Phillipsdale Landing
Sondes were swapped this week on the morning of November 14th. Overall, the water quality at Phillipsdale Landing was good to fair this week. Weather conditions were dry this week, with only 0.09 inches of precipitation recorded at T.F. Green. The Blackstone River flow declined through the week, while remaining below the 21-year daily median. Surface salinity averaged 22.3 ppt and ranged from 11.7 ppt to 27.6 ppt. At the bottom, salinity averaged 25.8 ppt and ranged from 18.8 ppt to 28.8 ppt. Temperatures continued to decrease this week, averaging 11.6°C at the surface and ranging 9.2°C – 13.8°C. At the bottom, temperatures averaged 12.2°C and ranged 10.9°C – 14.0°C.
Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO averaged 8.2 mg/L and ranged from 6.7 mg/L to 9.3 mg/L. Bottom DO concentrations averaged 7.7 mg/L and ranged from 6.0 mg/L to 9.2 mg/L. Chlorophyll readings decreased from last week, averaging 1.27 µg/L at the surface and 1.6 µg/L at the bottom. Maximum chlorophyll at the surface reached 8.48 µg/L on the morning of November 11th. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.
Bullock Reach
Overall, the water quality was good to fair at Bullock Reach this week. Salinity averaged 28.7 ppt, 29.5 ppt, and 30.3 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 27.4 – 29.6 ppt, mid salinity ranged 28.4 – 30.4 ppt, and bottom salinity ranged 28.8 – 31.1 ppt. Surface temperature averaged 11.6°C and ranged from 9.9°C to 13.9°C. Mid temperatures averaged 11.7°C and ranged from 10.4°C to 13.4°C. Bottom temperatures averaged 11.8°C and ranged from 10.5°C to 13.6°C.
Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO averaged 8.9 mg/L and ranged 8.5 – 10.3 mg/L. In the mid waters, DO averaged 8.8 mg/L and ranged 8.3 – 9.4 mg/L. At the bottom, DO averaged 8.9 mg/L and ranged 8.0 – 9.0 mg/L. Chlorophyll readings ranged from low to moderate throughout the week. Readings averaged 2.0 µg/L at the surface, 2.4 µg/L at mid-depth, and 3.1 µg/L at the bottom. The maximum surface chlorophyll was 4.0 µg/L on the afternoon of November 11th.