1. Neponset River Estuary Assessment Lynn Ficarra

2. General Characteristics From Walter Baker Dam to Dorchester Bay 1 7 km long 2 25-250 m wide at low tide, up to 1 km at high tide 2 Depth ranges from <2-4 m at low tide 2 3 m tidal range 3 Large portion of water in estuary exchanged at each tide 3 Surface area 0.88 km 2 at low tide, 2.17 km 2 at high tide 2 River flow through dam 0.6-3.1 m 3 /s

3. Neponset River Estuary 1 Shallow Tidally dominant 2 Probably well-mixed Vertical salinity stratification unknown Total volume of water in estuary unknown Bottom topography unknown

4. Habitats Salt marsh 4 – Was dominated by native Smooth cordgrass (Spartina alterniflora) and Saltmeadow cordgrass (Spartina patens) – Now invasive Common reed (Phragmites australis) – Past dredging, loss of natives, opportunity for invasives to move in 5 Spartina alternifloraSpartina patensPhragmites australis

5. Habitats cont. Mud flats 2 Intertidal: 29% non-vegetated 2

6. Habitat cont. In 1991, estuary had 311.64 acres of wetlands 5 – 25.92 acres of non-vegetated wetland – 265.67 acres of salt marsh – 20.05 acres of common reed marsh But what about today? – All remaining salt marshes degraded 7 Sediment characters unknown

7. Organisms Anadromous fisheries 4 – Rainbow smelt – Herring – American shad River dams shortened runs 4 and pollution lead to declining fish populations 6 Nursery 4 Hunting grounds 4 Rainbow smelt Herring American shad

8. Residence Time 2 ≤1 day Nutrient Limitation 7 Nitrogen limited Conclusions A lot of missing data Outdated information Projects – Remove dam to improve fish populations – Restore salt marshes Will eelgrass and oysters help?

9. References 1.Breault R.F. 2011. Concentrations, Loads, and Sources of Polychlorinated Biphenyls, Neponset River and Neponset River Estuary, Eastern Massachusetts. U.S. Geological Survey Scientific Investigations Report 2011-5004, 143 p. 2.Gardner G.B., R.F. Chen, and A. Berry. 2005. High-resolution measurements of chromophoric dissolved organic matter (CDOM) in the Neponset River Estuary, Boston Harbor, MA. Marine Chemistry. Vol. 96:137-154. 3.Zhu J. and C.R. Olsen. 2009. Beryllium-7 atmospheric deposition and sediment inventories in the Neponset River estuary, Massachusetts, USA. Journal of Environmental Radioactivity. Vol. 100:192-197. 4.NepRWA. 2006. Neponset Salt Marsh Restoration. The Neponset River Watershed Association. http://www.neponset.org/Restoration-SaltMarsh.htm 5.Tiner R.W., D.B. Foulis, C. Nichols, S. Schaller, D. Petersen, K. Andersen, and J. Swords. 1998. Wetland Status and Recent Trends for the Neponset Watershed, Massachusetts (1977-1991). U.S. Fish and Wildlife Service National Wetlands Inventory Project Northeast Region. 32 p. 6.Massachusetts Government. 1998. Neponset River Subwatershed-River and Estuary Segment Assessments. Boston Harbor Watershed 1999 Water Quality Assessment Report. p. 87-188. 7.NepRWA. 2004. Neponset River Watershed 2004 Assessment Report. Massachusetts Executive Office of Environmental Affairs. 56 p.