Nutrient samples were collected from seven river stations and seven bay stations on June 14th. All bay stations were sampled at the surface and bottom. In the five days prior to sampling, there were 0.59 inches of rainfall recorded at T.F. Green.
Among the river stations sampled, the highest total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) concentrations were observed at Pawtuxet River @ Broad St. (TN = 1,560 ppb, TDN = 1,360 ppb, DIN = 1,150 ppb). The lowest TN and TDN was observed at Woonasquatucket River @ Manton Ave. Bridge (TN = 796 ppb, TDN = 772 ppb), while the lowest DIN was at Blackstone River @ Bikepath Bridge (314 ppb).
Among the bay stations sampled, the highest surface TN, TDN, and DIN concentrations were observed at Pawtuxet Cove (TN = 1,220 ppb, TDN = 984 ppb, DIN = 767 ppb). The lowest surface TN and TDN concentrations were observed at Conimicut Point (TN = 586 ppb, TDN = 153 ppb), while three locations – Conimicut Point, Edgewood Yacht Club, and Phillipsdale Landing – had surface DIN concentrations below the detection limit of 13.0 ppb. Chlorophyll a concentrations at the surface bay stations were relatively low, averaging 5.59 μg/L across all sites with a maximum of 11.9 μg/L at Phillipsdale Landing.
The next scheduled sampling date is June 28, 2023.