ML072040177

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NUREG/CR-2727, Vol. 1, Ecological Studies of Wood-Boring Bivalves in the Vicinity of the Oyster Creek Nuclear Generating Station, Progress Report September - November 1981.
ML072040177
Person / Time
Site: Oyster Creek
Issue date: 06/01/1982
From: Crocket L, Hoagland K
Lehigh Univ, Office of Nuclear Regulatory Research
To:
Davis J, NRR/DLR/REBB, 415-3835
References
NUREG/CR-2727 V1
Download: ML072040177 (58)
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NUREG/CR-2727 Vol. 1 Ecological Studies of Wood-Boring Bivalves in the Vicinity of the Oyster Creek Nuclear Generating Station Progress Report September - November 1981 Prepared by K. E. Hoagland, L. Crocket Wetlands Institute Lehigh University Prepared for U.S. Nuclear Regulatory Commission

NOTICE This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, or any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for any third party's use, or the results of such use, of any information, apparatus product or process disclosed in this report, or represents that its use by such third party would not infringe privately owned rights.

Available from GPO.Sales Program Division of Technical Information and Document Control U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Printed copy price: $3.25 and National Technical Information Service Springfield, Virginia 22161

NUREG/CR-2727 Vol. 1 RE Ecological Studies of Wood-Boring Bivalves in the Vicinity of the Oyster Creek Nuclear Generating Station Progress Report September - November 1981 Manuscript Completed: May 1982 Date Published: June 1982 Prepared by K. E. Hoagland, L. Crocket Wetlands Institute Lehigh University Stone Harbor, NJ 08247 Prepared for Division of Health, Siting and Waste Management Office of Nuclear Regulatory Research U.S. Nuclear Regulatory Commission Washington, D.C. 20555 NRC FIN B5744

PREVIOUS REPORTS Twelve reports have been prepared under Contract AT(49-24)-0347

(=NRC-04-76-347) during three years of funding from the U. S. Nuclear Regulatory Commission, 1976-1979, under the title:

Analysis of Populations of boring and fouling organisms in the vicinity of the Oyster Creek Nuclear Generating Station with discussion of relevant physical parameters.

Those reports with NTIS numbers are:

NUREG/CR-0223 Dec. 1, 1977-Feb. 28, 1978 NUREG/CR-0380 Mar. I, 1978-May 31, 1978 NUREG/CR-0634 Sept. 1, 1977-Aug. 31, 1978 NUREG/CR-0812 Sept. 1, 1978-Nov. 30, 1978 NUREG/CR-0896 Dec. i~, 1978-Feb. 28, 1979 NUREG/CR-1015 Mar. 1, 1979-May 31, 1979 NUREG/CR-1209 June i, 1979-Aug. 31, 1979 Six reports have been published in this current series:

Ecological studies of wood-boring bivalves in the vicinity of the Oyster Creek Nuclear Generating Station.

NUREG/CR-1517 Sept. 1, 1979-Feb. 28, 1980, 65 pp.

NUREG/CR-1795 March 1-May 31, 1980, 31 pp.

NUREG/CR-1855 June 1-Aug. 31, 1980, 48 pp.

NUREG/CR-1939 Vol. 1 Sept. 1, 1980-Nov. 30, 1980, 36 pp.

Vol. 2 Dec. 1, 1980-Feb. 28, 1981, 41 pp-PP.

Vol. 3 March 1, 1981-May 31, 1981, 38 Pp.

Vol. 4 June-August, 1981, 44 PP.

ABSTRACT The species composition, distribution, and population dynamics of wood-boring bivalves are being studied in the vicinity of the Oyster Creek Nuclear Generating Station, Barnegat Bay, New Jersey. Untreated wood test panels are used to collect organisms at 12 stations.

Physiological tolerances of 3 species are also under investigation in the laboratory. Competition among the species is being analyzed. In the fall of 1981, Teredo bartschi remained in Oyster Creek despite continuous prolonged outages of the Oyster Creek Nuclear Generating Station. It did not spread to Forked River or Waretown as it had done in other years-when the effluent was present. The peak in larval production and settlement of T. bartschi occurred between September and October. Settlement of shipworms occurred on no monthly panels except those in Oyster Creek during the period of this report.

Laboratory experiments revealed that T. bartschi becomes inactive at 50 C (24%0/0) and T. navalis shows signs of osmotic stress below 10 0 /.o at 180 C. The shipworms in Barnegat Bay do not show a preference for settling at the mudline when the substrate is not limited.

iii

SUMMARY

OF FINDINGS The purpose of this investigation is to understand the population dynamics and competitive interactions of shipworms in the vicinity of the Oyster Creek Nuclear Generating Station (OCNGS) and at control stations outside the influence of the station. The relative importance of the introduced species Teredo bartschi in causing damage, and physiological tolerances of all species, are being assessed. On a monthly basis, wood panels are added and removed for analysis of population dynamics and to obtain live animals for the lab studies. We also record temperature, salinity, and we estimate siltation levels at each station.

1. The generating station was not operating during a significant portion of the period of this report, and had not been operating during the 2 weeks preceding this period.
2. When present, the thermal effluent in Oyster Creek caused a AT of about +40 C.
3. The salinity in Oyster Creek and Forked River was similar to that of nearby portions of Barnegat Bay.
4. Teredo bartschi was common at stations 11 and 12 in Oyster Creek.

One individual was found at station 10 in Oyster Creek.

5. Teredo navalis and T. bartschi suffered more mortality than Bankia gouldi.
6. Larvae of Teredo bartschi settled late September and early October, 1981, in Oyster Creek only. Veligers of T. navalis and T. bartschi were found in the water in the first week of October. More specimens settled on the October than the September panels. No shipworms settled at stations outside Oyster Creek during Sept.-Nov., 1981.
7. Ctenophores are present at the same time and place as shipworm larvae in in Oyster Creek.
8. Larvae of Teredo bartschi are inactive at 50 C but are not killed outright.

They may be effectively dead, as they seem not to recover when returned to 170 C.

9. Adults of T. navalis are behaviorally affected by salinities of 7-10 0/o0 at ~180 C.
10. Analysis of position of entry and direction of boring has shown that Teredo navalis, T. bartschi, and Bankia gouldi do not settle preferentially at the mudline.
11. Teredo bartschi can survive in Oyster Creek even in the absence of a thermal plume. This introduced species numerically dominates the 2 native species.

There was no outbreak of shipworms outside of Oyster Creek despite low rainfall over the past 2 years.

v

TABLE OF CONTENTS ABSTRACT .... ........ iii

SUMMARY

OF FINDINGS . . V LIST OF TABLES ........ ix ACKNOWLEDGMENTS .... xi INTRODUCTION ...........

METHODS .............. 2 RESULTS AND DISCUSSION ........... 5 PHYSICAL FACTORS ............. 5 SHIPWORM POPULATIONS .........

SHIPWORM PHYSIOLOGICAL ECOLOGY .. . . . . . 30 GENERAL DISCUSSION AND CONCLUSION .. . . . . . 33 REFERENCES ........ .............. .. . . . . . 35 APPENDIX. STATION LOCALITIES . . . . . . . . . . . 3.

37 DISTRIBUTION LIST 39 vii

LIST OF TABLES Page

1. Temperature Profiles in 0 C, Sept. - Nov., 1981 ...... ....... 6
2. Continuous Temperature Recorder Data ( 0 C) for Sept. 3-Dec. 3, 7 1981
3. Salinity Profiles in 0/0., Sept. - Nov., 1981 ....... 9
4. Oyster Creek Nuclear Generating Station Outages, Circulation and Dilution Flow in gal. x 106 for Sept. - Nov., 1981 10
5. Average Temperature and Precipitation in New Jersey, Deviation from Normal. Sept. - Nov., 1981 ............. .............. 10
6. Numbers of Shipworms in Monthly Panels .. . . ........ .. 12
7. Numbers of Living Shipworms in Cumulative Panels Submerged May 7, 13 1981
8. Numbers of Living Shipworms plus Empty Tubes, Cumulative Panels 15
9. Percentage of Specimens that were Alive when Collected, Cumulative Panels ..................... ..................... 16
10. Length Ranges of Shipworms, in mm, Cumulative Panels . ..... .. 17
11. Numbers of Living Shipworms in Yearly Panels ... .......... .. 18
12. Numbers of Living Shipworms plus Empty Tubes, Yearly Panels . 19
13. Percentage of Specimens that were Alive when Collected, Yearly Panels ................... .......................... .. 20
14. Length Ranges of Shipworms, in mm, Yearly Panels ....... .. 22
15. Percentage of Wood Weight Lost by Panels .... ............ .. 23
16. Percentage of Living Teredo Carrying Larvae in the Gills .... 24
17. Contents of Plankton Samples Collected Oct. 6, 1981 ...... 26
18. Position of Entry and Direction of Growth in 2x4" Stakes at several stations ............. ...................... 27
19. Behavior of Pediveligers of Teredo bartschi at Low Temperature . 31
20. Behavior of Adult Teredo navalis exposed to reduced salinity . . 31 ix

ACKNOWLEDGMENTS We thank the many residents of Oyster Creek who have cooperated in our field work. James Selman, Sheila Turner, and Dominic Dragotta provided technical assistance. Eugenia Bohlke of the Academy of Natural Sciences of Philadelphia served as X-ray technologist. J.C.P. & L. Co.

provided data on the operation of the Generating Station.

xi

ECOLOGICAL STUDIES OF WOOD-BORING BIVALVES IN THE VICINITY OF THE OYSTER CREEK NUCLEAR GENERATING STATION September 1-November 30, 1981 INTRODUCTION Previous studies have shown a direct causal relationship between the effluent of the Oyster Creek Nuclear Generating Station and the proliferation of shipworms (Teredinidae) in Oyster Creek and adjacent portions of Barnegat Bay, New Jersey (Turner, 1974; Hoagland et al.,

1977; Hoagland et al., 1978; Hoagland and Crocket, 1979; Hoagland and Turner, 1980; Hoagland et al., 1980). The effluent adds heat to the receiving waters, which extends the breeding season of teredinids, increases their growth rates, and reduces their winter mortality rates.

It has allowed the establishment of a tropical-subtropical shipworm, Teredo bartschi, in Oyster Creek and Forked River. The design of the generating station's cooling system, taking salt water from Barnegat Bay up Forked River, through the plant, and out into Oyster Creek, has increased the salinity of these two creeks. Shipworms now can reside in these creeks, which previously were unsuitable in salinity level and constancy for the establishment of actively breeding shipworm populations.

The populations of Teredo bartschi compared with the native species in Oyster Creek and Forked River are the focus of current studies.

This report summarizes an ongoing collection of data on physical parameters of Barnegat Bay, as well as species composition, distri-bution, growth, mortality, and reproduction of teredinids. We assess the degree of shipworm damage occurring at each station. We also report on physiological studies comparing the native and introduced shipworms with regard to temperature and salinity tolerances.

METHODS Stations Over the first three years of our study, 20 stations were established in Barnegat Bay to monitor boring and fouling organisms. In September, 1979, the number was reduced to 12. The stations are shown in Hoagland and Turner, 1980, and are listed in the appendix. The station numbers are not contiguous because some have been discontinued.

Station 1 is a northern control station on Barnegat Bay outside the influence of the heated effluent. Some shipworms, primarily Bankia gouldi, are traditionally found there. Station 3 is a control station in a tidal creek outside the influence of the effluent. Shipworms are rarely found there. Stations 4, 5, and 6 are in Forked River, influenced by the plant's water intake system. There is some recirculation of heated water that affects these stations, but the main influence is that the salinity is essentially that of the bay. Station 6 is sampled on a reduced schedule, only 4 times a year.

Station 8 is on the bay between Oyster Creek and Forked River. Stations 10-12 are in Oyster Creek, influenced directly by heat, increased (and constant) salinity, and other components of the effluent (heavy metals, silt, increased flow rate, etc.). Since JCP & L calculates average values of heavy metal input per month, exact data necessary to characterize the effluent completely are not available.

Stations 14 and 15 are at or near the southern limit of the thermal plume, on Barnegat Bay. Station 15, like Station 6, is being sampled on a reduced schedule. Station 18 on Long Beach Island is being used only as a reliable source of Teredo navalis for laboratory experiments.

Field Work Once each month, the water temperature and salinity are measured at each station. Air temperature and time of day are also recorded. The amount of silt settling on wood panels submerged for one month is estimated as trace, light, moderate, or heavy. At stations 1, 5, 11, and 14, records of temperature and salinity are kept by means of constant recording instruments that are serviced once a month.

White pine panels, approximately 3/4" x 4" x 8", are used to obtain ship-worms for study. There are three panel series: 1) Each month, a panel that has been in the water for 1 month is removed and replaced. In this way data on monthly settlement and early growth of borers are obtained.

2) Each month, a panel that has been in the water for 12 months is 2

removed and replaced. It provides data on timing of reproduction, species and age structure of established borer communities, and other population data. 3) Each May, a series of 12 panels is deployed. These panels are removed one per month. They provide information on the cumulative growth and maturation of individual borers as well as development of the boring and fouling communities. The cumulative monthly amount of wood destruction can be evaluated. These three panel series are called M, Y, and C, respectively. The Y and C series are replicated at some stations, as indicated in the data tables to follow. Replication is not possible at all stations because of limited space where the water is deep enough to submerge a series of shipworm panels.

Panels are presoaked for 2 weeks, then set on aluminum frame racks against bulkheading or off finger docks. They rest about 6" above the water-sediment interface.

In May, 1980, three 5 x 10 cm wooden stakes were installed each at stations 1, 4, 8, 10, 11, and 14. Those at stations 1 and 8 were lost. One from each remaining station was removed in September, 1980, and reported upon in an earlier report. One from each station was removed in September, 1981 and is reported upon here. The stakes were X-rayed and the position of entry, direction of growth, and length of each specimen recorded. The species were identified from the images of the pallets in the X-rays.

Plankton tows were taken near the test racks at stations 8, 10, 11, and 12 on October 6, 1981. The concentrated plankton samples were examined while still alive for bivalve larvae and other organisms.

Laboratory Work Panels are examined for pediveliger shipworm larvae and boring isopods, scraped, and X-rayed to locate the shipworms and provide a permanent record of damage. It is possible to count and often to identify shipworms from the X-rays in uncrowded panels, but X-rays do not provide quantitative data in most cases. Therefore, using the X-rays as guides, the panels are dissected. All the shipworms are removed, identified, examined for larvae in the gills, and measured (length only). They are preserved in 75% buffered alcohol. Identifications are first made by technicians, but all Teredo spp.

are checked by one of the senior investigators.

Wood fragments from the dissected panels are saved. Calcareous tubes and other debris left by the shipworms are removed with HCk. The wood is washed in fresh water, then dried to constant weight, allowed to cool to room temperature, and weighed. The panels are also weighed before going into the water. The weight difference is a measure of wood destruction due to boring organisms.

During dissection of the wood panels, we estimate the percentage of empty tubes, which indicate mortality. If pallets are still present in the empty tubes, we can record the species of the dead shipworm.

3

Shipworms from the replicate 12-month panels are not preserved but are kept alive and allowed to spawn in tanks containing filtered sea water (22% salinity) and new pine panels. In this way, we have established pure laboratory populations of Teredo bartschi. Individuals of B. gouldi and T. navalis from the field are being maintained in the laboratory.

These stocks are used for temperature and salinity tolerance experiments.

Attempts. are underway to establish breeding colonies of Teredo navalis.

Shipworm Physiological Ecology The behavior of the pediveliger larvae of Teredo bartschi was recorded at low temperature (50 C) and at a control temperature of 17-20° C. Twelve individuals were placed in each of 2 shallow dishes containing 2400 seawater and observed over a 5-day period. A piece of white pine wood was available in each dish. The behaviors recorded were swimming, burrowing, crawling, closed on the bottom, and gaping on the bottom.

Adults of Teredo navalis were obtained in pure culture in wood from Station

18. For 3 panels, the salinity was gradually reduced, 30 /o per day, from 220/.o to 70/.o while the temperature was maintained at 17-180 C. Another 3 panels (controls) remained at 22*/oo. The number of pairs of siphons per panel was counted daily as a measure of the activity of the individuals.

The number of individuals per panel varied from 30 to 50. Observations continued for 24 days, after which the salinity was returned to 220/oa and observations were made for 2 additional days. The water was changed every morning in both the control and experimental aquaria. Observations were made in the late afternoon.

4

RESULTS AND DISCUSSION Physical Factors The temperatures recorded at the time of sampling for shipworms are reported in Table 1. There was no heated, effluent present in Oyster Creek on September 3rd or October 6th. On November 4th, the Oyster Creek Nuclear Generating Station had just resumed operation after a brief shutdown, and there was evidence of a thermal effluent in Oyster Creek. The AT was about 40 C. The general range of temperatures in Barnegat Bay in fall, 1981, was much cooler in the month of September, yet warmer in November, compared with 1980. The temperature profilesin 1979 and 1981 were more similar, except September was slightly cooler in 1981.

The continuous temperature recorder data (Table 2) showed very similar temperatures for the 4 stations in September. There was some thermal dis-charge in October, as seen by the mean daily maximum temperature of 14.50 in Oyster Creek, 13.2' in Forked River, and 12.80 at the two control stations north and south of the power plant. The value at Forked River indicates recirculation of the effluent. In November, the temperature recorder and panels at station 14 were totally destroyed by a bulkheading crew. A comparison of stations 1 and 11 does reveal an average AT of about 40 C in Oyster Creek.

We have discontinued use of constant recording salinometers at stations 1, 4, 11, and 14 due to continual repair problems that could not be resolved by Beckman Corporation. Salinity profiles taken at the regular sampling times are reported in Table 3. Salinity increased from September to November at all stations. The change in salinity was greatest at Stout's Creek (station 3). Oyster Creek had salinity readings within 1-2*o/. of inner shores of Barnegat Bay (e.g., stations 8 and 14).

Table 4 provides the data on the operation levels of the power plant.

Outages were extensive, including all of September and half of October (combined with the last half of August). Water flow was maintained at a level of about 50% during September when there was no heated effluent.

From the data in Table 4, it can be seen that slight augmentation of shipworm growth and breeding could be expected in October and November.

Table 5 presents general weather data for New Jersey. The low precipitation in November could explain the higher salinity found then, especially at the creek station 3. However, the timing is not perfect, since the salinity values were recorded in the first week of November. No overall trends of drought have been observed in the period of this report, although precipitation is below average.

5

Table 1 Temperature Profiles in °C, September-November 1981 Differential Station Sept. 3 Oct. 6 Nov. 4 among months 1 22 .5 b 16.5 14.0 8.5 3 23.5 19 .0a 15.0 8.5 4 23.0 1 6 .0 b 14.0 9.0 5 2 2 . 5b 17.0 15.0 7.5 8 23.0 16.5

  • 10 24 .0a 16.5 17.5 -

11 23.0 17.0 1 7.0a 6.0 12 23.0 18.0

  • 14 23.5 1 6 .0 b 13 . 0b 10.5 Differential among stations 1.5 3.0 4.0 a highest value each month b lowest value each month
  • no data 6

Table 2 Continuous Temperature Recorder Data (0 C) for Sept. 3 to Dec. 3, 1981 I. Temperature at 1: 00 PM (EST)

Sept. 3-Oct. 6 Oct. 6-Nov. 4 Nov. 4-Dec. 3 1 5 11 14 1 5 11 14 1 5* 11 14*

Mean Daily Temp. at 1PM 19 .1 19.3 19.1 18.9 12.2 12.8 13.8 12.1 7.1 7.1 12.0 Standard deviation 2.9 2.8 2.7 3.0 0.9 1.0 2.1 1.1 2.4 2.3 Highest value of Temp.

at I PM 23.2 23.3 23.5 23.2 14.4 14.6 17.9 15.5 13.0 17.5 Lowest value of Temp.

at 1 PM 13.5 14.4 13.7 13.0 10.6 11.0 10.7 10.7 2.8 8.1 Monthly Temp. Range at 1 PM 9.7 8.9 9.8 10.2 3.8 3.6 7.2 4.8 10.2 9.4 II. Maximum Daily Temperature Sept. 3-Oct. 6 Oct. 6-Nov. 4 Nov. 4-Dec. 3 1 5 11 14 5 11 14 1 5* 11 14*

Mean value of Max. 19.8 19.7 19.4 19.6 12.8 13.2 14.5 12.8 7.6 12.5 Daily Temp.

Standard Deviation 2.9 2.8 2.7 3.0 0.9 1.0 2.1 1.0 2.5 2.2 Highest value of Max.

Daily Temp. 23.4 23.5 23.5 24.3 15.2 15.1 18.1 15.0 13.1 17.5 Lowest value of Max.

Daily Temp. 13.8 14.5 13.8 13.6 10.8 11.2 11.3 11.3 3.7 8.4 Monthly Range of Max.

Daily Temp. 9.6 9.0 9.7 10.7 4.4 3.9 7.8 3.7 9.4 9.1

Table 2, continued III. Minimum Daily Temperature Sept. 3-Oct. 6 Oct. 6-Nov. 4 Nov. 4-Dec. 3 1 5 11 14 1 5 11 14 1 5* 11 14*

Mean value of Minimum Daily Temp. 18.3 17.9 17.5 18.3 11.6 11.5 12.5 11.6 6.7 11.0 Standard Deviation 3.1 3.1 3.1 3.0 0.8 1.1 2.2 0.8 2.3 2.2 Highest value of Minimum Daily Temp. 23.0 22.5 22.3 22.8 13.3 13.7 16.8 13.4 11.5 15.5 Lowest value of Min. Daily Temp. 12.8 12.4 11.6 12.5 10.6 8.8 10.2 10.4 2.8 7.0 Monthly Range of Min. Daily Temp. 10.2 10.1 10.7 10.3 2.7 4.9 6.6 3.0 8.7 8.5 IV. Daily Temperature Range Sept. 3-Oct. 6 Oct. 6-Nov. 4 Nov. 4 - Dec. 3 1 5 11 14 i1 5 11 14 1 5* 11 14*

Mean Daily AT 1.4 1.8 1.7 1.5 1.2 1.7 2.0 1.1 0.9 1.5 Standard Deviation 0.7 0.9 0.8 0.7 0.5 0.9 0.9 0.4 0.4 0.9 Largest Daily AT for one month 3.2 4.6 4.2 3.3 2.1 4.7 4.1 2.2 1.7 4.0 Smallest Daily AT for one month 0.4 0.4 0.4 0.5 0.2 0.5 0.8 0.3 0.1 0.4

  • Sta. 5 paper failed to record completely.

Sta. 14 recorder destroyed by workmen.

Table 3 Salinity Profiles in 0/00, September-November 1981 Differential Station Sept. 3 Oct. 6 Nov. 4 among months 1 22 24 25 b 3 3 16b 29b 25b 9 4 26 a 2 7a 29 3 5 26 a 2 7a 29 3 8 26a 2 7a 28 2 30a 10 24 27a 6 11 24 26 28 4 12 24 26 28 4 25 27a 29 14 3 Differential among stations 10 8 5 a highest value each month b lowest value each month 9

Table 4 Oyster Creek Nuclear Generating Station Outages, Circulation and Dilution Flow in gal. x 106 for Sept.-Nov., 1981 Total Water Flow (gal. x 106) Outage Dates Sept. 19,657 1-30 Oct. 33,820 1-19; 31 Nov. 42,270 1 Table 5 Average Temperature and Precipitation in New Jersey, Deviation from Normal. Sept.-Nov., 1981 Temperature (0 F) Precipitation (inches)

Sept. -1.0 0 Oct. -4.7 +0.68 Nov. -1.0 -2.26 10

Shipworm Populations Table 6 shows that juvenile shipworms settled at only 2 stations during September and October, 1981. Both stations were in Oyster Creek. All of the identifiable juveniles were Teredo bartschi, and those too small to be identified beyond Teredo sp. were most likely also T. bartschi.

Specimens settling in September and removed in October showed less growth than specimens settling in August and removed in September. Two of the 27 individuals at station 12 were dead when collected on October 6; all other specimens were collected alive. It is interesting that the number of settling young was greater in the October panels than in those collected in September. Release and settlement of the pediveligers of T. bartschi seems to occur in waves. There was no settlement on monthly panels deployed on October 6 and retrieved on November 4, 1981.

In previous years, there was much heavier attack of monthly panels removed in fall months. In September of 1978, shipworms of 3 species were found in monthly panels at stations from Holly Park to Waretown Creek, and settlement of Teredo bartschi in Oyster Creek included 133 specimens at the 3 stations.. However,. only 5 specimens settled in the following month.

In September of 1979, settlement was recorded at most stations, and all 3 species were represented. Thousands of T. bartschi occurred on panels at the 3 stations in Oyster Creek. Only T. bartschi were found in October (a total of 184 specimens, all in Oyster Creek). In 1980, only 1 shipworm was retrieved from the September monthly panels, but hundreds of T. bartschi were found at station 12 in Oyster Creek the following month, and 35 T. bartschi were found at station 12 in the November monthly panel. The reduced settlement of shipworms in the fall of 1981 might be related to the frequent and prolonged outages of the Oyster Creek generating station in the period August-October, 1981 (Table 4).

The cumulative panels deployed in May and removed in the fall (Table 7) revealed Teredo bartschi only at stations 11 and 12 in Oyster Creek. The attack was moderate (less than 100 per panel) at station 11, but heavy (over 500 per panel) at station 12. This pattern has existed for two seasons. It suggests that larvae need not travel far before boring into wood, and that station 12 is more suitable than station 11 for proliferation of T. bartschi.

T. bartschi was last found in Forked River in July, 1981. It was very abundant at all 3 Oyster Creek stations in the fall of 1978 and 1979.

The percentage of the living specimens in all Barnegat Bay stations that were Teredo bartschi increased from 65% in September to 82% in October and 94% in November. This was due to reproduction of T. bartschi at station 12. Bankia gouldi was slightly more abundant than T. navalis, due to greater abundance at station i, Holly Park. Replicate panel pairs at stations 1, 4, 8, and 11 were similar in species composition and abundance.

As in past years, there was no shipworm attack at the control creek station 3.

Shipworm attack was low at all stations outside of Oyster Creek except for station 1.

11

Table 6 Numbers of Shipworms in Monthly Panels September 3, 1981 October 6, 1981 StationI T.bartschi i Teredo sp. Total T.bartschi Teredo sp. Total  %

Alive Alive 11 1 1 2 100 10 10 100 (3)* (2) (0.5-1) 12 1 3 4 100 27 27 93 (3) (0.5-1) (0.5-1)

  • Numbers in parentheses are lengths, in mm.

12

Table 7 Numbers of Living Shipworms in Cumulative Panels Submerged May 7, 1981 Date Removed: September 3 October 6 November 4 Ni-~,i-nntR.* T~n Th5 T~sr.* Total E.g. T~n. T-Jb. B.2. T.n. T.b. Total Total 1 10 3 0 0 13 24 3 0 27 13 6 0 19 3 0 0 0 0 0 0 0 0 0 0 0 0 0 4 0 3 0 0 3 1 3 0 4 2 0 0 2 5 0 3 0 0 3 0 2 0 2 2 0 0 2 8 1 3 0 0 4 3 2 0 5 2 3 0 5 10 0 0 0 0 0 0 0 0 0 0 0 0 0 11 2 2 31 3 38 1 2 59 62 1 1 15 17 12 0 1 83 28 112 0 1 132 133 1 0 516 517 14 1 2 0 0 3 0 1 0 1 0 2 0 2 Total 14 17 114 31 176 29 14 191 234 21 12 531 564 Replicates 1 10 2 0 0 12 7 1 0 8 4 0 4 0 0 4 II 1 3 0 4 8 1 3 0 0 4 2 2 0 4 11 0 0 7 0 7 0 0 13 13

  • Based on November's data, nearly all are T. bartschi, but a few may be T. navalis.
  1. Panels used for laboratory experiments.

Tables 8 and 9 reveal the extent of mortality over the May-November 1981 period. There tended to be high mortality in Forked River, followed by Oyster Creek. Control stations 1 and 14 were nearly free of mortality.

The differential mortality by area is in part due to species composition.

Teredo navalis in Forked River and T. bartschi in Oyster Creek suffered the greatest mortality.

Growth over the May-November, 1981, period is shown in Table 10. The largest specimens were not associated with any particular station. Such an association was not expected, because of the absence of the thermal effluent over much-of the period. Because the density of the shipworms per panel was low, growth was rapid. Comparing Table 10 with Table 14 of our last report, a monthly size increase of the largest individuals of all 3 species was noticable through October 6. Specimens of Teredo bartschi were no larger in November than in October. The 1981 year class of all species was large enough to be sexually mature in August. Comparing the sizes of specimens removed from cumulative panels in 1981 with previous years, we find that growth was lower for Bankia gouldi in 1981 than in 1978-1980, but about the same for the other two species.

The results from the yearly panels submerged in the fall of 1980 are reported in Tables 11-14. The replicate panel pairs at station 11 show the effects of patchy settlement accumulated over an entire year (e.g.,

45 specimens in one panel, only 8 in another removed in October). However, the replicate panel pairs at station 1 and at station 14 are similar (e.g., 18 Bankia gouldi in one panel, 14 B. gouldi and one T. navalis in another at station 1, November). The difference is due to the species involved: T. bartschi, with its release of pediveligers, is more prone to' patchy distribution.

The pattern of settlement on the yearly panels is similar to that of the cumulative panels. Teredo bartschi was restricted to Oyster Creek and was abundant only at station 12. Bankia gouldi was moderately abundant at station 1. There was only one shipworm found at station 3. Overall, 93% of the specimens found alive in Barnegat Bay were T. bartschi.

Comparing Tables 8 and 12, there was greater settlement but higher mortality in the September and October yearly panels than the cumulative panels of the same months. Some of the settlement occurred in September and October, 1980, but many of these individuals died over the winter of 1980-81. The lower number of shipworms in the November, 1981 yearly panel indicates little settlement in November, 1980. The greatest settlement of the period appears to have occurred in October, 1980. This agrees with our findings of that year (Hoagland and Crocket, 1981, report #1939).

Mortality was great in the Teredo species, but virtually absent in Bankia gouldi (Table 12). Of all the panels, mortality was greatest in that from station 12 in September (Table 13). The percent mortality figures are somewhat misleading unless one considers the total number of specimens involved.

14

Table 8 Numbers of Living Shipworms Plus Empty Tubes, Cumulative Panels Date Removed: September 3 October 6 November 4 Station B._. T.n. T.b. T.sp. tere- Totali B.g. T.n. T.b. Total B.. T.n. T.b. tere- Total dinid dinid 1 10 3 0 0 0 13 24 3 0 27 14 6 0 2 22 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 0 7 0 0 0 7 1 4 0 5 2 2 0 0 4 5 0 4 0 0 0 4 0 5 0 5 2 1 0 0 3 8 1 8 0 0 1 10 3 3 0 6 2 10 0 0 12 10 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 11 2 2 31 9 0 44 1 2 72 75 1 3 34 1 39 12 0 1 84 52 0 137 0 1 133 134 1 1 541 0 543 14 1 2 0 0 0 3 0 1 0 1 0 2 0 0 2 Total 14 27 115 61 1 218 29 19 205 253 22 25 575 3 625 I,

Replicates 1 10 2 0 0 1 13 7 2 0 0 9 4 0 5 0 0 0 5 1 4 0 0 5 8 1 5 0 0 0 6 2 2 0 0 4 11 0 0 8 0 0 8 0 0 14 0 14

Table 9 Percentage of Specimens that were Alive when Collected, Cumulative Panels Month Collected: September 3 October 6 November 4 Station Number Total No. Number Total No. Number Total No.

Living Tubes Alive Living Tubes Alive Living Tubes Alive Specimens Observed Specinnens Observed Specimens Observed 1 13 13 100 27 27 100 19 22 86 3 0 0 - 0 0 . 0 0 -

4 3 7 43 4 5 80 2 4 50 5 3 4 75 2 5 40 2 3 67 8 4 10 40 5 6 83 5 12 42 10 0 0 - 0 0 - 0 0 -

11 38 44 86 62 75 83 17 39 44 12 112 137 82 133 134 99 517 543 95 14 3 3 100 1 1 100 2 2 100 O'.

Total 176 218 81 234 253 92 564 625 90 1 12 13 92 8 9 89 4 4 5 80 4 5 80 8 4 6 66 4 4 100 11 7 8 88 13 14 93

Table 10 Length Ranges of Shipworms, in mm, Cumulative Panels Date Removed: September 3 October 6 November 4 Station aF. TCn.a . T-n. -T-jn 1 13-143 43-96 52-209* 124-132 8-185 106-165 3

4 74-151* 178 79-152 153-158 92-97 5 48-102 62-193* 148-239* 82 8 90 42-90 8-127 67-89 182-228 45-154 10 11 56-164" 64-120 1-33 28 90-117 2-131* 32 112-208 1-102*

12 18 1-35 87 .5-69 35 124 .5-84 14 119 14-78 79 13-50 I-J Replicates

-.1 1 6-60 17-90 25-106 147-162 4 64-127 215 78-210*

8 74 53-76 155-175 60-85 11 2.5-55* 3-54

  • Largest specimen of each species, each month.

Table 11 Numbers of Living Shipworms in Yearly Panels Date Removed: September 3, 1981 October 6, 1981 November 4, 1981 Station I.g. T.n. T.b. Total B.g T.n. T.b. Total B.g. T.n. T.b. Total 1 12 0 0 12 15 0 0 15 18 0 0 18 3 0 0 0 0 0 0 0 0 1 0 0 1 4 0 0 0 0 0 1 0 1 1 1 0 2 5 2 1 0 3 1 1 0 2 1 4 0 5 8 7 1 0 8 3 2 0 5 5 0 0 5 10 0 0 1 1 0 0 1 1 0 0 1 1 11 0 1 2 3 0 0 8 8 0 0 2 2 12 0 0 48 48 0 0 673 673 0 0 363 363 14 0 1 0 1 1 1 0 2 0 3 0 3 00 Total 21 4 51 76 21 5 682 707 26 8 366 400 Replicates 1 11 0 0 11 18 1 0 19 14 1 0 15 11 0 0 9 9 1 0 45 46 1 0 33 34 14 0 2 0 2 0 1 0 1 0 5 0 5

Table 12 Numbers of Living Shipworms Plus Empty Tubes, Yearly Panels Date Removed: September 3, 1981 October 6, 1981 November 4, 1981 Station T.n. T.b. Total B.g. T.n. T.b. tere- Total B.g. T.n. T.b. T.sp. tere- Total dinid dinid 1 12 0 0 12 15 1 0 0 16 18 0 0 0 3 21 3 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 4 0 0 0 0 0 1 0 0 1 1 1 0 0 0 2 5 2 3 0 5 1 3 0 1 5 1 4 0 0 0 5 8 7 11 0 18 3 5 0 1 9 5 4 0 1 0 10 10 0 0 1 1 0 0 1 0 1 0 0 1 0 0 1 11 0 1 3 4 0 1 9 0 10 0 1 2 0 0 3 12 0 0 330 330 0 0 787 0 787 0 0 406 0 0 406 14 0 3 0 3 1 1 0 0 2 0 4 0 0 0 4 HD Total 21 18 334 373 21 12 797 2 831 26 14 409 1 3 453 Replicates 1 11 0 0 11 18 1 0 0 19 14 1 0 0 0 15 11 0 4 9 13 1 3 45 0 49 1 39 0 0 41 14 0 5 0 5 i 2 0 0 3 0 6 0 0 0 6

Table 13 Percentage of Specimens that were Alive when Collected, Yearly Panels Date Removed September 3, 1981 October 6, 1981 November 4, 1981 Station Number Total No. Number Total No.  % Number Total No.

Living Tubes Alive Living Tubes Alive Living Tubes Alive Specimens Observed Specimens Observed Specimens Observed 1 12 12 100 15 16 94 18 21 86 3 0 0 - 0 0 - 1 1 100 4 0 0 - 1 1 100 2 2 100 5 3 5 60 2 5 40 5 5 100 8 8 18 44 5 9 56 5 10 50 10 1 1 100 1 1 100 1 1 100 11 3 4 75 8 10 80 2 3 67 12 48 330 15 673 787 86 363 406 89 C

14 1 3 33 2 2 100 3 4 75 Total 76 373 20 707 831 85 400 453 88 Replicates 1 11 11 100 19 19 100 15 15 100 8 13 62 46 49 94 34 41 83 14 2 5 40 1 3 33 5 6 83

The lengths of the shipworms from the yearly panels are in Table 14. As for the cumulative series, there was no strong tendency for the largest specimens to be in Oyster Creek. Specimens of the Teredo species were larger in September than in October and November, because both T. bartschi and T. navalis settled in September of 1980. Bankia gouldi does not settle that late in the year. The length ranges of specimens collected in the yearly and cumulative series in October and November are similar because most of the surviving specimens in both settled over the 1981 season.

Table 15 gives the percentages of wood lost from the various test panels.

Despite the greater number of shipworms in the cumulative panels at station 12, wood destruction was no greater than in other cumulative panels.

The small size of Teredo bartschi is responsible for this result. The percentage wood weight lost increased between October and November only at stations 8, 12, and 14. Because of the equality of the age of most specimens in the yearly and cumulative panels, the wood weight data from the two series are comparable.

The percentage of the Teredo navalis carrying larvae in the gills is given in Table 16. In September, 78% of the individuals were brooding young. In October, the percentage was 73%; in November, it fell to 38%.

There were no young juveniles of T. navalis reported; all specimens were large enough to be sexually mature as females.

On the contrary, the fall panels contained numerous immature specimens of Teredo bartschi. The smallest mature specimen measured 7 mm in length.

The percentage of adults brooding young for September, October, and November was 62%, 87%, and 63%, respectively. The peak of production of pediveligers occurs in October.

Shipworm larvae were found in plankton samples from stations 8, 11, and 12.

The straight-hinge larvae were probably Teredo navalis. They could also have been Bankia gouldi, but most B. gouldi settles before October. The greatest density of larvae occurred at station 11 in Oyster Creek; station 8 had only 2 larvae.

Other organisms found in the plankton samples are listed in Table 17. Very little was found alive in the 3 replicate tows at station 10 in a lagoon near the mouth of Oyster Creek. At the other stations, barnacle nauplii were common. Ctenophores and gastropod veligers were also common at the Oyster Creek stations. There were many more species represented in the samples from Oyster Creek than those from Forked River.

The position of entry and direction of growth of shipworms entering 5x10 cm stakes is shown in Table 18. There is no pattern of entry at the mudline for any species, nor is there a preference for entering on the lee side or the side of the stake facing the currents. However, most specimens grow downward, regardless of the species. Most T. bartschi were clustered at 50-60 cm above the mudline. In 1980, the data were comparable except that T. bartschi were clustered about 8 cm above the mudline.

21

Table 14 Length Ranges of Shipworms, in mm, Yearly Panels Date Removed: September 3, 1981 October 6, 1981 November 4, 1981 Station I T.n. T.b. B.g. T.n. T.b. B.g. T.n. T.b.

1 34-94 13-211 60 18-202 3 46 4 - 181 57 28 5 63-68 80-270* 156 105-111 138 20-200*

8 43-194* 61-155 137-171 47-122 85-210 25-73 10 11 43 33 11 233 6-28 137 1-52 127 36-46 12 .5-130* .5-64* .5-57*

14 27-69 18 6 68-114 I'.,

NJ Replicates 1 64 62-214* 139 67-162 137 48-270* 4-34 204 130-185* .5-59 211* 120 1-40 14 61-110 156 84-91 19-199

  • Largest specimen, each species, each month

Table 15 Percentage of Wood Weight Lost by Panels A. May 7, 1981 Cumulative Series Date Removed: September 3 October 6 November 4 I I Station 1 8.21 36.54 25.52 3 0.00 0.00 0.00 4 0.00 14.27 10.66 5 6.73 11.13 9.63 8 6.86 8.16 12.67 10 0.00 0.00 0.00 11 8.55 14.57 12.33 12 8.67 13.00 19.21 14 8.54 7.30 8.64 Replicates 1 9.44 10.37 4 9.57 12.78 8 8.26 9.48 11 8.04 8.46 B. Yearly Series 1 12.28 26.18 22.63 3 0.00 0.00 7.67 4 0.00 6.83 7.60 5 13.93 12.55 8.30 8 15.32 15.82 12.27 10 9.75 8.81 8.53 11 11.11 6.50 9.27 12 13.54 31.5 14 12.06 13.41 10.66 Replicates 1 9.15 35.04 20.22 11 12.35 10.80 10.04 14 12.33 9.80 12.65

  • No data 23

Table 16 Percentage of Living Teredo Carrying Larvae in the Gills Months Max. Length Min. Length Max. Length Min. Length  % of Adult Sample Submerged of ship- of ship- of ship- of ship- shipworms Size worms with worms with worms without worms without with Larvae Larvae Larvae Larvae Larvae (mm) (mm) (mm) (mm)

T. navalis Sta. Month 4 Sept. 4 151 118 89 89 67 3 4 Sept. 4 127 64 100 4 5 Sept. 4 92 92 102 48 33 3 8 Sept. 4 90 55 100 3 8 Sept. 4 72 68 57 57 67 3 11 Sept. 4 120 120 64 64 50 2 12 Sept. 4 18 18 100 14 Sept. 4 78 78 100 5 Sept. 12 80 80 100 8 Sept. 12 76 76 100 11 Sept. 12 233 233 100 4 Oct. 5 129 105 152 152 67 3 5 Oct. 5 173 108 100 2 8 Oct. 5 89 89 67 67 50 2 11 Oct. 5 117 117 90 90 50 2 1

12 Oct. 5 87 87 100 1 14 Oct. 5 79 79 100 1 4 Oct. 12 181 181 100 1 8 Oct. 12 122 122 95 95 50 2 14 Oct. 12 91 91 100 1 4 Nov. 6 146 146 210 210 50 2 8 Nov. 6 154 154 127 117 33 3 14 Nov. 12 92 92 114 85 33 3 14 Nov. 12 64 64 99 55 20 5

Table 16, continued Percentage of Living Teredo Carrying Larvae in the Gills Months Max. Length Min. Length Max.Length Min.Length  % of Adult Sample Submerged of ship- of ship- of ship- of ship- shipworms Size worms with worms with worms without worms without with Larvae Larvae Larvae Larvae Larvae (mm) (mm) (mm) (mm)

T. bartschi Sta. Month i1 Sept. 4 55 55 28 2.5 33 3 11 Sept. 4 33 10 51 2 86 22 12 Sept. 4 35 7 12 2 45 31 10 Sept. 12 11 11 100 1 11 Sept. 12 28 28 11 11 50 2 11 Sept. 12 34 13 100 7 12 Sept. 12 20 7 130 7 50 18 "I3 11 Oct. 5 74 11 131 7 76 59 I-n 12 Oct. 5 69 7 10 0.5 99 74 10 Oct. 12 43 43 100 1 11 Oct. 12 48 29 3 1 100 4 11 Oct. 12 59 13 2 0.5 100 8 12 Oct. 12 64 7 38 0.5 86 341 11 Nov. 6 71 44 64 3 40 10 11 Nov. 6 43 28 54 4 73 11 12 Nov. 6 61 15 72 0.5 47 162 10 Nov. 12 33 33 100 1 11 Nov. 12 46 36 100 2 11 Nov. 12 32 21 4 1 100 2 Nov. 12 0.5 141 12 57 12 50 81

Table 17 Contents of Plankton Samples Collected Oct. 6, 1981 Station 8 10 11 12 Teredo navalis larvae present - common common Barnacle nauplii common - common common Polychaete trochophore present - present present Late-juvenile polychaete pre.sent rare common present Nematodes present - present present Polydora ligni present - -

Bryozoan larvae present - present -

Calanoid copepods present present present Harpacticoid copepods present - present present Paleomonetes sp. rare - -

Protozoans present - present present Foraminifera - present present Fish eggs - - present Chaetognath eggs & larvae - - present present Lorica - - present Ctenophore - - common common Gastropod veligers - - common common Ostracode - - present -

Plant seeds common - -

Marine mite - present 26

Table 18 Length, Position of Entry, and Direction of Growth in Stakes at Several Stations.

Station Position of Distance of Entry Direction Length Species Entry hole Hole above Mud Line of Growth (cm) 4 in currents 21 cm down 36.5 B. gouldi edge, currents 68 down 14.5 B. gouldi in currents 59 down 16.0 T. navalis 10 edge, currents 5 down 11.5 B. gouldi in currents 17 down 52.0 B. gouldi leeside 20 down 38.0 B. gouldi in currents 19 down 40.0 B. gouldi in currents 3 down 1.3 B. gouldi leeside 17 up 43.0 B. gouldi in currents 56 down 3.0 B. gouldi leeside 76 down 28.5 B. gouldi edge, currents 72 diagonal, 32.0 T. navalis down in currents 12 down 0.6 T. bartschi 11 leeside 70 down 33.0 B. gouldi lees ide 13 up 25.0 T. navalis leeside 61 up 37.0 T. navalis leeside 8 down 1.5 T. bartschi leeside 15 down 0.8 T. bartschi leeside 35 up 1.6 T. bartschi leeside 44 down 5.5 T. bartschi in currents 16 down 1.4 T. bartschi in currents 37 down 7.5 T. bartschi in currents 42 down 2.0 T. bartschi in currents 48 down 5.9 T. bartschi in currents 48 down 1.2 T. bartschi in currents 49 up 1.3 T. bartschi in currents 50 up 1.2 T. bartschi in currents 51 down 0.8 T. bartschi in currents 51 up 1.2 T. bartschi in currents 51 up 1.5 T. bartschi in currents 52 down 0.8 T. bartschi in currents 53 down 1.2 T. bartschi in currents 53 down 1.2 T. bartschi in currents 53 down 0.8 T. bartschi in currents 55 up 1.2 T. bartschi in currents 55 down 1.4 T. bartschi in currents 58 down 1.5 T. bartschi edge, currents 60 down 2.3 T. bartschi edge, currents 22 up 3.2 T. bartschi edge, currents 51 down 1.1 T. bartschi edge, currents 54 up 1.4 T. bartschi edge, currents 56 up 1.5 T. bartschi 27

Table 18, continued Station Position of Distance of Entry Direction Length Species Entry hole Hole above Mud Line of Growth (cm) 11 edge, lee 62 up 1.0 T. bartschi edge, lee 48 up 1.0 T. bartschi edge, lee 48 up 2.1 T. bartschi edge, lee 49 up 8.0 T. bartschi edge, lee 52 down 2.0 T. bartschi edge, lee 52 up 1.6 T. bartschi edge, lee 53 down 1.6 T. bartschi edge, lee 54 diagonal 1.2 T. bartschi edge, lee 54 down 2.3 T. bartschi edge, lee 55 down 2.1 T. bartschi edge, lee 55 down 1.4 T. bartschi edge, lee 56 down 2.2 T. bartschi edge, lee 55 up 0.8 T. bartschi edge, lee 57 down 2.3 T. bartschi edge, lee 60 down 6.3 T. bartschi edge, lee 60 down 0.5 T. bartschi edge, lee 62 down 0.8 T. bartschi edge, lee 64 down 0.6 T. bartschi edge, lee 65 down 0.3 T. bartschi edge, lee 68 down 0.4 T. bartschi edge, lee 69 down 4.4 T. bartschi edge, lee 57 down 0.3 T. bartschi in currents 54 borehole in currents 80 borehole in currents 80 borehole in currents 75 borehole in currents 61 borehole in currents 60 borehole in currents 60 borehole in currents 40 borehole in currents 57 borehole in currents 57 borehole in currents 54 borehole in currents 54 borehole in currents 57 borehole in currents 52 borehole in currents 52 borehole in currents 60 borehole in currents 61 borehole in currents 61 borehole in currents 62 borehole in currents 66 borehole in currents 53 borehole in currents 48 borehole in currents 48 borehole in currents 47 borehole 28

Table 18, continued Station Position of Distance of Entry Direction Length Species Entry hole Hole above Mud Line of Growth (cm) 14 edge, currents 0.3 down 5.8 B. gouldi in currents 2 down 5.5 T. navalis leeside 21 down 8.1 T. navalis in currents 31 down 9.1 T. navalis

SUMMARY

Settlement Growth Within 10 cm of mudline in currents leeside up down yes no B. gouldi 8 4 1 11 3 9 T. navalis 4 3 2 5 1 6 T. bartschi 24 living 26 15 35 0 74 29 dead 29

Shipworm Physiological Ecology The pediveligers of Teredo bartschi were inactive at 50 C (Table 19). They remained alive after 5 days at that temperature. However, when returned to room temperature (170 C), they did not succeed in penetrating the wood.

Control specimens from the same female were more active at the control temperature range of 17-200 C, and 5 of the 12 eventually penetrated the wood. The salinity for all experiments was 24 0/00.

The effect of reduced salinity on adults of Teredo navalis is shown in Table

20. Activity of the control individuals was quite variable among panels.

Panel A averaged over 90% active individuals with little day-to-day variance.

Panel B was usually above 85% active, but on one day, only 25% of the individuals were seen. Panel C showed the lowest and most variable activity (often under 50%). There was no trend from day to day.

The experimental panels showed activity levels comparable to those for control panel C. No ill effects of reduction of salinity were observed until the salinity reached 10 0/00. Then, recovery time after the water was changed extended over 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. The salinity was left at 10 0/00 for 3 days, and activity increased in all 3 panels each day. Then. the salinity was reduced to 7 0/00, and again there was a prolonged recovery period, with activity increasing over a 3 day period. The siphons were never extended fully at 7 0/00. Therefore, to avoid losing the specimens, the salinity was returned to 22 0/oo. Activity levels of the experimental panels were again comparable to thoseýof the controls. These results are very similar to those given in an earlier report (#1517) for Teredo bartschi.

30

Table 19 Behavior of Teredo bartschi larvae at Low Temperature Day: 0 1 2 3 4 5 50 170 50 170 50 180 50 190 50 200 Behavior TemD:17° 170 Swimming 5 5 0 4 0 2 0 3 0 4 0 1 Burrowing 2 3 0 1 0 1 0 1 0 2 0 1 Crawling 2 1 0 1 0 1 0 3 0 1 0 5 Closed on bottom 3 3 11 4 3 7 5 5 1 3 4 1 Gaping on bottom* 0 0 1 2 9 1 7 0 11 2 8 4

  • Not dead. Capable of responding to touch.

Table 20 Behavior of Adult Teredo navalis Exposed to Reduced Salinity

% of Animals with Siphons Extended Day Reduced Salinity 0/o. Controls (22 /oo)

Salinity A B C A B C 1 22 71 100 66 91 90 55 3 19 75 94 61 96 100 55 4 16 79 90 55 93 25 14 5 13 83 90 61 91 85 28 6 10 17 6 5 93 85 66 7 10 71 62 41 93 95 38 9 10 100 82 59 16 7 13* 24* 39* 91 90 34 17 7 46* 74* 55*

19 7 33* 80* 68* 98 85 100 26 22 58 80 100 100 95 90

  • Siphons partially extended.

31

GENERAL DISCUSSION AND CONCLUSION The data collected in the fall of 1981 fit the pattern established in previous years. Teredo bartschi accounts for most of the shipworms in Oyster Creek. It survives periods when the thermal effluent is absent, but does not spread to nearby localities as it does when there is an effluent. The native species were few in number throughout Barnegat Bay in 1981; they were apparently not influenced by the low rainfall in New Jersey during the past 2 years.

Field data on settlement of larvae indicate that no species clusters at the mudline, although settlement of Teredo bartschi is patchy. The seasonal peaks of settlement of larvae of the three species do not coincide.

The major peak for Bankia gouldi is mid-summer, while those for Teredo bartschi and T. navalis are in late September or early October.

T. bartschi has multiple peaks of settlement.

Physiological studies conducted thus far show that shipworms of all species have similar low salinity tolerances, and that below 10 0/00, symptoms of osmotic stress occur. This result is important in that the operation of the Oyster Creek Nuclear Generating Station has eliminated periods of low salinity in the affected portions of Oyster Creek and Forked River (particularly the south branch). Therefore it has increased the potential for shipworm outbreaks in these areas.

Fortunately for those concerned about shipworm damage, frequent and prolonged plant outages have reduced woodborer attack in Oyster Creek and Forked River.

The persistence of Teredo bartschi in Oyster Creek since 1974 and its population characteristics allowing rapid.population growth indicate that the only final solution will be the cessation of operation of the plant.

However, the infestation can be reduced by removing infected wood.

We have found higher mortality in the Teredo species than in Bankia gouldi.

The role of heavy metals, disease, and parasites in mortality of woodborers and fouling organisms requires further study.

33

REFERENCES Hoagland, K. E. and L. Crocket. 1979. Analysis of populations of boring and fouling organisms in the vicinity of the Oyster Creek Nuclear Gener-ating Station. Annual Progress Report. Sept. 1, 1977-Aug. 31, 1978.

NUREG/CR-0634. 113 pp.*

Hoagland, K. E. and L. Crocket. 1981. Ecological studies of wood-boring bivalves in the vicinity of the Oyster Creek Nuclear Generating Station.

Sept. - Nov., 1980. NTIS #1939, vol. 1, 36 pp.

Hoagland, K. E. and R. D. Turner. 1980. Range extensions of teredinids (shipworms) and polychaetes in the vicinity of a temperate-zone nuclear generating station. Marine Biology 58:55-64.

Hoagland, K. E., L. Crocket and M. Rochester. 1978. Analysis of popu-lations of boring and fouling organisms in the vicinity of the Oyster Creek Nuclear Generating Station with discussion of relevant physical factors over the period: Dec. 1, 1977 - Feb. 28, 1978.

NUREG/CR-0223. 44 pp.

  • Hoagland, K. E., L. Crocket and R. D. Turner. 1980. Ecological studies of wood-boring bivalves in the vicinity of the Oyster Creek Nuclear Generating Station, Sept. 1, 1979 - Feb. 28, 1980. NUREG/CR-1517. 65 pp.*

Hoagland, K. E., R. D. Turner and M. Rochester. 1977. Analysis of boring and fouling organisms in the vicinity of the Oyster Creek Nuclear Generating Station with discussion of relevant physical parameters over the period:

April 30-November 30, 1976. Report to the U. S. Nuclear Regulatory Commission. Jan. 1, 1977. 61 pp.

Turner, R. D. 1974. In the path of a warm, saline effluent. American Malacol. Union Bull. for 1973. 39:36-41.

  • Available for purchase from the NRC/GPO Sales Program, U. S. Nuclear Regulatory Commission, Washington, D. C. 20555, and the National Technical Information Service, Springfield, VA 22161.

35

APPENDIX: STATION LOCALITIES STATION NUMBER NAME DESCRIPTION COORDINATES 1 Holly Park Dick's Landing Lat. 390 54' N Island Drive Lon. 740 8' W Bayville, NJ Bay control 3 Stout's Creek End of Raleigh Drive 390 50.7' Gustav Walters' residence 740 9' 4 Mouth of South Shore 390 49.6' Forked River Developed property 740 9.8' Possible temperature increase increased oceanic influence due to reverse flow 5 Leilani Drive At branch point of 390 49.6' Forked River 740 10.5' 6 Elk's Club South Branch 390 49.4' Forked River 740 10.9' Increase in salinity due to plant intake canal 8 Bayside Beach On bay between Oyster Creek 390 49.0' Club and Forked River across 740 9.7' from 1815 Beach Blvd.,

Forked River, NJ Temperature increase since plant operation.

10 Kochman's End of Compass Rd. on 390 48.5' Residence #1 Lagoon, Oyster Creek 740 10.6' Waretown, NJ Temperature, salinity siltation increase 11 Crisman's Dock Ave. on Oyster Creek 390 48.5' Residence Waretown, NJ 740 11.0' Temperature, salinity, siltation increase 37

STATION NUMBER NAME DESCRIPTION COORDINATES 12 Gilmore's 20 Dock Ave. on Oyster Creek 390 48.5' N Residence Waretown, NJ. Temperature, 740 11.3' W salinity, siltation increase 14 Cottrell's End of North Harbor Rd. 390 47.7' N Clam Factory Waretown, NJ (Mouth of 740 10.9' W Waretown Creek)

Within but near limits of reported thermal plume 15 Carl's Boats Washington & Liberty Sts. 390 47' N Waretown, NJ (on the bay) 740 11' W 18 Barnegat Light Marina adjacent to Coast Guard 390 45.8' N Station 740 6.5' W 38

DISTRIBUTION LIST Distribution Category: RE Supplemental Distribution: Part A Mr. Richard Baumgardt Dick's Landing Holly Park Bayville, New Jersey 08721 Mr. William Campbell P.O. Box 668 108 Long John Silver Way Waretown, New Jersey 08758 Mr. Stan Cottrell North Harbor Road Waretown, New Jersey 08758 Mr. Wilson T. Crisman 901 Hudson Street Hoboken, New Jersey 07030 Mr. and Mrs. Thomas Gilmore 20 Dock Ave., Box 205 E, R.R.I.

Waretown, New Jersey 08758 Mr. Walter Holzman 1915 Beach Blvd.

Forked River Beach, New Jersey 08731 Mr. Charles Kochman Compass Road Waretown, New Jersey 08758 Mr. Ed Sheridan 1108 Leilani Drive Forked River, New Jersey 08731 Mr. Gustav Walters 100 Manhattan Avenue, Apt. 706 Union City, New Jersey 07087 Mr. Edward Wheiler 16 River View Drive P.O. Box 642 Forked River, New Jersey 08731 39

Part B Battelle Columbus Laboratories Clapp Laboratories Duxbury, Massachusetts 02332 Mr. Michael Roche Supervisor of Environmental Science Jersey Central Power and Light Co.

Madison Ave. at Punchbowl Road Morristown, New Jersey 07960 Dr. Glenn Paulson Asst. Commissioner for Science Dept. of Environmental Protection State of New Jersey P. 0. Box 1390 Trenton, New Jersey 08625 Mr. Alan R. Hoffman Lynch, Brewer, Hoffman & Sands Ten Post Office Square Suite 329 Boston, Massachusetts 02109 Mr. John Makai Nacote Creek Research Station Star Route Absecon, New Jersey 08201 Mr. Steve Lubow NJDEP-Division of Water Resources P.O. Box CN-029 Trenton, New Jersey 08625 Dr. Harry L. Allen US EPA Region II 26 Federal Plaza Room 832 New York, New York 10007 Dr. John Strand Ecosystems Department Battelle Northwest Lab Richland, Washington 99352 Dr. D. Heyward Hamilton, Jr.

EV-34, GTN U. S. Dept. of Energy Washington, D. C. 20545 40

NRC FORM 335 1. REPORT NUMBER (Assigned by DDC) f7 77) U.S. NUCLEAR REGULATORY COMMISSION NUREG/.CR-2727, Vol. 1 BIBLIOGRAPHIC DATA SHEET

4. TITLE AND SUBTITLE (Add Volume No., if wpropriare) 2. (Leave blak)

Ecological Studies of Wood-Boring Bivalves in the Vicinity of the Oyster Creek Nuclear Generating Station Pro qress Report 3. RECIPIENT'S ACCESSION NO.

September - November 1981

7. AUTHOR(S) 5. DATE REPORT COMPLETED K. E. Hoagland and L. Crocket MONTH YEAR May 1982
9. PERFORMING ORGANIZATION NAME AND MAILING ADDRESS (Include Zip Code) DATE REPORT ISSUED Lehigh University MONTH YEAR Wetland Institute .lne Stone Harbor, NJ 08247 6.(Leave blank)
8. (Leave blank)
12. SPONSORING ORGANIZATION NAME AND MAILING ADDRESS (Include Zip Code) 10. PROJECT/TASK/WORK UNIT NO*

U.S. Nuclear Regulatory Commission Office of Nuclear Regulatory Research 11.CONTRACT NO.

Division of Health, Siting, and Waste Management B5744 Washington, D. C. 20555

13. TYPE OF REPORT PERIOD COVERED (Inclusive dares)

Quarterly Progress Report September 1, 1981 - November 30, 1981

15. SUPPLEMENTARY NOTES 14. (Leave olank)
16. ABSTRACT (200 words or less)

The species composition, distribution, and population dynamics of wood-boring bivalves are being studied in the vicinity of the Oyster Creek Nuclepr Generating Station, Barnegat Bay, New Jersey. Untreated wood test panels are used to collect organisms at 12 stations.

Physiological tolerances of 3 species are also under investigation in the laboratory. Competition among the species is being analyzed. In the fall of 1981, Teredo bartschi remained in Oyster Creek despite continuous prolonged outages of the Oyster Creek Nuclear Generating Station. It did not spread to Forked River or Waretown as it had done in other years when the effluent was present. The peak in larval production and settlement of T. bartschi occurred between September and October. Settlement of shipworms occurred on no monthly panels except those in Oyster Creek during the period of this report.

Laboratory experiments revealed that T. bartschi becomes inactive at 50 C (240/o0) and T. navalis shows signs of osmotic stress below 10 /..

at 180 C. The shipworms in Barnegat Bay do not show a preference for settling at the mudline when the substrate is not limited.

17. KEY WORDS AND DOCUMENT ANALYSIS 17a.'DESCRIPTORS Thermal Effluents Shi pworms Oyster Creek Teredo bartschi Teredo navalis Bankia gould 17b. IDENTIFIERS/OPEN-ENDED TERMS
18. AVAILABILITY STATEMENT 19. SECURITY CLASS (Ths reporT) 21. NO. OF PAGES UNCLASSIFIED Unlimited 20. SECURITY CLASS (Thi,spagej 22. PRICE UNCLASsiFTFn S NRC FORM 335 (7-77)

Federal Recycling Program

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