Historical News
Week of March 21 - 27, 2021
Fixed Site Network
Phillipsdale Landing
Water quality at Phillipsdale was good this week. Light rain was recorded at TF Green, a total of 0.21 inches over March 24-26. Blackstone River flows declined all week. Salinity at the Phillipsdale surface averaged 4.6 ppt and ranged from 1.2 ppt to 17.9 ppt. Bottom salinity averaged 19.4 ppt and ranged from 2.7 ppt to 28.6 ppt. Surface and bottom water temperatures warmed slightly this week, averaging 9.9°C and 7.1°C, respectively. Surface temperatures ranged from 5.9°C to 13.0°C, while bottom temperatures ranged from 4.6°C to 11.1°C.
Dissolved oxygen (DO) was high at both depths, typical for this time of year, and well above the hypoxia threshold (2.9 mg/L). Surface DO averaged 12.1 mg/L, with a minimum of 9.7 mg/L, and bottom DO averaged 10.7 mg/L, with a minimum of 8.5 mg/L. Chlorophyll concentrations declined from the previous week, averaging 3.9 ug/L at the surface and 5.0 ug/L at the bottom. Maximum surface chlorophyll concentrations reached 40.2 ug/L, measured on March 21. Please note that tidal fluctuations and Blackstone River flow greatly influence water column salinity, temperature, and dissolved oxygen at this location; chlorophyll readings are also frequently impacted by suspended particulates.
Bullock Reach
Bullock Reach sondes are expected to be deployed in May 2021.
Week of March 14 – 20, 2021
Water Column Clarity
Water clarity was measured at seven locations in the Providence and Seekonk Rivers on March 17, 2021. No precipitation was recorded in the five days prior to the survey. Overall, water clarity decreased from the previous survey. Secchi depth averaged 2.56 meters, compared to 4.04 meters on February 24, 2021. The lowest clarity (2.30 meters) was measured at India Point Park, while the greatest clarity (2.90 meters) was measured at Conimicut Point. Generally, water clarity increased along a down-bay gradient this week.
Week of March 14 - 20, 2021
Fixed Site Network
Phillipsdale Landing
Sondes were changed out for routine maintenance this week mid-day on March 16. Water quality at Phillipsdale was good this week. Heavy rains totaling 1.01 inches were recorded on March 18-19 at TF Green. Blackstone River flows exhibited an increase following these rains, but remain below average for this time of year. Salinity at the Phillipsdale surface averaged 11.4 ppt and ranged from 2.9 ppt to 24.5 ppt. Bottom salinity averaged 21.7 ppt and ranged from 6.3 ppt to 29.5 ppt. Surface and bottom water temperatures remain cold, averaging 5.1°C and 4.7°C, respectively. Surface temperatures ranged from 1.9°C to 8.4°C, while bottom temperatures ranged from 3.4°C to 7.6°C.
Dissolved oxygen (DO) was high at both depths, typical for this time of year, and well above the hypoxia threshold (2.9 mg/L). Surface DO averaged 12.9 mg/L, with a minimum of 11.7 mg/L, and bottom DO averaged 11.9 mg/L, with a minimum of 9.4 mg/L. Chlorophyll concentrations came up from the previous week, averaging 8.2 ug/L at the surface and 51.0 ug/L at the bottom. Maximum surface chlorophyll concentrations reached 37.2 ug/L, measured on March 15; note elevated chlorophyll readings (particularly at the bottom this week) may be impacted by suspended particulates or other matter. Please note that tidal fluctuations and Blackstone River flow greatly influence water column salinity, temperature, and dissolved oxygen at this location.
Bullock Reach
Bullock Reach sondes are expected to be deployed in May 2021.
Week of March 7 - 13, 2021
Fixed Site Network
Phillipsdale Landing
Water quality at Phillipsdale was good this week. The weather was dry, with no recorded precipitation at TF Green. Blackstone River flows exhibited a slight uptick mid-week, but remain below average for this time of year. Salinity at the Phillipsdale surface averaged 7.1 ppt and ranged from 2.3 ppt to 16.1 ppt. Bottom salinity averaged 19.8 ppt and ranged from 3.9 ppt to 28.4 ppt. Surface and bottom water temperatures remain cold, averaging 5.4°C and 4.5°C, respectively. Surface temperatures ranged from 1.6°C to 9.4°C, while bottom temperatures ranged from 2.2°C to 8.2°C.
Dissolved oxygen (DO) was high at both depths, typical for this time of year, and well above the hypoxia threshold (2.9 mg/L). Surface DO averaged 13.0 mg/L, with a minimum of 11.2 mg/L, and bottom DO averaged 11.5 mg/L, with a minimum of 10.0 mg/L. Chlorophyll concentrations came up from the previous week, averaging 5.5 ug/L at the surface and 22.8 ug/L at the bottom. Maximum surface chlorophyll concentrations reached 55.8 ug/L, measured on March 10; note elevated chlorophyll may be due to interference by sediment or macroalgae, as these readings were not associated with changes in pH or DO saturation that typically co-occur with phytoplankton bloom activity. Please note also that tidal fluctuations and Blackstone River flow greatly influence water column salinity, temperature, and dissolved oxygen at this location.
Bullock Reach
Bullock Reach sondes are expected to be deployed in May 2021.
Week of February 28 - March 6, 2021
Fixed Site Network
Phillipsdale Landing
Phillipsdale Landing sondes were deployed for the start of the 2021 monitoring season on March 3. Water quality at this site was good this week. Moderate rain events on February 27-28 (0.69 inches) and March 1 (0.34 inches) preceded sonde deployment, though the rest of the week was dry (NOAA TF Green data). Blackstone River flows were declining over the course of the week. This week, salinity at the surface averaged 6.2 ppt and ranged from 2.6 ppt to 10.7 ppt. Bottom salinity averaged 17.6 ppt and ranged from 3.5 ppt to 27.5 ppt. Surface and bottom water temperatures remain cold, averaging 3.1°C and 3.2°C, respectively. Surface temperatures ranged from 1.5°C to 4.9°C, while bottom temperatures ranged from 2.3°C to 4.3°C.
Dissolved oxygen (DO) was high at both depths, typical for this time of year, and well above the hypoxia threshold (2.9 mg/L). Surface DO averaged 13.0 mg/L, with a minimum of 12.4 mg/L, and bottom DO averaged 11.4 mg/L, with a minimum of 10.2 mg/L. Chlorophyll concentrations were low, averaging 2.9 ug/L at the surface and 5.3 ug/L at the bottom. Maximum surface chlorophyll concentrations reached 9.2 ug/L, measured on March 6. Please note that tidal fluctuations and Blackstone River flow greatly influence water column salinity, temperature, and dissolved oxygen at this location.
Bullock Reach
Bullock Reach sondes are expected to be deployed in May 2021.
