ML20198E904
| ML20198E904 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 07/31/1997 |
| From: | Keser M NORTHEAST NUCLEAR ENERGY CO. |
| To: | |
| Shared Package | |
| ML20198E902 | List: |
| References | |
| NUDOCS 9708110079 | |
| Download: ML20198E904 (15) | |
Text
......... _
. to Letter No. D11303 l
ECOLOGICAL STUDIES PROPOSED FOR 1998 AT hilLLSTONE NUCLEAR POWER STATION NORTilEAST NUCLEAR ENERGY COhlPANY hilLLSTONE NUCLEAR POWER STATION NPDES PERhilT No. CT0003263 Northeast Utilities Service Company PO Box 270 liartford, Connecticut 061410270 July 1997 9700110079 970725
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ECOLOGICAL STUDIES PROPOSED FOR 1998 AT N!!LLSTONE NUCLEAR POWER STATION 1
NORTHEAST NUCLEAR ENEROY COh1PANY h!!LLSTONE NUCLEAR POWER STATION NPDES PER$11T No. CT0003263 Prepared by: Staff of Northeast Utilities Environmental Laboratory Environmental, Health & Safety Services Northeast Utilities Service Company Approved by: _.*'A /d ~ ~
Milan Keser Northeast Utilities Environmental Laboratory
FISII ECOLOGY STUDIES The objectives of the fish ecology sampling program are to moniter the occurrence, relative abundance, and distribution of finfish in the vicinity of Millstone Nuclear Power Station (MNPS) and to assess whether any power plant induced changes in local fish communities have occurred.
No changes are proposed for fish ecology studies in 1998.
l Shore-zone Seine Shore zone fish will be collected with a 30-foot seine net of 0.25-inch mesh at one station, Jordan Cove (JC), biweekly from May through November (Fig.1). Three 100-foot hauls at the adjacent beach area will be made approximately parallel to the shoreline. The fish in each haul will be identified, counted, and measured. When a large number of a fish is caught, measurements oflength will be taken for a representative subsample; every etTort will be made to return all fish to the water.
Trawl Sampling by otter trawl will be conducted biweekly in 1998 at three sites (Fig.1): Niantic River (NR), Jordan Cove (JC), and Intake (IN). Triplicate tows at a standardized distance of 0.69 km will be made using a 30-foot otter trawl with a 0.25-inch cod-end liner. Under certain rarely occurring conditions, which would include damage or threat of damage to the research vessel or
.rawl net and severe weather, the number of tows at a station may be reduced from three to two.
If only one tow was completed, the station will be re-sampled later in the week. If the trawl experiences excessive loading because of macroalgae and detritus, tow distance may be reduced, but catches will be standardized to 0.69 km. All fish collected will be identified, counted, and a representative number of selected species will be measured in the field. Every effort will be made to retum all fish to the water, Ichthyoplankton Entrainment Monitoring Fish populations are potentially impacted by losses through the condenser cooling-water system during MNPS operation. The objectives of the ichthyoplankton entrainment program are to identify potentially impacted species, estimate annual entrainment, and monitor changes in annual abundance and seasonal occurrence of early life history stages of selected fishes. At oresent, these selected taxa and entrained life stages include, but are not limited to: American sand lance larvae, anchon eggs and larvae, cunner eggs and larvae, grubby larvae, tautog eggs and larvae, and winter flounder larvat If condenser cooling water is being discharged, entrainment samples will be collected at one of the three plant discharges (station EN; Fig.1. Collections will be made with a 1-m,333-pm Ecological Studies for 1998 Page 1 of 13
i
'hiesh net, and each sample will consist of about 200 m) of filtered water. Sample volume may be reduced during periods of high plankton or detritus concentrations. The monthly sampling frequencies and the early life history stages (eggs and/or larvae) that are identined and enumerated are provided in Table 1. Sampling frequency may be modified if no condenser cooling water is being discharged by any of the three units.
impingement Monitoring Routine impingement monitoring at Unit 2 was discontinued in December 1987 and replaced by a procedure to monitor unusual impingement events (more than 300 fish or crustaceans in a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period). No changes are proposed for this procedure in 1998. Plant operators check the impingement basket as part of their regular inspections and iflarge numbers of fish or crustaceans are found in the basket they will notify the Northeast Utilities Environmental Laboratory (NUEL). Personnel from the latter would then identify, count, and measure up to 50 specimens and send results to the Connecticut Depanment of Environmental Protection (DEP) as part of the monthly Discharge Monitoring Report.
Tautog Studies In discussions with DEP resulting from the reduction in the trawl monitoring program for 1996 (three stations were deleted), Northeast Utilities Service Company, on behalf of Nonheast Nuclear Energy Company (NNECO), agreed to expend an equivalent amount of effort on tautog studies (NNECO 1995). Field work during the summers of 1996 and 1997 was designed to provide more information on the early life history of tautog. Proposed tautog studies for 1998 will be based, in part, on the studies completed during the summer of 1997. Therefore, a formal tautog study plan for 1998 will be provided separately to DEP on or before October 31,1997 as an addendum to this study plan.
Winter Flounder Studies The objectives of the winter flounder studies are to describe the population dynamics of this species and to assess the long-term effects of possible MNPS impacts, such as the entrainment of larvae through the cooling-water system. Studies of winter flounder in the area of Long Island Sound near MNPS have been conducted since 1973 and have largely focused on the stock known to spawn in the Niantic River. No changes are proposed for winter flounder studies in 1998.
Adult Population Abundance Population abundance for adult (>20 cm) Niantic River winter flounder will be estimated during the spawning season using both a mark-recapture model and a trawl catch-per-unit-effort (CPUE) index. The survey of adult winter flounder abundance in the Niantic River will begin after ice-out, which occurs in February or early March. Sampling will be conducted on at least 2 days each week (weather or water conditions permitting) and will continue until the proportion of Ecological Studies for 1998 Page 2 of 13
-gravid females decreases to less than 10% of all females examined during 2 consecutive weeks (usually occurring in late hfarch or early April). Weather permitting, during each week, approximately 30 to 40 or more tows will be made using an otter trawl in up to eight areas of the river (stations 1,2,4,6,51,52,53, and 54 in Fig. 2). Tows will be allocated to stations based on area and observed abundance of winter flowder. Sex ratio and length distribution of the population will be estimated from survey data.
Lan al Studies Sampling will be conducted to estimate natural sunival rates, to determine the spatial and temporal distribution oflarvae in Niantic River and Bay, and to estimate the number of winter flounder larvae entrained at hfNPS. Sampling in the Niantic River will start in February (ice conditions permitting) with preliminary tows made in the upper portion of the river to determine when larvae are first present. After larvae are present, routine sampling will be conducted at stations A, B, C, and NB (Fig.1). Weather permitting, sampling will be conducted on one day a l
week with a 60-cm bongo sampler. Oblique stepwise tows will be made for at least 6 minutes with equal sampling time at surface, mid-depth, and near bottom. From the start of routine sampling through the end of March, collections in the river will be made during daylight within I hour oflow slack tide using 202-m mesh nets. For the remainder of the season, collections in the river will be made at night, generally with 333 m mesh nets, during the second half of a flood tide. Sampling will continue at each river station until no larvae are found or they are 3
collected in low dcasities (<30 per 500 m ). The weekly sample at station NB will be takenjust before or after those in the river and collections there will be discontinued when sampling in the river is completed. Entrainment sampling during the occurrence oflarval winter flounder will be conducted as discussed previously (see Ichthyoplankton hionitoring section).
Post-larval Juvenile Studies Post larval age-O winter flounder will be sampled every other week beginning in late hiay, which is when most larvae will have metamorphosed to become demersaljuveniles. Four tows of a 1-m beam trawl (two replicates with each of two successive mesh sizes) will be made during the day at two stations in the Niantic River (LR and WA in Fig. 2) within a period extending from 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> before to I hour after high tide. The final collections are usually taken during the last week of September; however, sampling at a station may cease earlier in the year if the mean 2
density of young winter flounder decreases to less than 1 per 100 m.
Specimens Supplied for Research If requested, NUEL will continue to supply adult winter flounder to Dr. Larry Renfro for physiological research at the University of Connecticut. NUEL may also cooperatively supply limited numbers of fish (e.g., skates, tautog) or invertebrates (e.g., spider crabs) for research at the Universities of Connecticut and Rhode Island, Wesleyan University, Brown University, the Ecological Studies for 1998 Page 3 of13
National Marine Fisheries Service, Connecticut Department of Environmental Protection, and to other legitimate scientific or educational institutions.
BENTIllC STUDIES Subtidal Benthic Infauna Study The objective of the subtidal benthic infauna study is to identify impacts to subtidal communities which might result from operation of MNPS. No changes are proposed for this program in 1998.
Samples will be collected in June and September at four stations (Fig. 3): Giants Neck (GN),
Intake (IN), Effluent (EF), and Jordan Cove (JC). At each station, ten replicate samples will be collected using a 10-cm diameter corer pushed into the sediments to a depth of 5 cm. Samples will be fixed with buffered formalin for at least 48 h and sieved through a 0.5-mm mesh screen, with the remaining sample stained with rose bengal and stored in 70% ethanol. The organisms will be sorted from the screened sample, identified to the lowest practicable taxon, and counted.
y Concurrent with the sampling of the infaunal conununity, two sediment samples will be taken to determine sedimentological characteristics. Analyses will be performed to assess changes in sediments, community abundance, species number and structure which might be attributable to MNPS operations.
Rocky Intertidal Studies The objectives of the rocky intertidal studies are to characterize the rocky intertidal areas in the vicinity of MNPS in terms of the attached algae and sessile invertebrates, and to determine if differences in abundance or distribution of these intertidal species could be attributed to the operation of MNPS. No changes are proposed for this program in 1998. The studies will continue to include qualitative algal collections, percentage cover estimates ofintertidal organisms, and growth studies of Ascophyllum nodosum. Rocky shore study sites are as follows:
Giants Neck, Millstone Point, Fox Island-Exposed, and White Point (Fig. 4).
Quantitative and qualitative collections will be made bimonthly in odd-numbered months at all stations. Each quantitative collection will consist of sampling permanently marked undisturbed strip transects (5 per station) that run from mean high to mean low water levels, and are divided into 0.5 x 0.5 m quadrats. The percentage of all organisms and remaining free space in each quadrat will be estimated. Qualitative algal collections will be made from the transect area and from habitats not sampled quantitatively (e.g., tide pools, crevices, and sublittoral fringe).
Inclusion of these microhabitats will allow the characterization of rocky shore sites in terms of
-the species and developmental stages found at each sampling time.
At three rocky shore sites (Giants Neck, Fox Island, and White Point), populations of Ascophyllum nodosum (a large perennial brown alga) will also be monitored. From June to April Ecological Studies for 1998 Page 4 of 13
'at each site,5 tagged growing tips on each of 50 tagged plants will be measured from top of:he most recently formed vesicle to the apex. Newly formed vesicles are not large enough to be tagged until June; therefore, during April and N!ay, tips on randomly chosen plants will be measured. The increase in length over time will be a measure of growth, and the pattern ofloss of tagged tips and plants will be a measure of mortality.
Lobster Studies Adult Population Abundance The lobster study is designed to assess the potential effect of MNPS operations on the lobster population in the Millstone Point area. No changes are proposed for lobster studies in 1998. The study area will include the nearshore coastal region surrounding hiillstone Point. Lobsters will be collected from May through October using 20 wire lobster traps at three stations (Intake, Jordan Cove, and Twotree Island) established near rocky outcrops (Fig. 5). Traps will be hauled on N!onday, Wednesday, and Friday, weather permitting. On weeks with holidays, pots will be checked on the first and last working days of the week. Lobsters will be tagged with serially numbered sphyrion tags. Carapace length, sex, crusher claw position, missing claws, and molt stage will be recorded for each lokter. Recaptured lobsters will be released after recording the tag number and the above information.
Lan al Studies If condenser cooling water is being discharged, entrainment samples will be taken during the period of occurrence (usually from May through July) oflobster larvae at the discharge of Unit 1, 2, or 3 (station EN in Fig.1). Collections will be made using a 1.0 x 6.0 m conical plankton net 3
(1 mm mesh) that filters about 4,000 m of water during a typical collection. The sample volume may be reduced when plankton or detritus is abundant or if the number of circulating-water pumps has been reduced. Three day and three night samples (total of six) will be collected each week. Sampling frequency may be modified if no condenser cooling water is being discharged by any of the three units Eelgrass Study Data collected during the 1998 eelgrass study will augment results of previous studies, indicate any increase or decrease in the size of the eelgrass beds, and allow the evaluation of potential impacts due to MNPS operation. No changes are proposed for the eelgrass program in 1998.
The objective of this study is to estimate the above-ground standing stock of eelgrass in Jordan Cove and the Niantic River. Two study sites (JC, WP) are located in Jordan Cove and one (NR) in the Niantic River (Fig. 6). The location of the Niantic River station is approximate and may vary slightly because of year to year changes in eelgrass density. Estimates of average blade length, biomass, and plant density will be obtained in June, July, August, and September. These Ecological Studies for 1998 Page 5 of 13
a:
t l
' months were selected because they represent periods of peak biomass. In each month, sixteen L
replicates (25 x 25 cm quadrats) will be taken at the three study sites.
SIISSING OR ADDITIONAL SA31PLES--
On rare occasions, a sample may not be available for laboratory processing (e.g., sample.
container was broken or sample was spilled) or sampling gear deployed in the field (e.g., lobster pots) was lost or damaged. Such incidents represent an insignificant fraction of the overall sampling effort for any program and the loss of data has not nor will likely affect the conclusions made as a result of any particular study. On occasion, additional sampling may be conducted to address specific issues that is beyond the scope of the current study plan. These issues may result from concerns of the DEP or the Millstone Ecological Advisory Committee and often arise after the annual study plan has been submitted. If the results of a special study are pertinent to the assessment of MNPS, such studies will be reported in a future annual report or as a separate submission.
REPORT SCllEDULE Northeast Nuclear Energy Company will submit on or before April 30,1998, a detailed report of ongoing biological studies, generally including information from the previous year. This report -
will include summaries of data from the monitoring programs and comprehensive analyses of temporal and spatial variation of marine communities. Reporting periods for each annual report section vary and are predicated on oiological considerations and processing time necessary for samples, as well as on regulatory requirements. Further, in cases where the seasonal abundance of organisms differ from these reporting periods, the periods chosen for analyses in the report will be adjusted to best define the season ofinterest for a particular species or community. Tlius, some collections made in 1998 may not be analyzed or discussed until the April 2000 annual report.
REFERENCE CITED NNECO (Northeast Nuclear Energy Company).1995. Letter (D09375), D.B. Miller to S.J.
Holbrook, Commissioner, DEP, dated November 29,1995.
Ecological Studies for 1998 Page 6 of 13
l TABLE 1. Planned distribution of sampling effort for monitoring entrained ichthyoplankton in l
1998.
Number of samples per week' for entrainment ichthyoplankton:
l J
F-M A
M J
J A
S O
N D
collected: 1D 1D,1N 3D,3N 3D,3N 3D,3N 2D,2N 2D,2N 2D,2N 1D,1N 1D 1D 1D processed '
for larvae:all all all all all ID,1N all.
all all all all all
- for eggs: none none none all all all all all none none none none
- D = day, N = night.
Ecological Studies for 1998 Page 7 of13
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o Fig.1. Location of seine, trawl, and ichthyoplankton sampling stations for 1998 (seine: JC =
Jordan Cove; trawl: NR = Niantic River, IN = Intake, JC = Jordan Cove; ichthyoplankton: Niantic River = A, B, and C, NB = Niantic Bav, EN = MNPS entramment).
Ecological Studies for 1998 Page 8 of13
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-1 LR Fig. 2. Location of sampling stations in the Niantic River during 1998 for adult winter flounder during the late February-carly April spawning season (numbers) and for age-0 winter flounder from late May through September (letters).
Ecological Studies for 1998 Page 9 of 13
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Ecological Studies for 1998 Page 10 of 13 l
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Location of the MNPS rocky intertidal sampling sites: GN= Giants Neck, MP= Millstone Point, FE= Fox island Exposed, WP= White Point.
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Detail map of the MNPS vicinity: FN=new experimental Ascophyllum site (1985-present); MP and FE as in Fig. 4A.
Ecological Studies for 1998 Page11of13
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30*tlett Reef Fig. 5. Location oflobster pot sampling stations for 1998 (JC = Jordan Cove, IN = Intake, TF =
Twotree).
Ecological Studies for 1998 Page 12 of 13
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Figure 6. Location of eelgrass sampling stations for 1998 (JC = Jordan Cove, NR = Niantic River, WP = White Point).
EcoJogical Studies for 1998 Page 13 or ;3