Nicole Flecchia – Page 3

October 13 – 19, 2025

Phillipsdale Landing

Overall, the water quality at Phillipsdale Landing was good this week. Weather conditions were moderately rainy, with 1.58 inches of rain recorded at T.F. Green. The Blackstone River flow decreased throughout the week. Surface salinity averaged 17.0 ppt and ranged from 8.0 ppt–26.6 ppt. At the bottom, salinity averaged 23.6 ppt and ranged from 11.0 ppt–30.7 ppt. Temperatures decreased this week, averaging 15.9°C at the surface and 16.9°C at the bottom. Surface temperatures ranged from 13.7°C–17.6°C, while bottom temperatures ranged from 14.2°C–19.0°C.

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold (i.e., DO>2.9mg/L) in both the surface and bottom waters. Surface DO averaged 7.6 mg/L and ranged from 5.7 mg/L–9.0 mg/L. Bottom DO concentrations averaged 6.3 mg/L and ranged from 4.7 mg/L–8.3 mg/L. Chlorophyll readings decreased from last week, averaging 1.8 µg/L at the surface and 1.9 µg/L at the bottom. Maximum chlorophyll at the surface reached 6.2 µg/L on the morning of October 15th. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.

Bullock’s Reach

Overall, water quality was good at Bullock’s Reach this week. Salinity averaged 28.5 ppt, 29.6 ppt, and 31.3 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 25.7–30.7 ppt, mid-depth salinity ranged 26.6–31.5 ppt, and bottom salinity ranged 28.5–32.3 ppt. Surface temperature averaged 16.5°C and ranged from 14.7°C to 18.1°C. Mid-depth temperatures averaged 16.7°C and ranged from 15.1°C to 18.1°C. Bottom temperatures averaged 16.9°C and ranged from 15.6°C to 18.2°C.

Dissolved oxygen (DO) at Bullock’s Reach remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO averaged 7.4 mg/L and ranged 6.6–8.5 mg/L. In the mid-depth waters, DO averaged 7.4 mg/L and ranged 6.6–8.0 mg/L. At the bottom, DO averaged 7.0 mg/L and ranged 6.3–7.6 mg/L. Chlorophyll concentrations in the surface and mid-depth waters decreased compared to week but increased in the bottom waters. Readings averaged 2.8 µg/L at the surface, 2.2 µg/L at mid-depth, and 9.6 µg/L at the bottom. The maximum surface chlorophyll was 5.9 µg/L on the afternoon of October 18th.

October 6 – 12, 2025

Phillipsdale Landing

Sondes were swapped this week on the morning of October 7th. Overall, the water quality at Phillipsdale Landing was good this week. Weather conditions were fairly dry, with 0.42 inches of rain recorded at T.F. Green. The Blackstone River flow peaked in the middle of the week. Surface salinity averaged 21.0 ppt and ranged from 12.1 ppt–27.2 ppt. At the bottom, salinity averaged 24.3 ppt and ranged from 16.9 ppt–28.6 ppt. Temperatures decreased this week, averaging 19.9°C at the surface and 20.3°C at the bottom. Surface temperatures ranged from 16.5°C–22.8°C, while bottom temperatures ranged from 17.1°C–22.7°C.

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold (i.e., DO>2.9mg/L) in both the surface and bottom waters. Surface DO averaged 5.9 mg/L and ranged from 4.2 mg/L–8.7 mg/L. Bottom DO concentrations averaged 5.5 mg/L and ranged from 4.1 mg/L–8.7 mg/L. Chlorophyll readings decreased from last week, averaging 3.7 µg/L at the surface and 4.7 µg/L at the bottom. Maximum chlorophyll at the surface reached 16.2 µg/L on the morning of October 6th. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.

Bullock’s Reach

Overall, water quality was good at Bullock’s Reach this week. Salinity averaged 29.5 ppt, 29.9 ppt, and 30.6 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 27.7–30.9 ppt, mid-depth salinity ranged 28.2–31.0 ppt, and bottom salinity ranged 28.4–31.5 ppt. Surface temperature averaged 19.4°C and ranged from 17.4°C to 21.3°C. Mid-depth temperatures averaged 19.5°C and ranged from 17.8°C to 21.2°C. Bottom temperatures averaged 19.5°C and ranged from 17.9°C to 20.8°C.

Dissolved oxygen (DO) at Bullock’s Reach remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO averaged 7.1 mg/L and ranged 6.2–9.7 mg/L. In the mid-depth waters, DO averaged 6.9 mg/L and ranged 5.9–8.9 mg/L. At the bottom, DO averaged 6.4 mg/L and ranged 5.2–7.3 mg/L. Chlorophyll concentrations decreased throughout the week. Readings averaged 8.9 µg/L at the surface, 5.4 µg/L at mid-depth, and 6.3 µg/L at the bottom. The maximum surface chlorophyll was 49.3 µg/L on the afternoon of October 6th.

October 15, 2025

Water column profiles were conducted using a Seabird Electronics profiler at five locations in the Providence River and one location in the Seekonk River on October 15, 2025. In the five days leading up to this there were 2.30 inches of rain recorded at T.F. Green International Airport (Warwick, RI). The water column was strongly stratified at India Point Park and Phillipsdale Landing, and weakly stratified at Bullock’s Reach, Edgewood Yacht Club, Pawtuxet Cove and Pomham Rocks.

Dissolved oxygen conditions were not below the hypoxia threshold (2.9 mg/L) at any of the visited locations. The highest fluorescence reading was observed about 1.25 meters below the surface at Phillipsdale Landing.

October 1, 2025

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 October 1, 2025. In the five days leading up to this there were 0.06 inches of rain recorded at T.F. Green International Airport (Warwick, RI). The water column was strongly stratified at Phillipsdale Landing, weakly stratified at Bullock’s Reach, Conimicut Point and Pomham Rocks, and well-mixed at Edgewood Shoals, Edgewood Yacht Club, India Point Park and Pawtuxet Cove.

Dissolved oxygen conditions were below the hypoxia threshold (2.9 mg/L) in the lower part of the water column at Edgewood Shoals, and the entire water column at Pomham Rocks and Phillipsdale Landing. The highest fluorescence reading was observed at about 1.75 meters below the surface at Phillipsdale Landing.

September 3, 2025

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 September 3, 2025. In the five days leading up to this there were 0.84 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 Bullock’s Reach, Conimicut Point, Phillipsdale Landing and Pomham Rocks, and well-mixed at Edgewood Yacht Club and Pawtuxet Cove.

Dissolved oxygen conditions were below the hypoxia threshold (2.9 mg/L) in the lower part of the water column at Bullock’s Reach, Edgewood Yacht Club and Pomham Rocks. The entire water column at Phillipsdale Landing was hypoxic. This is also where the highest fluorescence reading was observed at about 1.5 meters below the surface of the water.

August 20, 2025

One water column profile was conducted using a Seabird Electronics profiler at Conimicut Point (Providence River) on August 20, 2025. 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 here was well-mixed with no dissolved oxygen concentrations below the hypoxia threshold (2.9 mg/L). The highest fluorescence reading was measured at about 3.5 meters below the surface.

August 13, 2025

Water column profiles were conducted using a Seabird Electronics profiler at three locations in the Providence River on August 13, 2025. In the five days leading up to this there were 0.00 inches of rain recorded at T.F. Green International Airport (Warwick, RI). Water column stratification was weak at all three locations— Conimicut Point, Bullock’s Reach and Edgewood Yacht Club.

Dissolved oxygen conditions were below the hypoxia threshold (2.9 mg/L) in the lower portion of the water column at Edgewood Yacht Club. This is also where the highest fluorescence reading was measured at about 1 meter below the surface.