Nutrient samples were collected from seven local river stations, and seven bay stations on March 22nd, 2023. All bay stations were sampled at surface and bottom. In the five days prior to sampling, 0.02 inches of rainfall was recorded at T.F. Green.
Among the river stations sampled, the highest total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) were observed at Blackstone River at Slater Mill. The TN, TDN, and DIN were 1,080 ppb, 1,160 ppb, and 885 ppb, respectively. The lowest TN (698 ppb) was observed at Woonasquatucket River at Manton Ave Bridge. The lowest TDN and DIN were observed at one of duplicate samples collected at the Moshassuck River at Footbridge at Mill Street; 697 ppb and 554 ppb, respectively.
Among the bay stations sampled, the highest TN (1,050 ppb) and TDN (978 ppb) was observed at Phillipsdale Landing. The highest DIN were observed at Pawtuxet Cove as 697.7 ppb. The lowest surface TN (485 ppb), TDN (328 ppb) and DIN (193 ppb) were observed at Conimicut Point. Chlorophyll a concentrations at the bay stations have decreased (averaging 2.66 ug/L over all sites) since the February 22nd sampling event. The maximum result of 4.78 ug/L occurred at India Point Park.
Data from additional sampling dates (typically every two weeks) are pending analysis and writeup.