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HomeMy WebLinkAboutDMF Letter Layton to Concom 1-3-23The Commonwealth of Massachusetts Division of Marine Fisheries 251 Causeway Street, Suite 400, Boston, MA 02114 p: (617) 626-1520 | f: (617) 626-1509 www.mass.gov/marinefisheries CHARLES D. BAKER KARYN E. POLITO BETHANY A. CARD RONALD S. AMIDON DANIEL J. MCKIERNAN Governor Lt. Governor Secretary Commissioner Director January 3, 2022 Barnstable Conservation Commission 200 Main St Hyannis MA 02601 Dear Commissioners: The Division of Marine Fisheries (MA DMF) has reviewed the Notice of Intent (NOI) by Jon and Pamela Layton to construct stairs, a boardwalk, pier, ramp, and float within/over Shoestring Bay at 592 Poponessett Road in the Town of Barnstable. The project was reviewed with respect to potential impacts to marine fisheries resources and habitat. The project site overlies salt marsh vegetation. Salt marsh provides a variety of ecosystem services, including habitat and energy sources for many fish and invertebrate species [1-2]. Ribbed mussels (Geukensia demissa) were present at the project site during a shellfish survey conducted in December 2022 by David Ryan. The project site is near mapped shellfish habitat for softshell clam (Mya arenaria). Waters near the project site have habitat characteristics suitable for this species. Land containing shellfish is deemed significant to the interest of the Wetlands Protection Act (310 CMR 10.34) and the protection of marine fisheries. Shoestring Bay has been identified by MA DMF as diadromous fish passage, migration, and/or spawning habitat for alewife (Alosa pseudoharengus), blueback herring (Alosa aestivalis), American eel (Anguilla rostrata), and white perch (Morone americana). Shoestring Bay acts as winter flounder (Pseudopleuronectes americanus) spawning habitat. Winter flounder enter the area and spawn from January through May; demersal eggs hatch approximately 15 to 20 days later. The Atlantic States Marine Fisheries Commission has designated winter flounder spawning habitat as a “Habitat Area of Particular Concern” (HAPC). The 2020 Southern New England/Mid Atlantic management track stock assessment indicates that although overfishing is not occurring, the stock remains overfished. Spawning stock biomass in 2019 was estimated to be 32% of the biomass target [3]. Given the status of the winter flounder stock, every effort should be made to protect the species and its spawning habitat. MA DMF offers the following comments for your consideration: • A new pier has the potential to negatively impact nearby shellfish resources and fisheries in a variety of ways [4]. While some of these impacts can be avoided or reduced with best management practices, others are unavoidable and will result in permanent impacts to shellfish habitat and associated fisheries access. Support piles will directly displace shellfish habitat, and piles may cause further indirect impacts that negatively affect bordering shellfish habitat. Leachates from any pressure treated wood used for support piles or decking may also negatively impact nearby shellfish. Associated boating activity could result in prop dredging if the float is installed in insufficient water depth relative to the size of vessels using the structure. The support piles, float, and adjacent footprints will likely not be accessible to commercial or recreational fisheries. • MA DMF conducted two field studies to assess the relationship between shading, marsh growth, and dock design; these studies collectively indicated that a height-to-width (H:W) ratio of 1.5:1 between the lowest horizontal stringer and the salt marsh substrate reduced shading and marsh loss relative to the typically required 1:1 H:W ratio. It is not clear if the current plans meet this recommendation. MA DMF recommends establishing a minimum 1.5:1 H:W ratio across the full extent of the marsh [4-6]. • The plans propose a boardwalk that traverses salt marsh on a diagonal angle. A straight, shorter boardwalk that traverses the salt marsh perpendicular to the coastal bank would reduce the area of shading impacts to the underlying salt marsh. • Any activities requiring a barge should be restricted to 2 hours before and after high tide to prevent barge grounding in mapped shellfish habitat. • Grounded floats can disturb bottom sediments, resulting in turbidity and direct impacts to benthic habitat. To minimize impacts, MA DMF recommends that the bottom of a proposed float be at least 2.5 feet (30 inches) above the substrate over mapped shellfish habitat and at least 1.5 feet (18 inches) in all marine/estuarine habitats, at MLW [4]. MA DMF recommends adjusting float stops at a height that would allow the float to maintain a 1.5-foot clearance above the substrate at MLW. Questions regarding this review may be directed to Amanda Davis in our New Bedford office at Amanda.davis@mass.gov. Sincerely, Amanda Davis Environmental Analyst MA Division of Marine Fisheries cc: Charles Rowland, Sullivan Engineering and Consulting, Inc. John Logan, Emma Gallagher, Terry O’Neil and Simone Wright, MA DMF Robert Boeri, CZM AD/eg References: 1. Boesch, D.F. and R.E. Turner. 1984. “Dependence of Fishery Species on Salt Marshes: The Role of Food and Refuge.” Estuaries 7(4):460-468. https://doi.org/10.2307/1351627. 2. Deegan, L.A. and R.H. Garritt. 1997. “Evidence for spatial variability in estuarine food webs.” Marine Ecology Progress Series 147:31-47. https://doi.org/10.3354/MEPS147031/ 3. ASMFC. 2020. Southern New England Mid-Atlantic Winter Flounder 2020 Assessment Update Report. http://www.asmfc.org/uploads/file/6008bd822020_SNE- MA_WinterFlounderAssessmentUpdate.pdf 4. Logan, J.M., A. Boeri, J. Carr, T. Evans, E.M. Feeney, K. Frew, F. Schenck, and K.H. Ford. 2022. A review of habitat impacts from residential docks and recommended Best Management Practices with an emphasis on the northeastern United States. Estuaries Coasts 45: 1189–1216. https://www.mass.gov/doc/dock-bmp- recommendations/download 5. Logan, J.M., A. Davis, C. Markos, K.H. Ford. 2018. “Effects of docks on salt marsh vegetation: An evaluation of ecological impacts and the efficacy of current design standards.” Estuaries and Coasts 41:661–675. https://doi.org/10.1007/s12237-017-0323-1 6. Logan, J.M., S. Voss, A. Davis, K.H. Ford. 2018. “An experimental evaluation of dock shading impacts on salt marsh vegetation in a New England estuary.” Estuaries and Coasts 41:13–24. https://doi.org/10.1007/s12237-017-0268-4