Phillipsdale Landing
Overall, water quality was good at Phillipsdale Landing this week. There were 1.14 inches of precipitation recorded at T.F. Green this week, mostly from rain events on the 29th and 30th. Blackstone River flow was higher than normal for this time of year. Surface salinity averaged 8.7 ppt and ranged from 2.0 ppt to 21.8 ppt. Bottom salinity averaged 20.5 ppt and ranged from 6.1 ppt to 27.9 ppt. Temperatures decreased this week, averaging 13.0°C at the surface and ranging from 8.8°C to 16.5°C. At the bottom, temperatures averaged 15.0°C and ranged from 11.2°C to 16.7°C.
Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold of 2.9 mg/L at both the surface and bottom. Surface DO remained similar to the previous week, averaging 8.7 mg/L and ranging from 5.6 to 11.1 mg/L. Bottom DO averaged 5.9 mg/L and ranged from 4.6 mg/L to 10.0 mg/L. Chlorophyll readings remained low, averaging 0.9 ug/L at the surface and 0.8 ug/L at the bottom. Maximum chlorophyll at the surface was only 3.5 ug/L, recorded on the morning of October 29th. . 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 31. Overall, water quality was good at Bullock Reach this week. Salinity averaged 23.9 ppt, 27.3 ppt, and 29.4 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 20.4 – 27.5 ppt, mid salinity ranged 23.0 – 29.3 ppt, and bottom salinity ranged 27.8 – 30.4 ppt. Surface temperature averaged 14.3°C and ranged from 11.6°C to 17.0°C. Mid temperatures averaged 15.2°C and ranged from 13.6°C to 16.8°C. Bottom temperatures averaged 15.6°C and ranged from 13.9°C to 16.2°C.
DO concentrations at Bullock Reach remained above the hypoxia threshold all week. Surface DO averaged 7.3 mg/L and ranged 6.2 – 8.9 mg/L. In the mid waters, DO averaged 6.8 mg/L and ranged 5.8 – 9.5 mg/L. At the bottom, DO averaged 6.5 mg/L and ranged 5.9 – 7.2 mg/L. Chlorophyll concentrations were low, averaging 1.9 ug/L, 2.5 ug/L, and 1.6 ug/L at the surface, mid, and bottom waters, respectively. The maximum surface chlorophyll of 4.7 ug/L occurred during the afternoon on November 4th.