Tara Franey – Page 4

May 5- May 11, 2025

Phillipsdale Landing

The Phillipsdale Landing sondes were deployed for the season on May 6, 2025. Overall, water quality at Phillipsdale Landing was fair to good this week. Weather conditions were wet this week, with a total of 3.51 inches recorded at T.F. Green, and the majority of rainfall occurring on the 5^th, 6^th, and 9^th. The Blackstone River flow increased on the 5^th and remained above the 20-year daily median for the remainder of the week. Salinity at the surface averaged 2.2 ppt and ranged from 0.5 ppt to 6.2 ppt. At the bottom, salinity averaged 11.3 ppt and ranged from 0.0 ppt to 28.4 ppt. Temperatures this week averaged 16.9 °C at the surface and 15.0 °C at the bottom. Surface temperatures ranged from 14.2 °C to 19.6 °C, while bottom temperatures ranged from 11.8 °C to 18.3 °C.

Dissolved oxygen (DO) at Phillipsdale Landing remained above the hypoxia threshold (i.e., DO >2.9 mg/L) throughout the week. Surface DO averaged 9.3 mg/L and ranged from 7.9 -10.6 mg/L. Bottom water DO concentration averaged 7.1 mg/L and ranged from 3.9 mg/L to 10.3 mg/L. Chlorophyll was low, averaging 2.11 ug/L at the surface and 4.5 ug/L at the bottom. Maximum surface chlorophyll readings reached 20.8 ug/L, recorded on the morning of May 6^th. Please note that tidal fluctuations and Blackstone River flows greatly influence water column salinity, temperature, and DO at this location.

The bottom sonde had a malfunctioning depth sensor this week, thus no depth data is available for the bottom sonde.

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-early summer.

June 25, 2025

Nutrient samples were collected from seven river stations and seven bay stations on June 25^th. All bay stations were sampled at the surface and bottom. In the five days prior to sampling, there were 0.01 inches of precipitation recorded at T.F. Green.

Among the river stations sampled, the highest total nitrogen (TN) was observed at Blackstone River @ Stateline (917 ppb). The highest total dissolved nitrogen (TDN) and dissolved inorganic nitrogen (DIN) were observed at Woonasquatucket River @ Valley St. (TDN = 946 ppb, DIN = 734.5, average of duplicates). The lowest TN, TDN and DIN were observed at Pawtuxet River @ Broad St. (TN = 587 ppb, TDN = 349 ppb, DIN = 41.9 ppb).

Among the bay stations sampled, the highest surface TN was observed at Phillipsdale Landing (973 ppb). The highest TDN and DIN were observed at Pawtuxet Cove (TDN = 546 ppb, DIN = 319.7 ppb). The lowest surface TN was observed at India Point Park (468 ppb). The lowest surface TDN was observed at Bullock Reach Buoy (151 ppb). The lowest surface DIN was observed at five of seven bay stations (13 ppb, reflecting minimum detection limits for DIN).

The next scheduled sampling date is July 8^th, 2025.

June 11, 2025

Nutrient samples were collected from seven river stations and seven bay stations on June 11^th. All bay stations were sampled at the surface and bottom. In the five days prior to sampling, there were 0.85 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) were observed at Pawtuxet River at Broad St. (TN = 1,090 ppb, TDN = 1,200 ppb, DIN = 863.7). The lowest TN and DIN were observed at Woonasquatucket River at Manton Ave. Bridge (TN = 638 ppb, DIN = 406.4 ppb, average of duplicates). The lowest TDN was observed Moshassuck River @ Footbridge at Mill St. (660 ppb).

Among the bay stations sampled, the highest surface TN was observed at Phillipsdale Landing (1,080 ppb). The highest TDN and DIN were observed at Pawtuxet Cove (TDN = 963 ppb, DIN = 654.7 ppb). The lowest surface TN, TDN, and DIN were observed at Edgewood Shoal (TN = 597 ppb, TDN = 176 ppb, DIN = 13 ppb, reflecting minimum detection limits for DIN)

The next scheduled sampling date is June 25^th, 2025.

July 8, 2025

Water column profiles were conducted at eight locations in the Providence and Seekonk River estuaries on July 8, 2025 using a Seabird Electronics profiler. In the five days leading up to the survey, 0.55 inches of precipitation were recorded at T.F. Green. Water column stratification varied between the sites this week from well-mixed at Pawtuxet Cove to moderately stratified at Pomham Rocks, India Point Park and Phillipsdale Landing.

Dissolved oxygen (DO) conditions were below the hypoxia threshold (2.9 mg/L) in the lower portion of the water column at India Point Park, Pomham Rocks, Bullock Reach Buoy, Edgewood Yacht Club, and Edgewood Shoal, and in the middle and lower portion of the water column at Phillipsdale Landing. The highest fluorescence readings for the week were measured around 1 meter below the surface at Phillipsdale Landing.

July 2, 2025

Water column profiles were conducted at eight locations in the Providence and Seekonk River estuaries on July 2, 2025 using a Seabird Electronics profiler. In the five days leading up to the survey, 0.02 inches of precipitation were recorded at T.F. Green. Water column stratification varied between the sites this week from well-mixed at Point Street Bridge and Pawtuxet Cove to moderately stratified at India Point Park and Phillipsdale Landing.

Dissolved oxygen (DO) conditions were below the hypoxia threshold (2.9 mg/L) in the middle and lower portion of the water column at Edgewood Yacht Club and India Point Park, and in all portions (upper, middle, and lower) of the water column at Point Street Bridge and Phillipsdale Landing. The highest fluorescence readings for the week were measured around 1 meter below the surface at Pawtuxet Cove.

June 25, 2025

Water column profiles were conducted at seven locations in the Providence and Seekonk River estuaries on June 25, 2025 using a Seabird Electronics profiler. In the five days leading up to the survey, 0.01 inches of precipitation were recorded at T.F. Green. Water column stratification varied between the sites this week from weakly stratified at Pawtuxet Cove to strongly stratified at Conimicut Point, Pomham Rocks, and Phillipsdale Landing.

Dissolved oxygen (DO) conditions were below the hypoxia threshold (2.9 mg/L) in the lower portion of the water column at India Point Park and Phillipsdale Landing. The highest fluorescence readings for the week were measured around 1 meter below the surface at Phillipsdale Landing.

June 11, 2025

Water column profiles were conducted at seven locations in the Providence and Seekonk River estuaries on June 11, 2025 using a Seabird Electronics profiler. In the five days leading up to the survey, 0.85 inches of precipitation were recorded at T.F. Green. Water column stratification varied between the sites this week from moderately stratified at India Point Park and Phillipsdale Landing to strongly stratified at all other sites.

Dissolved oxygen (DO) conditions were not observed to be below the hypoxia threshold (2.9 mg/L) at any site profiled this week. The highest fluorescence recorded this week was measured around 2 meters below the surface at Bullock Reach Buoy.

June 4, 2025

Water column profiles were conducted at eight locations in the Providence and Seekonk River estuaries on June 4, 2025 using a Seabird Electronics profiler. In the five days leading up to the survey, 0.39 inches of precipitation were recorded at T.F. Green. Water column stratification varied between the sites this week from weakly stratified at Point Street Bridge to strongly stratified at all other sites.

May 28, 2025

Water column profiles were conducted at eight locations in the Providence and Seekonk River estuaries on May 28, 2025 using a Seabird Electronics profiler. In the five days leading up to the survey, 0.15 inches of precipitation were recorded at T.F. Green. Water column stratification varied between the sites this week from moderately stratified at Bullock Reach Buoy and India Point Park to strongly stratified at all other sites.

May 21, 2025

Water column profiles were conducted at eight locations in the Providence and Seekonk River estuaries on May 21, 2025 using a Seabird Electronics profiler. In the five days leading up to the survey, less than 0.1 inches of precipitation were recorded at T.F. Green. Water column stratification varied between the sites this week from weakly stratified at Phillipsdale Landing and Pawtuxet Cove to well-mixed at all other sites.