June 6, 2018
Mr. Andrew Bennett, Chair Nantucket Conservation Commission 2 Bathing Beach Road Nantucket, MA 02554
Re: 10 Fargo Way Map 14 Parcel 15 & 61 MassDEP File No. SE48-2939 Annual Report
Dear Mr. Bennett:
I am writing to provide the required plan and report for the referenced project. The fiber roll array was installed last year per the approved plans. Attached are invertebrate study, existing conditions site plan and photographs. Sand cover was contributed to the system during the 2018 winter storm season. Approximately 200 cubic yards of nourishment from the Reis sand pit was added to cover the system in April 2018.
The bank is stable and well-vegetated, with no apparent adverse impacts to any resource area.
Sincerely, Nantucket Engineering & Survey, P.C. By: Arthur D. Gasbarro, PE, PLS, LEED AP
CC: Fargo Way Realty Trust
20 Mary Ann Drive • Nantucket, MA 02554 508-825-5053 • www.NantucketEngineer.com Town and County of Nantucket, MA September 12, 2016 Locus Map - 10 Fargo Way
1" = 319 ft
Property Information
Property 14 15 ID Location 10 FARGO WY Owner FAY MICHAEL L TRUSTEE MAP FOR REFERENCE ONLY NOT A LEGAL DOCUMENT
Town and County of Nantucket, MA makes no claims and no warranties, expressed or implied, concerning the validity or accuracy of the GIS data presented on this map.
Parcels updated December, 2014 Properties updated January, 2015 May 1, 2018
June 5, 2018
Benthic Infaunal Monitoring Report – Pocomo Beach, Nantucket Island, MA
Prepared for: Fargo Way Realty Trust Wauwinet Realty Trust and Nantucket Engineering & Survey, Inc.
Prepared by: Allyn Sullivan
Reviewed By: Pamela Neubert, Ph.D. and Matt Lajoie
10 Fargo Way Nantucket, MA 02554
June 7, 2017 Insert revision record BENTHIC INFAUNAL MONITORING REPORT – POCOMO BEACH, NANTUCKET ISLAND, MA
June 7, 2017
Contents
1.0 INTRODUCTION ...... 2
2.0 METHODS ...... 2 2.1 FIELD COLLECTION, TAXONOMIC PROCEDURES ...... 2 2.2 BENTHIC INFAUNAL COMMUNITY ANALYSIS ...... 2
3.0 RESULTS ...... 3 3.1 BENTHIC INFAUNAL COMMUNITY ANALYSIS ...... 3
4.0 CONCLUSIONS ...... 5
Appendix A Figure 1a. Project Plan (Site Locus) ...... 7 Figure 1b. Sample locations…………………………………………………………………………7
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BENTHIC INFAUNAL MONITORING REPORT – POCOMO BEACH, NANTUCKET ISLAND, MA
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1.0 INTRODUCTION
The coastal dune and bank along Pocomo Beach, Nantucket has been eroding through surf action and undercutting. This beach divides Nantucket Harbor from Head of the Harbor and serves as a natural barrier, providing resiliency to coastal habitat and properties. To protect their beachfront property from coastal erosion at 10 Fargo Way, Nantucket, Massacusetts the current homeowners are proposing beach renourishment. Stantec was contracted to provide a benthic infaunal habitat assessment to determine existing intertidal biodiversity of lower trophic organisms. This monitoring was specified by the Town of Nantucket (Town) Conservation Commission.
2.0 METHODS
2.1 FIELD COLLECTION, TAXONOMIC PROCEDURES
Stantec collected five (5) 4-inch PVC sediment core samples within the mid-tidal area along Pocomo Beach on April 14, 2017 in collaboration with Nantucket Engineering & Survey. One sample was collected from each of three transects established within the proposed Project footprint (Figure 1). Additionally, two (2) samples were collected outside the proposed project area to serve as control site locations should post-construction studies be determined necessary. The project footprint extends along approximately 208 linear feet of beachfront. Samples were collected and preserved in the field with 10% buffered formalin. Samples were subsequently transported to Stantec’s Woods Hole, MA laboratory for sorting and identification. The collected sediment remained in formalin for 24 hours and then was transferred to ethanol following sieving on a 500 micron mesh screen. Organisms that were retained on the 500 micron screen were preserved in 70% ethanol with Rose Bengal added to facilitate the sorting process. Sorting was performed by separating organisms into major taxonomic groups and individual specimens were subsequently identified to the lowest practicable taxonomic level.
2.2 BENTHIC INFAUNAL COMMUNITY ANALYSIS
Data analysis included evaluation of univariate metrics including species richness, abundance, Pileou’s evenness (J′), and Shannon-Weiner Diversity (H′).
Community Metrics
Abundance: The number of individuals observed at a sampled location. Species Richness: The number of species observed at a sampled location. Shannon-Weiner Index (H′): The Shannon-Weiner Index is a commonly utilized measure of diversity in ecological studies. The Shannon-Weiner Index quantifies the uncertainty associated with the proportion of characters (i.e. species) and the ability to predict how many characters
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BENTHIC INFAUNAL MONITORING REPORT – POCOMO BEACH, NANTUCKET ISLAND, MA
June 7, 2017 may be represented as well as the certainty of predicting which character will be next in the series. Pileou’s Evenness (J′): Pileou’s Evenness metric is a diversity index that evaluates the evenness of distribution within the biological community. Evenness is measured on a scale of 0 to 1. If community composition is proportionally distributed to show a high degree of evenness, it will have a value near 1, and if there is a greater disparity between the abundance of various taxa, , then the community would be demonstrate less evenness with a value closer to 0.
3.0 RESULTS
3.1 BENTHIC INFAUNAL COMMUNITY ANALYSIS
Taxonomic identifications of benthic infauna were performed to the lowest practical level. Table 1 presents a taxa list of species identified during the study. Table 2 represents abundance of individual taxa collected at the 11 stations. These data were analyzed in PRIMER + Version 6.0 statistical software to calculate univariate metrics, presented within Table 3.
Table 1. Taxa List.
Phylum Class Order Family Genus Species Author Nematoda Nemertea Nemertea Enopla Monostilifera Tetrastemmatidae Treast emma Ehrenberg, 1831 Mollusks Gastropoda Littorinimorpha Caecidae Caecum Gray, 1850 Annelida Polychaet a Capitellida Capitellidae Mediomastus ambiseta Hartman, 1944 Annelida Polychaet a Phyllodocida Syllidae Parapionosyllis longicirrata Fauvel, 1923 Annelida Polychaet a Sedentaria Orbiniidae Leit oscoloplos robust us Verrill, 1873 Annelida Polychaet a Sedentaria Paraonidae Paraonis fulgens Levinsen, 1184 Annelida Oligocheata Timm, 2005
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BENTHIC INFAUNAL MONITORING REPORT – POCOMO BEACH, NANTUCKET ISLAND, MA
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Table 2. Benthic Community Metrics
North Project Footprint South Location Location (outside (outside project project footprint) footprint) Row Labels PBG-PR1 PBG-1 PBG-2 PGB-3 PBG-PR2 Caecum sp. 0 0 0 0 1
Leitoscoloplos robustus 1 1 5 1 2 Mediomastus ambiseta 0 9 0 0 13 Nematoda spp. 76 5 72 3 110 Nemertea sp. 0 0 37 1 13 Oligochaeta spp. 41 0 11 3 0 Paraonidae fulgens 23 0 0 3 13 Parapionosyllia longicurrata 0 0 8 1 26
Tetrastemma sp. 0 120 0 0 0
Table 3. Benthic Infaunal Abundance and Diversity Community Metric
Shannon- Species Pileou's Log Series Weiner Sample Abundance Richness Evenness (J’) Fisher Alpha Diversity Log(e) (H’) PBG-PR1 4 141 0.7381 0.7662 1.0232 PBG-1 4 135 0.3200 0.7741 0.4436 PBG-2 5 133 0.7373 1.0262 1.1867 PBG-3 6 12 0.9270 4.7668 1.6609 PBG-PR2 7 178 0.6328 1.4535 1.2313
Univariate benthic community metrics demonstrated similar community compositions among station locations for the metrics calculated except abundances at Station PBG-3 was lower than other stations samples. Reference locations had similar abundances and number of species when compared to stations sampled within the proposed beach renourishment area. Station PBG-PR2 had the greatest number of species (n=7) with stations PBG-PR1 and PBG-1 having the lowest species richness (n=4), and Station PGB-3 with the lowest abundance (n=12). Evenness ranged from a low value of 0.3200 at Station PBG-1 to a high of 0.9270 at Station PBG-3. Species diversity as measured with Shannon-Weiner and Log Series alpha was low and typical of a New England sandy intertidal beach.
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4.0 CONCLUSIONS
New England intertidal sandy beaches are dynamic environments affected by multiple environmental factors. This type of habitat is subjected to flooding, desiccation, storm action, ice, and freshwater runoff. The species identified from the five (5) samples are common to sandy New England beach habitat and represent a benthic community with the ability to tolerate stressful environmental conditions. They have adaptively developed to be opportunistic, rapidly reproduce, and tolerate ecological stressors. This study provides baseline documentation for benthic community existing conditions along Pocomo Beach that can be used to compare to samples collected following project related activities and to evaluate recolonization following beach renourishment efforts.
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BENTHIC INFAUNAL MONITORING REPORT – POCOMO BEACH, NANTUCKET ISLAND, MA
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Appendix A.
Figure 1a. Project locus in yellow.
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BENTHIC INFAUNAL MONITORING REPORT – POCOMO BEACH, NANTUCKET ISLAND, MA
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Figure 2b. Project Plan (approximate sample locations in red text)
PBG-PR2
PBG-3
PBG-2
PBG-1
PBG-PR1
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