ratio of adult American shad sampled at the Vernon Fishway favored males at least in the early part of the spring immigration, and usually overall (Smith and Downey 1995). This trend continued in 1997. Male dominance, particularly during the early and middle stage of spawning runs has also been reported in the Susquehanna River (Susquehanna River Anadromous Fish Restoration Committee 1993 - 1996) and at the Holyoke fish passage facility on the Connecticut River (Mather 1997).
The percentage of male adult American shad sampled in 1997 was lower (63.1%) than that reported during 1990-1995. The range during 1990-1995 was 71 - 91% males; the mean was 83% (Smith and Downey 1995). The dominance of four and five-year old female American shad at the Vernon Fishway was generally consistent with data from previous years. Five-year old females have been reported as being an important component of the population sampled at the Vernon fish in previous years (Downey 1991), and continued that trend in 1997, constituting more than half of the females sampled.
Comparisons of total adult shad passed at Holyoke, Turners Falls, and Vernon fish ladders from 1995
- 1997 show a noticeable drop in the number of shad immigrating from Holyoke to Turners Falls in 1997 compared to the two previous years (Table 4). However, a large majority (80%) of the shad that passed Turners Falls also passed Vernon. Based on the facts that most fish pass Vernon Dam and that the proportion of femals increased in 1997 compared to 1990 - 1995 indicates that the Vermont Yankee Nuclear Power Project has no significant impact on the immigration of adult shad up the Connecticut River.
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DRAFT LITERATURE CITED Cating, J. 1953. Determining age of Atlantic shad from their scales. Fishery Bulletin 85, Vol. 4.
Washington, D.C.
Mather, M. 1997. Job Performance Report - Anadromous Fish Investigations. Study 1 - Connecticut River anadromous fish investigations. Job 1 - Holyoke fish passage facility. Project Number F-45-R-15. Amherst, MA.
Smith, R.L. and P.C. Downey. 1995. Composition of adult American shad at Turners Falls and Vernon Dam fishways, 1995. Vermont Yankee /Connecticut River System Analytical Bulletin
Normandeau Associates Inc. 1994. Job 1. Summary of the operations at the Conowingo Dam fish passage facilities in spring 1993. in. Restoration of American shad to the Susquehanna River, Annual Progress Report, 1994. Susquehanna River Anadromous Fish Restoration Committee.
Normandeau Associates Inc. 1995. Job 1. Summary of the operations at the Conowingo Dam fish passage facilities in spring 1994. in. Restoration of American shad to the Susquehanna River, Annual Progress Report, 1995.' Susquehanna River Anadromous Fish Restoration Committee.
Normandeau Associates Inc. 1996. Job 1. Summary of the operations at the Conowingo Dam fish passage facilities in spring 1995. in: Restoration of American shad to the Susquehanna River, Annual Progress Report, 1996. Susquehanna River Anadromous Fish Restoration Committee.
Normandeau Associates Inc. 1997. Job 1. Summary of the operations at the Conowingo Dam fish passage facilities in spring 1996. in: Restoration of American shad to the Susquehanna River, Annual Progress Report, 1997. Susquehanna River Anadromous Fish Restoration Committee.
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Table 1. Listing of all adult American shad processed at the Vernon Fishway, Spring 1997.
DATE
.................................................................. n........................
10JUN97 12JUN97
............................................. ........................ ........ eee..*..ge..
Weight Length Sexual Weight Length Sexual Fish ID Sex (g) (mm) Age SC Condition Sex (g) (mm) Age SC Condition
...... °.... ..........................................................................................
1 F 800 485 4 Green H 750 460 5 Ripe 2 N 1050 469 5 Ripe F 900 455 4 Green 3 H 750 448 4 Ripe H 800 462 4 Green 4 H 1000 480 5 2 Green F 1250 529 5 1 Green 5 4 900 488 4 1 Green F 1100 511 5 Green 6 M 1000 479 4 2 Ripe F 1000 490 5 Ripe 7 K 950 453 4 Green H 1000 471 4 Ripe 8 N 1000 485 5 Green H 1100 520 5 Green 9 F 1700 515 5 Green K 750 450 4 Ripe 10 N 800 474 4 1 Green F 1000 466 4 Green 11 H 1200 478 4 Green N 800 471 4 Green 12 H 750 397 4 Green F 1400 524 5 Ripe 13 N 750 433 4 Ripe H 800 473 5 Ripe 14 M 650 405 3 Green N 700 443 3 Ripe 15 H 1100 480 6 Green H 700 455 4 Ripe 16 F 1200 483 4 1 Green F 1400 517 5 ,Green 17 N 950 492 5 2 Green H 950 522 5 1 Green 18 N 650 435 4 Green N 700 445 3 Ripe 19 F 1100 485 5 Green N 500 410 3 Ripe 20 M 800 459 4 Green M 800 468 4 Ripe 21 F 1450 484 4 Green H 750 448 3 Ripe 22 F 1350 501 5 Green F 1000 449 4 Green 23 M 950 461 4 Green N 700 438 4 ,Ripe 24 K 850 452 4 Ripe K 800 460 4 1 Ripe 25 N 950 459 4 Ripe F 1000 477 4 Green DATE 17JUN97 20JUN97 Weight Length Sexual Weight Length Sexual Fish ID Sex (g) (mm) Age SC Condition Sex (g) (mi) Age SC Condition 1 1300 523 5 1 Green M 650 440 4 Ripe 2 H 900 466 4 Ripe F 1150 490 5 Ripe 3 N 600 395 3 Ripe F 1300 505 4 Partially Spent 4 M 800 435 4 Ripe H 800 438 4 Ripe 5 F 1400 482 5 Green M 800 455 4 Ripe 6 N 600 405 3 Ripe F 1500 500 5 Partially Spent 7 F 1400 524 5 1 Green F 1400 495 5 Ripe 8 F 1060 504 5 Ripe H 650 432 4 Ripe 9 H 600 414 4 Ripe F 1150 460 4 Ripe 10 F 1200 535 6 Ripe N 700 460 5 Ripe 11 F 900 502 4 1 Ripe H 900 470 4 Ripe 12 F 1100 472 5 Ripe F 1200 495 4 Ripe 13 F 1050 502 5 Ripe F 1300 500 5 *Ripe 14 H 650 436 4 Ripe N 600 390 3 Ripe 15 M 1000 491 4 Ripe M 900 460 5 Ripe 16 F 1500 505 6 Ripe 17 M 500 305 3 Ripe 18 H 900 480 4 Ripe 19 M 700 460 4 Ripe 20 F 1400 535 5 Ripe 21 22 23 24 25 NOTE: SC = Spawning Check.
C C (-
DRAFT Table 2. Summary of adult American shad sexual condition over four sampling dates at the Vernon fishway, June 1997.
SAMPLING DATE 10-Jun 12-Jun __17.-Jun ... _20.Jun N sample percent N N sample percent N N sample. percent N N sample percent N
females total ofsample males females total ofsample males females total ofsample males females total of sample Sexual Condition males 6 19 76 "4 7 11 44 0 2 2 14 0 0 0 0 Green 13 0 6 24 12 2 14 56 7 5 12 86 11 7 15 90 Ripe 6 0 0 0 0 0 0 0 0 0 0 0 0 0 2 2 10 Partially spent Note: Males. N = 53 Females N - 31 (1 shad sex unknown).
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DRAFT Table 3. Age breakdown and percent repeat spawners for all adult American shad processed at the Vernon Dam Fishway, Spring 1997.
Age Class 1I IV V VI Total *RS Total %RS Total I RS Total %RS Total by N N N N Sex Males 9 0.0 33 12 10 30 1 0.0 53 Females 11 18 18 11 2 0.0 31 Total 9 44 28 3 84 overall percent 0.0 14 21 0.0 repeat spawners A:W97ASHAD.WPD 1129/98
DRAFr Table 4. Comparison of adult American shad that passed the Holyoke, Turners Falls, and Vernon Fishways during 1995 - 1997. (Ken Cox VT. Dept. Fish and Wildlife -
personal communication).
Approximate number of Approximate number of Approximate number shad passed at Holyoke shad passed at Turners of shad passed at Year Falls Vernon 1995 190,000 18,912 15,771 1996 276,289 18,485 18,884 1997 298,000 9,216 7,384 C\kVTYANKEEREMRTSkl997\97ASHAD.WPD 1/29/98
C C C ON, Tainter Gates i olo ++e+°. , o........
6 U,,5.. I.4. l..e .U1.
Underwater Flood Gates
-J Fish Fishplpe Ladder Sluice 100 300 500 feet Figure 1. Plan view of the Vernon Project.
9] Males Z Females P
E 10JUN97 12JUN97 17JUN97 20JUN97 Sample Date Figure 2. Sex composition by date for all American shad processed at the Vernon fishway, Spring 1997.
J G Males z Females 1800 1700 1600 1500 A
1400 A
1300 1200 0b 1100 A OA s a A AeO*S 1000 0
900 *S AO D A 00 00 800 0 0 SO 00 00 700 0 cOo 00 OS 600 500 0 400 300 350 400 450 500 550 600 Total Length (mm)
Figure 3. Length-weight plot of male and female adult American shad processed at the Vernon Fishway, Spring 1997.