Fixed-Site Network

November 3 – 9, 2025

Phillipsdale Landing

Sondes were retrieved for the end of the season on the morning of November 4th. Overall, the water quality at Phillipsdale Landing was good this week. There was no rain recorded at T.F. Green. The Blackstone River flow reached a minimum on November 5th, and then increased for the remainder of the week. Surface salinity averaged 15.1 ppt and ranged from 6.1 ppt–25.1 ppt. At the bottom, salinity averaged 24.3 ppt and ranged from 14.1 ppt–28.9 ppt. Temperatures decreased this week, averaging 12.4°C at the surface and 13.9°C at the bottom. Surface temperatures ranged from 10.1°C–14.1°C, while bottom temperatures ranged from 12.4°C–14.6°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 8.1 mg/L and ranged from 6.3 mg/L–9.9 mg/L. Bottom DO concentrations averaged 6.4 mg/L and ranged from 5.7 mg/L–7.6 mg/L. Chlorophyll readings remained relatively constant compared to last week, averaging 0.4 µg/L at the surface and 2.5 µg/L at the bottom. Maximum chlorophyll at the surface reached 1.6 µg/L on the morning of November 3rd. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.

Bullock’s Reach

Sondes were retrieved for the end of the season on the morning of November 7th. Overall, water quality was good at Bullock’s Reach this week. Salinity averaged 24.5 ppt, 24.0 ppt, and 29.3 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 10.0–29.3 ppt, mid-depth salinity ranged 9.6–30.1 ppt, and bottom salinity ranged 27.2–30.5 ppt. Surface temperature averaged 12.3°C and ranged from 10.4°C to 13.3C. Mid-depth temperatures averaged 12.6°C and ranged from 11.7°C to 13.5°C. Bottom temperatures averaged 12.6°C and ranged from 11.6°C to 13.5°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 8.4 mg/L and ranged 8.0–9.3 mg/L. In the mid-depth waters, DO averaged 8.5 mg/L and ranged 7.8–9.3 mg/L. At the bottom, DO averaged 8.2 mg/L and ranged 7.7–8.9 mg/L.  Chlorophyll concentrations remained relatively constant compared to last week. Readings averaged 1.6 µg/L at the surface, 2.4 µg/L at mid-depth, and 4.7 µg/L at the bottom.  The maximum surface chlorophyll was 3.1 µg/L on the morning of November 3rd.

October 27 – November 2, 2025

Phillipsdale Landing

Overall, the water quality at Phillipsdale Landing was good this week. There was light rain with 0.92 inches of rain recorded at T.F. Green. The Blackstone River flow increased throughout the week. Surface salinity averaged 11.9 ppt and ranged from 3.2 ppt–25.9 ppt. At the bottom, salinity averaged 24.0 ppt and ranged from 3.9 ppt–30.3 ppt. Temperatures decreased this week, averaging 12.6°C at the surface and 14.6°C at the bottom. Surface temperatures ranged from 10.0°C–14.8°C, while bottom temperatures ranged from 11.0°C–16.0°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 8.8 mg/L and ranged from 6.2 mg/L–10.5 mg/L. Bottom DO concentrations averaged 6.1 mg/L and ranged from 4.2 mg/L–9.8 mg/L. Chlorophyll readings remained relatively constant compared to last week, averaging 0.5 µg/L at the surface and 2.0 µg/L at the bottom. Maximum chlorophyll at the surface reached 2.8 µg/L on the morning of November 2nd. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.

Bullock’s Reach

Sondes were swapped the afternoon of October 27th. Overall, water quality was good at Bullock’s Reach this week. Salinity averaged 27.8 ppt, 29.3 ppt, and 30.9 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 9.8–30.5 ppt, mid-depth salinity ranged 26.8–30.9 ppt, and bottom salinity ranged 29.4–32.0 ppt. Surface temperature averaged 14.1°C and ranged from 12.0°C to 15.2°C. Mid-depth temperatures averaged 14.3°C and ranged from 12.8°C to 15.6°C. Bottom temperatures averaged 14.7°C and ranged from 12.9°C to 15.9°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 8.1 mg/L and ranged 7.6–10.4 mg/L. In the mid-depth waters, DO averaged 7.9 mg/L and ranged 7.3–9.6 mg/L. At the bottom, DO averaged 7.5 mg/L and ranged 6.8–8.3 mg/L.  Chlorophyll concentrations decreased at all depths compared to last week. Readings averaged 1.3 µg/L at the surface, 2.6 µg/L at mid-depth, and 4.9 µg/L at the bottom.  The maximum surface chlorophyll was 3.2 µg/L on the morning of October 27th.

October 20 – 26, 2025

Phillipsdale Landing

Sondes were swapped the morning of October 21st. Overall, the water quality at Phillipsdale Landing was good this week. There was light rain with 0.73 inches of rain recorded at T.F. Green. The Blackstone River flow was at its highest between October 21st and October 23rd. Surface salinity averaged 8.8 ppt and ranged from 2.5 ppt–24.6 ppt. At the bottom, salinity averaged 20.9 ppt and ranged from 4.4 ppt–29.1 ppt. Temperatures decreased this week, averaging 14.9°C at the surface and 16.2°C at the bottom. Surface temperatures ranged from 12.3°C–17.1°C, while bottom temperatures ranged from 14.3°C–17.3°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 8.5 mg/L and ranged from 6.1 mg/L–10.1 mg/L. Bottom DO concentrations averaged 6.2 mg/L and ranged from 4.5 mg/L–9.3 mg/L. Chlorophyll readings decreased from last week, averaging 0.9 µg/L at the surface and 1.8 µg/L at the bottom. Maximum chlorophyll at the surface reached 4.5 µg/L on the morning of October 20th. 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 27.6 ppt, 29.8 ppt, and 30.9 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 22.1–30.7 ppt, mid-depth salinity ranged 27.5–31.1 ppt, and bottom salinity ranged 29.9–31.8 ppt. Surface temperature averaged 15.8°C and ranged from 14.1°C to 16.7°C. Mid-depth temperatures averaged 15.8°C and ranged from 15.2°C to 16.5°C. Bottom temperatures averaged 15.7°C and ranged from 15.3°C to 16.3°C.

Dissolved oxygen (DO) at Bullock Reach’s remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO averaged 7.8 mg/L and ranged 7.2–8.5 mg/L. In the mid-depth waters, DO averaged 7.7 mg/L and ranged 6.9–9.2 mg/L. At the bottom, DO averaged 7.3 mg/L and ranged 6.6–7.8 mg/L.  Chlorophyll concentrations increased at all depths compared to last week. Readings averaged 4.1 µg/L at the surface, 4.5 µg/L at mid-depth, and 24.1 µg/L at the bottom.  The maximum surface chlorophyll was 11.4 µg/L on the afternoon of October 24th.

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.

September 29 – October 5, 2025

Phillipsdale Landing

Overall, the water quality at Phillipsdale Landing was fair to good this week. Weather conditions were dry, with no precipitation recorded at T.F. Green. The Blackstone River flow fluctuated throughout the week. Surface salinity averaged 21.0 ppt and ranged from 10.6 ppt to 27.3 ppt. At the bottom, salinity averaged 21.0 ppt and ranged from 10.6 ppt to 27.3 ppt. Temperatures decreased this week, averaging 21.1°C at the surface and 21.3°C at the bottom. Surface temperatures ranged from 17.9°C to 23.2°C, while bottom temperatures ranged from 19.4°C to 23.0°C.

Dissolved oxygen (DO) at Phillipsdale Landing 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 7.5 hours, occurring at the bottom depth from the morning of October 2nd.  During this period, the bottom DO averaged around 1.93 mg/L. Surface DO averaged 6.6 mg/L and ranged from 3.1 mg/L to 11.3 mg/L. Bottom DO concentrations averaged 3.7 mg/L and ranged from 1.1 mg/L to 9.5 mg/L. Chlorophyll readings increased from last week, averaging 10.5 µg/L at the surface and 12.7 µg/L at the bottom. Maximum chlorophyll at the surface reached 31.8 µg/L on the afternoon of October 2nd. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location. 

Bullock Reach

Sondes were swapped this week on the afternoon of September 30th. Overall, water quality was good at Bullock Reach this week. Salinity averaged 28.7 ppt, 30.3 ppt, and 31.9 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 24.6– 30.8 ppt, mid salinity ranged 26.4 – 32.2 ppt, and bottom salinity ranged 29.9 – 33.0 ppt. Surface temperature averaged 20.5°C and ranged from 18.6°C to 22.7°C. Mid temperatures averaged 20.5°C and ranged from 19.2°C to 22.2°C. Bottom temperatures averaged 20.4°C and ranged from 19.7°C to 21.3°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 7.3 mg/L and ranged 5.3 – 10.8 mg/L. In the mid waters, DO averaged 6.2 mg/L and ranged 3.4 – 8.4 mg/L. At the bottom, DO averaged 5.0 mg/L and ranged 3.7 – 6.8 mg/L.  Chlorophyll readings ranged from low to elevated throughout the week. Readings averaged 12.9 µg/L at the surface, 10.8 µg/L at mid-depth, and 7.7 µg/L at the bottom.  The maximum surface chlorophyll was 33.3 µg/L on the afternoon of September 30th.

September 22 – 28, 2025

Phillipsdale Landing

Sondes were swapped this week on the morning of September 23rd. Overall, the water quality at Phillipsdale Landing was fair this week Weather conditions included frequent rain events this week, with 4.33 inches of precipitation recorded at T.F. Green. The Blackstone River flow fluctuated throughout the week. Surface salinity averaged 19.8 ppt and ranged from 9.2 ppt to 26.4 ppt. At the bottom, salinity averaged 24.6 ppt and ranged from 15.1 ppt to 28.5 ppt. Temperatures averaged 22.0°C at the surface and 21.8°C at the bottom. Surface temperatures ranged from 20.2°C to 23.8°C, while bottom temperatures ranged from 21.2°C to 22.7°C.

Dissolved oxygen (DO) at Phillipsdale Landing dropped below the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. The longest periods of hypoxic conditions spanned 18.25 hours, occurring during the night of September 27th to the afternoon of September 28th. During this period, the bottom DO averaged around 2.13 mg/L. Surface DO averaged 5.3 mg/L and ranged from 2.4 mg/L to 9.9 mg/L. Bottom DO concentrations averaged 3.5 mg/L and ranged from 1.3 mg/L to 8.7 mg/L. Chlorophyll readings averaged 8.0 µg/L at the surface and 9.3 µg/L at the bottom. Maximum chlorophyll at the surface reached 42.9 µg/L on the morning of September 24th. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location. 

Bullock Reach

Overall, water quality was good at Bullock Reach this week. Salinity averaged 28.1 ppt, 31.5 ppt, and 32.1 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 25.0 – 30.4 ppt, middle salinity range 28.9 – 32.5 ppt, and bottom salinity ranged 31.1 – 32.7 ppt. Surface temperature averaged 21.3°C and ranged from 20.2°C to 22.8°C. Middle temperature averaged 21.0°C and ranged from 20.3°C to 21.7°C. Bottom temperatures averaged 20.8°C and ranged from 20.4°C to 21.2°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 6.8 mg/L and ranged 4.8 – 10.1 mg/L. Middle DO averaged 5.9 mg/L and ranged 4.1 – 8.5 mg/L. At the bottom, DO averaged 5.5 mg/L and ranged 4.3 – 6.5 mg/L.  Chlorophyll readings ranged from low to elevated throughout the week. Readings averaged 6.6 µg/L at the surface, 10.4 µg/L at the middle, and 6.4 µg/L at the bottom.  The maximum surface chlorophyll was 21.9 µg/L on the afternoon of September 28th.

September 15 – 21, 2025

Phillipsdale Landing

Overall, the water quality at Phillipsdale Landing was fair this week. Weather conditions were wet this week, with 0.32 inches of precipitation recorded at T.F. Green. The Blackstone River flow fluctuated throughout the week, while remaining below the 20-year daily median. Surface salinity averaged 23.7 ppt and ranged from 17.8 ppt to 27.3 ppt. At the bottom, salinity averaged 26.7 ppt and ranged from 22.6 ppt to 28.7 ppt. Temperatures averaged 21.9°C at the surface and 21.8°C at the bottom. Surface temperatures ranged from 19.6°C to 23.7°C, while bottom temperatures ranged from 21.3°C to 22.8°C.

Dissolved oxygen (DO) at Phillipsdale Landing dropped below the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. The longest periods of hypoxic conditions spanned 3.5 hours, occurring at the bottom depth from the morning of September 19th.  During this period, the bottom DO averaged around 2.57 mg/L. Surface DO averaged 5.9 mg/L and ranged from 2.8 mg/L to 14.1 mg/L. Bottom DO concentrations averaged 3.8 mg/L and ranged from 2.3 mg/L to 7.0 mg/L. Chlorophyll readings decreased from last week, averaging 9.7 µg/L at the surface and 3.1 µg/L at the bottom. Maximum chlorophyll at the surface reached 55.7 µg/L on the afternoon of September 15th. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location. 

Bullock Reach

Sondes were swapped this week on the morning of September 16th. Overall, water quality was good at Bullock Reach this week. Salinity averaged 28.8 ppt, 31.2ppt, and 32.4 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 27.2– 30.3 ppt, mid salinity ranged 28.9 – 32.9 ppt, and bottom salinity ranged 30.8 – 33.1 ppt. Surface temperature averaged 21.4°C and ranged from 20.1°C to 22.9°C. Mid temperatures averaged 21.3°C and ranged from 20.4°C to 22.3°C. Bottom temperatures averaged 21.0C and ranged from 20.7°C to 21.3°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 7.8 mg/L and ranged 6.0 – 10.6 mg/L. In the mid waters, DO averaged 6.6 mg/L and ranged 4.4 – 9.7 mg/L. At the bottom, DO averaged 5.3 mg/L and ranged 4.3 – 6.5 mg/L.  Chlorophyll readings ranged from low to elevated throughout the week. Readings averaged 9.5 µg/L at the surface, 15.0 µg/L at mid-depth, and 7.5 µg/L at the bottom.  The maximum surface chlorophyll was 66.0 µg/L on the morning of September 17th.

September 8 – 14, 2025

Phillipsdale Landing

Sondes were swapped this week on the morning of September 9th. Overall, the water quality at Phillipsdale Landing was fair this week. Weather conditions were dry, with no precipitation recorded at T.F. Green. The Blackstone River flow fluctuated throughout the week, rising above the 20-year daily median. Surface salinity averaged 22.6 ppt and ranged from 15.1 ppt to 27.2 ppt. Bottom salinity averaged 25.9 ppt and ranged from 15.0 ppt to 29.5 ppt. Temperatures averaged 22.0°C at the surface and 22.2°C at the bottom. Surface temperatures ranged from 20.1°C to 24.2°C, while bottom temperatures ranged from 21.1°C to 23.2°C.

Dissolved oxygen (DO) at Phillipsdale Landing dropped below the hypoxia threshold (i.e., DO >2.9 mg/L) briefly at the start of the week. The longest periods of hypoxic conditions spanned 2.25 hours, occurring during the morning of September 8th. During this period, the bottom DO averaged around 2.53 mg/L. Surface DO averaged 6.0 mg/L and ranged from 2.6 mg/L to 14.4 mg/L. Bottom DO concentrations averaged 4.3 mg/L and ranged from 2.3 mg/L to 9.3 mg/L. Chlorophyll readings decreased from last week, averaging 7.8 µg/L at the surface and 5.3 µg/L at the bottom. Maximum chlorophyll at the surface reached 60.8 µg/L on the afternoon of September 14th. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location. 

Bullock Reach

Overall, water quality was good at Bullock Reach this week. Salinity averaged 28.9 ppt, 30.3 ppt, and 31.7 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 27.3– 30.3 ppt, middle salinity ranged 28.3-31.4 ppt, and bottom salinity ranged 29.9 – 32.6 ppt. Surface temperature averaged 21.5°C and ranged from 20.5°C to 22.6°C. Middle temperatures averaged 21.4°C and ranged from 20.7°C to 22.8°C. Bottom temperatures averaged 21.2°C and ranged from 20.7°C to 22.5°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 6.8 mg/L and ranged 5.1 – 8.8 mg/L. Middle DO averaged 6.3 mg/L and ranged 4.9 – 8.5 mg/L. At the bottom, DO averaged 5.6 mg/L and ranged 4.6 – 7.4 mg/L.  Chlorophyll readings ranged from low to elevated throughout the week. Readings averaged 12.2 µg/L at the surface, 9.2 µg/L at the middle, and 3.76 µg/L at the bottom.  The maximum surface chlorophyll was 27.9 µg/L on the afternoon of September 9th.

September 1 – 7, 2025

Phillipsdale Landing

Overall, the water quality at Phillipsdale Landing was fair this week. Weather conditions included frequent rain events this week, with 1.59 inches of precipitation recorded at T.F. Green. The Blackstone River had a low flow throughout the week, remaining below the 20-year daily median throughout the week.  Surface salinity averaged 21.3 ppt and ranged from 12.4 ppt to 25.9 ppt. At the bottom, salinity averaged 25.8 ppt and ranged from 17.9 ppt to 30.2 ppt. Temperatures averaged 23.1°C at the surface and 23.0°C at the bottom. Surface temperatures ranged from 20.9°C to 24.8°C, while bottom temperatures ranged from 21.8°C to 24.4°C.

Dissolved oxygen (DO) at Phillipsdale Landing dropped below the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. The longest periods of hypoxic conditions spanned 11 hours, occurring at the bottom depth from the night of September 2nd until September 3rd. During this period, the bottom DO averaged around 1.02 mg/L. Surface DO averaged 8.0 mg/L and ranged from 2.6 mg/L to 16.6 mg/L. Bottom DO concentrations averaged 3.7 mg/L and ranged from 0.1 mg/L to 11.0 mg/L. Chlorophyll readings decreased from last week, averaging 36.3 µg/L at the surface and 39.0 µg/L at the bottom. Maximum chlorophyll at the surface reached 121.7 µg/L on the morning of September 1st. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location. 

Bullock Reach

Sondes were swapped this week on the morning of September 4th. Overall, water quality was good at Bullock Reach this week. Salinity averaged 29.5 ppt, 30.8 ppt, and 32.2 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 26.8– 30.7 ppt, mid salinity ranged 28.4 – 31.8 ppt, and bottom salinity ranged 30.2 – 33.3 ppt. Surface temperature averaged 22.2°C and ranged from 21.0°C to 23.4°C. Mid temperatures averaged 22.1°C and ranged from 21.2°C to 23.1°C. Bottom temperatures averaged 21.6°C and ranged from 20.5°C to 23.0°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 7.3 mg/L and ranged 6.0 – 10.0 mg/L. In the mid waters, DO averaged 6.0 mg/L and ranged 4.0 – 8.7 mg/L. At the bottom, DO averaged 5.0 mg/L and ranged 3.2 – 6.7 mg/L.  Chlorophyll readings ranged from low to elevated throughout the week. Readings averaged 9.6 µg/L at the surface, 11.0 µg/L at mid-depth, and 4.8 µg/L at the bottom.  The maximum surface chlorophyll was 26.8 µg/L on the morning of September 6th.

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