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HomeMy WebLinkAboutshellfish survey 2024Shellfish Survey 104 River Street Yarmouth, MA 1 SHELLFISH SURVEY DESCRIPTION 1.0 INTRODUCTION On March 26th, 2024, Paul Mancuso and Conor Gilbertson, Wetland Scientists of BSC Group (BSC) conducted a shellfish survey from MHW into Land Under the Ocean within the Bass River at 104 River Street in Yarmouth (the Site). The purpose of the survey was to evaluate shellfish habitat, shellfish species, and shellfish population density within the proposed project area. This shellfish survey accompanies a Notice of Intent application for a proposed pier, ramp, and float at the Site. 2.0 SITE DESCRIPTION The Site is located on the western bank of the Bass River near the mouth of the river which drains into Nantucket Sound. Single-family homes line Bass River to the north and south of the Site and also to the west. The Bass River is an estuary with numerous existing residential piers, ramp, and float systems. The proposed project involves the construction of a pier, ramp, and float system at 104 River Street to allow for access to the water and a place for boat storage. The Bass River is recognized as suitable habitat for quahogs, soft-shell clams, and bay scallops. The following resource areas are located onsite: • Coastal Bank • Land Under the Ocean • Land Containing Shellfish • Land Subject to Coastal Storm Flowage (LSCSF) 3.0 SHELLFISH INVENTORY In order to evaluate existing shellfish habitat at the site, BSC conducted a shellfish survey from the Mean Highwater (MHW) line (the wooden bulkhead) out approximately 50’. The proposed pier extends 43’ beyond MHW so the survey included areas ~7’ beyond the pier, ramp, and float system. The weather during the survey was overcast with light rain and wind with temperatures around 40F. The survey commenced at approximately low tide at 8:00 am. In order to sample for shellfish within the project area, 5 transects, located ~10 feet apart, with plots located ~10 feet apart were surveyed as follows… Transect 1 – Located ~20 feet to the south of the center line of proposed pier, ramp, and float. Extending ~50 feet seaward from MHW. Transect 2 – Located ~10 feet to the south of the center line of proposed pier, ramp, and float. Extending ~50 feet seaward from MHW. Transect 3 – Located along center line of proposed pier, ramp, and float. Extending ~50 seaward of MHW. Transect 4 – Located ~10 feet to the north of the center line of proposed pier, ramp, and float. Extending ~50 feet seaward from MHW. Transect 5 – Located ~20 feet to the north of the center line of proposed pier, ramp, and float. Extending ~50 feet seaward from MHW. Shellfish Survey 104 River Street Yarmouth, MA 2 Figure 1: Showing approximate location of Transects for the shellfish survey at 104 River Street in Yarmouth. “T” stands for Transect. Each excavated plot was approximately 3’ x 3’ x 3’ and was surveyed using a standard clam rake. All shellfish uncovered during the survey were recorded and then placed back into their respective plot and buried back in the sand. Table 1 on the next page details the shellfish inventory observed in the waters of Bass River adjacent to 104 River Street. Quahog clams were recorded based on size. Sizes of quahogs are as follows ; seed (<1.5”), littleneck (1.5” -2”), cherrystone (2”-4”), chowder (>4”). Shellfish Survey 104 River Street Yarmouth, MA 3 Table 1 – 104 River Street Shellfish Inventory Plot – Description Shellfish Substrate and Other Observations Transect 1 1: MHW 2 soft-shell Sandy 2: 10’ seaward 0 Sandy 3: 20’ seaward 1 oyster Sandy 4: 30’ seaward 0 Sandy 5: 40’ seaward 1 littleneck Sandy 6: 50’ seaward 0 Sandy Transect 2 1: MHW 0 Sandy 2: 10’ seaward 0 Sandy 3: 20’ seaward 0 Sandy 4: 30’ seaward 0 Sandy 5: 40’ seaward 0 Sandy 6: 50’ seaward 1 soft-shell Sandy Transect 3 1: MHW 0 Sandy 2: 10’ seaward 2 soft-shell Sandy 3: 20’ seaward 0 Sandy 4: 30’ seaward 0 Sandy 5: 40’ seaward 1 littleneck Sandy 6: 50’ seaward 0 Sandy Transect 4 1: MHW 0 Sandy 2: 10’ seaward 0 Sandy 3: 20’ seaward 1 cherrystone Sandy 4: 30’ seaward 0 Sandy 5: 40’ seaward 1 soft-shell Sandy 6: 50’ seaward 0 Sandy Transect 5 1: MHW 1 oyster Sandy 2: 10’ seaward 0 Sandy 3: 20’ seaward 1 soft-shell Sandy 4: 30’ seaward 1 cherrystone Sandy 5: 40’ seaward 0 Sandy 6: 50’ seaward 0 Sandy TOTAL NUMBER OF OBSERVATION PLOTS = 30 TOTAL NUMBER OF QUAHOGS = 4 TOTAL NUMBER OF SOFT-SHELL CLAMS = 7 TOTAL NUMBER OF RAZOR CLAMS= 0 TOTAL NUMBER OF BAY SCALLOPS = 0 TOTAL NUMBER OF OYSTERS = 2 The shellfish survey indicated this area within the Bass River is suitable habitat for shellfish. In total, 30 plots were surveyed for the presence of shellfish. Shellfish were found within 11 of the 30 (36%) plots. Shells of deceased individuals were found within some of the plot and observed on top of the sediment. In total, 4 living quahogs, 7 soft-shell clams, and 2 oysters were observed. Also found within the shellfish survey plots were numerous slipper snails. Along the wooden bulkhead there are healthy populations of barnacles and some oysters as well . Numerous jelly fish were observed floating through the survey area. Shellfish Survey 104 River Street Yarmouth, MA 4 4.0 TEMPORARY IMPACTS The proposed work includes construction of a pier, ramp, and float out into the waters of Bass River. This work will only have minor impacts to the intertidal area, Land Under Ocean, and Land Containing Shellfish. To minimize impacts to shellfish, the project will adhere to any time-of-year restrictions recommended by DMF. Specifically, the work could occur during the fall/winter/early spring months when shellfish life cycle activity is reduced. During the winter, shellfish live at increased depths in the tidal bottom with reduced metabolism. This would reduce potential impacts to shellfish compared to performing the work during the summer. The pile driving will occur at high tide to prevent the barge from resting on the sediment surface. If necessary , the shellfish can be relocated prior to the work. 5.0 SUMMARY BSC’s shellfish survey identified the following: ▪ 4 Quahogs (Mercenaria mercenaria) were found within the 30 shellfish plots surveyed. ▪ 7 Soft-shell clams (Mya arenaria) were found within the 30 plots. ▪ 2 Eastern oysters (Crossostrea virginica) were found within the 30 plots and more growing along wooden bulkhead.