On the morning of December 4th, the Phillipsdale Landing sondes were successfully removed for the 2023 season! For the one day of data available this week, water quality remained good, with similar conditions to last week.
The sondes at Bullock Reach were retrieved on November 14th for the 2023 season.
Overall, water quality was good at Phillipsdale Landing this week. There were 0.74 inches of precipitation recorded at T.F. Green this week, and Blackstone flows continued to be higher than normal for this time of year. Surface salinity averaged 8.0 ppt and ranged from 3.2 ppt to 20.4 ppt. Bottom salinity averaged 19.8 ppt and ranged from 6.2 ppt to 27.2 ppt. Temperatures continued to decline, averaging 6.4°C at the surface and ranging from 3.6°C to 8.8°C. At the bottom, temperatures averaged 8.5°C and ranged from 5.5°C to 10.1°C.
Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold of 2.9 mg/L at both the surface and bottom all week. Surface DO was similar to last week, averaging 10.9 mg/L and ranging from 8.8 to 12.4 mg/L. Bottom DO averaged 8.7 mg/L and ranged from 7.3 mg/L to 11.0 mg/L. Chlorophyll readings remained mostly low with a few slightly elevated readings at the bottom. Chlorophyll averaged 0.6 ug/L at the surface and 1.9 ug/L at the bottom. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.
The sondes at Bullock Reach have been retrieved for the 2023 season.
Overall, water quality was good at Phillipsdale Landing this week. There were 1.82 inches of precipitation recorded at T.F. Green this week, 1.71 of which occurred on 11/22. Blackstone flows were higher than historical averages all week, but particularly following the 11/22 rain event. Surface salinity averaged 8.8 ppt and ranged from 2.9 ppt to 20.7 ppt. Bottom salinity averaged 21.4 ppt and ranged from 6.5 ppt to 27.7 ppt. Temperatures continued to decline, averaging 8.1°C at the surface and ranging from 5.1°C to 10.5°C. At the bottom, temperatures averaged 10.4°C and ranged from 7.2°C to 12.4°C.
Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold of 2.9 mg/L at both the surface and bottom all week. Surface DO was slightly higher than the previous week, averaging 10.2 mg/L and ranging from 8.3 to 11.8 mg/L. Bottom DO averaged 7.8 mg/L and ranged from 6.4 mg/L to 11.1 mg/L. Chlorophyll readings remained low, averaging 0.6 ug/L at the surface and 2.6 ug/L at the bottom. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.
The sondes at Bullock Reach have been retrieved for the 2023 season.
On November 21, 2023, 15 stations were sampled for fecal coliform bacteria in the Providence and Seekonk Rivers; 3 of these stations were also sampled for enterococci bacteria. There was a smaller set of locations sampled than normal due to cold weather conditions and time constraints. In the five days prior to sampling, precipitation totaled 0.15 inches as recorded at TF Green.
Overall, bacteria levels were lower in both the Seekonk and Providence Rivers this week than during the previous sampling event on October 25th. Fecal coliform levels similar in the Seekonk River and Providence River sites (geometric means of 22 MPN/100 mL and 23 MPN/100 mL, respectively). The maximum concentration (230 MPN/100 mL) was measured at Point St Bridge.
Enterococci results had an overall geometric mean of 19 MPN/100 mL and ranged from <10 MPN/100 mL at Phillipsdale Landing and South FP East to 134 MPN/100 mL at Point St. Bridge.
The table below lists the Rhode Island bacteria standards for primary contact and shellfishing established by the Rhode Island Department of Environmental Management (RIDEM). RIDEM defines primary contact as any recreational activities in which there is prolonged and intimate contact with water, involving considerable risk of ingesting water (e.g., swimming, diving, water skiing and surfing). Please note that the RIDEM bacteria standards are provided here for informational purposes only and are not intended to indicate official state compliance with primary contact or shellfishing standards.
Summary of Rhode Island Bacteria Standards for Saltwater Primary Contact and Shellfishing
| | Fecal Coliform | Enterococci |
| Primary Contact1 | Geometric mean ≤50 MPN/100 mL <10% of samples >400 MPN/100 mL | Geometric mean ≤35 colonies/100 mL All samples ≤104 colonies/100 mL2 |
| Shellfishing | Geometric mean ≤14 MPN/100 mL <10% of samples >49 MPN/100 mL3 | NO ENTEROCOCCI CRITERIA |
1Fecal coliform primary contact criteria applied only when adequate enterococci data are not available; 2Single sample maximum criterion for determining beach swimming advisories at designated beaches as evaluated by the Rhode Island Department of Health; 3For a three-tube decimal dilution
Table adapted from Rhode Island Water Quality Regulations (250-RICR-150-05-1); see regulations for complete details.
Overall, water quality was good at Phillipsdale Landing this week. There were 0.16 inches of precipitation recorded at T.F. Green this week and Blackstone River flow was slightly higher than normal for this time of year. Surface salinity averaged 13.7 ppt and ranged from 3.7 ppt to 22.6 ppt. Bottom salinity averaged 22.9 ppt and ranged from 11.8 ppt to 28.3 ppt. Temperatures were slightly lower than last week, averaging 10.4°C at the surface and ranging from 7.9°C to 12.4°C. At the bottom, temperatures averaged 12.4°C and ranged from 10.5°C to 14.0°C.
Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold of 2.9 mg/L at both the surface and bottom all week. Surface DO remained similar to the previous week, averaging 8.9 mg/L and ranging from 6.7 to 11.0 mg/L. Bottom DO averaged 6.8 mg/L and ranged from 5.4 mg/L to 8.8 mg/L. Chlorophyll readings remained low, averaging 0.6 ug/L at the surface and 1.3 ug/L at the bottom. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.
The sondes at Bullock Reach were retrieved on the morning of November 14th for the 2023 season. For the two and half days of data this week before retrieval, water quality was good. Salinity averaged 25.7 ppt, 27.9 ppt, and 29.8 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 23.5 – 27.9 ppt, mid salinity ranged 25.1 – 29.7 ppt, and bottom salinity ranged 29.0 – 30.4 ppt. Surface temperatures averaged 11.4°C and ranged from 10.2°C to 12.4°C. Mid temperatures averaged 12.4°C and ranged from 11.3°C to 13.2°C. Bottom temperatures averaged 13.2°C and ranged from 12.5°C to 13.7°C.
DO concentrations at Bullock Reach remained above the hypoxia threshold all week. Surface DO averaged 8.0 mg/L and ranged 7.4 – 8.8 mg/L. In the mid waters, DO averaged 7.5 mg/L and ranged 7.1 – 8.1 mg/L. At the bottom, DO averaged 7.1 mg/L and ranged 6.7 – 7.5 mg/L. Chlorophyll concentrations were low, averaging 1.2 ug/L, 1.9 ug/L, and 1.3 ug/L at the surface, mid, and bottom waters, respectively.
Overall, water quality was good at Phillipsdale Landing this week. Sondes were swapped this week on the morning of November 7th. There were 0.18 inches of precipitation recorded at T.F. Green this week. Blackstone River flow was higher than normal for this time of year. Surface salinity averaged 5.9 ppt and ranged from 2.0 ppt to 19.3 ppt. Bottom salinity averaged 21.1 ppt and ranged from 4.6 ppt to 28.3 ppt. Temperatures decreased this week, averaging 10.6°C at the surface and ranging from 8.1°C to 12.6°C. At the bottom, temperatures averaged 13.5°C and ranged from 10.5°C to 15.3°C.
Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold of 2.9 mg/L at both the surface and bottom all week. Surface DO remained similar to the previous week, averaging 9.8 mg/L and ranging from 7.2 to 10.8 mg/L. Bottom DO averaged 5.9 mg/L and ranged from 4.0 mg/L to 10.0 mg/L. Chlorophyll readings remained low, averaging 0.6 ug/L at the surface and 0.9 ug/L at the bottom. Maximum chlorophyll at the surface was only 1.0 ug/L. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.
Overall, water quality was good at Bullock Reach this week. Salinity averaged 24.4 ppt, 27.5 ppt, and 29.7 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 18.5 – 27.2 ppt, mid salinity ranged 24.0 – 29.9 ppt, and bottom salinity ranged 28.2 – 30.7 ppt. Surface temperatures averaged 12.8°C and ranged from 10.7°C to 14.1°C. Mid temperatures averaged 13.4°C and ranged from 12.3°C to 14.3°C. Bottom temperatures averaged 14.2°C and ranged from 13.3°C to 14.8°C.
DO concentrations at Bullock Reach remained above the hypoxia threshold all week. Surface DO averaged 7.8 mg/L and ranged 6.8 – 9.5 mg/L. In the mid waters, DO averaged 7.3 mg/L and ranged 6.3 – 8.0 mg/L. At the bottom, DO averaged 6.7 mg/L and ranged 5.6 – 7.3 mg/L. Chlorophyll concentrations were low, averaging 2.0 ug/L, 2.5 ug/L, and 2.1 ug/L at the surface, mid, and bottom waters, respectively. The maximum surface chlorophyll of 5.0 ug/L occurred during the afternoon on November 5th.
Overall, water quality was good at Phillipsdale Landing this week. There were 1.14 inches of precipitation recorded at T.F. Green this week, mostly from rain events on the 29th and 30th. Blackstone River flow was higher than normal for this time of year. Surface salinity averaged 8.7 ppt and ranged from 2.0 ppt to 21.8 ppt. Bottom salinity averaged 20.5 ppt and ranged from 6.1 ppt to 27.9 ppt. Temperatures decreased this week, averaging 13.0°C at the surface and ranging from 8.8°C to 16.5°C. At the bottom, temperatures averaged 15.0°C and ranged from 11.2°C to 16.7°C.
Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold of 2.9 mg/L at both the surface and bottom. Surface DO remained similar to the previous week, averaging 8.7 mg/L and ranging from 5.6 to 11.1 mg/L. Bottom DO averaged 5.9 mg/L and ranged from 4.6 mg/L to 10.0 mg/L. Chlorophyll readings remained low, averaging 0.9 ug/L at the surface and 0.8 ug/L at the bottom. Maximum chlorophyll at the surface was only 3.5 ug/L, recorded on the morning of October 29th. . Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.
Sondes were swapped this week on the morning of October 31. Overall, water quality was good at Bullock Reach this week. Salinity averaged 23.9 ppt, 27.3 ppt, and 29.4 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 20.4 – 27.5 ppt, mid salinity ranged 23.0 – 29.3 ppt, and bottom salinity ranged 27.8 – 30.4 ppt. Surface temperature averaged 14.3°C and ranged from 11.6°C to 17.0°C. Mid temperatures averaged 15.2°C and ranged from 13.6°C to 16.8°C. Bottom temperatures averaged 15.6°C and ranged from 13.9°C to 16.2°C.
DO concentrations at Bullock Reach remained above the hypoxia threshold all week. Surface DO averaged 7.3 mg/L and ranged 6.2 – 8.9 mg/L. In the mid waters, DO averaged 6.8 mg/L and ranged 5.8 – 9.5 mg/L. At the bottom, DO averaged 6.5 mg/L and ranged 5.9 – 7.2 mg/L. Chlorophyll concentrations were low, averaging 1.9 ug/L, 2.5 ug/L, and 1.6 ug/L at the surface, mid, and bottom waters, respectively. The maximum surface chlorophyll of 4.7 ug/L occurred during the afternoon on November 4th.
The R/V Monitor has been retired since the last blog update for the week of February 19-25, 2023. However, the Narragansett Bay Commission is excited to announce its new monitoring vessel, Data Stream. The Data Stream is a brand new 2023 Parker 23290 SL: Sport cabin boat. The Data Stream is equipped with state-of-the-art electronics, including the latest Garmin GPS with Radar overlay capability, a remote-control spotlight, and salt and freshwater wash down. Data Stream’s Yamaha engine is a 300hp electronic shift engine which is an upgrade from the 250 HP Mercury on the Monitor.
The Data Stream picked up where the Monitor left off monitoring water quality in the upper Narragansett Bay. Throughout the Spring and Summer, the crew of the Data Stream was out on the upper Bay collecting bacteria, 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. In addition, the fixed site monitoring stations were deployed and continuously maintained. The featured photo shows the new monitoring vessel, Data Stream.
The Phillipsdale Landing sondes have been deployed for the season since May 9th, 2023 utilizing a new setup allowing staff access to the equipment from the boat instead of standing on the dock. During the month of October, sondes were changed out for routine maintenance on October 10th and 24th.
Surface DO remained above the hypoxia threshold all month. The bottom waters were hypoxic periodically throughout the month, with the longest sustained hypoxic periods (8 hours) occurring in the early morning of October 14th. DO averaged 8.4 mg/L at the surface with a minimum of 4.9 mg/L, while bottom waters averaged 5.5 mg/L with a minimum of 2.3 mg/L.
Chlorophyll readings were relatively low all month with a couple of moderately elevated readings in the bottom waters. The surface and bottom readings averaged 1.1 µg/L and 1.5 µg/L, respectively.
The Bullock Reach buoy was deployed June 1st for the 2023 season. During the month of October, sondes were changed out for routine maintenance on October 3rd, 17th, and 31st.
DO remained above the hypoxia threshold all month at the surface, middle, and bottom and averaged 7.7 mg/L, 6.7 mg/L, and 5.8 mg/L, respectively.
Chlorophyll readings ranged from low to elevated, with evidence of moderate phytoplankton blooms occurring throughout the month and some highly elevated (>200 ug/L) chlorophyll levels at the middle sonde throughout the day on October 16th. Readings averaged 6.5 µg/L at the surface, 18.3 µg/L at mid-depth, and 3.1 µg/L at the bottom.
Please note that data from the Bullock Reach Surface sonde were not available between 11:15am on October 21st and 9:15 am on October 24th due to an equipment issue.
Surface chlorophyll data were collected on October 25, 2023 while the R/V Monitor was underway collecting nutrient samples in the Providence and Seekonk River estuaries. The average chlorophyll concentrations were categorized Good in the areas surveyed. Overall, chlorophyll ranged from 0.91 µg/L to 4.06 µg/L with an average of 1.73 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.
