Historical News

Week of November 17 - 23, 2019

Nutrients Sampling

Nutrient samples were collected at seven local river stations and seven bay stations (surface and bottom) on November 20, 2019. The sampling day was preceded by approximately 0.25 inches of rainfall over the two days prior.

Among the river stations sampled, highest total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) were observed in the sample from the Ten Mile River at Roger Williams Avenue, at 1,680 ppb, 1,760 ppb, and 1,440.6 ppb, respectively. The lowest TN (631 ppb) and TDN (345 ppb) results were observed at the Pawtuxet River at Broad Street, though results from the Moshassuck River at Higginson Avenue were similarly low (641 ppb and 360.5 ppb, respectively, average of duplicates). DIN results were also lowest at these two sites, with 206.2 ppb at the Pawtuxet River and 162.9 ppb (average of duplicates) at the Moshassuck River.

Among the bay stations sampled, the greatest TN (1,055 ppb) and DIN (774.5 ppb) in surface waters occurred at Pawtuxet Cove (average of duplicates); the highest TDN (912 ppb) occurred at Phillipsdale Landing. The lowest surface TN (468 ppb), TDN (217 ppb), and DIN (198.8 ppb) occurred at India Point Park.

Results from sampling on December 4 and 18 are pending analysis. The next scheduled date of sampling is January 2, 2020.

Week of November 3 - 9, 2019

Nutrients Sampling

Nutrient samples were collected at fourteen local and border river stations and eight bay stations on November 6, 2019; most bay stations were sampled at the surface only, with Edgewood Shoal sampled at the surface and bottom. The sampling day was preceded by approximately half an inch of rainfall on the day before.

Among the river stations sampled, highest total nitrogen (TN), total dissolved nitrogen (TDN), and dissolved inorganic nitrogen (DIN) were observed in the sample from the Ten Mile River at Central Avenue site, at 1,880 ppb, 1,960 ppb, and 1,617.9 ppb, respectively. The lowest TN and TDN values occurred in the samples from the Moshassuck River at Higginson Avenue, with results of 433 ppb and 459 ppb; the lowest DIN results were from Coles River at Milford Road, at 78.6 ppb (average of duplicates).

Among the bay stations sampled, the greatest TN (1,170 ppb), TDN (1,010 ppb), and DIN (773 ppb) in surface waters occurred at Phillipsdale Landing. The lowest surface TN (605 ppb), TDN (290 ppb), and DIN (244.5 ppb) occurred at Edgewood Shoal (average of duplicates).

Results from sampling on November 20 and December 4 and 18 are pending analysis. The next scheduled date of sampling is January 2, 2020.

Week of December 1 – 7, 2019

Water Column Clarity

​Water clarity was measured at six locations in the Providence River on December 4, 2019.  Approximately 1.4 inches of rainfall occurred over the three days prior to the survey.  The average Secchi depth increased clarity since the last survey on November 4, from 2.4 m to 3.2 m.  India Point Park is the only site that exhibited decreased clarity since the previous survey, down 0.2 m.  Four sites exhibited increase clarity, the greatest of which was seen at both Conimicut Point and Ponham Rocks (up 0.93 m). The remaining site (Edgewood Shoals) had not been surveyed recently.  Water clarity ranged from 2.5 m at India Point Park to 3.6 m at Conimicut Point.  Overall, water clarity in Upper Narragansett Bay increased from north to south.

Week of November 24 – November 30, 2019

Fixed Site Network

Phillipsdale Landing

Water quality was good this week at Phillipsdale Landing.  The sondes were changed out for routine maintenance on the morning of November 26.  Approximately 1.6 inches of precipitation was recorded over the week, with most of the rain occurring on November 24.  Surface salinity decreased at Phillipsdale in response to the precipitation and increase in freshwater flow from the Blackstone River.  Surface salinity averaged 11.1 ppt and ranged from 2.2 ppt to 24.1 ppt while bottom salinity averaged 21.2 ppt and ranged from 6.4 ppt to 29.3 ppt. Compared to the rest of the November, the water temperatures at both depths continued to cool.  Surface temperatures for the week averaged 6.8°C and bottom temperatures averaged 8.1°C.  Dissolved oxygen (DO) concentrations continue to be good for the week, remaining above the hypoxia threshold (2.9 mg/L) at both depths. Surface DO averaged 10.9 mg/L with a minimum of 8.3 mg/L and bottom DO averaged 9.2 mg/L with a minimum of 7.8 mg/L. Surface chlorophyll-a remained low all week, averaging 2.1 ug/L with a maximum of 5.4 ug/L. Note that tidal fluctuations and Blackstone River flow greatly influence water column DO, temperature, and salinity at this location.

Bullock Reach

Due to remote data transfer issues, there are no current Bullock Reach data available since October 19.  The data are being internally logged by the sondes, and will be updated to the blog as they become available.

Please note, the Bullock Reach sondes were removed for the 2019 season on November 19.

Week of December 1 - 7, 2019

R/V Monitor's Blog

​On Wednesday, December 4th, the crew of the R/V Monitor was out on the upper Bay collecting nutrients 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.  Sara captained the boat while monitoring professionals Mike and Fern collected the samples and data.  It was a very cloudy day with no wind.  A heavy fog in the early morning resulted in a delay getting underway.  The photo featured this day shows Field's Point in the foreground with the City of Providence in the background.

12-4-19.jpg 

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