Nutrient samples were collected from 14 river stations and eight bay stations on May 3rd. Edgewood Shoal 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 3.64 inches of rainfall recorded at T.F. Green due to some heavy rain events on April 29th and 30th.
Among the river stations sampled, the highest total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) concentrations were observed at Ten Mile River @ Central Ave. (TN and TDN = 1,020 ppb, DIN = 686 ppb). The lowest TN and TDN concentrations were observed at Blackstone River @ Stateline (TN = 565 ppb, TDN = 512 ppb), while the lowest DIN was observed at Palmer River @ Rt. 6 (69.9 ppb).
Among the bay stations sampled, the highest surface TN concentration was observed at Edgewood Shoal (895 ppb), while the highest surface TDN and DIN were observed at Phillipsdale Landing (TDN = 798 ppb, DIN = 507 ppb). The lowest surface TN was observed at Pawtuxet Cove (753 ppb), the lowest surface TDN was observed at Pomham Rocks (662 ppb), and the lowest surface DIN was observed at India Point Park (437 ppb, average of duplicates). Chlorophyll a concentrations at the surface bay stations were relatively low, averaging 2.33 μg/L across all sites with a maximum of 4.10 μg/L at Edgewood Shoal.
The next scheduled sampling date is May 17, 2023.