Historical News

Week of May 19 - 25, 2019

R/V Monitor's Blog

​On Wednesday, May 22nd, the crew of the R/V Monitor was out on the upper Bay collecting nutrients 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 Mike and Steve collected the samples and data.  It was a brisk, partly cloudy, day with a strong wind out of the northwest, making the water very choppy.  The below photo was taken from the east side of India Point looking westward.

5-21-19.jpg 

Week of May 12 - 18, 2019

Fixed Site Network

Phillipsdale
This week at Phillipsdale, sonde data revealed good water quality. Sondes were switched out for routine maintenance on May 14. There was about 1.85 inches of rainfall, mostly at the beginning of the week, with still above average but steadily decreasing riverflow from the Blackstone River. Overall, surface and bottom salinity decreased slightly this week, with surface salinity remaining mostly under 9 psu for the entire week. The average surface salinity was 4.8 psu with a minimum of 1.9 psu, and a maximum of 9.0 psu. Bottom salinity fluctuated with the tides and had an average of 16.9 psu and a range of 4.2 psu – 28.1 psu. Surface and bottom temperatures had a slight increase over the week, though colder than the previous week with surface temperatures averaging 13.6oC with a range of 11.3oC – 16.9oC; bottom temperatures had an average of 12.3oC and ranged between 10.3oC – 15.4oC. Dissolved oxygen (DO) for the week was good at both the surface and the bottom and increased over the course of the week; surface DO had an average of 9.3 mg/L and a range of 7.8 mg/L – 10.3 mg/L. Dissolved oxygen in the bottom waters had a weekly average of 7.6 mg/l and ranged from a minimum of 6.1 mg/L to a maximum of 10.2 mg/L. Chlorophyll was increased this week as compared to last week with a weekly average of 3.2 ug/L at the surface and 1.2 ug/L at the bottom. Note that tidal fluctuations and Blackstone River flow greatly influence bottom DO, temperature and salinity at this location.

Bullock Reach
The buoy at Bullock Reach was deployed on May 9. It is anticipated that the sondes will be deployed at the buoy the week of May 19th.

Week of May 19 - 25, 2019

Surface Mapping

​Data was collected on May 21, 2019 while the R/V Monitor was underway collecting nutrient samples and performing vertical profiles in the Providence and Seekonk River estuaries. The chlorophyll concentrations were low in areas surveyed. From north to south, average chlorophyll concentrations were as follows: Seekonk River (2.91 µg/l), Upper Providence River (2.44 µg/l), Edgewood Shoals area (2.52 µg/l), Pawtuxet River area (2.08 µg/l), and the Lower Providence River (2.75 µg/l). Overall, chlorophyll ranged between non-detectable and 5.90 µg/l with an overall average of 2.56 µg/l. The chlorophyll data from this date is presented in the map below:

Dataflow 2019-05-21_small.jpg 

Week of May 12 - 18, 2019

Water Column Clarity

Water clarity was measured at eight locations in the Providence and Seekonk Rivers on May 15, 2019. In the five days prior to sampling, 1.81 inches of rainfall was recorded, with over 0.8 inches of rainfall occurring on both May 12 and May 13. Light rain was reported the morning of sampling. Average water clarity decreased from the previous week, from 2.5 m to 2.4 m.

Water clarity increased at India Point Park, Pomham Rocks, and Edgewood Yacht Club. Water clarity decreased at Pawtuxet Cove, Bullock Reach, and Conimicut Point. The largest increase in clarity, 0.93 m, occurred at Pomham Rocks. Secchi depth ranged from 1.07 m at Phillipsdale Landing to 3.43 m at Pomham Rocks. A north to south water clarity gradient was not observed.

Week of May 5- 11, 2019

Fixed Site Network

​Phillipsdale
This week at Phillipsdale, sonde data revealed good water quality. There was about 0.87 inches of rainfall, mostly at the beginning of the week, and above average but decreasing riverflow from the Blackstone River. Overall, surface salinity decreased slightly this week, and remained mostly under 10 psu for the entire week; the average surface salinity was 3.9 psu with a minimum of 0.9 psu, and a maximum of 10.2 psu. Bottom salinity fluctuated with the tides and had an average of 14.4 psu and a range of 1.1 psu – 29.6 psu. Surface and bottom temperatures increased on average by about 3 – 4.0oC over the week with surface temperatures averaging 14.5oC with a range of 11.9oC – 17.6oC; bottom temperatures had an average of 12.9oC and ranged between 9.7oC – 16.9oC. Dissolved oxygen (DO) for the week was very good at both the surface and the bottom; surface DO had an average of 9.1 mg/L and a range of 8.1 mg/L – 9.8 mg/L. Dissolved oxygen in the bottom waters had a weekly average of 7.7 mg/l and ranged from a minimum of 6.2 mg/L to a maximum of 9.6 mg/L. Chlorophyll was very low this week with a weekly average of 0.7 ug/L. Note that tidal fluctuations and Blackstone River flow greatly influence bottom DO, temperature and salinity at this location.

Bullock Reach
The buoy at Bullock Reach was deployed on May 9. It is anticipated that the sondes will be deployed at the buoy the week of May 19th.

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