FINAL SUMMARY REPORT Summary of the Pre- and Post-Construction Seafloor Mapping and Benthic Biology Survey Results

Transcription

1 FINAL SUMMARY REPORT Summary of the - and -Construction Seafloor Mapping and Benthic Biology Survey Results Long Island Replacement Cable Project January 2007 through June 2010 Submitted by: The Connecticut Light & Power Company pared by: ESS Project No. N May 10, 2011

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3 FINAL SUMMARY REPORT SUMMARY OF PRE- AND POST-CONSTRUCTION SEAFLOOR MAPPING AND BENTHIC BIOLOGY SURVEY RESULTS Long Island Replacement Cable Project January 2007 through June 2010 pared For: Northeast Utilities Services Company 107 Selden Street, NUE2 Berlin, Connecticut pared By: ESS Group, Inc. 888 Worcester Street, Suite 240 Wellesley, Massachusetts ESS Project No. N May 10, 2011 ESS Group, Inc This document or any part may not be reproduced or transmitted in any form or by any means, electronic, or mechanical, including photocopying, microfilming, and recording without the express written consent of ESS Group, Inc. All rights reserved.

4 TABLE OF CONTENTS SECTION PAGE 1.0 INTRODUCTION SEAFLOOR MAPPING SURVEYS (TASK 5 AND TASK 8) Purpose and Methods Results Multibeam and Side Scan Sonar Sediment Profile Imagery BENTHIC HABITAT GROUND TRUTHING Sediment Grab Sampling (Task 1a) Methods Results Discussion Underwater Video Camera Surveys (Task 1c) Methods Results Discussion SHELLFISH SURVEYS Quantitative Shellfish Sampling (Task 1b) Methods Results Discussion Deployment of Calibrated Oyster Trays (Task 3) Methods Results Discussion Portable Oyster Dredge Sampling (Task 4) Methods Results Discussion Summary of Shellfish Results OVERALL CONCLUSIONS REFERENCES TABLES Table 1 Table 2 Table 3 Monitoring Activity Matrix with Summary Analysis Location Trench Depths along Cable 2 within Sheffield Harbor Trench Depths along Cable 1, 2, and 3 within Sheffield Harbor Copyright ESS Group, Inc., 2011 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

5 FIGURES Figure 1 NU Cable Replacement Monitoring Matrix - Schedule for Sampling Figure 2 Five Monitoring Areas Designated for Remote Sensing Surveys Figure 3 Seabed Change Map Area 4 (July 2010 versus Fall 2007) Figure 4 Benthic Biology Survey Program (January 2007 June 2010) Figure 5 Photograph of Oyster Tray used to Monitor Shellfish Survival and Growth Figure 6 Portable Oyster Dredge Transect Locations (October 2007 and July 2008) ATTACHMENTS Attachment A Attachment B Attachment C Benthic Macroinvertebrate Statistical Analysis Underwater Video Survey Observed Habitat and Species Shellfish Survey Analyses

6 1.0 INTRODUCTION This report contains a summary of results from the pre-construction and post-construction seafloor mapping and benthic biology surveys conducted as part of the Long Island Replacement Cable Project (LIRC) in Connecticut waters. These surveys were conducted in accordance with the Monitoring and Mitigation Plan ( Monitoring Plan ) that was filed with the Connecticut Siting Council (CSC) and the Connecticut Department of Environmental Protection (CT DEP) in September The monitoring activities were conducted by Ocean Surveys, Inc. (OSI), Dr. Robert Whitlatch (benthic and shellfish biology), Dr. Robert Diaz (Sediment Profile Imagery), ESS Group, Inc. (ESS) (benthic and shellfish biology), and Dr. W. Frank Bohlen (physical oceanography and sediment processes), with overall coordination by ESS. -construction surveys were conducted from January 2007 through October 2007 prior to any in-water cable removal or cable installation activities in Connecticut waters. construction surveys were conducted from July 2008 through July 2010 at approximately 0, 3, 6, 12, 18, and 24-month intervals following construction. The purpose of this summary report is to provide an overall comparison of pre and post-construction seafloor and benthic biology conditions based on the monitoring surveys. Some of the other monitoring tasks identified in the Monitoring Plan have already been completed and summarized in previous report submittals. To facilitate comparison of the monitoring plan tasks with the summary of results contained in this report, a table was created matching the tasks identified in the Monitoring Plan with the appropriate summary contained in this report or in a previously submitted report (see Table 1). The matrix outlining the full time table for field work conducted during all construction stages is included for reference (see Figure 1). Table 1 Monitoring Activity Matrix with Corresponding Summary Analysis Location Task (as identified in Monitoring Plan submitted September 2007) Task 1 Benthic Habitat Ground Truthing Task 1a Sediment grabs Task 1b Quantitative shellfish sampling Task 1c Underwater video camera surveys Task 2 Current Velocity, Turbidity, Radio Dating Cores Location of Final Summary Analysis Section 3.1 of this Report Section 4.1 of this Report Section 3.2 of this Report viously Submitted (Bohlen and Howard-Strobel, 2009) Section 4.2 of this Report Section 4.3 of this Report Task 3 Deployment of Calibrated Oyster Trays Task 4 Portable Oyster Dredge Sampling Task 5 Construction Seafloor Mapping in 4 Areas Task 5a Multibeam hydrography Section of this Report Task 5b Side scan sonar imagery Section of this Report Task 5c Underwater TV Section 3.2 of this Report Task 5d Sediment profile imagery Section of this Report Task 6 Real-Time Suspended Sediment Plume Mapping in CT State Waters viously Submitted (OSI, 2008) Task 7 Real-Time Suspended Sediment Plume Mapping in NY State Waters viously Submitted (OSI, 2009a) Task 8 Construction Seafloor Mapping in 4 Areas Task 8a Multibeam Hydrography Task 8b Side Scan Sonar Imagery Task 8c Underwater TV Task 8d Sediment Profile Imagery Section of this Report Section of this Report Section 3.2 of this Report Section of this Report Copyright ESS Group, Inc., 2011 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

7 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, SEAFLOOR MAPPING SURVEYS (TASK 5 AND TASK 8) 2.1 Purpose and Methods The primary objective of the seafloor mapping surveys was to provide a pre- and post-construction record of the seafloor morphology in designated areas representing the different marine environments throughout the cable corridor. The remote sensing surveys (Tasks 5 and 8) were conducted in Connecticut waters, across the northern part of the cable corridor around Sheffield Island where the cable corridor crosses the shellfish beds, and in one area approximately 2 miles south of Sheffield Island in Long Island Sound, outside the shellfish beds (see Figure 2). The study areas selected conform to those specified in the Monitoring Plan and coincide with the monitoring areas required in the CT DEP and USACE permits. The effect of the Project on seafloor morphology was monitored using data collected with three instruments: a multibeam depth sounder, side-scan sonar, and sediment profile imagery (SPI) camera. The multibeam depth sounding data were collected to provide high-resolution bathymetric data throughout the monitoring areas to evaluate the impact of construction related activities on the seafloor including the cable embedment process and the formation of trenches over the cables. The side scan sonar was utilized to complement the multibeam data to provide additional detail of the seafloor. In addition, the side scan sonar reflectivity was used to identify areas where the surface sediment type has changed possibly due to re-suspension of the sediment during construction. SPI data was used primarily to identify thin layers of re-suspended sediment distributed during construction with some additional observations on biological activity. Monitoring data were collected in areas representative of the three marine environments associated with the cable corridor within Connecticut waters (Figure 2) as follows: Area 1-North and Area 1-South represent shallow water zones within Sheffield Harbor. Area 2 is an exposed coastal zone south of Sheffield Island. Area 3 represents the deep-water zones of mid-long Island Sound. An additional area (Area 4) was monitored which extends the entire length of the existing cable corridor across Sheffield Harbor following the path of the new center cable. A complete description of the remote sensing tasks required and conducted in each study area is provided in Table 1 of the 24-month post-construction seafloor mapping report (OSI, 2010b). 2.2 Results Multibeam and Side Scan Sonar Multibeam and side scan sonar data revealed the seafloor morphology in each site which could be characterized as typical for each marine environment. Circular drag marks were evident in Areas 1-North, 1-South, and 2, which are the result of shellfishing activity in the area. The main Copyright ESS Group, Inc., 2011 Page 2 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

8 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, 2011 morphological difference between the pre-construction and post-construction surveys was the presence of the new cable trenches. The trenches for the new cables were evident in the side scan images but an actual change in seabed elevation between the pre-construction and twenty-four month post-construction surveys can be best quantified in the seabed change maps (OSI, 2010b). The seabed elevation change was typically less than 2 feet, depending on the area and trench as anticipated in the Project application and observed in the post-construction surveys. Eight isolated exceptions within Sheffield Harbor (Areas 1N, 1S, and 4) and two outside the Harbor in Area 2 were greater than 2 feet, and one depression in Area 3 reached depths of six feet (OSI, 2010b). At all the areas surveyed, there appeared to be no evidence of the cable removal process on the side scan sonar data or the multibeam data. Slight depressions (<0.5 feet) observed in the multibeam data in the vicinity of the old cables in each of the areas are most likely associated with the old cable installation process. In the 24-month period following construction, trench depths began to slowly fill in with sediment on the order of 0 to 0.5 feet of sedimentation. However, Area 2 gained upwards of 2 feet of sediment over the twenty-four month post-construction period which may be due to Area 2 s location relative to the Long Island Sound wave climate. In the twenty-four month post-construction survey, some fishing activity was still evident in Areas 1-North and Area 2 with drag marks visible in both the side scan and multibeam data. Primarily these drag marks were not new and were evident in previous surveys. Area 1-South still showed signs of fishing activity in the 24-month post-construction survey, but significant new drag marks had not been observed since the initial post-construction survey in the Summer of The data from the multibeam survey of Area 4 allows for a comparison of the Cable 2 trench depths observed in each of the post-construction surveys using the Fall 2007 pre-construction survey as a baseline (see Figure 3). Table 2 provides a measure of trench depth reduction since construction concluded in the summer of The table illustrates the cumulative linear distance of various trench depths, broken down into depths between ft, ft, ft, ft, and greater than 3.0 ft. This table reveals a continued reduction in trench depths over the last twenty-four months of monitoring, indicating that the trenches continued to fill in naturally over this period. Copyright ESS Group, Inc., 2011 Page 3 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

9 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, 2011 Table 2. Trench Depths along Cable 2 within Sheffield Harbor Survey Depth of Trench (ft) Total >3.0 Length (ft) July February June December July Cumulative Linear Distance (ft) * Fall 2007 pre-construction survey served as a baseline elevation. As an additional task, the 12-month, 18-month and 24-month post-construction seafloor mapping surveys included a multibeam dataset of the entire Sheffield Harbor cable corridor, giving an overview of the trench depths for all three cables within Sheffield Harbor (OSI, 2009b, OSI, 2010a, OSI, 2010b). The December 2005 multibeam dataset, the only pre-construction dataset covering all three cables, was used as the baseline elevation. Table 3 shows the linear trench depths for each of the three newly installed cables in Sheffield Harbor observed in the 12- month (Summer 2009), 18-month (December 2009), and 24-month (July 2010) post-construction surveys. This table also reveals a continued reduction in trench depths over the last twenty-four months of monitoring, indicating that the trenches continued to fill in naturally over this period. Table 3. Trench Depths along Cables 1, 2, and 3 within Sheffield Harbor Survey Survey Comparison Depth of Trench (ft) Total >3.0 Length (ft) Cable 1 June Cable 1 December Cable 1 July Cable 2 June Cable 2 December Cable 2 July Cable 3 June Cable 3 December Cable 3 July Cumulative Linear Distance (ft) * December 2005 pre-construction survey served as a baseline elevation. Copyright ESS Group, Inc., 2011 Page 4 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

10 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, 2011 The multibeam and side scan sonar data revealed that trenches formed over each new cable during the jetting process, as expected. Trenches in high energy locations, such as shallow water south of Sheffield Island, showed the most significant recovery. In addition, side scan sonar results revealed that sediment type boundaries remained the same as pre-construction conditions. Therefore, these results indicate that the LIRC Project has not had an effect on sediment type boundaries and that trenches formed during LIRC cable installation are continuing to fill in naturally, with some areas recovering at a faster rate than others Sediment Profile Imagery The sediment profile camera imagery results indicate finer-grained sediments and less compaction present within Sheffield Harbor relative to the sites located south of Sheffield Harbor. Biogenic activity of epifauna and infauna was a predominant factor in structuring the surficial sediments in the areas investigated with the SPI camera. The Redox Potential Discontinuity (RPD) measurements, developed from the SPI camera data, indicate a moderate level of biogenic activity. Small tubes were the most common surface biogenic feature that occurred in the images. Densities of small tubes ranged from about 1 per image to less than 25 per image. Shell at the sediment surface was the second most common biogenic feature. Possible shell beds were observed at six stations (5, 10, 11, 12, 13 and 14) in Area 1-North. SPI data collected from the pre-construction through the twenty-four month post-construction surveys indicate the sediment classification did not change at any of the 42 stations and there were no noticeable layers of newly distributed sediment. The SPI data showed that the most common biogenic feature, small tubes, showed a decrease in density during the postconstruction surveys. During the pre-construction survey, the tube density ranged between 10 per image to 100s per image yet from the initial post-construction survey to the current survey, tube density ranged from about 1 per image to less than 25 per image. However, the results of the benthic macroinvertebrate monitoring do not suggest that the observed reduction in tube density during the 24-month study period was directly due to cable installation or operation. Rather, this change may be related to a larger scale shift in the benthic macroinvertebrate community over the region, as discussed in Section 3.1. SPI data were used primarily to identify thin layers of re-suspended sediment distributed during construction, which may impact the benthic biology. While re-suspension occurred during jetting operations, there was no evidence of layers of suspended sediment over the existing sediments through the SPI photos. This is also supported by the biological indicators (infauna, burrows, oxic voids, and anaerobic voids) that the SPI camera system monitored over the twenty-four month period. All three indicators revealed only small variations throughout the survey periods, which were indicative of seasonal changes in biological activity. Copyright ESS Group, Inc., 2011 Page 5 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

11 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, BENTHIC HABITAT GROUND TRUTHING 3.1 Sediment Grab Sampling (Task 1a) Methods The primary objective of the sediment grab sampling surveys was to establish a pre- and postconstruction record of the benthic macroinvertebrate community within and at varying distances outside the cable corridor. Sediment grab sampling was initiated during the pre-construction period to establish baseline conditions. A total of 15 stations were sampled during the initial January 2007 pre-construction event and no replicate samples were collected. Subsequently, the scope of benthic grab sampling was expanded for subsequent events to allow for a more statistically useful analysis of the results. During the October 2007 pre-construction event and each of the post-construction sampling events, a total of 23 stations were sampled, with three replicate grab samples taken at each station. Samples were collected at fixed stations located along five of the ten video transect lines (1, 3, 4, 6, and 9). Four of these transects were located north of Sheffield Island and one was located south of Sheffield Island. Along each transect, grab samples were collected from the center, the eastern and western edges of the existing cable corridor; as well as from background stations outside the cable corridor (Figure 4). A complete description of the collection and analysis methods used for this task is provided in the 24-month post-construction benthic biology survey report (OSI, 2010c). Benthic macrofaunal samples from June 2010 were sorted, identified and enumerated directly by ESS. All other samples were sorted, identified and enumerated under the supervision of Dr. Robert Whitlatch at the University of Connecticut. Data reduction methods were used to organize the 2007 to 2010 benthic macroinvertebrate dataset into a useful format for statistical analysis. First, possible taxonomic redundancy was eliminated by combining records for taxa that were not certain to be distinct, typically to the highest (i.e., least specific) identification level of the records. Second, pre-construction data collected in the January 2007 pre-construction survey were eliminated from the dataset. These data were collected only at 15 stations (rather than the full 23) and were collected as single samples (rather than as three replicates). Therefore, only data from the October 2007 preconstruction survey and the subsequent post-construction surveys were used. Third, data from replicate samples were pooled for each station, in order to obtain the most representative community data. Univariate descriptors of the benthic macroinvertebrate community, such as taxa richness and diversity were examined for trends over time. Additionally, benthic community abundance data were analyzed with a non-parametric multivariate statistical approach using PRIMER 6 software (Clarke and Gorley, 2006). These data were plotted under various scenarios on non-metric multidimensional scaling (nmds) ordination plots to explore dissimilarities in the dataset over time and space. Hypothesis testing was primarily conducted using 2-way crossed analysis of similarity (ANOSIM) with replication to evaluate whether community differences over time and Copyright ESS Group, Inc., 2011 Page 6 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

12 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, 2011 space were significant. ANOSIM was run using default settings in the software and included 999 permutations for each analysis. ANOSIM was used to test the following questions: 1. Accounting for interactions over time, was the benthic community at stations distant from the LIRC cable array (control stations) different from stations within the cable array (impact stations)? Control stations were considered to be the station farthest from the cable array along each transect (i.e., 1A, 2E, 3A, 4E, and 5A). Impact stations were represented by station 1C, 2C, and so on through transect 5 (Figure 4). 2. Accounting for spatial interactions, was the benthic community significantly different at any point in time over the duration of the study? Subsequently, a Mantel-type test on model correlation matrices (RELATE) was used to test the following question: 1. If the benthic community was significantly different at some point in time over the duration of the study, was there a trend over time? A similarity percentages (SIMPER) routine was used to identify the individual taxa contributing most to the observed differences detected by ANOSIM Results On average, taxa richness decreased over time between the pre-construction sampling event and the 24-month (June 2010) post-construction sampling event (Attachment A, Figure 1). However, the decrease in taxa richness at impact stations (Station C) averaged somewhat less than the decrease at control stations (Attachment A, Figure 2). Diversity increased over time between the pre-construction sampling event and the 24-month (June 2010) post-construction sampling event (Attachment A, Figure 3). Taxa richness and diversity were both most variable, on average, at Transect 5 although no consistent difference in these measures was noted between the control and impact stations on any transect. When set up to show dissimilarities over time, the nmds analysis suggests a gradual shift over time in the composition of the benthic macrofaunal community with stations from earlier sampling events tending to be located toward the bottom right sector of the ordination plot and stations from later sampling events tending to be located closer to the top and left sectors of the plot (Attachment A, Figure 4). However, when the nmds ordination plot is set up to show dissimilarities over space, there is no easily identifiable trend (Attachment A, Figure 5). A significant change in benthic community composition was observed over the period of study (2- way crossed ANOSIM with replication, R= 0.216, P = 0.001). The change was also detectable when sampling events were considered in chronological order (RELATE Mantel-type test, Rho= 0.342, P = 0.001). However no significant shift in benthic community composition was found Copyright ESS Group, Inc., 2011 Page 7 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

13 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, 2011 between control and impact stations (2-way crossed ANOSIM with replication, R= , P = 0.917). SIMPER analysis also produced an ordered list of species contributing the first 50% of the overall abundance to the control and impact stations separately. The results indicate that Oligochaeta, Mediomastus ambiseta, Streblospio benedicti, and Cossura longocirrata each contributed to the first 50% of overall abundance in both groups (i.e., control and impact stations). The only species in the list that were different were Tharyx acutus (control stations) and Tellina agilis (impact stations). Although control and impact stations were not significantly different in community composition, the average similarity between samples decreased over time, beginning at 62.26% in October 2007 and falling to 43.63% by June 2010 (Attachment A, Figure 6). This suggests that the benthic community has become more variable from location to location over the period of the monitoring study Discussion Although the benthic community does appear to be shifting in a consistent direction over time, this change appears to be part of a larger scale trend or cycle and no evidence was found that it is linked to the installation or operation of the LIRC project. Outside of the LIRC benthic monitoring study, trends in the benthic macrofaunal community of Norwalk Harbor and across Long Island Sound are not well documented in readily available literature. However, some trends in water quality have been documented. Although hypoxia in Long Island Sound as a whole has been decreasing (LISS, 2011), there is some evidence that more severe phytoplankton blooms and therefore increasing hypoxia has been affecting western Long Island Sound in recent years, possibly due to changes in summertime wind patterns (Wilson et al., 2008). The fact that average similarity between stations decreased over time suggests that the observed changes in benthic community composition may have been driven by an increase in variability among locations within the study area. Additionally, the changes in community composition over time were mostly related to differences in the abundance of common species with no direct commercial importance. The observed decrease in taxa richness and increase in diversity over time was not a consistent trend. Rather, each measure saw alternating periods of decline and increase over the study area. Taxa richness shows a steep decline between the October 2008 (3-month post-construction) and January 2009 (6-month post-construction) sampling events with each transect falling to its lowest levels in the time series up to that point. A large decline in diversity was also noted at this point although a lag time of six months is apparent at Transects 1 through 4. This type of response is suggestive of a regional disturbance event or series of events rather than cable installation or operation. Major coastal storms or arrival of a particularly strong cohort of an important benthic predator are natural occurrences that could possibly trigger such a response. Copyright ESS Group, Inc., 2011 Page 8 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

14 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, Underwater Video Camera Surveys (Task 1c) Methods General Methods Underwater video was recorded along ten transects (Figure 4) for the pre-construction and postconstruction surveys. Eight transects were performed north of Sheffield Island, perpendicular to the existing power cables. Two transects were performed south of Sheffield Island, one oriented perpendicular to the existing cables while the other was oriented parallel to the centerline of the old cable corridor. The survey design for the video transects was primarily based on benthic habitat information derived from the side-scan sonar and video camera surveys originally conducted in The underwater video camera was mounted on an epi-benthic sled deployed from a small vessel. Data were recorded on DVDs, which also included a timestamp and transect number for a frame of reference. The timestamp was interfaced with a ship-board GPS navigation system which allowed an accurate estimate of the ship s position along each survey line and the ability to correlate ship-position with the video camera image position on the seafloor. Video transect surveys were used for benthic habitat characterization as described below. Benthic Habitat Characterization For each survey, benthic habitat characterization was conducted by recording all the species and habitat types discernable on the DVD images for the entire length of each transect line. At approximately one-minute intervals, video-images were captured and processed to assess the relative percentage of the major benthic habitat elements (e.g., substrate type, shell hash, biogenic structures) found on the video images. For each survey, data at each one-minute interval were pooled into three-minute time blocks. While the vessel operator attempted to maintain a constant speed and direction, variability in water current velocity and wind speed and direction caused differences in the distance that the video-sled traveled from minute-to-minute. On average, the video-sled was estimated to travel from approximately 12 m to 15 m (40 to 50 ) per minute depending on the survey period. Data pooled for three-minute intervals are presented in the benthic habitat characterization figures (see individual survey reports) and typically covered a transect length of approximately 120 feet to 150 feet depending on the survey period Results A list of organisms found in each of the video transects, as well as the occurrence of the major benthic habitat elements found in each of the survey lines during the two pre-construction and six post-construction surveys (January 2007 through June 2010), can be found in Attachment B. A summary of the recorded benthic habitat characteristics of each survey line over the entire survey period is provided below. More detailed information from each survey is found in the individual survey reports previously submitted. Copyright ESS Group, Inc., 2011 Page 9 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

15 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, 2011 Transect Line 1 - This transect line, positioned off the western side of Manresa Island, ran across the cable corridor and over the survey period was dominated by muddy sediments and macroalgae. The macroalgae encountered was primarily sea lettuce (Ulva spp.) and often kelp (Laminiaria spp.). All of the surveys recorded various degrees of scattered shell debris along portions of the transect line. Biogenic structures, common Atlantic slippersnails (Crepidula fornicata), and Eastern mud snails (Ilyanassa obsoleta) were observed during all of the preconstruction and post-construction surveys. Eastern oysters (Crassostrea virginica) were observed in scattered areas in the last three post-construction survey periods. Hermit crabs (Pagurus sp.), green crabs (Carcinus maenas), and spider crabs (Libinia emarginata) were occasionally observed during some of the pre and post-construction surveys. Whelk (Busycon sp.) were observed sporadically during two of the post-construction survey events (see Attachment B). Lobster and lobster burrows were occasionally observed along this transect line. Transect Line 2 - This transect line ran across the cable corridor and was positioned south of Line 1. Over the survey period, this transect was dominated by muddy sediments with scattered shell debris; the eastern half of the transect was often composed of a relatively high coverage of shell and shell hash. Some surveys recorded the eastern third of the transect as having high shell/shell hash and others showed the eastern half of the transect with high shell/shell hash. Eastern oysters were also present scattered mainly in the areas containing large amounts of shell and shell hash. Some of the post-construction surveys showed high macroalgae in portions of the transect, while others showed little to no macroalgae. In the areas composed of muddy sediments, mud snails (Ilyanassa obsoleta) were often quite abundant. Mud snails were recorded along this transect in all but one of the surveys. Biogenic structures, cancer crabs (Cancer sp.), and common Atlantic slippersnails were observed during the majority of the surveys. Hermit crabs, green crabs, spider crabs, and red sponge were occasionally observed during some of the surveys. Some of the rare sightings (one or two surveys only) included mud crabs (Panopeus sp.), yellow sponge (Cliona sp.), American lobster (Homarus americanus), shrimp (Crangon sp.), razor clams, and whelk (Busycon sp.) (Attachment B). Transect Line 3 - This transect line ran across the cable corridor and was positioned south of Line 2. The bottom type was primarily composed of muddy sediment with varying degrees of shell/shell hash and macroalgae depending on the survey. The higher percentages of shell and shell hash occurred toward the eastern half of the transect for most surveys. All of the surveys recorded various degrees of Eastern oysters along portions of the transect line. Biogenic structures and Eastern mud snails were observed during all of the pre-construction and postconstruction surveys. Most of the surveys recorded dredge marks, hermit crabs, spider crabs, and common Atlantic slippersnails. Rare sightings (observed in one or two surveys only) included mud crabs, horseshoe crab, American lobster, whelk, red sponge (Microciona), and razor clams (Attachment B). Transect Line 4 - This transect line, positioned south of Line 3, ran across the cable corridor and crossed the harbor boat channel. This transect line was composed of muddy sediment with varying degrees of macroalgae and shell hash depending on the survey. All of the surveys Copyright ESS Group, Inc., 2011 Page 10 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

16 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, 2011 recorded various degrees of Eastern oysters along portions of the transect line. Biogenic structures, common Atlantic slippersnails, and Eastern mud snails were observed during all of the pre-construction and post-construction surveys. The most abundant epifaunal organisms at this site were mud snails and common Atlantic slippersnails. Most of the post-construction surveys recorded hermit crabs and spider crabs. All but two surveys recorded yellow sponge and shrimp. Rare sightings (observed in one or two surveys only) included green crabs, cancer crabs, mud crabs, horseshoe crab, and American lobster. The green crab and cancer crab were only observed during the January 2007 pre-construction survey. Whelk and red sponge were recorded at 3 out of 6 post-construction surveys, but not in the pre-construction surveys (Attachment B). Transect Line 5 - This transect line, positioned to the south of Line 4, also traversed the cable corridor and the harbor channel. The bottom was composed of muddy sediments and shell or shell hash. Small amounts of macroalgae were also observed during all of the surveys. Scattered patches of Eastern oysters were observed during all surveys along much of the transect, with higher densities typically observed at the eastern end. Biogenic structures, common Atlantic slippersnails, and Eastern mud snails were observed during all of the preconstruction and post-construction surveys. Rare sightings (observed in one or two surveys only) included hermit crabs, green crabs, yellow sponge, horseshoe crab, moonsnail (Euspira sp.), red sponge, and whelk. Spider crabs were observed in both pre-construction surveys and in three of the post-construction surveys. Shrimp were observed during three of the post-construction surveys (Attachment B). Transect Line 6 - This transect line was positioned south of Line 5 and crossed the cable corridor and part of the harbor channel at the western end of the transect. The bottom was composed of muddy sediments and shell or shell hash. Two surveys recorded large amounts of algae during some of the pooled sampling intervals; however, all surveys recorded macroalgae along some portions of the transect. Small amounts of sand were observed in a few pooled sampling intervals during the last post-construction survey. All of the surveys recorded various degrees of Eastern oysters along portions of the transect line, but often they were more prevalent along the eastern half of the transect. Biogenic structures, common Atlantic slippersnails, and Eastern mud snails were observed during all of the pre-construction and postconstruction surveys. Hermit crabs, spider crabs, and yellow sponge were observed during one of the pre-construction surveys and during four or more of the post-construction surveys. Horseshoe crabs were observed during four of the six post-construction surveys and whelk and red sponge were observed during three of the six post-construction surveys. Rare sightings (observed in one or two surveys only) included cancer crabs, mud crabs, moonsnail, and razor clams (Attachment B). Transect Line 7 - This transect was located further to the south of Line 6. Throughout this transect for all surveys, muddy sediments dominated with varying amounts of shell/shell hash and occasionally algae and rock/cobbles. The last survey recorded a higher percentage of algae than previous surveys. Patches of Eastern oysters were observed during all the surveys in Copyright ESS Group, Inc., 2011 Page 11 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

17 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, 2011 portions of the transect, but not in high densities. Biogenic structures, common Atlantic slippersnails, and Eastern mud snails were observed during all of the pre-construction and postconstruction surveys. Shrimp, hermit crabs, and spider crabs and shrimp were observed in three, four, and five post-construction surveys, respectively. Rare sightings (observed in one or two surveys only) included green crabs, yellow sponge, red sponge, and whelk (Attachment B). Transect Line 8 - Line 8 was positioned south of Line 7, close to the northern shore of Sheffield Island. The bottom was predominately composed of mud with varying amounts of shell and shell hash. Some of the pooled sampling intervals in certain surveys contained algae in smaller amounts. Two of the post-construction surveys recorded rock/cobble in one of the pooled sampling intervals and cobbles and boulders were observed occasionally along the transect during most surveys. Eastern oysters were observed during all of the surveys which were patchily distributed along most of the transect. Biogenic structures, common Atlantic slippersnails, and Eastern mud snails were observed during all of the pre-construction and postconstruction surveys and horseshoe crabs were observed during all but one of the surveys. Spider crabs were observed during the last three post-construction surveys. Rare sightings (observed in one or two surveys only) included hermit crabs, yellow sponge, shrimp, whelk, red sponge, and razor clams (Attachment B). Transect Line 9 - Line 9 ran across the cable corridor on the south side of Sheffield Island. During all surveys, the transect consisted of firm sandy sediment with scattered shell debris (primarily composed of razor clam, hard clam and oyster shells). Eastern oysters were observed occasionally along the transect during all surveys. Water clarity was poor during the last two post-construction surveys; therefore, it was often difficult to accurately assess objects on the bottom or to determine the presence or absence of Eastern oysters. Shell/shell hash, algae, biogenic structures, and common Atlantic slippersnails were observed during all of the preconstruction and post-construction surveys and Eastern mud snails were observed during all of the post-construction surveys. Hermit crabs, spider crabs, shrimp, and moonsnail were observed in both pre-construction surveys and during two to four post-construction surveys. Rare sightings (observed in one or two surveys only) included yellow sponge, horseshoe crab, and American lobster (Attachment B). Lobster pots and lines were observed in several places along this transect line during the last post-construction survey. Transect Line 10 - This transect line ran perpendicular to the southern side of Sheffield Island, onshore to offshore along the center of the cable corridor. Near the island, the bottom was composed of gravel, cobbles and boulders. Moving offshore, the bottom was composed of sandy sediment with occasional small amounts of shell/shell hash and was similar to that described for Line 9. Eastern oysters were observed in patchy distributions along portions of the transect during all of the surveys except the last survey due to poor water clarity. Algae, biogenic structures, and common Atlantic slippersnails were observed during all of the pre-construction and post-construction surveys. Spider crabs were observed during all surveys except one of the pre-construction surveys and hermit crabs were observed during all surveys except two of the post-construction surveys. Eastern mudsnails were observed during all of the post-construction Copyright ESS Group, Inc., 2011 Page 12 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

18 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, 2011 surveys and seastars (Astrias forbesi) were occasionally observed during some of the surveys. Rare sightings (observed in one or two surveys only) included horseshoe crab, sea squirt (Botrylloides), Atlantic oyster drill (Urosalpinx), urchin, and red sponge (Attachment B) Discussion The underwater video camera surveys revealed similar types and distributions of benthic habitat before and after construction of the LIRC project. Overall benthic habitat features and benthic organisms did not seem to vary when comparing pre- and post-construction video transects. The surveys showed that the area inside of Sheffield Island was composed primarily of muddy sediments with varying coverage of shell and shell debris composed primarily of common Atlantic slippersnails, oyster and hard clam shells. Surveys inside of Sheffield Island also had varying amounts of macroalgae during some of the surveys. The most abundant epibenthic invertebrates were mud snails, common Atlantic slippersnails, and spider crabs. Numerous biogenic structures (e.g., burrows, mounds) were found throughout the survey area, but were more prevalent north of Sheffield Island. In contrast, the study area on the south side of Sheffield Island was generally composed of firmer, finer sand sediments that typically contained a lower coverage of shell debris. The results from the video survey suggest that the installation and operation of the LIRC project has not changed or altered the benthic habitat features along the video transect lines. 4.0 SHELLFISH SURVEYS Several shellfish sampling techniques were used during the LIRC pre- and post-construction biological surveys including quantitative shellfish sampling using diver-placed quadrats, calibrated oyster trays, and portable oyster dredge sampling. Each of these survey techniques and results are described below. 4.1 Quantitative Shellfish Sampling (Task 1b) Methods During the two pre-construction surveys and each of the post-construction surveys, quantitative estimates of shellfish abundance and size were made at 20 stations (Figure 4) within the monitoring area (15 north and 5 south of Sheffield Island) by way of SCUBA divers. At each site, divers placed a 2.7 ft 2 (0.25m 2 ) quadrat on the seafloor and collected all material inside the quadrat to a depth of approximately 0.3 to 0.5 feet (10 to 15 cm) below the sediment surface. The material was placed in mesh bags and brought to the surface where the contents of the bag were washed. All living shellfish (oysters and clams) were removed and sediment and shell matter were discarded. Living oysters and hard clams were counted and the maximum shell length was recorded using a vernier caliper. Three replicates were collected at each station using a random sampling method to ensure collection of unbiased samples. Quantitative shellfish quadrat data from the entire 2007 to 2010 dataset were analyzed, with a focus on the size frequency distribution and overall distribution and density of shellfish within the study area. Copyright ESS Group, Inc., 2011 Page 13 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

19 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, Results Oysters Oysters were relatively uncommon at sampling stations over the duration of the monitoring program and were not found at more than 5 of the 20 stations for any given survey (Attachment C, Figure 1). Oyster abundance at the stations varied from 2 individuals in July 2008 to 51 in October 2008 and demonstrated no consistent trend over time (Attachment C, Figure 2). The only station at which oysters were observed during each sampling event was Station F (Figure 4), located north of Sheffield Island and west of the replacement cable array. The total number of oysters collected during each quantitative sampling event was sometimes very low. However, during most sampling events, data were sufficient to infer something about the size distribution of oysters in the study area. Most events suggested a unimodal distribution with the majority of individuals in the spat (20-30 mm) to early maturity size range. Among harvest size oysters, which are typically four or more years old and greater than 76 mm (Eastern Oyster Biological Review Team, 2007), the frequency of observation decreased with increasing size (OSI, 2010c). Hard Clams Hard clams were relatively common during the first three sampling events in October 2007 (preconstruction), July 2008 (post-construction), and October 2008 (post-construction) when they were present, on average, at 17 to 18 of 20 stations (Attachment C, Figure 1). Hard clams were much less common at the sampling stations in January 2009 (observed at six stations) but were more frequently observed from June 2009 to June Hard clam abundance at the stations varied from 8 individuals in June 2009 to 134 in October 2007 and demonstrated a slow decline from October 2007 to October 2008, followed by a large drop in January 2009 and a subsequent small increase in June 2009 (Attachment C, Figure 2). Since June 2009, hard clam abundance has been relatively stable. The only station at which hard clams were observed during each sampling event was Station S, located south of Sheffield Island and west of the replacement cable array. The total number of hard clams collected during each quantitative sampling event was also sometimes very low, especially in January 2009 and to a lesser degree during subsequent surveys. Most surveys suggested a bimodal distribution with a primary peak in the harvest size range (60 to 100 mm) and a secondary peak in the small harvest size range (30 to 40 mm) (OSI, 2010c). Sexual maturity is typically reached at one year of age and harvest size hard clams are likely to be in their second year of growth or older (Mackenzie, 2002). Immature hard clams (less than approximately 30 mm) were not frequently observed during any event. Although this could be attributed to a lack of natural recruitment, it may also be related to reduced search efficiency for smaller individuals, which would be more difficult for divers to locate and extract for measurement. Copyright ESS Group, Inc., 2011 Page 14 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

20 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, Discussion Although quantitative shellfish quadrat sampling suggests that hard clam numbers in the study area have fallen since October 2007, this change does not appear directly linked to the installation or operation of the LIRC project. The decline mirrors a fall in the overall benthic macroinvertebrate community taxa richness in that it appears to be primarily related to a regional event or series of events occurring between October 2008 (3-month post-construction survey) and January 2009 (6-month post-construction survey), as suggested by the sharp drop in hard clam abundance over this period. Whether the observed decline in hard clam numbers within the study area is natural or directly related to harvesting or some other anthropogenic stressor is unknown. The number of hard clams harvested in Long Island Sound increased each year from 2001 to 2007 (Long Island Sound Study, 2011). It is uncertain whether total harvests continued to increase in 2008 and 2009 because Connecticut commercial shellfish harvesters did not report their catch to the state during these years. However, harvests declined each year in 2008 and 2009 in adjacent New York waters, leaving open the possibility that a regional decline in hard clams occurred at this time. Oyster numbers in the sampled quadrat areas were variable but low for the duration of the sampling program. As no change in the study area was noted, it is unlikely that the installation or operation of the LIRC project has had a negative impact on oysters. 4.2 Deployment of Calibrated Oyster Trays (Task 3) Methods Trays of Eastern oysters (Crassostrea virginica) were out-planted at five stations throughout the monitoring area (Figure 4). The trays were constructed of plastic-coated wire mesh (1 inch mesh) and were lined on the bottom with plastic mesh (1/4 inch mesh) and a plastic mesh partition was used to divide the trays in half. The trays were designed to allow the oysters to live and grow during pre- and post-construction phases of the monitoring program (Figure 5). The cages were 2ft x 2ft x 1/2ft and consisted of two internal chambers that separate two different age classes. Approximately 8-10 oysters of each age class were placed within each tray. Six trays were deployed at each station: two located at the edge of the cable corridor, two located 50 m from the cables and two located 200 m from the cables. Stations 1 and 2 are located in Sheffield Harbor south of the federal navigation channel on NU/CL&P shellfish leases. Stations 3 and 4 are located south of Sheffield Island on NU/CL&P shellfish leases. The fifth station was located in Sheffield Harbor north of the federal navigation channel just outside the western edge of the cable corridor in the Norwalk recreational shellfishing area. Oysters were identified with small numbered tags that were glued to the shells. Prior to deployment (April 21, 2007), the oysters were photographed with a digital camera for later image analysis of shell size and area. The trays were periodically recovered by SCUBA divers in order to estimate oyster growth and mortality in each of the trays. Individual sampling dates in the pre-construction, construction, and post-construction phases were: 6/19/07, 7/18/07, 8/20/07, and 10/2/07 for the pre- Copyright ESS Group, Inc., 2011 Page 15 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

21 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, 2011 construction phase; 12/5/07, 1/9/08, 3/13/08, and 5/20/08 for the construction phase and 7/21/08, 10/21/08 and 1/19/09 for the post-construction phase. On each sampling date, oysters in each of the cages were examined to record the number of dead individuals and all the oysters were photographed with a digital camera. The trays were cleaned and the oysters were then redeployed at their individual study sites and positions. Following the July 2008 sampling, oysters were removed and replaced with a new series of small and large size classes. Subsamples of the removed oysters from each of the sites were frozen for later examination. Individual oyster dorsal surface shell area and maximum shell length were obtained from the photographs using an image analysis program (NIH Image J) Results The oyster trays were sampled four times during the pre-construction phase, four times during construction, and three times during the post-construction phase to determine oyster growth and mortality in the survey area. Analysis of shell growth indicates that for both small and large size classes, the relative percent of shell growth did not significantly vary within or between station locations (analysis of variance, p > 0.05). A summary of the average shell area for small and large oysters at the different oyster tray sites is provided in Attachment C, Table 1. Growth of small oysters was greater in 2007 than during similar periods in This pattern was noted for both the March/April to early July periods of 2007 and 2008 (one-tailed paired t- test, df=3, α =0.05, p<0.01) and the late July to October periods (one-tailed paired t-test, df=3, α =0.05, p<0.01). Growth of large oysters was lower on average during the pre-construction spring to early summer period in 2008 (4.5±4.2 cm 2 ) than in 2007 (12.5±5.7cm 2 ), although this difference was not statistically significant (one-tailed paired t-test, df=3, α =0.05, p=0.06). Conversely, growth during the pre-/post-construction late summer to winter periods was greater in 2008 (0.3±0.12 cm 2 ) than in 2007 (-0.3±25.0cm 2 ), although this difference was also not statistically significant (one-tailed paired t-test, df=3, α =0.05, p=0.410). In general, oyster mortality in the trays was relatively low (Attachment C, Table 1) during the study to date. The exception to this pattern was at Station 4, where mortality of large oysters sampled on June 19, 2007 (pre-construction) was greater than 10%. When the oyster trays were retrieved from the bottom at this time, they were filled with sediment; likely causing the high oyster mortality found at site. Divers noted that there were a number of dredge scour marks around the site at this time, indicating evidence that active shellfish harvesting was occurring in the area. This activity likely was responsible for the high amounts of sediment deposited in some of the oyster trays at Station 4. In addition, two trays were lost sometime before the October 2007 (pre-construction) sampling date and four trays were lost before the December 2007 (during construction) sampling date; presumably also due to shellfishing activities around this station. Similarly, 2 trays were lost at Station 3 sometime before the Copyright ESS Group, Inc., 2011 Page 16 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

22 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, 2011 October 2007 (pre-construction) sampling date. Because all of these losses took place before the cable replacement work had started, the cause could not have been cable-related Discussion The calibrated oyster trays proved to be an effective method for assessing oyster growth and mortality during the pre- and post-construction phases of the monitoring project. Statistical analysis indicates that within oyster size-class growth did not significantly vary within and between-sites. Growth of large oysters did not significantly differ between 2007 and However, small oyster growth was significantly slower during the post-construction period between July and October 2008 than during the pre-construction period in the previous year. Growth of small oysters was also significantly slower during the spring/early summer 2008 (construction/postconstruction) than spring/early summer 2007 (pre-construction). This suggests that 2008 may not have been as favorable a year for young oyster growth as It is likely that the observed reduction is at least partly related to the fact that oyster growth naturally declines with increasing age (Eastern Oyster Biological Review Team, 2007). Therefore, growth rates in 2008 would be expected to naturally decline relative to 2007 rates, especially for the younger cohort of oysters (i.e., the trays with small oysters). Whether construction activities played a role in slowing the growth of young oysters is not certain. However, the fact that no significant difference was observed in oyster growth between sites suggests that the observed difference in young oyster growth between 2007 and 2008 was due to natural inter-annual variation rather than localized disturbance by cable construction activities. Oyster mortality was generally low (0-1 individuals per month at each station). The exception was at Station 4, located on the south side of Sheffield Island where mortality of the larger sizeclass of oysters was ~3-10% per month in June 2007 (pre-construction). The likely cause of this mortality was due to high levels of sediment deposition inside the trays caused by hard clam shellfishing activities at this site. Therefore, oyster survival, as measured in the calibrated oyster trays, was not adversely affected by LIRC project construction. 4.3 Portable Oyster Dredge Sampling (Task 4) Methods A series of shellfish dredges were conducted to supplement the results obtained from the quantitative shellfish quadrat surveys (Task 1b) and to provide more spatial coverage for estimating shellfish abundance and distribution. The 31 inch (79 cm) dredge was deployed from a vessel along 20 transects (Figure 6) in the study area. Seven transects were located in the Norwalk Recreational Beds (five north of the channel and two south of the channel), nine transects in Sheffield Harbor north of Sheffield Island, and four transects south of Sheffield Island. For each transect, the dredge was lowered to the bottom and dragged for approximately 100 feet. Upon recovery, individual shellfish were identified, counted, measured and returned to the seafloor. Copyright ESS Group, Inc., 2011 Page 17 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

23 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, 2011 Data from the October 2007 pre-construction and July 2008 post-construction dredge surveys were compared using a paired sample t-test. Dredge transects that did not collect any shellfish during either survey were excluded from this statistical analysis Results Hard clams showed a small increase in average abundance during the post-construction dredge survey from 2.87±3.28 to 3.38±3.91 (mean±1 SD) (Attachment C, Table 2). However, this increase was not statistically significant (one-tailed paired t-test, df=15, T=-0.63, α =0.05, p=0.27). The post-construction dredge survey collected fewer oysters than the pre-construction survey, falling from 16.19±23.86 to 5.29±6.20 (mean±1 SD) (Attachment C, Table 2). However, this decline was not statistically significant (one-tailed paired t-test, df=8, T=1.64, α =0.05, p=0.07) Discussion The results of the dredge surveys do not indicate a significant difference in either hard clam or oyster abundance over the project area between October 2007 and July This corroborates data from the oyster tray study and quantitative shellfish sampling over the same period, which also suggest no significant impact to shellfish from the LIRC project construction. 4.4 Summary of Shellfish Results Three methods were used to evaluate shellfish in the LIRC Project area: quantitative shellfish sampling using diver-placed quadrats, calibrated oyster trays, and portable oyster dredge sampling. Results from these sampling techniques indicated that oyster abundance was generally low; however, no significant difference in oyster abundance was found between pre- and post-construction survey conditions in the quantitative shellfish sampling or portable oyster dredge study. Similarly, the calibrated oyster tray study showed that oyster shell growth did not significantly vary within or between station locations and oyster mortality was consistently low throughout both pre-construction and post-construction survey events. Therefore, these results suggest that the installation and operation of the LIRC project did not adversely affect oyster growth or abundance. Hard clam abundance, as recorded in the quantitative shellfish sampling and portable oyster dredge sampling, was typically higher than what was reported for oysters. The quantitative shellfish sampling technique showed a decrease in hard clam abundance over time; however, this decrease is not believed to be linked to the LIRC project. The steep decline in hard clam abundance and distribution between October 2008 and January 2009 coincides with a similar decline in benthic macroinvertebrate taxa richness and diversity. This, along with the fact that the change occurred well after the construction of the LIRC project was complete, suggests that the observed decline was primarily related to a regional event or series of events unrelated to the cable installation or operation. It is uncertain whether the disturbance that caused the decline was natural or anthropogenic. However, the benthic macroinvertebrate community appears to have recovered from the initial disturbance while hard clam abundance and distribution shows signs of stabilization. The Copyright ESS Group, Inc., 2011 Page 18 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

24 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, 2011 portable oyster dredge sampling showed a small increase in average hard clam abundance during the post-construction survey; however, statistical analyses indicated that the increase in hard clam abundance was not significant. Therefore, these results suggest that the installation and operation of the LIRC project did not adversely affect hard clam abundance or distribution. 5.0 OVERALL CONCLUSIONS The seafloor mapping and benthic biology monitoring programs conducted as part of the LIRC Project in Connecticut waters provide pre- and post-construction data for a three-and-a-half year period. The results, as summarized in this report, indicate that there were no substantial or long-term impacts from LIRC project construction during this monitoring period. Impacts attributed to the LIRC project construction were primarily noted in the seafloor mapping surveys as trenches formed over each new cable by the jet plow embedment process. Side scan sonar results from the post-construction seafloor survey revealed that sediment type boundaries remained the same as pre-construction conditions; therefore, the LIRC Project has not had an effect on sediment type boundaries. Similarly, SPI data showed that there was no evidence of layers of suspended sediment over the existing surficial sediments through the SPI photos. The two years of post-construction monitoring have shown that these impacts are localized and temporary, with any remaining trenches continuing to fill in naturally, and areas in higher energy locations recovering at a faster rate. Benthic macroinvertebrate sampling results over the survey period suggest that any observed changes in benthic community composition are not linked to the installation or operation of the LIRC project. The underwater video camera survey results revealed similar types and distributions of benthic habitat before and after construction of the LIRC project and suggest that the installation and operation of the LIRC project has not changed or altered the benthic habitat features along the video transect lines. Shellfish sampling results over the survey period indicated that oyster abundance was generally low; however, no significant difference in oyster abundance was found between pre- and post-construction survey conditions in the quantitative shellfish sampling or portable oyster dredge study. Similarly, the calibrated oyster tray study showed that oyster shell growth did not significantly vary within or between station locations and oyster mortality was consistently low throughout both pre-construction and postconstruction survey events. Hard clam abundance, as recorded in the quantitative shellfish sampling and portable oyster dredge sampling, was typically higher than what was reported for oysters. The quantitative shellfish sampling technique showed a decrease in hard clam abundance over time; however, this decrease is not believed to be linked to the LIRC project since the steep decline in hard clam abundance and distribution between October 2008 and January 2009 coincides with a similar decline in benthic macroinvertebrate taxa richness and diversity. This, along with the fact that the change occurred well after the construction of the LIRC project was complete, suggests that the observed decline was primarily related to a regional event or series of events not directly linked to the LIRC project. Additionally, the portable oyster dredge sampling results did not indicate a significant change in hard clam or oyster abundance between the pre-construction and post-construction surveys. Therefore, these results suggest that the installation and operation of the LIRC project did not adversely affect hard clam abundance or distribution or oyster growth or abundance. Copyright ESS Group, Inc., 2011 Page 19 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

25 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, 2011 This report completes the requirements outlined in the Monitoring and Mitigation Plan and no further monitoring related to seafloor mapping or benthic biology is required under DEP Permit MG, Connecticut Siting Council Docket No. 224, or USACE Permit NAE REFERENCES Bohlen, F and M. M. Howard-Strobel Long Island Replacement Cable (LIRC) Project - An Analysis of the Effects of the Removal and Replacement of Submarine Electrical Cables on the Sediment Transport Regime in Sheffield Harbor, Norwalk, Connecticut. pared for ESS Group, Inc. September 8, Clarke, K.R. and R.N. Gorley Primer v6: User Manual/Tutorial. PRIMER-E: Plymouth, U.K. Clarke, K.R. and R.M. Warwick Change in Marine Communities: An Approach to Statistical Analysis and Interpretation, 2nd ed. PRIMER-E: Plymouth, U.K. Eastern Oyster Biological Review Team Status Review of the Eastern Oyster (Crassostrea virginica). Report to the National Marine Fisheries Service, Northeast Regional Office. February 16, Long Island Sound Study (LISS) Status and Trends: LISS Environmental Indicators: Hard Clam Harvest. Accessed on February 2, 2011 at Mackenzie, C.L., A. Morrison, D.L. Taylor, V.G. Burrell, W.S. Arnold, and A.T. Wakida-Kusunoki Quahogs in Eastern North America: Part I, Biology, Ecology, and Historical Uses. Marine Fisheries Review, 64(2): National Marine Fisheries Service Publication Office. Ocean Surveys, Inc Final Report Total Suspended Sediment Monitoring for Connecticut Waters. LIPA/CL&P Cable Replacement Project. Power Cable Removal and Embedment Operations. Long Island Sound and Sheffield Harbor, Norwalk, Connecticut. Report No. 08ES008. In: ESS, OSI, UCONN, Marine Environmental Monitoring Surveys for the Connecticut Portion of the Long Island Replacement Cable Project. Part II Construction and Early -Construction Survey Reports. October 2007 July Ocean Surveys, Inc. 2009a. Final Report Total Suspended Sediment Monitoring for New York Waters. LIPA/CL&P Cable Replacement Project. Power Cable Embedment Operations. Long Island Sound, New York. Report No. 08ES010. Ocean Surveys, Inc. 2009b. Final Report Twelve-Month Construction Seafloor Mapping Survey. A Component of the Benthic Monitoring Study for the Long Island Replacement Cable Project. Summer 2009, Sheffield Harbor and Long Island Sound, Norwalk, Connecticut. Report No. 07ES077.5A, 26p. Copyright ESS Group, Inc., 2011 Page 20 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

26 Final Summary Report LIRC - and -Construction Seafloor Mapping and Benthic Biology Surveys May 10, 2011 Ocean Surveys, Inc. 2010a. Final Report Eighteen-Month Construction Seafloor Mapping Survey. A Component of the Benthic Monitoring Study for the Long Island Replacement Cable Project. December 2009, Sheffield Harbor and Long Island Sound, Norwalk, Connecticut. Report No. 07ES077.6A, 27p. Ocean Surveys, Inc. 2010b. Final Report Twenty-Four Month Construction Seafloor Mapping Survey. A Component of the Benthic Monitoring Study for the Long Island Replacement Cable Project. June/July 2010, Sheffield Harbor and Long Island Sound, Norwalk, Connecticut. Report No. 07ES077.7A, 28p. Ocean Surveys, Inc. 2010c. Final Report Twenty-Four Month Benthic Biology Survey. A Component of the Benthic Monitoring Study for the Long Island Replacement Cable Project. June 2010, Sheffield Harbor and Long Island Sound, Norwalk, Connecticut. Report No. 07ES077.7B. Wilson, R.E., R.L. Swanson, and H.A. Crowley Perspectives on long-term variations in hypoxic conditions in western Long Island Sound. Journal of Geophysical Research, 113 C12011: Copyright ESS Group, Inc., 2011 Page 21 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\final summary report.doc

27 Figures

28 Figure 1 NU Cable Replacement Monitoring Matrix - Schedule for Sampling -Construction Period Construction Period -Construction Period TASK One Season Construction Window - Construction Survey Remove Cables 1-7 Install New Cables & Embed New Cables Month 0 -Construction Survey Month 3 3 Month Survey Month 6 6 Month Survey Month 12 Month 18 Month 24 Jun-10 May-10 Apr-10 Mar-10 Feb-10 Jan-10 Dec-09 Nov-09 Oct-09 Sep-09 Aug-09 Jul-09 Jun-09 May-09 Apr-09 Mar-09 Feb-09 Jan-09 Dec-08 Nov-08 Oct-08 Sep-08 Aug-08 Jul-08 Jun-08 May-08 Apr-08 Mar-08 Feb-08 Jan-08 Dec-07 Nov-07 Oct Oct 1-15 Sep-07 Aug-07 Jul-07 Jun-07 May-07 Apr-07 Mar-07 Feb-07 Jan-07 -Construction Time Frame Task #1: Benthic Habitat Ground-Truthing Task #1a Sediment grabs Task #1b Quantitative shellfish sampling Task #1c Under-water video-camera surveys 9/27-10/ /21-8/ /20-10/ Early Jan 2009 Jun-09 Dec-09 Jun-10 Task #2: Bohlen Current Velocity & Turbidity Monitoring & Radio Dating Coring Task #2a In Situ Instruments 9/27-10/10 Task #2b Radio Dating Cores 2007 Task #2c Add-On In Situ Instruments for Aquaculture Task #2d Add-On Radio Dating Cores for Aquaculture Task #3: Deployment of Calibrated Oyster Trays Task #3a Field Servicing of Trays 9/27-10/10 Task #3b Growth & Mortality Analysis /6/07 1/10/08 Task #3c Collect shellfish meats for storage and future analysis Task #3d Deploy New Set of Cages on Town Bed 12/6/07 1/10/08 Task #4: Portable Oyster Dredge Sampling Task #4a Oyster Dredge Sampling Town Recreational Beds Task #4b Oyster Dredge Sampling NU Area N Sheffield Is Task #4c Oyster Dredge Sampling NU Area S Sheffield Is 9/27-10/ /21-8/ Task #5: -Construction Monitoring in 4 Areas Task #5a Multibean Hydrography Task #5b Side Scan Sonar Imagery Task #5c Underwater TV Task #5d Sediment Profile Imagery 9/28-10/ Construction Time Frame Task #6: Real-Time Suspended Sediment Plume Mapping in CT State Waters Task #6a Monitoring during cable removal inshore waters 11/7 Task #6b Monitoring during cable embedment inshore waters 2/28-3/18/2008 Task #6c Monitoring during cable removal nearshore waters 11/7 Task #6d Monitoring during cable embedment nearshore waters 2/28-3/18/2008 Task #6e Monitoring during cable removal offshore waters 11/7 Task #6f Monitoring during cable embedment offshore waters 2/28-3/18/2008 Task #7: NY State Monitoring Plan 10/24-12/14/2007 -Construction Time Frame Task #8: -Construction Monitoring in 4 Areas Task #8a Multibean Hydrography Task #8b Side Scan Sonar Imagery Task #8c Underwater TV Task #8d Sediment Profile Imagery 7/27-8/ Early Jan 2009 Jun-09 Dec-09 Jun-10 Task #9: Benthic Sediment In Situ Temp Monitoring Program Task #9a Benthic Sediment In Situ Temp Monitoring Program 9/17/2008-1/27/09 4/14/10-6/3/10 Task #10: New Cable EMF Variations Task #10a New Cable EMF Variations 11/2-11/5 9/7-9/9 4/14/20112:19 PM

29 Figure 2: Five monitoring areas designated for remote sensing surveys.

30

31

32 Figure 5. Photograph of Oyster Tray used to Monitor Shellfish Survival and Growth.

33

34 Attachment A Benthic Macroinvertebrate Statistical Analysis

35 Figure 1. Macroinvertebrate Taxa Richness by Transect, October 2007 to June 2010 y = x R 2 = Oct-07 Dec-07 Feb-08 Apr-08 Jun-08 Aug-08 Oct-08 Dec-08 Feb-09 Apr-09 Jun-09 Aug-09 Oct-09 Dec-09 Feb-10 Apr-10 Jun-10 Date T1 Average T2 Average T3 Average T4 Average T5 Average Linear (Overall Average) Taxa Richness

36 Figure 2. Macroinvertebrate Taxa Richness at Impact and Control Stations October 2007 to June Impact Stations: Control Stations: y = x R 2 = y = x R 2 = Taxa Richness Oct-07 Dec-07 Feb-08 Apr-08 Jun-08 Aug-08 Oct-08 Dec-08 Feb-09 Apr-09 Jun-09 Aug-09 Oct-09 Dec-09 Feb-10 Apr-10 Jun-10 Date Impact Stations Control Stations Linear (Impact Stations) Linear (Control Stations)

37 Figure 3. Macroinvertebrate Diversity by Transect, October 2007 to June 2010 y = x R 2 = Oct-07 Dec-07 Feb-08 Apr-08 Jun-08 Aug-08 Oct-08 Dec-08 Feb-09 Apr-09 Jun-09 Aug-09 Oct-09 Dec-09 Feb-10 Apr-10 Jun-10 Date T1 Average T2 Average T3 Average T4 Average T5 Average Linear (Overall Average) Diversity

38 Transform: Fourth root Resemblance: S17 Bray Curtis similarity 3C 1C 2C 1A 1C 2E 4E 2E 3A 2D Stress: 0.23 Date Oct07 Jul08 Oct08 Jan09 Jun09 Dec09 Jun10 5A 5C 4C 5C 5C 5A 5C 5A 4C 5C 3C 3C 5A 5A 4C 1C 3A 4E 4E 4E 3A 3C 2C 3A 3A 4C 4E 3A 3C 3C 2C 2C 2E 4C 4C 3A 1C 2E 2E 2C 2E 1A 2E 3C 1C 1C 1A 1C 4C 5C 2C 5C 4E 1A 1A 4E 1A 1A 5A 5A Figure 4. Non-metric Multidimensional Scaling (nmds) Plot of Benthic Macroinvertebrate Community, Emphasizing Community Dissimilarity over the October 2007 to June 2010 period J:\N345 NUSCO\NU - LIRC \N _Biol Monitoring\Final Summary report\attachments\attachment A\attach a_fig 4 and 5.doc

39 Transform: Fourth root Resemblance: S17 Bray Curtis similarity 5D 2D Stress: 0.25 Position A C D/E 5A 5A 5C 5C 5A 5C 5A 5D 4A 5A 5A 5C 5A 3E 5C 5C 5D 5D 5D 5D 3C 4A 4C 3E 5C 4C 3E 3C 3C 2A 1C 2A 3E 2C 2A 2A 4C 2A 3C 3A 2C 2E 1A 1C 4A 4C 2E 1C 2E 2C 1D 4C 1C 4E 3C 4C 3E 3C 2C 1D 3A 3E 4A 4E 4A 3A 3C 2C 3A 1D 1D 4A 1A 3E 1A 4E 3A 4E 4A 1D 1C 4E 2E 1A 3A 1A 5D 2C 1C 2E 3A 4E 1D 4E 2A 1A Figure 5. Non-metric Multidimensional Scaling (nmds) Plot of Benthic Macroinvertebrate Community, Emphasizing Community Dissimilarity by Transect Position over the October 2007 to June 2010 Period J:\N345 NUSCO\NU - LIRC \N _Biol Monitoring\Final Summary report\attachments\attachment A\attach a_fig 4 and 5.doc

40 Figure 6. Average Macroinvertebrate Community Similarity, October 2007 to June Average Similarity (%) Date

41 Attachment B Underwater Video Survey Observed Habitat and Species

42 ATTACHMENT B Summary of Major Benthic Habitat Elements and Epibenthic Species Observed in Underwater Video Surveys (January 2007 June 2010) Habitat Element 1/07 10/07 Transect 1 7/08 10/08 1/09 6/09 12/09 6/10 Gravel Muddy/sand sandy/mud sediment Shell/shell hash (oyster shells, slipper shells, clam shells) Drift algae (e.g. Ulva, Fucus) Fine sand sediment Biogenic structures (e.g. burrows, tubes) Cobbles Coarse sand Boulders Dredge marks Hermit crabs (Pagurus sp.) Green crabs (Carcinus maenas) Cancer crabs (Cancer sp.) Spider crabs (Libinia emarginata) Mud crabs (Panopeus sp.) Yellow sponge (Cliona sp.) Atlantic slipper shell (Crepidula fornicate) Copyright ESS Group, Inc., 2011 Page 1 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

43 Habitat Element 1/07 10/07 Transect 1 7/08 10/08 1/09 6/09 12/09 6/10 Eastern oyster (Crassostrea virginica) Horseshoe crab (Limulus polyphemus) Seastar (Astrias forbesi) Shrimp (Crangon sp.) Moonsnail (Euspira sp.) Eastern mudsnail (Ilyanassa obsoleta) American Lobster (Homarus americanus)? Whelk (Busycon sp.) Crab (unidentified) Copyright ESS Group, Inc., 2011 Page 2 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

44 Habitat Element 1/07 10/07 Transect 2 7/08 10/08 1/09 6/09 12/09 6/10 Gravel Muddy/sand sandy/mud sediment Shell/shell hash (oyster shells, slipper shells, clam shells) Drift algae (e.g. Ulva, Fucus) Fine sand sediment Biogenic structures (e.g. burrows, tubes) Cobbles Coarse sand Boulders Dredge marks Hermit crabs (Pagurus sp.) Green crabs (Carcinus maenas) Cancer crabs (Cancer sp.) Spider crabs (Libinia emarginata) Mud crabs (Panopeus sp.) Yellow sponge (Cliona sp.) Atlantic slipper shell (Crepidula fornicate) Eastern oyster (Crassostrea virginica) Horseshoe crab (Limulus polyphemus) Copyright ESS Group, Inc., 2011 Page 3 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

45 Habitat Element 1/07 10/07 Transect 2 7/08 10/08 1/09 6/09 12/09 6/10 Seastar (Astrias forbesi) Shrimp (Crangon sp.) Moonsnail (Euspira sp.) Eastern mudsnail (Ilyanassa obsoleta) American Lobster (Homarus americanus) Whelk (Busycon sp.) Red sponge (Microciona) Haliclona sp. Botrylloides Whelk egg case Razor clam or razor clam siphons Ctenophore Copyright ESS Group, Inc., 2011 Page 4 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

46 Habitat Element 1/07 10/07 Transect 3 7/08 10/08 1/09 6/09 12/09 6/10 Gravel Muddy/sand sandy/mud sediment Shell/shell hash (oyster shells, slipper shells, clam shells) Drift algae (e.g. Ulva, Fucus) Fine sand sediment Biogenic structures (e.g. burrows, tubes) Cobbles Coarse sand Boulders Dredge marks Hermit crabs (Pagurus sp.) Green crabs (Carcinus maenas) Cancer crabs (Cancer sp.) Spider crabs (Libinia emarginata) Mud crabs (Panopeus sp.) Yellow sponge (Cliona spp.) Atlantic slipper shell (Crepidula fornicate) Eastern oyster (Crassostrea virginica) Horseshoe crab (Limulus polyphemus) Copyright ESS Group, Inc., 2011 Page 5 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

47 Habitat Element 1/07 10/07 Transect 3 7/08 10/08 1/09 6/09 12/09 6/10 Seastar (Astrias forbesi) Shrimp (Crangon sp.) Moonsnail (Euspira sp.) Eastern mudsnail (Ilyanassa obsoleta) American Lobster (Homarus americanus) Whelk (Busycon sp.) Red sponge (Microciona) Razor clam or razor clam siphons Ctenophore Copyright ESS Group, Inc., 2011 Page 6 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

48 Habitat Element 1/07 10/07 Transect 4 7/08 10/08 1/09 6/09 12/09 6/10 Gravel Muddy/sand sandy/mud sediment Shell/shell hash (oyster shells, slipper shells, clam shells) Drift algae (e.g. Ulva, Fucus) Fine sand sediment Biogenic structures (e.g. burrows, tubes) Cobbles Coarse sand Boulders Dredge marks Hermit crabs (Pagurus sp.) Green crabs (Carcinus maenas) Cancer crabs (Cancer sp.) Spider crabs (Libinia emarginata) Mud crabs (Panopeus sp.) Yellow sponge (Cliona sp.) Atlantic slipper shell (Crepidula fornicate) Eastern oyster (Crassostrea virginica) Horseshoe crab (Limulus polyphemus) Copyright ESS Group, Inc., 2011 Page 7 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

49 Habitat Element 1/07 10/07 Transect 4 7/08 10/08 1/09 6/09 12/09 6/10 Seastar (Astrias forbesi) Shrimp (Crangon sp.) Moonsnail (Euspira sp.) Eastern mudsnail (Ilyanassa obsoleta) American Lobster (Homarus americanus) Whelk (Busycon sp.) Red sponge (Microciona) Whelk egg case Botrylloides? Crab (unidentified) Copyright ESS Group, Inc., 2011 Page 8 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

50 Habitat Element 1/07 10/07 Transect 5 7/08 10/08 1/09 6/09 12/09 6/10 Gravel Muddy/sand sandy/mud sediment Shell/shell hash (oyster shells, slipper shells, clam shells) Drift algae (e.g. Ulva, Fucus) Fine sand sediment Biogenic structures (e.g. burrows, tubes) Cobbles Coarse sand Boulders Dredge marks Hermit crabs (Pagurus sp.) Green crabs (Carcinus maenas) Cancer crabs (Cancer sp.) Spider crabs (Libinia emarginata) Mud crabs (Panopeus sp.) Yellow sponge (Cliona sp.) Atlantic slipper shell (Crepidula fornicate) Eastern oyster (Crassostrea virginica) Horseshoe crab (Limulus polyphemus) Copyright ESS Group, Inc., 2011 Page 9 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

51 Habitat Element 1/07 10/07 Transect 5 7/08 10/08 1/09 6/09 12/09 6/10 Seastar (Astrias forbesi) Shrimp (Crangon sp.) Moonsnail (Euspira sp.) Eastern mudsnail (Ilyanassa obsoleta) American Lobster (Homarus americanus) Red sponge Whelk egg case Crab (unidentified) Whelk (Busycon sp.) Ctenophore Copyright ESS Group, Inc., 2011 Page 10 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

52 Habitat Element 1/07 10/07 Transect 6 7/08 10/08 1/09 6/09 12/09 6/10 Gravel Muddy/sand sandy/mud sediment Shell/shell hash (oyster shells, slipper shells, clam shells) Drift algae (e.g. Ulva, Fucus) Fine sand sediment Biogenic structures (e.g. burrows, tubes) Cobbles Coarse sand Boulders Dredge marks Hermit crabs (Pagurus sp.) Green crabs (Carcinus maenas) Cancer crabs (Cancer sp.) Spider crabs (Libinia emarginata) Mud crabs (Panopeus sp.) Yellow sponge (Cliona sp.) Atlantic slipper shell (Crepidula fornicate) Eastern oyster (Crassostrea virginica) Horseshoe crab (Limulus polyphemus) Copyright ESS Group, Inc., 2011 Page 11 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

53 Habitat Element 1/07 10/07 Transect 6 7/08 10/08 1/09 6/09 12/09 6/10 Seastar (Astrias forbesi) Shrimp (Crangon sp.) Moonsnail (Euspira sp.) Eastern mudsnail (Ilyanassa obsoleta) American Lobster (Homarus americanus) Whelk (Busycon sp.) Red sponge (Microciona) Whelk egg case Crab (unidentified) Razor clam or razor clam siphon Copyright ESS Group, Inc., 2011 Page 12 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

54 Habitat Element 1/07 10/07 Transect 7 7/08 10/08 1/09 6/09 12/09 6/10 Gravel Muddy/sand sandy/mud sediment Shell/shell hash (oyster shells, slipper shells, clam shells) Drift algae (e.g. Ulva, Fucus) Fine sand sediment Biogenic structures (e.g. burrows, tubes) Cobbles Coarse sand Boulders Dredge marks Hermit crabs (Pagurus sp.) Green crabs (Carcinus maenas) Cancer crabs (Cancer sp.) Spider crabs (Libinia emarginata) Mud crabs (Panopeus sp.) Yellow sponge (Cliona sp.) Atlantic slipper shell (Crepidula fornicate) Eastern oyster (Crassostrea virginica) Horseshoe crab (Limulus polyphemus) Copyright ESS Group, Inc., 2011 Page 13 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

55 Habitat Element 1/07 10/07 Transect 7 7/08 10/08 1/09 6/09 12/09 6/10 Seastar (Astrias forbesi) Shrimp (Crangon sp.) Moonsnail (Euspira sp.) Eastern mudsnail (Ilyanassa obsoleta) American Lobster (Homarus americanus) Red sponge Whelk egg case Filamentous algae Whelk (Busycon sp.) Copyright ESS Group, Inc., 2011 Page 14 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

56 Habitat Element 1/07 10/07 Transect 8 7/08 10/08 1/09 6/09 12/09 6/10 Gravel Muddy/sand sandy/mud sediment Shell/shell hash (oyster shells, slipper shells, clam shells) Drift algae (e.g. Ulva, Fucus) Fine sand sediment Biogenic structures (e.g. burrows, tubes) Cobbles Coarse sand Boulders Dredge marks Hermit crabs (Pagurus sp.) Green crabs (Carcinus maenas) Cancer crabs (Cancer sp.) Spider crabs (Libinia emarginata) Mud crabs (Panopeus sp.) Yellow sponge (Cliona sp.) Atlantic slipper shell (Crepidula fornicate) Eastern oyster (Crassostrea virginica) Horseshoe crab (Limulus polyphemus) Copyright ESS Group, Inc., 2011 Page 15 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

57 Habitat Element 1/07 10/07 Transect 8 7/08 10/08 1/09 6/09 12/09 6/10 Seastar (Astrias forbesi) Shrimp (Crangon sp.) Moonsnail (Euspira sp.) Eastern mudsnail (Ilyanassa obsoleta) American Lobster (Homarus americanus) Whelk (Busycon sp.) Red Sponge Whelk egg case Crab (unidentified) Razor clam or razor clam siphons Copyright ESS Group, Inc., 2011 Page 16 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

58 Habitat Element 1/07 10/07 Transect 9 7/08 10/08 1/09 6/09 12/09 6/10 Gravel Muddy/sand sandy/mud sediment Shell/shell hash (oyster shells, slipper shells, clam shells) Drift algae (e.g. Ulva, Fucus) Fine sand sediment Biogenic structures (e.g. burrows, tubes) Cobbles Coarse sand Boulders Dredge marks Hermit crabs (Pagurus sp.) Green crabs (Carcinus maenas) Cancer crabs (Cancer sp.) Spider crabs (Libinia emarginata) Mud crabs (Panopeus sp.) Yellow sponge (Cliona sp.) Atlantic slipper shell (Crepidula fornicate) Eastern oyster (Crassostrea virginica) Horseshoe crab (Limulus polyphemus) Copyright ESS Group, Inc., 2011 Page 17 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

59 Habitat Element 1/07 10/07 Transect 9 7/08 10/08 1/09 6/09 12/09 6/10 Seastar (Astrias forbesi) Shrimp (Crangon sp.) Moonsnail (Euspira sp.) Eastern mudsnail (Ilyanassa obsoleta) American Lobster (Homarus americanus) Whelk (Busycon sp.) Whelk egg case Crab (unidentified) Lobster traps Copyright ESS Group, Inc., 2011 Page 18 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

60 Habitat Element 1/07 10/07 Transect 10 7/08 10/08 1/09 6/09 12/09 6/10 Gravel Muddy/sand sandy/mud sediment Shell/shell hash (oyster shells, slipper shells, clam shells) Drift algae (e.g. Ulva, Fucus) Fine sand sediment Biogenic structures (e.g. burrows, tubes) Cobbles Coarse sand Boulders Dredge marks Hermit crabs (Pagurus sp.) Green crabs (Carcinus maenas) Cancer crabs (Cancer sp.) Spider crabs (Libinia emarginata) Mud crabs (Panopeus sp.) Yellow sponge (Cliona sp.) Atlantic slipper shell (Crepidula fornicate) Eastern oyster (Crassostrea virginica) Poor visibility Horseshoe crab (Limulus polyphemus) Copyright ESS Group, Inc., 2011 Page 19 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

61 Habitat Element 1/07 10/07 Transect 10 7/08 10/08 1/09 6/09 12/09 6/10 Seastar (Astrias forbesi) Shrimp (Crangon sp.) Moonsnail (Euspira sp.) Eastern mudsnail (Ilyanassa obsoleta) American Lobster (Homarus americanus) Botrylloides? Urosalpinx Urchin Red sponge (Microciona) Copyright ESS Group, Inc., 2011 Page 20 j:\n345 nusco\nu - lirc \n _biol monitoring\final summary report\attachments\attach b_transect tables.doc

62 Attachment C Shellfish Survey Analyses