May 12-13, 2026

Nutrient samples were collected from thirteen river stations and eight bay stations on May 12-13th. All bay stations were sampled at the surface, and Edgewood Shoal was sampled at the surface and bottom. In the five days prior to sampling, 0.57 inches of precipitation were recorded at T.F. Green. 

Among the river stations sampled, the highest total nitrogen (TN), and dissolved inorganic nitrogen (DIN) were observed Ten Mile River at Central Ave. (TN = 1,510 ppb, DIN = 1,041.1 ppb). The highest  total dissolved nitrogen (TDN) was observed at Moshassuck River @ Footbridge at Mill St. (1,610 ppb). However, a significantly higher TDN compared to the TN observed at this site may indicate an issue with the sampling or analysis. The lowest TN, and TDN were observed at Moshassuck River @ Higginson Ave (TN = 470 ppb, TDN = 329 ppb). The lowest DIN was observed at Coles River @ Milford Rd. (45.4 ppb).

Among the bay stations sampled, the highest surface TN and TDN were observed at Phillipsdale Landing (TN = 1,110 ppb, TDN = 1,080 ppb). The highest surface DIN was observed at Pawtuxet Cove (598.2 ppb). The lowest surface TN was observed at Edgewood Shoal (507 ppb). The lowest TDN was observed at Conimicut Point (<100.0 ppb). The lowest surface DIN was observed at Edgewood Yacht Club and Edgewood Shoal (13 ppb, reflecting minimum detection limits for DIN).

The next scheduled sampling date is May 27th, 2026.​

June 22 – 28, 2026

Walkers Point

Overall, the water quality at Walkers Point was good to fair this week. Weather conditions included light rain events this week, with 2.09 inches of precipitation recorded at T.F. Green. Surface salinity averaged 20.5 ppt and ranged from 10.0 ppt to 27.5 ppt. At the bottom, salinity averaged 20.5 ppt and ranged from 10.0 ppt to 27.5 ppt. Temperatures averaged 22.4°C at the surface and 21.3°C at the bottom. Surface temperatures ranged from 20.8°C to 25.7°C, while bottom temperatures ranged from 20.1°C to 22.6°C.

Dissolved oxygen (DO) at Walkers Point remained above the hypoxia threshold (i.e., DO>2.9mg/L) at the surface but dropped below the hypoxia threshold at the bottom depths. The longest periods of hypoxic conditions spanned 20.25 hours, occurring at the bottom depth from the night of June 24th to the afternoon of June 25th. During this period, the DO averaged around 2.46 mg/L. Surface DO averaged 7.0 mg/L and ranged from 3.5 mg/L to 12.8 mg/L. Bottom DO concentrations averaged 3.0 mg/L and ranged from 1.2 mg/L to 5.2 mg/L. Chlorophyll readings averaged 10.34 µg/L at the surface and 3.43 µg/L at the bottom. Maximum chlorophyll at the surface reached 37.45 µg/L on the afternoon of June 27th.

Please note that DCP connection issues are ongoing during this deployment and data will be updated once deployment is retrieved.

Bullock Reach

Sondes were swapped this week on the morning of June 24th. Overall, water quality was good to fair at Bullock Reach this week. Salinity averaged 28.8 ppt, 30.0 ppt, and 20.6 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 26.6 – 30.1 ppt, middle salinity range 28.1 – 31.6 ppt, and bottom salinity ranged 30.52 – 32.8 ppt. Surface temperature averaged 22.1°C and ranged from 20.8°C to 24.7°C. Middle temperature averaged 21.4°C and ranged from 19.6°C to 23.4°C. Bottom temperatures averaged 19.3°C and ranged from 18.1°C to 22.1°C.

Dissolved oxygen (DO) at Bullock Reach remained above the hypoxia threshold (i.e., DO>2.9mg/L) at the surface and middle depths, but dropped below the hypoxia threshold at the bottom depth. The longest periods of hypoxic conditions spanned 1 hours, occurring at the bottom depth from the night of June 28th.  During this period, the bottom DO averaged around 2.82 mg/L. Surface DO averaged 7.5 mg/L and ranged 5.8 – 10.2 mg/L. Middle DO averaged 6.2 mg/L and ranged 4.1 – 8.2 mg/L. At the bottom, DO averaged 4.5 mg/L and ranged 2.6 – 8.1 mg/L.  Chlorophyll readings ranged from low to elevated throughout the week. Readings averaged 10.7 µg/L at the surface, 13.3 µg/L at the middle, and 12.7 µg/L at the bottom.  The maximum bottom chlorophyll was 45.7 µg/L on the morning of June 26th.

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.

June 17, 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 June 17, 2026. In the five days leading up to this, there were 0.01 inches of rain recorded at T.F. Green International Airport (Warwick, RI). The water column was moderately stratified at India Point Park, weakly stratified at Pomham Rocks, Point St. Bridge, Conimicut Point, Edgewood Yacht Club, and Bullock’s Reach, and well-mixed at Phillipsdale Landing. 

Dissolved oxygen conditions were slightly below the hypoxia threshold (2.9 mg/L) in the lower part of the water column at Edgewood Yacht Club and India Point Park. The highest fluorescence reading was observed about 2.00 meters below the surface at India Point Park.

May 26, 2026

Phytoplankton samples were collected on May 26, 2026, at Bullock’s Reach and analyzed in the laboratory shortly after collection.

On this day, the water temperature was 18.12 °C, the salinity was 26.71 PSU, and the chlorophyll a was 1.68 µg/L.

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

The analysis of the quantitative whole water sample revealed a total of 2,932,000 cells/L. The microflagellates were found at 846,000 cells/L. The most predominant phytoplankton genera were Dactyliosolen spp. at 1,742,000 cells/L, Gonyaulax spp. at 246,000 cells/L, and Skeletonema spp. at 34,000 cells/L.

200x phase contrast image of Dactyliosolen spp.

Dactyliosolen is a type of cylindrical diatom which can be found sporadically in coastal waters throughout the year. They may be capable of storing nutrients, which would make them adaptable to living in environments where nutrient availability is variable. After sedimentation, blooms of this diatom can inhibit growth of benthic shellfish by clogging their gills.

June 24, 2026

Water clarity was measured at seven locations in the Providence River and Seekonk River estuaries on June 24, 2026. In the five days prior to the survey, 2.01 inches of precipitation were recorded at TF Green. Secchi depth averaged 2.9 meters. The lowest clarity this week (2.3 meters) was measured at Phillipsdale Landing and Pawtuxet Cove, while the greatest clarity (3.5 meters) was measured at Conimicut Point. There was no clear north-to-south gradient in water clarity among the sites this week. Overall, water clarity increased from the previous measurements (data collected June 17, 2026).

June 15 – 21, 2026

Walkers Point

Sondes were swapped this week on the morning of June 16th. Overall, the water quality at Walkers Point was good to fair this week. Weather conditions were dry this week, with 0.03 inches of precipitation recorded at T.F. Green. Surface salinity averaged 22.7 ppt and ranged from 15.4 ppt to 28.0 ppt. At the bottom, salinity averaged 26.3 ppt and ranged from 21.9 ppt to 29.3 ppt. Temperatures averaged 22.1°C at the surface and 21.5°C at the bottom. Surface temperatures ranged from 20.1°C to 24.8°C, while bottom temperatures ranged from 20.2°C to 23.3°C.

Dissolved oxygen (DO) at Walkers Point remained above the hypoxia threshold (i.e., DO>2.9mg/L) at the surface, but dropped below the hypoxia threshold at the bottom depths. The longest periods of hypoxic conditions spanned 1.5 hours, occurring at the bottom depth from the morning of June 21st.  During this period, the bottom DO averaged around 2.79 mg/L. Surface DO averaged 7.0 mg/L and ranged from 4.8 mg/L to 14.4 mg/L. Bottom DO concentrations averaged 5.0 mg/L and ranged from 2.6 mg/L to 8.2 mg/L. Chlorophyll readings averaged 11.16 µg/L at the surface and 6.4 µg/L at the bottom. Maximum chlorophyll at the bottom reached 42.4 µg/L on the evening of June 17th.

Bullock Reach

Overall, water quality was good at Bullock Reach this week. Salinity averaged 29.3 ppt, 29.5 ppt, and 29.9 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 27.8 – 30.5 ppt, middle salinity range 27.8 – 30.4 ppt, and bottom salinity ranged 28.8 – 30.7 ppt. Surface temperature averaged 21.4°C and ranged from 20.6°C to 22.8°C. Middle temperature averaged 20.9°C and ranged from 19.4°C to 22.0°C. Bottom temperatures averaged 20.1°C and ranged from 18.4°C to 21.6°C.

Dissolved oxygen (DO) at Bullock Reach remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO averaged 7.36 mg/L and ranged 5.81 – 9.18 mg/L. Middle DO averaged 6.80 mg/L and ranged 4.93 – 8.48 mg/L. At the bottom, DO averaged 6.47 mg/L and ranged 4.51 – 8.52 mg/L.  Chlorophyll readings ranged from low to elevated throughout the week. Readings averaged 9.52 µg/L at the surface, 12.99 µg/L at the middle, and 13.06 µg/L at the bottom.  The maximum bottom chlorophyll was 48.44 µg/L on the evening of June 16th.

June 8 – 14, 2026

Walkers Point

Overall, the water quality at Walkers Point was good this week. Weather conditions were dry this week, with no precipitation recorded at T.F. Green. Surface salinity averaged 20.4 ppt and ranged from 8.2 ppt to 28.5 ppt. At the bottom, salinity averaged 26.4 ppt and ranged from 21.8 ppt to 29.5 ppt. Temperatures averaged 21.5°C at the surface and 19.1°C at the bottom. Surface temperatures ranged from 16.6°C to 27.4°C, while bottom temperatures ranged from 16.0°C to 21.9°C.

Dissolved oxygen (DO) at Walkers Point remained above the hypoxia threshold (i.e., DO>2.9mg/L) at the surface and bottom depths. Surface DO averaged 11.3 mg/L and ranged from 4.6 mg/L to 20.8 mg/L. Bottom DO concentrations averaged 6.2 mg/L and ranged from 3.5 mg/L to 10.5 mg/L. Chlorophyll readings averaged 25.48 µg/L at the surface and 11.1 µg/L at the bottom. Maximum chlorophyll at the surface reached 60.96 µg/L on the morning of June 8th.

Bullock Reach

Sondes were swapped this week on the morning of June 9th. Overall, water quality was good at Bullock Reach this week. Salinity averaged 28.3 ppt, 29.2 ppt, and 30.6 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 25.7 – 30.0 ppt, middle salinity range 26.4 – 31.7 ppt, and bottom salinity ranged 28.6 – 32.8 ppt. Surface temperature averaged 21.0°C and ranged from 18.5°C to 24.2°C. Middle temperature averaged 19.6°C and ranged from 15.9°C to 22.0°C. Bottom temperatures averaged 17.2°C and ranged from 14.7°C to 20.7°C.

Dissolved oxygen (DO) at Bullock Reach remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO averaged 8.75 mg/L and ranged 6.61 – 12.98 mg/L. Middle DO averaged 7.27 mg/L and ranged 5.02 – 9.44 mg/L. At the bottom, DO averaged 5.65 mg/L and ranged 4.46 – 7.24 mg/L.  Chlorophyll readings ranged from low to elevated throughout the week. Readings averaged 10.82 µg/L at the surface, 12.44 µg/L at the middle, and 11.52 µg/L at the bottom.  The maximum surface chlorophyll was 46.02 µg/L on the evening of June 8th.

June 1 – 7, 2026

Walkers Point

Sondes were swapped this week on the morning of June 2nd. Overall, the water quality at Walkers Point was good this week. Weather conditions included light rain events this week, with 0.26 inches of precipitation recorded at T.F. Green. Surface salinity averaged 18.0 ppt and ranged from 8.7 ppt to 26.5 ppt. At the bottom, salinity averaged 26.5 ppt and ranged from 21.4 ppt to 30.2 ppt. Temperatures averaged 19.3°C at the surface and 16.6°C at the bottom. Surface temperatures ranged from 14.7°C to 24.2°C, while bottom temperatures ranged from 14.3°C to 20.5°C.

Dissolved oxygen (DO) at Walkers Point remained above the hypoxia threshold (i.e., DO>2.9mg/L) at the surface and bottom depths. Surface DO averaged 9.7 mg/L and ranged from 6.1 mg/L to 17.9 mg/L. Bottom DO concentrations averaged 5.8 mg/L and ranged from 3.6 mg/L to 9.4 mg/L. Chlorophyll readings averaged 10.87 µg/L at the surface and 3.8 µg/L at the bottom. Maximum chlorophyll at the surface reached 51.51 µg/L on the evening of June 7th.

Bullock Reach

Overall, water quality was good at Bullock Reach this week. Salinity averaged 28.3 ppt, 29.9 ppt, and 31.9 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 26.2 – 29.6 ppt, middle salinity range 27.6 – 31.3 ppt, and bottom salinity ranged 30.4 – 32.7 ppt. Surface temperature averaged 17.9°C and ranged from 14.6°C to 21.2°C. Middle temperature averaged 17.1°C and ranged from 14.3°C to 20.6°C. Bottom temperatures averaged 15.1°C and ranged from 13.9°C to 18.0°C. Dissolved oxygen (DO) at Bullock Reach remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO averaged 9.67 mg/L and ranged 7.49 – 12.74 mg/L. Middle DO averaged 8.66 mg/L and ranged 6.4 – 10.67 mg/L. At the bottom, DO averaged 6.34 mg/L and ranged 4.99 – 8.48 mg/L.  Chlorophyll readings ranged from low to elevated throughout the week. Readings averaged 12.53 µg/L at the surface, 11.00 µg/L at the middle, and 4.63 µg/L at the bottom.  The maximum surface chlorophyll was 45.58 µg/L on the afternoon of June 7th.

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