Phillipsdale Landing
Overall, water quality at Phillipsdale Landing was good this week. Weather conditions included sporadic rain events, with 1.19 inches of precipitation recorded at T.F. Green. The Blackstone River flow declined this week, remaining above the 19-year daily median for the week. Surface salinity averaged 9.9 ppt and ranged from 3.6 ppt to 17.5 ppt. At the bottom, salinity averaged 18.6 ppt and ranged from 8.9 ppt to 26.0 ppt. Temperatures continued to increase this week, averaging 21.6°C at the surface and ranging 19.6°C – 24.0°C. At the bottom, temperatures averaged 18.9°C and ranged 15.9°C – 21.8°C.
Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO average 7.8 mg/L and ranged from 5.4 mg/L to 12.1 mg/L. Bottom DO concentrations averaged 5.9 mg/L and ranged from 4.3 mg/L to 10.3 mg/L. Chlorophyll readings have risen from last week, averaging 14.82 µg/L at the surface and 12.1 µg/L at the bottom. Maximum chlorophyll at the surface reached 52.1 µg/L on the night of June 8th. 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 June 4th. Overall, water quality was good at Bullock Reach this week. Salinity averaged 21.7 ppt, 22.5 ppt, and 27.9 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 17.8 – 24.8 ppt, mid salinity ranged 0.0 – 28.5 ppt, and bottom salinity ranged 0.0 – 30.3 ppt. Surface temperature averaged 20.4°C and ranged from 18.8°C to 22.9°C. Mid temperatures averaged 18.9°C and ranged from 16.1°C to 21.9°C. Bottom temperatures averaged 15.8°C and ranged from 14.1°C to 26.0°C.
DO at Bullock Reach remained above the hypoxia threshold (i.e., DO >2.9 mg/L) at all depths throughout the week. Surface DO averaged 10.5 mg/L and ranged 7.4 – 16.0 mg/L. In the mid waters, DO averaged 8.1 mg/L and ranged 5.6 – 12.0 mg/L. At the bottom, DO averaged 5.9 mg/L and ranged 4.9 – 9.4 mg/L. Chlorophyll readings ranged from low to elevated, with evidence of moderate phytoplankton blooms occurring throughout the month. Readings averaged 22.3 µg/L at the surface, 9.7 µg/L at mid-depth, and 4.1 µg/L at the bottom. The maximum surface chlorophyll was 55.3 µg/L on the afternoon of June 3rd.
Please note that data gaps occurred in the bottom dataset on June 3rd, 4th and 5th is due to equipment failure.