Week of January 15 - 21, 2023
R/V Monitor's Blog
On Wednesday, January 18th, the crew of the R/V Monitor was out on the upper Bay collecting bacteria samples, taking Secchi Disk water clarity measurements, and conducting real-time surface mapping of water quality parameters, including dissolved oxygen, chlorophyll, water temperature, salinity, and pH, all in an effort to document water quality improvements associated with NBC construction projects. Jeff captained the boat while monitoring professionals Amanda and Daryll collected the samples and data. It was mostly cloudy but relatively warm with calm waters. The featured photo taken was of the Pomham Rocks Lighthouse.
Week of January 15 - 21, 2023
Water Column Clarity
Water clarity was measured at six locations in the Providence River and Seekonk River estuaries on January 18. Rainfall totaling 0.52 inches was recorded at TF Green in the five days prior to the survey. Secchi depth averaged 2.7 meters, compared to 3.3 meters on the previous survey (January 10). The lowest clarity this week (2.6 meters) was measured at India Point Park, Phillipsdale Landing, and Pomham Rocks, while the greatest clarity (2.9 meters) was measured at Bullock Reach and Conimicut Point. There was a general north-to-south gradient of increasing water clarity among the sites this week.
Week of October 16-22, 2022
Nutrients Sampling
Nutrient samples were collected from seven bay stations and seven local river stations on October 19th. Most of the bay stations, except for Phillipsdale Landing, were sampled at the surface and bottom. In the five days prior to sampling, 1.10 inches of rainfall was 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 @ Broad St. The TN, TDN, and DIN at this site were 1,340 ppb, 1,200 ppb, and 922 ppb, respectively. The lowest TN, TDN, and DIN were observed at Moshassuck River at Higginson Ave. The TN, TDN, and DIN at this site were 488 ppb, 493 ppb, and 226.3 ppb, respectively.
Among the bay stations sampled, the highest surface nitrogen concentrations were observed at Pawtuxet Cove. The TN, TDN, and DIN at this site were 1,300 ppb, 1,180 ppb, and 908 ppb, respectively. The lowest surface nitrogen concentrations were observed at Bullock Reach Buoy. The TN, TDN, and DIN at this site were 759 ppb, 563 ppb, and 376 ppb, respectively. Chlorophyll a concentrations at the surface bay stations were low, averaging 1.52 ug/L across all sites. The maximum result (2.62 ug/L) occurred at Bullock Reach Buoy.
Results from nutrient sampling in November through December are pending analysis. The next scheduled sample date is January 25th.
Week of October 2-8, 2022
Nutrients Sampling
Nutrient samples were collected from thirteen local and border river stations and one bay station (Phillipsdale Landing) on October 5th. Phillipsdale Landing was sampled at the surface and bottom. In the five days prior to sampling, 1.38 inches of rainfall was 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 Blackstone River at Bikepath Bridge. Results at this site (average of duplicates) for TN, TDN, and DIN were 2,140 ppb, 2,280 ppb, and 1,920 ppb, respectively. The lowest TN and TDN were observed at Runnins River at River Road. The TN and TDN were 530 ppb and 517 ppb, respectively. The lowest DIN, observed at Coles River at Milford Rd., was 31.6 ppb.
The Phillipsdale Landing bay sample had TN, TDN, and DIN surface results of 1,200 ppb, 1,220 ppb, and 849 ppb, respectively. Chlorophyll a concentration at Phillipsdale Landing decreased from 53.60 ug/L to 2.71 ug/L since the previous sampling event.
Results from nutrient sampling in late October through December are pending analysis. The next scheduled sample date is January 25th.
Week of January 8 - 14, 2023
Water Column Clarity
Water clarity was measured at six locations in the Providence River estuary on January 10. Rainfall totaling 0.18 inches was recorded at TF Green in the five days prior to the survey. Secchi depth averaged 3.3 meters, compared to 4.2 meters on the previous survey (November 29, 2022). The lowest clarity this week (2.6 meters) was measured at India Point Park, while the greatest clarity (4.2 meters) was measured at Conimicut Point. There was a general north-to-south gradient of increasing water clarity among the sites this week.
