Historical News
Water Column Clarity
Water clarity was measured at five locations in the Providence River and Seekonk Rivers on September 10, 2020. On the day of the survey there was 0.03 inches of recorded rainfall, with no recorded rainfall in the three days prior. Water clarity increased slightly compared to the previous survey day. Overall, sites surveyed averaged 1.36 meters Secchi depth, compared to 1.35 meters on September 2. The lowest clarity (0.83 m) was measured at the India Point Park site, while the greatest clarity (1.77 m) was measured at the Conimicut Point site. Overall, a gradient of increasing clarity from north to south was observed among the sites.
Water Column Clarity
Water clarity was measured at seven locations in the Providence and Seekonk Rivers on September 2, 2020. On the day of the survey there was 0.42 inches of recorded rainfall, with no recorded rainfall in the three days prior. Water clarity decreased slightly compared to the previous survey day. Overall, sites surveyed averaged 1.35 meters Secchi depth, compared to 1.95 meters on August 19. The lowest clarity (0.90 m) was measured at the Phillipsdale Landing site, while the greatest clarity was measured at the Bullock's Reach site (2.03 m). Overall, a gradient of increasing clarity from north to south was observed among the sites.
Bacteria Sampling
Twenty stations were sampled for fecal coliform in the Providence and Seekonk Rivers on September 16, 2020. Five of these stations were also sampled for enterococci bacteria. Conditions leading up to the September 16 sampling day were dry with no recorded rainfall over the five days prior.
The geometric mean of fecal coliform results for all sites was 21 MPN/100 mL, with Seekonk River sites having higher counts than Providence River sites (geometric means of 93 and 10 MPN/100 mL, respectively). The maximum count (430 MPN/100 mL) was measured at three sites; Division St. Dock and Bishop Point in the Seekonk River and Point St. Bridge in the Providence River. Fecal coliform results in the Providence River were within the state standards for primary contact and shellfishing, however, results from the Seekonk River exceeded both state standards.
The enterococci results increased from the previous sampling event, from an overall geomean of 11 MPN/100 mL to 18 MPN/100 mL. Enterococci results ranged from <10 MPN/100 mL at Gaspee Pt. to 116 MPN/100 mL at Point St. Bridge site. Enterococci results from both the Seekonk and Providence Rivers exceeded state primary contact standards.
Please note: the results of NBC's fecal coliform and enterococci monitoring are for informational/research purposes only and are not to intended to suggest official state compliance with bathing or shellfishing standards.
Surface Mapping
Data
were collected on September 16, 2020 while the R/V Monitor was underway
collecting bacteria samples and performing vertical profiles in the Providence
and Seekonk River estuaries. The chlorophyll concentrations were good to fair in
the areas surveyed. From north to south, average chlorophyll concentrations
were as follows: Seekonk River (12.55 µg/L), Upper Providence River (8.90 µg/L), Edgewood Shoals area (7.37
µg/L), Pawtuxet River area (8.37 µg/L), and Lower Providence River area (5.42
µg/L). Overall, chlorophyll ranged between 2.20 µg/L and 21.60 µg/L with an
overall average of 8.69 µg/L. The chlorophyll data from this date are
presented in the map below:
R/V Monitor's Blog
On Wednesday, September 16th, the crew of the R/V Monitor was out on the upper Bay collecting bacteria samples, taking Secchi Disk and Par sensor water clarity measurements, conducting water column profiles using the Seabird instrument, 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 Bekki, Gerard and Sara collected the samples and data. In the afternoon, Jeff captained the boat while the crew serviced the temporary buoy located in Pawtuxet Cove and collected a chlorophyll sample at that site. The day started brisk with little wind and a hazy sky. By afternoon, the sun broke through the haze, warming the air up nicely and a Southwest wind developed. The featured photo is of a kayaker enjoying the day by Phillipsdale landing in the Seekonk River.
