June 12, 2024

​Nutrient samples were collected from seven river stations and seven bay stations on June 12th. In the five days prior to sampling, there were 0.21 inches of precipitation recorded at T.F. Green. 

Among the river stations sampled, the highest total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) concentrations were observed at Pawtuxet River @ Broad Street (TN = 1,340 ppb, TDN = 1,420 ppb, DIN = 1,148 ppb). The lowest TN and TDN were observed at Woonasquatucket River @ Manton Ave. Bridge (TN = 892 ppb, TDN = 922 ppb), while the lowest DIN was at Moshassuck River @ Footbridge at Mill St. (DIN = 626 ppb).

Among the bay stations sampled, the highest surface TN, TDN, and DIN were observed at Pawtuxet Cove (TN = 1,120 ppb, TDN = 976 ppb, and DIN = 762 ppb. The lowest surface TN and TDN were observed at Conimicut Point (TN = 433 ppb, TDN = 232 ppb), while the lowest surface DIN was at Conimicut Point, Edgewood Yacht Club and the Bullock Reach Buoy. (DIN = 13 ppb). Chlorophyll a concentrations at the surface bay stations averaged 11.63 μg/L overall with a maximum of 29.57 μg/L at the India Point Park.

The next scheduled sampling date is June 26, 2024.

June 6, 2024

​The Data Stream had some visitors while doing routine sonde swaps at Bullocks Reach.  Below is a picture taken by Tyler, an Environmental Monitoring Supervisor.  Tyler identified the birds as Common Terns.  These birds are seen often hanging around the Bullocks Reach buoy eating fish.

May 29, 2024

​Nutrient samples were collected from thirteen river stations and nine bay stations on May 29th. In the five days prior to sampling, there were 0.37 inches of precipitation recorded at T.F. Green. 

Among the river stations sampled, the highest total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) concentrations were observed at Ten Mile River @ Central Ave. (TN = 1,380 ppb, TDN = 1,340 ppb, DIN = 948 ppb). The lowest TN and TDN were observed at Moshassuck River @ Higginson Ave. (TN = 658 ppb, TDN = 590 ppb), while the lowest DIN was at Coles River @ Milford Rd. (DIN = 188.6 ppb, average of duplicates).

Among the bay stations sampled, the highest surface TN, TDN and DIN were observed at Phillipsdale Landing (TN = 1,070 ppb, TDN = 931 ppb, DIN = 648 ppb). The lowest surface TN were observed at Bullock Reach Buoy (TN = 698 ppb), while the lowest surface TDN and DIN were observed at Conimicut Point (TDN = 333 ppb, DIN = 165 ppb). Chlorophyll a concentrations at the surface bay stations averaged 1.67 μg/L overall with a maximum of 4.05 μg/L at the Edgewood Shoal.

The next scheduled sampling date is June 12, 2024.

May 20, 2024

Today a new MET Sensor Assembly was installed on the recently deployed Bullocks Reach Buoy.  The assembly includes a weather station that can monitor wind speed, humidity, air pressure, and temperature.   The buoy was deployed on May 14th and staff have been diligently working to get the buoy up and running for the 2024 Fixed Site Monitoring Season.

May 14-15, 2024

​Nutrient samples were collected from seven river stations on May 15th and seven bay stations on May 14th. In the five days prior to sampling, there were 0.1 inches of precipitation recorded at T.F. Green. 

Among the river stations sampled, the highest total nitrogen (TN) and dissolved inorganic nitrogen (DIN) concentrations were observed at Pawtuxet River @ Broad St. (TN = 855 ppb, DIN = 687 ppb), while the highest total dissolved nitrogen (TDN) were observed at Moshassuck River @ Footbridge at Mill St. (TDN = 907 ppb). The lowest TN, TDN, and DIN were observed at Moshassuck River @ Higginson Ave. (TN = 525 ppb, TDN = 530 ppb, DIN = 308 ppb).

Among the bay stations sampled, the highest surface TN were observed at India Point Park (TN = 926 ppb), while the highest surface TDN and DIN were observed at Phillipsdale Landing (TDN = 804 ppb, DIN = 620 ppb). The lowest surface TN and TDN were observed at Conimicut Point (TN = 396 ppb, TDN = 160 ppb), while the lowest surface DIN was at Bullock Reach Buoy (DIN = 13 ppb). Chlorophyll a concentrations at the surface bay stations averaged 9.45 μg/L overall with a maximum of 27.95 μg/L at Pomham Rocks.

The next scheduled sampling date is May 29, 2024.

May 1, 2024

Phytoplankton samples were collected on May 1, 2024 at Bullock Reach and analyzed in the laboratory shortly after collection. It was a cold and breeze day on Narragansett Bay with cloudy conditions. The qualitative tow net sample had a long filtration time, and the filtrate was a reddish brown and slightly cloudy.

The analysis of the quantitative whole water sample revealed a total of 4,006,000 cells per Liter. The micro flagellates were found at 24,000 cells/L. The most predominant phytoplankton genus was Skeletonema spp. at 1,646,000 cells/L. Other representative genera include Thalassiosira spp., Leptocylindrus spp., and Chaetoceros spp. This week’s featured image is Eucampia spp. (200x phase contrast), a type of diatomic phytoplankton that is often found in the North Atlantic Ocean. This genus is often found in a curved form and in helical chains. This diatom is yellow-brown in color with numerous green chloroplasts.

May 1, 2024

​Nutrient samples were collected from thirteen river stations on May 1st. In the five days prior to sampling, there were 0.13 inches of precipitation recorded at T.F. Green. 

Among the river stations sampled, the highest total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) concentrations were observed at Ten Mile River @ Central Ave (TN = 1,340 ppb, TDN = 1,260 ppb, DIN = 946.2 ppb). The lowest TN and TDN were observed at Moshassuck River @ Higginson (TN = 530 ppb, TDN = 436 ppb, each being duplicate samples taken at the site). The lowest DIN were observed at Coles River @ Milford Rd. (DIN = 58 ppb). 

Among the bay stations sampled, the highest surface TN, TDN, and DIN were observed at Phillipsdale Landing (TN = 1,000 ppb, TDN = 836 ppb, DIN = 663 ppb). The lowest surface TN were observed at Conimicut Point (TN = 544 ppb), while lowest surface TDN and DIN were observed at Edgewood Shoal (TDN = 124 ppb, DIN = 17 ppb). Chlorophyll a concentrations at the surface bay stations averaged 19.62 μg/L overall with a maximum of 35.12 μg/L at the Bullock Reach Buoy.

The next scheduled sampling date is May 14, 2024.

April 22 – 28, 2024

​Phillipsdale Landing

Overall, water quality at Phillipsdale Landing was good this week. Weather conditions were dry, with only 0.05 inches on April 30th, recorded at T.F. Green. The Blackstone River flow declined this week, remaining below the 19-year daily median for the majority of the week. Surface salinity averaged 4.1 ppt and ranged from 1.2 ppt to 9.1 ppt. At the bottom, salinity averaged 13.5 ppt and ranged from 2.3 ppt to 27.1 ppt. Temperatures remained stabilized this week, averaging 12.7°C at the surface and ranging 10.0°C – 14.5°C. At the bottom, temperatures averaged 11.3°C and ranged 8.0°C – 14.4°C.

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO average 10.5 mg/L and ranged from 9.5 mg/L to 11.7 mg/L.. Bottom DO concentrations averaged 9.3 mg/L and ranged from 8.1 mg/L to 11.3 mg/L. Chlorophyll readings remained comparable from last week, averaging 2.6 ug/L at the surface and 2.9 ug/L at the bottom. Maximum chlorophyll at the surface reached 14.3 ug/L on the afternoon of April 24th. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location. Also, please note that isolated portions of suspect chlorophyll data from April 28th were excluded from the summary.

Bullock Reach 

The Bullock Reach Buoy remains out of the water for the winter.  EM will coordinate with RIDEM to redeploy the buoy in late spring.

April 24, 2024

On April 24th, 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, precipitation totaled 0.28 inches as recorded at TF Green. Overall, bacteria counts were lower in both the Seekonk and Providence Rivers this week than during the previous sampling event on March 27th, likely because of the drier weather leading up to sampling. 

Fecal coliform counts were higher in the Seekonk River sites than in the Providence River sites (geometric means of 59 MPN/100 mL and 7 MPN/100 mL, respectively). The maximum count (430 MPN/100 mL) was measured at Point St Bridge. 

Enterococci results had an overall geometric mean of 14 MPN/100 mL. Enterococci counts ranged from <10 MPN/100 mL at South FP East, Gaspee Point, and Conimicut Point to 41 MPN/100 mL at Phillipsdale Landing.

The next scheduled sampling date is May 8.

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

 ​​Fec​al Coli​fo​rmEnterococci
Primary Con​​​t​a​c​t1​​​​​Geom​e​tric ​m​e​a​n​ ≤50 MPN/1​​00​ mL
<10% ​o​f​​ samples >400 MPN/100 ​mL		Geom​etric mean ≤35 colo​nies​/100 mL​
All sa​mples ≤104 colonies/100 ​​mL2
ShellfishingGeometric mean ≤14 MPN/100​ mL
<10% of samples >49 MPN/100 mL3​		NO ENTEROCOCCI CR​ITERIA

1Fecal coliform primary contact criteria app​lied 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.​​​​​​​​​​

April 16-17, 2024

​Nutrient samples were collected from seven river stations on April 17th and eight bay stations on April 16th. In the five days prior to sampling, there were 1.04 inches of precipitation recorded at T.F. Green. 

Among the river stations sampled, the highest total nitrogen (TN), and dissolved inorganic nitrogen (DIN) concentrations were observed at Blackstone River @ Slater Mill (TN = 751 ppb, DIN = 571 ppb).  The highest total dissolved nitrogen (TDN) was observed at Blackstone River @ Bikepath Bridge (TDN = 787 ppb). The lowest TN, TDN, and DIN were observed at Moshassuck River @ Higginson Ave. (TN = 483.5 ppb, TDN = 489 ppb, DIN = 291 ppb, all averaged with duplicates).

Among the bay stations sampled, the highest surface TN, TDN, and DIN were observed at Phillipsdale Landing Surface (TN = 844 ppb, TDN = 678, and DIN = 545 ppb).  The lowest surface TN were at Pawtuxet Cove (TN = 633 ppb). The lowest surface TDN were observed at Bullock Reach Buoy (TDN = 402 ppb, average of duplicates). The lowest surface DIN were observed at Conimicut Point Surface (DIN = 301 ppb). Chlorophyll a concentrations at the surface bay stations averaged 2.39 μg/L overall with a maximum of 3.35 μg/L at the Conimicut Point.

The next scheduled sampling date is May 1, 2024.

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