Nutrient samples were collected from 7 river stations and 8 bay stations on November 1st. Bullock Reach Buoy was sampled at the surface and bottom; all other bay stations were sampled at the surface only. In the five days prior to sampling, there were 1.14 inches of precipitation recorded at T.F. Green.
Among the river stations sampled, the highest total nitrogen (TN) concentration was observed at Blackstone River @ Bikepath Bridge (923 ppb). The highest total dissolved nitrogen (TDN) and dissolved inorganic nitrogen (DIN) concentrations were observed at Pawtuxet River @ Broad St. (TDN = 957 ppb, DIN = 615 ppb, average of duplicates.) The lowest TN, TDN, and DIN were observed at Woonasquatucket River @ Manton Ave Bridge (TN = 560 ppb, TDN = 613 ppb, DIN = 352 ppb).
Among the bay stations sampled, the highest surface TN was observed at Phillipsdale Landing (972 ppb); the highest surface TDN and DIN were observed at Pawtuxet Cove (TDN = 1,030 ppb, DIN = 528 ppb). The lowest surface TN, TDN, and DIN were at Conimicut Point (TN = 559 ppb, TDN = 641 ppb, DIN = 227 ppb). Chlorophyll a concentrations at the surface bay stations were low this week; concentrations averaged 1.08 μg/L overall with a maximum of 1.88 μg/L at Pomham Rocks.
The next scheduled sampling date is November 15, 2023.