Fixed-Site Network

Phillipsdale Landing

Overall, water quality at Phillipsdale Landing was good this week. ​Weather conditions were moderately wet, with 0.93 inches of precipitation recorded at T.F. Green over the course of the week. The largest rain events occurred on January 3rd (0.35 inches) and 4th (0.32 inches). Blackstone River flow increased all week, remaining above historical 18-year median flow rates. Salinity at the surface at Phillipsdale was low all week, while bottom salinity varied with the tide. Surface salinity averaged 3.6 ppt and ranged from 1.9 ppt to 5.6 ppt. At the bottom, salinity averaged 16.9 ppt and ranged from 3.0 ppt to 29.5 ppt. Temperatures increased slightly over the week, averaging 5.3°C at the surface and ranging 3.6°C – 6.5°C. At the bottom, temperatures averaged 5.3°C and ranged 4.5°C – 6.1°C.

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold of 2.9 mg/L throughout the week. Surface DO averaged 11.9 mg/L and ranged 11.4 – 12.5 mg/L. Bottom DO concentrations averaged 10.6 mg/L and ranged from 8.7 mg/L to 12.8 mg/L. Chlorophyll readings remained low, averaging 2.0 ug/L at the surface and 2.2 ug/L at the bottom. Maximum chlorophyll at the surface reached just 3.2 ug/L this week. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location. 

Bullock Reach 

Bullock Reach sondes will be deployed later this spring for the 2023 monitoring season. 

​Phillipsdale Landing

​Sondes were swapped for routine maintenance during the morning on October 4th. Overall, water quality at Phillipsdale Landing was good this week. Weather conditions were moderately wet, with 1.28 inches of rainfall recorded at T.F. Green. The Blackstone River flow increased above the 17-year median flow rate towards the end of the week. Salinity at the surface averaged 21.0 ppt and ranged from 8.9 ppt – 26.3 ppt. At the bottom, salinity averaged 26.0 ppt and ranged from 19.3 ppt – 29.8 ppt. Temperatures cooled this week, averaging 16.6°C at the surface and 17.1°C at the bottom. Surface temperatures ranged from 15.1°C to 19.5°C, while bottom temperatures ranged from 15.4°C to 18.9°C.

Dissolved oxygen (DO) has increased at Phillipsdale Landing, with the surface and bottom waters above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Bottom water DO concentration averaged 5.7 mg/L and ranged from 3.8 mg/L to 7.0 mg/L. Surface DO was higher, averaging 6.5 mg/L and ranging 4.7 – 8.3 mg/L. Chlorophyll concentrations were low, averaging 2.8 ug/L at the surface and 2.3 ug/L at the bottom. Maximum surface chlorophyll readings reached just 7.5 ug/L, recorded on the morning of October 2nd and afternoon on October 7th. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location. 

Bullock Reach  

Overall, water quality was good at Bullock Reach this week. Salinity averaged 29.0 ppt, 29.9 ppt, and 31.4 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 26.3 – 30.2 ppt, mid salinity ranged 28.4 – 31.4 ppt, and bottom salinity ranged 29.4 – 32.3 ppt. Temperatures decreased from the previous week. Surface temperature averaged 16.8°C and ranged from 15.8°C to 18.0°C. Mid temperatures averaged 16.8°C and ranged from 16.2°C to 18.1°C. Bottom temperatures averaged 16.9°C and ranged from 16.2°C to 18.6°C.

DO concentrations at Bullock Reach remained above the hypoxia threshold all week. Surface DO averaged 7.4 mg/L and ranged 6.2 – 8.9 mg/L. In the mid waters, DO averaged 7.3 mg/L and ranged 6.2 – 8.3 mg/L. At the bottom, DO averaged 7.0 mg/L and ranged 5.7– 7.5 mg/L. Chlorophyll concentrations were low all week. Overall, chlorophyll averaged 3.0 ug/L, 4.0 ug/L, and 1.8 ug/L at the surface, mid, and bottom waters, respectively. The maximum surface chlorophyll reading was 6.2 ug/L on October 7th.