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Home My WebLink AboutshellfishShellfish Survey 172 Pawkannkawkut Drive Yarmouth, MA 1 SHELLFISH SURVEY DESCRIPTION 1.0 INTRODUCTION On April 30th, 2024, Paul Mancuso and Conor Gilbertson, Wetland Scientists of BSC Group (BSC) conducted a shellfish survey from MHW into Land Under the Ocean within Parker’s River off of Pawkannawkut Drive (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 Parker’s River between Route 28 and Route 6. Single-family homes line the western bank of Parker’s River to the north and south of the Site. Parker’s 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 into the waters of Parker’s River across from 172 Pawkannawkut Drive. Parker’s River is recognized as suitable habitat for quahogs, soft-shell clams, razor clams, american oysters, and blue mussels. 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 out approximately 50’. The proposed pier, ramp, and float system extends ~10’ beyond MHW. Conditions at the Site made it unsafe to survey for shellfish more then 50’ beyond MHW due to knee-deep mucky sediments. The weather during the survey was partly cloudy with temperatures around 50F. The survey commenced at approximately 11:30 am as low tide was approaching. In order to sample for shellfish within the project area, 3 transects, located ~10 feet apart, with plots located ~10 feet apart were surveyed as follows… Transect 1 – Located ~10 feet to the south of the center line of proposed pier, ramp, and float. Extending ~50 feet seaward from MHW. Transect 2 – Located along center line of proposed pier, ramp, and float. Extending ~50 seaward of MHW. Transect 3 – Located ~10 feet to the north of the center line of proposed pier, ramp, and float. Extending ~50 feet seaward from MHW. Shellfish Survey 172 Pawkannkawkut Drive Yarmouth, MA 2 Figure 1: Showing approximate location of Transects for the shellfish survey at 172 Pawkannawkut Drive in Yarmouth. “T” stands for Transect. Each excavated plot was approximately 3’ x 3’ x 3’ and was surveyed using a standard clam rake. Any 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 Parker’s River across from 172 Pawkannawkut Drive. 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 172 Pawkannkawkut Drive Yarmouth, MA 3 Table 1 – 172 Pawkannawkut Drive Shellfish Inventory Plot – Description Shellfish Substrate and Other Observations Transect 1 1: MHW 0 Sand/ muck 2: 10’ seaward 0 Muck 3: 20’ seaward 0 Deep muck 4: 30’ seaward 0 Deep Muck 5: 40’ seaward 0 Deep muck 6: 50’ seaward 0 Deep muck Transect 2 1: MHW 0 Sand/ muck 2: 10’ seaward 0 Muck 3: 20’ seaward 0 Deep muck 4: 30’ seaward N/A Deep Muck 5: 40’ seaward N/A Deep muck 6: 50’ seaward N/A Deep muck Transect 3 1: MHW 0 Sand/ muck 2: 10’ seaward 0 Muck 3: 20’ seaward 0 Deep muck 4: 30’ seaward 0 Deep Muck 5: 40’ seaward 0 Deep muck 6: 50’ seaward 0 Deep muck TOTAL NUMBER OF OBSERVATION PLOTS = 15 TOTAL NUMBER OF QUAHOGS = 0 TOTAL NUMBER OF SOFT-SHELL CLAMS = 0 TOTAL NUMBER OF RAZOR CLAMS= 0 TOTAL NUMBER OF BLUE MUSSELS = 0 TOTAL NUMBER OF OYSTERS = 0 The shellfish survey indicated this area within Parker’s River is not suitable habitat for shellfish. In total, 15 plots were surveyed for the presence of shellfish. Sediment at the Site consisted of a sandy muck along the MHW line that quickly transitioned to a deep mucky sediment. Within 20’ of MHW, the sediment consisted of a deep muck and the shellfish surveyors sunk up to their knees. For this reason, transect 2 was only surveyed out to 20’ beyond MHW. The surveyors were able to hold onto adjacent floats while surveying for shellfish along transects 1 and 3 and were able to safely check for shellfish further from MHW. Live shellfish were found within 0 of the 18 (0%) plots. The surveyors noted the odor of sulfur as they sifted through the mucky sediments. This odor is indicative of hypoxic or anoxic sediments which are not suitable for shellfish. The survey was completed around low tide, so portions of intertidal area were exposed. Only a few deceased oyster and ribbed mussel shells were observed on the substate; no quahog or soft-shell clam shells. There were a few clumps of ribbed mussels and oysters growing on the wooden bulkhead. A summer flounder (Paralichthys dentatus) and a spider crab (Libinia emarginata) were observed within the shellfish survey area. Clumps of rockweed algae (Fucus distichus) and dead man’s fingers (Codium fragile) were also observed at the Site. MassMapper.com provides MassGIS data layers that can be viewed throughout the state. A Shellfish Suitability data layer displays polygons representing habitats suitable for ten species of shellfish along the coast of Massachusetts. This data layer indicates that portions of Parker’s River are suitable for shellfish, however the section of the Parker’s River where is pier, ramp, and Shellfish Survey 172 Pawkannkawkut Drive Yarmouth, MA 4 float is proposed is recognized as suitable for only blue mussels and American oysters (see image below). Blue mussels and American oysters both attach themselves to rocks and other hard substrate within the intertidal zone. Therefore, you would not expect to find mussels or oysters living within the sediments where the shellfish survey was conducted. The data layer does not indicate that this area is suitable habitat for quahogs or soft-shell clams. The shellfish survey indicates that this area is not suitable for quahogs or soft-shell clams. Figure 2: Screenshot of MassMapper.com with the Shellfish Suitability data layer turned on. Red line shows approximate location of proposed pier, ramp, and float for 172 Pawkannawkut Drive. The Shellfish Suitability data indicates that the location of the proposed pier, ramp, and float is within American oyster and blue mussel habitat. 4.0 TEMPORARY IMPACTS The proposed work includes construction of a pier, ramp, and float out into the waters of Parker’s 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 deemed necessary by the commission, shellfish can be relocated prior to the work. 5.0 SUMMARY BSC’s shellfish survey identified the following: ▪ 0 Quahogs (Mercenaria mercenaria), 0 soft-shell clams (mya arenaria), and 0 eastern oysters (Crossostrea virginica) were found within the 15 excavated shellfish plots. ▪ Deep mucky sediments which may likely be anoxic/hypoxic exist within the project area which are not suitable for shellfish habitat. Photo 1: View of the shellfish survey area. The proposed pier, ramp, and float will be located approximately where the existing piling is located. Facing east Photo 2: View of the shellfish survey area. The proposed pier, ramp, and float will be located approximately where the existing piling is located. Facing east Site Photographs: Shellfish Survey 172 Pawkanawkut Drive Yarmouth, MA 02673 04/30/2024 Page 1 Photo 3: Close up view of mucky sediment encountered throughout shellfish survey area. Photo 4: Close up view of a bunch of ribbed mussels growing along the existing wooden bulkhead. Site Photographs: Shellfish Survey 172 Pawkanawkut Drive Yarmouth, MA 02673 04/30/2024 Page 2 Photo 5: Close up view of some oysters growing along the existing wooden bulkhead. Photo 6: Close up view of a winter flounder observed within the shellfish survey area. Site Photographs: Shellfish Survey 172 Pawkanawkut Drive Yarmouth, MA 02673 04/30/2024 Page 3