Nicole Flecchia – Narrabay

August 26, 2026

Water column profiles were conducted using a Seabird Electronics profiler at six locations in the Providence River and one location in the Seekonk River on August 26, 2026. In the five days leading up to this, there were 0.73 inches of rain recorded at T.F. Green International Airport (Warwick, RI). Strong water column stratification was observed at Edgewood Yacht Club and Phillipsdale Landing. The water column was moderately stratified at Pomham Rocks. Bullock Reach, Conimicut Point, and India Point Park exhibited weak stratification. The water column at Pawtuxet Cove was well mixed.

Dissolved oxygen conditions below the hypoxia threshold (2.9 mg/L) were observed in the lower part of the water column at Bullock Reach, Conimicut Point, Pomham Rocks, India Point Park and Phillipsdale Landing had dissolved oxygen conditions below the hypoxia threshold (2.9 mg/L). The highest fluorescence reading was observed one meter below the surface at Pawtuxet Cove.

July 8, 2026

Phytoplankton samples were collected on July 8, 2026 at Bullock Reach and analyzed in the laboratory shortly after collection.

The water temperature was 21.7 °C, the salinity was 27.4 PSU, and the chlorophyll a was 1.09 ug/L.

The qualitative tow net sample had a long filtration time. It had a dark brown coloration and contained jellyfish.

The analysis of the quantitative whole water sample revealed a total of 625,000 cells/L. The microflagellates were found at 367,000 cells/L. The most predominant phytoplankton genera were Thalassiosira spp. at 93,000 cells/L, Chaetoceros spp. at 60,000 cells/L, and Skeletonema spp. at 13,000 cells/L.

200x phase contrast image of Coscinodiscus spp.

Coscinodiscus is a widespread genus of solitary, disc-shaped diatoms. It is often regarded as one of the largest marine planktonic diatom genera with 400 – 500 described taxa. One singular freshwater species has also been identified.

June 24, 2026

Phytoplankton samples were collected on June 24, 2026 at Bullock Reach and analyzed in the laboratory shortly after collection.

It was sunny and clear on this day. The water temperature was 21.3 °C, the salinity was 27.2 PSU, and the chlorophyll a was 0.84 ug/L.

The qualitative tow net sample had a short filtration time and was cloudy and medium brown in coloration.

The analysis of the quantitative whole water sample revealed a total of 1,316,000 cells/L. The microflagellates were found at 1,106,000 cells/L. The most predominant phytoplankton genera were Cerataulina spp. at 110,000 cells/L, Skeletonema spp. at 27,000 cells/L, and Heterocapsa spp. at 23,000 cells/L.

200x phase contrast image of Chaetoceros lorenzianus

Chaetoceros lorenzianus is a species of centric diatom with a large diameter of 7 – 85 μm. Individual cells are usually joined in straight, stiff chains, connected by the touching of cell corners and fused adjacent spines. They have a wide distribution throughout the world and are commonly found throughout spring and summer in warm, shallow, marine waters.

August 19, 2026

Water column profiles were conducted using a Seabird Electronics profiler at sixlocations in the Providence River and one location in the Seekonk River on August 19, 2026. In the five days leading up to this, there were 0.31 inches of rain recorded at T.F. Green International Airport (Warwick, RI). Moderate water column stratification was observed at Phillipsdale Landing. The water column was weakly stratified at Conimicut Point, Bullock Reach, Edgewood Yacht Club, Pomham Rocks, and India Point Park. The water column at Pawtuxet Cove was well mixed.

Dissolved oxygen conditions below the hypoxia threshold (2.9 mg/L) were observed throughout the water column at India Point Park. The lower part of the water column at Bullock Reach, Pawtuxet Cove, Edgewood Yacht Club, Pomham Rocks and Phillipsdale Landing had dissolved oxygen conditions below the hypoxia threshold (2.9 mg/L). The highest fluorescence reading was observed two meters below the surface at Edgewood Yacht Club.

August 5, 2026

Water column profiles were conducted using a Seabird Electronics profiler at seven locations in the Providence River and one location in the Seekonk River on August 5, 2026. In the five days leading up to this, there were 2.57 inches of rain recorded at T.F. Green International Airport (Warwick, RI). The water column was strongly stratified at Conimicut Point, Edgewood Yacht Club, Edgewood Shoal, India Point Park and Phillipsdale Landing; moderate water column stratification was observed at Bullock Reach, Pawtuxet Cove and Pomham Rocks.

Dissolved oxygen conditions below the hypoxia threshold (2.9 mg/L) were observed in the lower part of the water column at Bullock Reach, Edgewood Yacht Club, Edgewood Shoal, Pomham Rocks, India Point Park and Phillipsdale Landing. The highest fluorescence reading was observed one meter below the surface at Edgewood Yacht Club.

June 10, 2026

Phytoplankton samples were collected on June 10, 2026 at Bullock’s Reach and analyzed in the laboratory shortly after collection.

On this day, the water temperature was 20.03 °C, the salinity was 27.2 PSU, and the chlorophyll a was 1.54 ug/L.

The qualitative tow net sample had a long filtration time and was cloudy and light golden brown in coloration.

The analysis of the quantitative whole water sample revealed a total of 5,570,000 cells/L. The microflagellates were found at 515,000 cells/L. The most predominant phytoplankton genera were Dactyliosolen spp. at 4,650,000 cells/L, Skeletonema spp. at 250,000 cells/L, and Chaetoceros spp. at 120,000 cells/L.

200x phase contrast image of Peridinium spp.

Peridinium spp. are cosmopolitan dinoflagellates mostly found in freshwater lakes, ponds and pools. Some inhabit brackish environments. This genus was originally described in the early 1830s, making it one of the first known groups of dinoflagellates. They are thought to be mixotrophic, which means they obtain energy through photosynthesis (autotrophy), and ingestion of small organisms (heterotrophy).

July 15, 2026

Surface chlorophyll data were collected on July 15, 2026, while the R/V Data Stream was underway collecting bacteria samples in the Providence and Seekonk River Estuaries. The chlorophyll concentrations were categorized as fair overall with all areas sampled having average chlorophyll concentrations between 5 µg/L and 20 µg/L. Overall, chlorophyll ranged from 0.92 µg/L to 145.69 µg/L with an average of 12.05 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.

July 8, 2026

Surface chlorophyll data were collected on July 8, 2026, while the R/V Data Stream was underway collecting nutrient samples in the Providence and Seekonk River Estuaries. The chlorophyll concentrations were categorized as fair overall. The North Providence River Channel, Southern Providence River and Pawtuxet River Area exhibited good water quality with average chlorophyll concentrations <5 µg/L. The Seekonk River and Edgewood Shoal had fair water quality with average chlorophyll concentrations that ranged between 5 µg/L and 20 µg/L. None of the sampled areas exhibited poor water quality with average chlorophyll concentration > 20 µg/L. Overall, chlorophyll ranged from 1.11 µg/L to 78.74 µg/L with an average of 7.31 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.

June 24, 2026

Surface chlorophyll data were collected on June 24, 2026, while the R/V Data Stream was underway collecting nutrient samples in the Providence and Seekonk River Estuaries. The chlorophyll concentrations were categorized as good overall. No areas exhibited fair or poor water quality (>10 µg/L and >20 µg/L, respectively). Overall, chlorophyll ranged from 1.08 µg/L to 12.65 µg/L with an average 3.98 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.

June 10, 2026

Surface chlorophyll data were collected on June 10, 2026, while the R/V Data Stream was underway collecting nutrient samples in the Providence and Seekonk River Estuaries. The chlorophyll concentrations were categorized as fair overall. Only the Seekonk River exhibited poor water quality (>20 µg/L) while the remaining areas sampled exhibited fair water quality (>10 µg/L). Overall, chlorophyll ranged from 2.56 µg/L to 45.25 µg/L with an average 14.57 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.