News – Page 3 – Narrabay

April 1, 2026

Nutrient samples were collected from fourteen river stations on April 1^st. In the five days prior to sampling, 0.08” of precipitation were recorded at T.F. Green.

Among the river stations sampled, the highest total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) were observed at Ten Mile River @ Central Ave (TN = 1,790 ppb, TDN = 2,240 ppb, DIN = 1,608 ppb). The lowest TN, TDN, and DIN were observed at Coles River @ Milford Rd (TN = 602 ppb, TDN = 574 ppb, DIN = 215.3 ppb).

The next scheduled sampling date is April 15^th, 2026.

June 3, 2026

Water clarity was measured at seven locations in the Providence River and Seekonk River estuaries on June 3, 2026. In the five days prior to the survey, 0.21 inches of precipitation were recorded at TF Green. Secchi depth averaged 2.7 meters. The lowest clarity this week (1.9 meters) was measured at Phillipsdale Landing and Edgewood Yacht Club, while the greatest clarity (3.5 meters) was measured at Conimicut Point. There was no clear north-to-south gradient in water clarity among the sites this week. Overall, water clarity increased from the previous measurements (data collected May 28, 2026).

May 20, 2026

On May 20^th, 2026, twenty stations were sampled for fecal coliform bacteria in the Providence and Seekonk Rivers; five of these stations were also sampled for enterococci bacteria. In the five days prior to sampling, trace amounts of precipitation were recorded at TF Green.

Fecal coliform counts were lower in the Seekonk River, compared to the previous sampling on May 7^th (geometric mean of 91 MPN/100 mL compared to 103 MPN/100 mL on 5/7). Fecal coliform counts were similar in the Providence River, compared to the previous sampling on May 7^th (geometric mean of 26 MPN/100 mL on both sampling days).

Enterococci results had an overall geometric mean of 13 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at most sites to 74 MPN/100 mL at Point Street Bridge.

The next scheduled sampling date is June 3^rd.

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.

May 7, 2026

On May 7^th, 2026, sixteen stations were sampled for fecal coliform bacteria in the Providence and Seekonk Rivers; five of these stations were also sampled for enterococci bacteria. In the five days prior to sampling, 0.28” of precipitation was recorded at TF Green.

Fecal coliform counts were lower in the Seekonk River, compared to the previous sampling on April 23^rd (geometric mean of 103 MPN/100 mL compared to 223 MPN/100 mL on 4/23). Fecal coliform counts were lower in the Providence River, compared to the previous sampling on April 23^rd (geometric mean of 26 MPN/100 mL compared to 16 MPN/100 mL on 4/23).

Enterococci results had an overall geometric mean of 21 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at most sites to 988 MPN/100 mL at Point Street Bridge.

The next scheduled sampling date is May 20^th.

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

Table adapted from Rhode Island Water Quality Regulations (250-RICR-150-05-1); see regulations for complete details.

May 27, 2026

Water column profiles were conducted using a Seabird Electronics profiler at six locations in the Providence River and one location in the Seekonk River on May 27, 2026. In the four days leading up to and including the survey day, there were 1.04 inches of rain recorded at T.F. Green International Airport (Warwick, RI). The water column was strongly stratified at Pawtuxet Cove, India Point Park, and Phillipsdale Landing, moderately stratified at Pomham Rocks, Bullock’s Reach and Conimicut Point, and weakly stratified at Edgewood Yacht Club.

Dissolved oxygen conditions were slightly below the hypoxia threshold (2.9 mg/L) in the lower part of the water column at Phillipsdale Landing. The highest fluorescence reading was observed about 2.25 meters below the surface at Pomham Rocks.

May 28, 2026

Water clarity was measured at seven locations in the Providence River and Seekonk River estuaries on May 28, 2026. In the five days prior to the survey, 1.04 inches of precipitation were recorded at TF Green. Secchi depth averaged 2.0 meters. The lowest clarity this week (1.5 meters) was measured at Pomham Rocks and Pawtuxet Cove, while the greatest clarity (2.7 meters) was measured at Bullock Reach and Conimicut Point. There was no clear north-to-south gradient in water clarity among the sites this week. Overall, water clarity decreased from the previous measurements (data collected May 19, 2026).

May 19, 2026

Water column profiles were conducted using a Seabird Electronics profiler at six locations in the Providence River and one location in the Seekonk River on May 19, 2026. Trace amounts of rain were recorded at T.F. Green International Airport (Warwick, RI) in the four days leading up to and including the survey day. The water column was strongly stratified at Pomham Rocks, moderately stratified at Edgewood Yacht Club, Conimicut Point, India Point Park, and Phillipsdale Landing, and weakly stratified at Point St. Bridge, and Bullock’s Reach.

Dissolved oxygen conditions were not below the hypoxia threshold (2.9 mg/L) at any of the visited locations. The highest fluorescence reading was observed about 2.25 meters below the surface at Edgewood Yacht Club.

May 12, 2026

Water column profiles were conducted using a Seabird Electronics profiler at seven locations in the Providence River and one location in the Seekonk River on May 12, 2026. In the four days leading up to and including the survey day, there were 0.34 inches of rain recorded at T.F. Green International Airport (Warwick, RI). The water column was strongly stratified at Conimicut Point, Bullock’s Reach, Pomham Rocks, Phillipsdale Landing, and India Point Park, and weakly stratified at Edgewood Shoal, Edgewood Yacht Club, and Pawtuxet Cove.

Dissolved oxygen conditions were not below the hypoxia threshold (2.9 mg/L) at any of the visited locations. The highest fluorescence reading was observed about 3.25 meters below the surface at Conimicut Point.

May 7, 2026

Water column profiles were conducted using a Seabird Electronics profiler at seven locations in the Providence River and one location in the Seekonk River on May 7, 2026. In the four days leading up to and including the survey day, there were 0.26 inches of rain recorded at T.F. Green International Airport (Warwick, RI). The water column was strongly stratified at Pawtuxet Cove and Phillipsdale Landing, and moderately stratified at Bullock’s Reach, Conimicut Point, India Point Park, Pomham Rocks, Edgewood Yacht Club, and Point St. Bridge.

Dissolved oxygen conditions were not below the hypoxia threshold (2.9 mg/L) at any of the visited locations. The highest fluorescence reading was observed about 2.5 meters below the surface at Pomham Rocks.

May 12, 2026

Phytoplankton samples were collected on May 12, 2026 at Bullock’s Reach and analyzed in the laboratory shortly after collection.

On this day, the water temperature was 13.60 °C, the salinity was 22.93 PSU, and the chlorophyll a was 8.36 µg/L.

It was sunny and clear on this day. The qualitative tow net sample had a short filtration time and contained a large volume of copepods.

The analysis of the quantitative whole water sample revealed a total of 749,000 cells/L. The microflagellates were found at 673,000 cells/L. The most predominant phytoplankton genera were Silicoflagellate spp. at 40,000 cells/L, Skeletonema spp. at 13,000 cells/L, and Unknown Diatom spp. at 10,000 cells/L.

200x phase contrast image of Pediastrum spp.

Pediastrum is a genus of freshwater green algae found in lakes, ponds and along shores where water is rich in nutrients such as nitrogen. They are nonmotile and form flat colonies with concentric rings that resemble snowflakes. These groupings can both improve their buoyancy in the water column and help prevent predation.