Historical News
Week of February 19 - 25, 2023
Water Column Clarity
Water clarity was measured at seven locations in the Providence River estuary on February 22. Rainfall totaling 0.52 inches was recorded at TF Green in the five days prior to the survey. Secchi depth averaged 2.8 meters, compared to 2.7 meters on the previous survey (January 18). The lowest clarity this week (2.6 meters) was measured at India Point Park, while the greatest clarity (3.0 meters) was measured at Conimicut Point. There was no clear north-to-south gradient in water clarity among the sites this week.
Week of February 19 - 25, 2023
R/V Monitor's Blog
On Wednesday, February 22nd, the crew of the R/V Monitor was out on the upper Bay collecting nutrients and plankton samples, taking Secchi Disk water clarity measurements, conducting water column profiles using the Seabird instrument, and conducting real-time surface mapping of water quality parameters, including dissolved oxygen, chlorophyll, water temperature, salinity, and pH, all in an effort to document water quality improvements associated with NBC construction projects. Jeff captained the boat while monitoring professionals Fern and Michael collected the samples and data. The day started sunny but turned cloudy by late morning with cool temperatures all day. The featured photo shows a cargo ship at ProvPort.
Week of November 27 - December 3, 2022
Fixed Site Network
Phillipsdale Landing
Sondes were swapped for routine maintenance on the morning of November 29th. Overall, water quality at Phillipsdale Landing was good this week. Weather conditions were rainy, with 0.52 inches on November 27th, 0.93 inches on November 30th, and 0.51 inches on December 3rd, all as recorded at T.F. Green. Blackstone River flow increased all week, and salinity at Phillipsdale declined. Surface salinity this week averaged 10.2 ppt and ranged from 2.1 ppt to 23.5 ppt. At the bottom, salinity averaged 19.8 ppt and ranged from 2.5 ppt to 27.6 ppt. Temperatures continued to decline this week, averaging 7.8°C at the surface and ranging 4.4°C – 9.5°C. At the bottom, temperatures averaged 8.9°C and ranged 6.7°C – 10.1°C.
Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold of 2.9 mg/L throughout the week. Surface DO averaged 10.3 mg/L and ranged 8.0 – 12.4 mg/L. Bottom DO concentrations averaged 8.8 mg/L and ranged from 7.6 mg/L to 11.5 mg/L. Chlorophyll readings remained low, averaging 1.4 ug/L at the surface and 1.6 ug/L at the bottom. Maximum chlorophyll at the surface reached just 3.3 ug/L on December 1st. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.
Please also note that the pH sensor on the surface sonde failed on November 26th, so surface pH data (not discussed here) through sonde retrieval on November 29th should be interpreted with caution if downloaded from the Snapshot website.
Bullock Reach
Bullock Reach sondes were removed for the 2022 season on the morning of November 22nd.
Week of November 20 - 26, 2022
Fixed Site Network
Phillipsdale Landing
Overall, water quality at Phillipsdale Landing was good this week. Weather conditions were relatively dry, with just 0.02 inches of rainfall recorded November 25th at T.F. Green. Blackstone River flow declined all week, and salinity at Phillipsdale increased. Surface salinity this week averaged 13.5 ppt and ranged from 2.7 ppt to 24.0 ppt. At the bottom, salinity averaged 22.3 ppt and ranged from 4.0 ppt to 27.6 ppt. Temperatures continued to decline this week, averaging 8.4°C at the surface and ranging 3.9°C – 11.0°C. At the bottom, temperatures averaged 10.8°C and ranged 5.8°C – 13.9°C.
Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO averaged 9.5 mg/L and ranged 7.0 – 12.0 mg/L. Bottom DO concentrations averaged 7.6 mg/L and ranged from 5.8 mg/L to 11.5 mg/L. Chlorophyll readings were low, averaging 0.5 ug/L at the surface and 1.7 ug/L at the bottom. Maximum chlorophyll at the surface reached just 1.3 ug/L on November 20th. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.
Please also note that the pH sensor on the surface sonde failed on November 26th, so pH data (not discussed here) should be interpreted with caution if downloaded from the Snapshot website.
Bullock Reach
Bullock Reach sondes were removed for the season on the morning of November 22nd, so this summary only includes data for the partial week. Water quality was good at Bullock Reach at the end of the monitoring season. Salinity averaged 27.2 ppt, 28.5 ppt, and 29.3 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 24.0 – 28.7 ppt, mid salinity ranged 26.9 – 30.3 ppt, and bottom salinity ranged 28.4 – 30.6 ppt. Temperatures at all three depths continued to drop this week. Surface temperature averaged 10.3°C and ranged from 8.3°C to 12.0°C. Mid temperatures averaged 10.7°C and ranged from 9.1°C to 13.4°C. Bottom temperatures averaged 11.5°C and ranged from 9.4°C to 13.9°C.
DO concentrations at Bullock Reach remained well above the hypoxia threshold. Surface DO averaged 8.7 mg/L and ranged 8.2 – 9.8 mg/L. In the mid waters, DO averaged 8.5 mg/L and ranged 7.4 – 9.6 mg/L. At the bottom, DO averaged 8.1 mg/L and ranged 7.1 – 8.9 mg/L. Chlorophyll concentrations were low (i.e., <20 ug/L). Overall, chlorophyll averaged 2.2 ug/L, 2.9 ug/L, and 2.7 ug/L at the surface, mid, and bottom waters, respectively. Maximum chlorophyll readings were observed on November 20th, reaching 9.8 ug/L at the mid-depth and 3.9 ug/L at the surface.
Week of November 13 - 19, 2022
Fixed Site Network
Phillipsdale Landing
Sondes were swapped for routine maintenance on the morning of November 15th. The surface sonde retrieved November 15th had continued buoyancy issues that began the week prior, resulting in approximately 16 hours of data between November 13th and 15th where the sonde was too deep at high tide; these deep data have been excluded from the following summary. Overall, water quality at Phillipsdale Landing was fair to good this week. There was substantial rainfall in the days prior to this week, and the wet weather continued with 0.11 inches on November 13th, 0.13 inches on November 15th, and 0.98 inches on November 16th (all as recorded at T.F. Green). Blackstone River flow remained elevated above the 18-year daily median statistic all week. Salinity at Phillipsdale dropped overall in response to this increase in freshwater flow. Salinity at the surface this week averaged 6.1 ppt and ranged from 2.6 ppt to 10.1 ppt. At the bottom, salinity averaged 21.3 ppt and ranged from 4.1 ppt to 28.5 ppt. Temperatures declined this week, averaging 10.5°C at the surface and ranging 6.5°C – 15.5°C. At the bottom, temperatures averaged 13.9°C and ranged 7.7°C – 16.0°C.
Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO this week averaged 9.6 mg/L and ranged 7.4 – 11.6 mg/L. Bottom DO concentrations averaged 6.5 mg/L and ranged from 4.8 mg/L to 10.9 mg/L. Chlorophyll readings were low, averaging 1.4 ug/L at the surface and 1.6 ug/L at the bottom. Maximum chlorophyll at the surface reached 12.4 ug/L on November 13th. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.
Bullock Reach
Water quality was good at Bullock Reach this week. Salinity averaged 26.4 ppt, 28.7 ppt, and 30.4 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 22.8 – 28.7 ppt, mid salinity ranged 26.3 – 30.3 ppt, and bottom salinity ranged 29.0 – 31.4 ppt. Temperatures cooled compared to the previous week. Surface temperature averaged 12.9°C and ranged from 10.5°C to 16.0°C. Mid temperatures averaged 13.6°C and ranged from 11.3°C to 15.8°C. Bottom temperatures averaged 14.6°C and ranged from 12.9°C to 15.5°C.
DO concentrations at Bullock Reach remained well above the hypoxia threshold all week. Surface DO averaged 8.2 mg/L and ranged 7.6 – 9.7 mg/L. In the mid waters, DO averaged 7.8 mg/L and ranged 7.1 – 8.9 mg/L. At the bottom, DO averaged 7.3 mg/L and ranged 6.9 – 7.9 mg/L. Chlorophyll concentrations were low all week (i.e., <20 ug/L). Overall, chlorophyll averaged 2.5 ug/L, 2.7 ug/L, and 2.6 ug/L at the surface, mid, and bottom waters, respectively. An isolated spike at the surface up to 52.4 ug/L on November 13th does not appear indicative of phytoplankton bloom activity.
