Historical News
R/V Monitor's Blog
On Wednesday, June 9th, the crew of the R/V Monitor was out on the upper Bay collecting bacteria samples, taking Secchi Disk and Par sensor 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. In addition, the Bullock's Reach buoy was serviced this day, as it was experiencing communications issues. Sara captained the boat while monitoring professionals Justin, Mike and Jeff serviced the buoy, and collected the samples and data. The day began cloudy and humid with no wind and calm waters. The sun broke through later in the morning. The featured photo was taken of the crew servicing NBC's Bullock's Reach buoy.
Fixed Site Network
Phillipsdale Landing
Phillipsdale Landing sondes were changed out for routine maintenance during mid-day on May 25. Overall, water quality at this site was good this week. A total of 1.95 inches of rainfall was recorded at TF Green, with a majority (1.93 inches) occurring during the last two days of the week. Blackstone River flows were low most of the week but increased during the large rain events impacting surface and bottom salinity concentrations. Salinity at the surface averaged 14.8 ppt and ranged from 4.7 ppt to 24.7 ppt, while bottom salinity averaged 20.8 ppt and ranged from 7.1 ppt to 28.1 ppt. Surface water temperatures this week were slightly warmer than the previous week, averaging 18.6°C and ranging from 15.1°C to 24.1°C. Bottom water temperatures averaged 17.1°C and ranged from 13.0°C to 22.2°C.
Dissolved oxygen (DO) remained well above the hypoxia threshold (2.9 mg/L) this week. Surface DO averaged 9.1 mg/L, with a minimum of 6.2 mg/L, while bottom DO averaged 7.8 mg/L, with a minimum of 5.4 mg/L. In general, chlorophyll concentrations decreased from the previous week, averaging 17.0 ug/L at the surface and 19.2 ug/L at the bottom. Bottom chlorophyll readings following the deployment of the new sonde on May 25 were not included in this summary due to quality control issues with the chlorophyll probe. Maximum surface concentrations reached 44.1 ug/L on May 23, suggesting an increase in phytoplankton earlier in the week. Please note that tidal fluctuations and Blackstone River flow greatly influence water column salinity, temperature, and dissolved oxygen at this location; chlorophyll readings could also be impacted by suspended matter/particulates and macroalgae.
Bullock Reach
Bullock Reach sondes will be deployed the first week of June.
Fixed Site Network
Phillipsdale Landing
Overall, water quality at Phillipsdale was good this week. In a mostly dry week, a total of 0.01 inches of rainfall was recorded at TF Green. Blackstone River flows decreased through the week, leading to a slight increase in surface salinity. Salinity at the surface averaged 6.9 ppt and ranged from 2.6 ppt to 19.1 ppt, while bottom salinity averaged 19.5 ppt and ranged from 5.0 ppt to 28.3 ppt. Surface water temperatures this week were warmer than the previous week, averaging 18.5°C and ranging from 15.7°C to 22.0°C. Bottom water temperatures averaged 14.9°C and ranged from 11.5°C to 20.3°C.
Dissolved oxygen (DO) remained well above the hypoxia threshold (2.9 mg/L) this week. Surface DO averaged 10.1 mg/L, with a minimum of 8.0 mg/L, while bottom DO averaged 7.2 mg/L, with a minimum of 5.0 mg/L. In general, chlorophyll concentrations increased through the week, averaging 19.8 ug/L at the surface and 11.8 ug/L at the bottom. Maximum surface concentrations reached 156.0 ug/L on May 22, suggesting an increase in phytoplankton later in the week. Please note that tidal fluctuations and Blackstone River flow greatly influence water column salinity, temperature, and dissolved oxygen at this location; chlorophyll readings could also be impacted by suspended matter/particulates and macroalgae.
Bullock Reach
Bullock Reach sondes will be deployed the first week of June.
Water Column Profiles
Phillipsdale Landing had the lowest water column salinities, with values ranging from 7.0 psu at the surface to 30.5 psu at the bottom. The greatest surface salinity (23.9 psu) was measured at Edgewood Shoal, while the greatest bottom salinity (30.5 psu) occurred at Conimicut Point. Coldest temperatures occurred at India Point Park, where temperatures ranged from 10.3°C in bottom waters to 14.1°C at the surface. Warmest surface temperature was measured at Phillipsdale Landing (18.7°C), while warmest bottom waters (13.6°C) occurred at Pawtuxet Cove.
Dissolved oxygen (DO) ranged from 6.9 mg/L at a depth of 4 meters at Edgewood Shoal to 12.9 mg/L in surface waters at Pawtuxet Cove. Hypoxic conditions (DO < 2.9 mg/L) were not observed at any of the sites during this survey. Generally, fluorescence was low, with some slight evidence of phytoplankton activity in surface waters at Conimicut Point and Phillipsdale Landing. Please note that due to a quality control issue, numerical fluorescence data are not posted at this time.
Fixed Site Network
Phillipsdale Landing
Phillipsdale Landing sondes were changed out for routine maintenance during mid-day on May 11. Overall, water quality at this site was good this week. A total of 1.02 inches of rainfall was recorded at TF Green, with a majority (0.85 inches) occurring on May 10. Following the rain event on May 10, Blackstone River flows decreased leading to a slight decrease in surface and bottom salinity. Salinity at the surface averaged 6.3 ppt and ranged from 1.9 ppt to 13.9 ppt, while bottom salinity averaged 19.6 ppt and ranged from 4.7 ppt to 29.1 ppt. Surface water temperatures this week were warmer than the previous week, averaging 14.9°C and ranging from 12.1°C to 18.8°C. Bottom water temperatures averaged 12.5°C and ranged from 10.4°C to 16.3°C.
Dissolved oxygen (DO) remained well above the hypoxia threshold (2.9 mg/L) this week. Surface DO averaged 9.4 mg/L, with a minimum of 8.1 mg/L, while bottom DO averaged 7.5 mg/L, with a minimum of 5.6 mg/L. In general, chlorophyll concentrations continue to remain low, averaging 2.6 ug/L at the surface and 4.1 ug/L at the bottom. Maximum surface concentrations reached 10.3 ug/L on May 9, suggesting a slight increase in phytoplankton activity earlier in the week and decreasing through the week. Please note that tidal fluctuations and Blackstone River flow greatly influence water column salinity, temperature, and dissolved oxygen at this location; chlorophyll readings could also be impacted by suspended matter/particulates and macroalgae.
Bullock Reach
Bullock Reach sondes will be deployed the first week of June.
