Fixed-Site Network

Phillipsdale Landing

The surface sonde deployed on February 7th failed to log data internally, and so there is a data gap until DCP communications were restored this week on February 15th. Unfortunately, restoration of this connection resulted in lost depth data for both sondes through the end of the deployment on February 23rd. Data in this week’s summary should be interpreted with caution due to the gap in surface data and lack of depth data to confirm sonde positioning at both depths. 

Weather conditions this week were mostly dry, with just 0.25 inches of rainfall on February 17th and trace rainfall on the 13th and 16th. Blackstone River flows continued to decline all week and fell below the 18-year median flow rates for this time of year. Surface salinity from the latter half of the week averaged 7.4 ppt and ranged from 2.0 ppt to 20.3 ppt. At the bottom, salinity averaged 20.6 ppt and ranged from 5.2 ppt to 29.8 ppt. Temperatures at the surface (latter half of the week) averaged 6.4°C, ranging 4.4°C – 8.1°C. At the bottom, temperatures averaged 5.4°C and ranged 4.6°C – 7.0°C. 

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold of 2.9 mg/L throughout the week. Surface DO (latter half of the week) averaged 11.3 mg/L and ranged 10.1 – 12.4 mg/L. Bottom DO concentrations averaged 9.9 mg/L and ranged from 8.8 mg/L to 12.3 mg/L. Chlorophyll readings generally remained low, averaging 0.8 ug/L at the surface (latter half of the week) and 2.9 ug/L at the bottom. Maximum chlorophyll at the surface reached just 6.8 ug/L in the data available this week. At the bottom, chlorophyll hit an isolated maximum of 25.1 ug/L on February 17th, though this does not appear to be related to phytoplankton activity as there were no concurrent changes to pH or DO. 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 on the morning of February 7th. The surface sonde continued to exhibit unusual buoyancy as began with the cold snap on February 3rd; for this week, approximately 27 hours of surface data were excluded from February 5th and 6th when the sonde was out of position. In addition the new surface sonde deployed on February 7th failed to log data, and so there is a data gap from this point through the end of the week. For these reasons, there are very limited surface data included in the following summary. 

Weather conditions this week were mostly dry, with just 0.05 inches of rainfall on February 7th and trace rainfall on the 8th and 9th. Blackstone River flows continued to decline all week, but overall remain above the 18-year median flow rates for this time of year. Surface salinity from the limited data available early in the week averaged 5.0 ppt and ranged from 1.4 ppt to 9.3 ppt. At the bottom, salinity averaged 18.4 ppt and ranged from 3.6 ppt to 29.5 ppt. Temperatures at the surface (limited data) averaged 1.7°C, ranging -0.4°C – 2.9°C. At the bottom, temperatures averaged 3.8°C and ranged 0.5°C – 6.0°C. 

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold of 2.9 mg/L throughout the week. Surface DO (limited data) averaged 13.0 mg/L and ranged 12.3 – 14.2 mg/L. Bottom DO concentrations averaged 11.0 mg/L and ranged from 9.2 mg/L to 14.2 mg/L. Chlorophyll readings remained low, averaging 1.5 ug/L at the surface (limited data) and 7.4 ug/L at the bottom. Maximum chlorophyll at the surface reached just 2.3 ug/L in this limited dataset. Chlorophyll at the bottom was elevated early in the week, though this does not appear to be related to phytoplankton activity as there were no concurrent changes to pH or DO; the spikes may have been related to the very cold temperatures or sediment interference. 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

Overall, water quality at Phillipsdale Landing was good this week. Weather conditions were mostly dry, with just trace rainfall on January 29th and February 1st, and minor snowfall on January 31st. Blackstone River flows declined over the course of the week. Surface salinity averaged 1.7 ppt and ranged from 0.2 ppt to 7.7 ppt. At the bottom, salinity averaged 11.4 ppt and ranged from 0.3 ppt to 29.7 ppt. February 3rd and 4th saw a blast of arctic air temperatures, and the waters responded by cooling dramatically at the end of the week. Temperatures overall averaged 4.0°C at the surface, ranging -0.3°C – 6.5°C. At the bottom, temperatures averaged 4.4°C and ranged 0.0°C – 6.0°C. During the cold snap, the surface sonde went out of position, possibly due to ice formation impacting sonde buoyancy; approximately 19 hours of surface data were excluded from this summary when the sonde was out of position. 

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold of 2.9 mg/L throughout the week. Surface DO averaged 12.9 mg/L and ranged 12.0 – 14.8 mg/L. Bottom DO concentrations averaged 11.8 mg/L and ranged from 8.4 mg/L to 14.2 mg/L. Chlorophyll readings remained low, averaging 2.0 ug/L at the surface and 9.9 ug/L at the bottom. Maximum chlorophyll at the surface reached just 8.4 ug/L this week. Chlorophyll at the bottom was elevated late in the week, though this does not appear to be related to phytoplankton activity as there were no concurrent changes to pH or DO; the spikes may have been related to the very cold temperatures or sediment interference. 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 on the morning of January 24th. Overall, water quality at Phillipsdale Landing was good this week. Weather conditions were rainy, including 0.34 inches on January 22nd, 0.92 inches on January 23rd (included some snow), 0.75 inches on January 25th, and 1.09 inches on January 26th (all as recorded at T.F. Green). Blackstone River flows were heavy all week in response to the precipitation, resulting in decreased salinity at Phillipsdale, particularly at the end of the week. Over the whole week, surface salinity averaged 2.0 ppt and ranged from 0.2 ppt to 9.9 ppt. At the bottom, salinity averaged 9.5 ppt and ranged from 0.2 ppt to 28.6 ppt. Temperatures cooled this week, averaging 3.8°C at the surface and ranging 2.3°C – 5.3°C. At the bottom, temperatures averaged 4.4°C and ranged 2.6°C – 5.9°C.

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold of 2.9 mg/L throughout the week. Surface DO averaged 13.4 mg/L and ranged 12.0 – 14.2 mg/L. Bottom DO concentrations averaged 12.4 mg/L and ranged from 9.4 mg/L to 14.6 mg/L. Chlorophyll readings remained low, averaging 1.7 ug/L at the surface and 2.5 ug/L at the bottom. Maximum chlorophyll at the surface reached just 3.0 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

Overall, water quality at Phillipsdale Landing was good this week. Weather conditions started dry, with Blackstone River flows declining compared to the week prior. Substantial rain on January 19th (1.05 inches as recorded at T.F. Green), led to increased Blackstone River flows, resulting in decreased salinity at Phillipsdale at the end of the week. Over the whole week, surface salinity averaged 5.4 ppt and ranged from 1.5 ppt to 10.2 ppt. At the bottom, salinity averaged 18.7 ppt and ranged from 2.0 ppt to 30.0 ppt. Temperatures were similar this week to last, averaging 4.6°C at the surface and ranging 3.1°C – 6.8°C. At the bottom, temperatures averaged 5.6°C and ranged 4.1°C – 6.6°C.

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold of 2.9 mg/L throughout the week. Surface DO averaged 12.4 mg/L and ranged 11.3 – 13.9 mg/L. Bottom DO concentrations averaged 10.4 mg/L and ranged from 8.7 mg/L to 13.8 mg/L. Chlorophyll readings remained low, averaging 0.7 ug/L at the surface and 4.0 ug/L at the bottom. Maximum chlorophyll at the surface reached just 1.3 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 on the morning of January 10th. The batteries in the bottom sonde retrieved this week died the day prior to retrieval, resulting in a data gap of approximately 16 hours from January 9th 18:00 to January 10th 9:30. Overall, water quality at Phillipsdale Landing was good this week. Weather conditions started dry, with Blackstone River flows declining compared to the week prior. Substantial rain on January 12th (0.69 inches) and 13th (0.65 inches), as recorded at T.F. Green, led to increased Blackstone River flows, resulting in decreased salinity at Phillipsdale at the end of the week. Over the whole week, surface salinity averaged 4.4 ppt and ranged from 1.4 ppt to 9.2 ppt. At the bottom, salinity averaged 17.3 ppt and ranged from 1.2 ppt to 30.0 ppt. Temperatures were similar this week to last, averaging 4.7°C at the surface and ranging 3.3°C – 6.4°C. At the bottom, temperatures averaged 5.7°C and ranged 3.9°C – 6.7°C.

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold of 2.9 mg/L throughout the week. Surface DO averaged 12.3 mg/L and ranged 11.6 – 13.0 mg/L. Bottom DO concentrations averaged 10.3 mg/L and ranged from 8.5 mg/L to 13.0 mg/L. Chlorophyll readings remained low, averaging 1.1 ug/L at the surface and 3.2 ug/L at the bottom. Maximum chlorophyll at the surface reached just 2.7 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

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.