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.