Historical News
R/V Monitor's Blog
On Thursday, May 24th, the crew of the R/V Monitor was out on the upper Bay collecting nutrients and plankton 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 Stephen and Heather collected the samples and data. It was a beautiful warm and sunny day with no wind and calm waters in the morning. It became a bit breezy in the afternoon with a wind out of the north, making the water slightly choppy. The photo below features someone fishing from the bank of the Seekonk River.
Water Column Clarity
Water clarity was measured at eight locations in the Providence and Seekonk Rivers on May 16, 2018. A total of 0.71 inches of rain occurred during the five days prior to sampling. Overall, average clarity increased from the previous week by 0.2 m, to 1.9 m. The largest increase (0.9 m) was observed at Conimicut Point. Secchi depth ranged from 1.4 m at India Point Park to 2.4 m at Bullock Reach. There was a very slight north to south water clarity gradient.
Water Column Profiles
Fixed Site Network
Phillipsdale
This week at Phillipsdale, data revealed good water quality. Over the course of the week there was a total rainfall of 1.4 inches with an increased Blackstone River flow as compared to the prior week, particularly on the 16th. Surface salinities increased over the course of the week and were higher than in the previous few weeks. Overall, surface salinity averaged 7.7 psu with a minimum of 1.9 psu, and a maximum of 15.0 psu. Bottom salinity fluctuated with the tides over the course of the week with an average of 17.4 psu and a range of 3.6 psu – 24.5 psu. Surface and bottom temperatures actually decreased slightly as compared to the prior week with surface temperatures averaging 16.3oC with a range of 14.3oC – 19.4oC and bottom temperatures averaging 13.9oC and ranged between 10.0oC – 17.9oC. Surface chlorophyll was increased as compared to the previous week with a weekly average of 7.6 ug/L, and a daily average peak of about 15.0 ug/L. Dissolved oxygen (DO) for the week was good at both the surface and the bottom though slightly decreased from previous weeks; surface DO had an average of 8.6 mg/L and a range of 6.8 mg/L – 11.7 mg/L. Dissolved oxygen in the bottom waters had a weekly average of 7.1 mg/l and ranged from a minimum of 4.6 mg/L to a maximum of 10.7 mg/L. Note that tidal fluctuations and Blackstone River flow greatly influence bottom DO, temperature and salinity at this location.
Bullocks Reach
Staff is currently testing and preparing new equipment for deployment for the 2018 season. It is anticipated that the station will be operational again for the season in May or June. The buoy is set for deployment in conjunction with RIDEM on May 22nd, though water quality equipment will be deployed at a later date.
Fixed Site Network
Phillipsdale
This week at Phillipsdale, data revealed good water quality. Over the course of the week there was minimal rainfall totaling 0.28 inches with a decreased Blackstone River flow as compared to the prior week. Surface salinities were still quite low and remained below 6.0 psu for most of the week, until the end of the week. Overall, surface salinity averaged 2.8 psu with a minimum of 1.2 psu, and a maximum of 10.3 psu. Bottom salinity fluctuated with the tides over the course of the week with an average of 14.2 psu and a range of 1.4 psu – 26.4 psu. Surface and bottom temperatures increased by approximately 1 - 2oC as compared to last week with surface temperatures averaging 17.9oC with a range of 15.4oC – 20.5oC and bottom temperatures averaging 14.2oC and ranged between 9.2oC – 19.2oC. Surface chlorophyll was increased as compared to the previous week with a weekly average of 5.1 ug/L, with a daily average peak of about 9.0 ug/L. Dissolved oxygen (DO) for the week was good at both the surface and the bottom though slightly decreased from previous weeks; surface DO had an average of 9.6 mg/L and a range of 7.6 mg/L – 13.7 mg/L. Dissolved oxygen in the bottom waters had a weekly average of 7.6 mg/l and ranged from a minimum of 5.8 mg/L to a maximum of 10.8 mg/L. Note that tidal fluctuations and Blackstone River flow greatly influence bottom DO, temperature and salinity at this location.
Bullock Reach
Staff is currently testing and preparing new equipment for deployment for the 2018 season. It is anticipated that the station will be operational again for the season in May or June. The buoy is set for deployment in conjunction with RIDEM on May 22nd, though water quality equipment will be deployed at a later date.
