Week of April 2-8, 2023
Fixed Site Network
Phillipsdale Landing
The sondes were removed this week on April 3rd after remaining deployed from March 7th due to safety concerns regarding the structural integrity of the dock. The site will be suspended until further noticed due to these safety concerns.
Due to the Phillipsdale Landing sondes being removed on April 3rd, we only have data from the first 3 days of April; all three days are discussed here rather than only discussing the two days of the focal week. The first of April saw 0.47 inches of precipitation recorded at T.F. Green, but the next two were dry. Blackstone River flows responded to the precipitation but remained below the 18-year median statistic of USGS. Surface salinity remained well below bottom salinity. Salinity at the surface averaged 3.4 ppt and ranged from 1.8 ppt to 6.2 ppt. At the bottom, salinity averaged 14.5 ppt and ranged from 2.3 ppt to 27.3 ppt. Temperatures averaged 9.4°C at the surface and 8.3°C at the bottom. Surface temperatures ranged from 7.0°C to 10.8°C, while bottom temperatures ranged from 7.0°C to 10.2°C.
Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold of 2.9 mg/L for these days. Surface DO averaged 11.1 mg/L and ranged 10.2-13.0 mg/L. Bottom water DO concentration averaged 9.9 mg/L and ranged from 8.6 mg/L to 12.4 mg/L. Chlorophyll concentrations were generally low (i.e., <20 µg/L), with no strong signs of phytoplankton bloom activity. Also, please note that portions of chlorophyll data from the bottom sonde from April 1st, 2nd, and 3rd are not included in the summary due to potential sediment interference which is common at this site.
Bullock Reach
Bullock Reach sondes will be deployed later this spring for the 2023 monitoring season.
Week of June 4 – 10, 2023
Water Column Profiles
Water column profiles were conducted at six locations in the Providence and Seekonk River estuaries on June 7, 2023 using a Seabird Electronics profiler. In the three days leading up to the survey, there were 0.12 inches of precipitation recorded at T.F. Green. Phillipsdale Landing exhibited moderate density stratification and all other sites were weakly stratified.
Dissolved oxygen (DO) conditions remained above the hypoxia threshold (2.9 mg/L) at all sites this week; the lowest DO observed was approximately 4.65 mg/L in the bottom waters of Phillipsdale Landing. Fluorescence was low this week, ranging from 1.06 to 4.64 mg/m3.
Week of May 28 – June 3, 2023
Water Column Profiles
Water column profiles were conducted at eight locations in the Providence and Seekonk River estuaries on May 31, 2023 using a Seabird Electronics profiler. There was no precipitation recorded at T.F. Green in the three days leading up to the survey. All sites exhibited strong density stratification except for Pomham Rocks, which was moderately stratified.
Dissolved oxygen (DO) conditions remained above the hypoxia threshold (2.9 mg/L) at all sites this week; the lowest DO observed was approximately 3.01 mg/L in the bottom waters of Edgewood Shoal. Fluorescence was fairly low this week, ranging from 1.80 to 11.9 mg/m3.
Week of August 27 - September 2, 2023
Surface Mapping
Surface chlorophyll data were collected on August 29, 2023 while the R/V Monitor was underway collecting nutrient samples in the Edgewood Shoals, Pawtuxet River and Southern Providence River areas (chlorophyll data were not collected for the Seekonk and Northern Providence River Channel areas due to data logging issues). The average chlorophyll concentrations were categorized fair in the areas surveyed. Overall, chlorophyll ranged from 5.57 µg/L to 12.80 µg/L with an average of 10.46 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.
Week of August 20 - 26, 2023
Surface Mapping
Surface chlorophyll data were collected on August 22, 2023 while the R/V Monitor was underway collecting nutrient samples in the Providence and Seekonk River estuaries. The average chlorophyll concentrations were categorized as good in the Seekonk River, Northern Providence River Channel, and Edgewood Shoals and as fair in all other areas. Overall, chlorophyll ranged from 1.56 to 44.70 µg/L with an average of 5.72 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.
