Phillipsdale Landing
Overall, water quality at Phillipsdale Landing was good to fair this week. The weather was dry, with no precipitation recorded at T.F. Green. The Blackstone River flow had small fluctuations throughout the week but remained below the 22-year daily median. Surface salinity averaged 20.5 ppt and ranged from 11.1 ppt to 25.6 ppt. At the bottom, salinity averaged 25.8 ppt and ranged from 20.6 ppt to 29.7 ppt. Temperatures remained stabilized this week, averaging 15.9°C at the surface and ranging 13.0°C – 17.5°C. At the bottom, temperatures averaged 16.0°C and ranged 14.8°C – 17.3°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 8.51 mg/L and ranged from 5.39 mg/L to 13.59 mg/L. Bottom DO concentrations averaged 6.6 mg/L and ranged from 4.4 mg/L to 10.1 mg/L. Chlorophyll readings decreased from last week, averaging 13.3 µg/L at the surface and 3.6 µg/L at the bottom. Maximum chlorophyll at the surface reached 123.5 µg/L on the morning of October 21st. 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 October 22nd. Overall, water quality was good at Bullock Reach this week. Salinity averaged 28.4 ppt, 29.7 ppt, and 31.4 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 27.3 – 29.7 ppt, mid salinity ranged 28.2 – 30.8 ppt, and bottom salinity ranged 29.8 – 32.5 ppt. Surface temperature averaged 15.4°C and ranged from 14.0°C to 16.5°C. Mid temperatures averaged 15.3°C and ranged from 14.4°C to 16.4°C. Bottom temperatures averaged 15.2°C and ranged from 14.7°C to 16.0°C.
DO at Bullock Reach remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO averaged 8.7 mg/L and ranged 7.8 – 10.3 mg/L. In the mid waters, DO averaged 8.4 mg/L and ranged 7.4 – 9.8 mg/L. At the bottom, DO averaged 7.8 mg/L and ranged 6.8 – 9.2mg/L. Chlorophyll readings ranged from low to elevated, with evidence of moderate phytoplankton blooms occurring throughout the week. Readings averaged 4.7 µg/L at the surface, 5.6 µg/L at mid-depth, and 3.3 µg/L at the bottom. The maximum surface chlorophyll was 15.3 µg/L on the afternoon of October 21st.