Historical News
R/V Monitor's Blog
On Wednesday, May 8th, the crew of the R/V Monitor was out on the upper Bay collecting nutrients samples, taking Secchi Disk water clarity measurements, and conducting water column profiles using the Seabird instrument, all in an effort to document water quality improvements associated with NBC construction projects. Real-time surface mapping of water quality parameters and Par water clarity measurements were not conducted due to equipment issues. Jeff captained the boat while monitoring professionals Mike, Fern and Dan collected the samples and data. It was a mostly clear day with some white puffy clouds, and a light breeze from the northwest and calm waters. The photo below highlights the Seabird instrument used for water column profiling.
Phytoplankton Sampling
Phytoplankton samples were collected on April 24, 2019 at Bullock's Reach and analyzed in the laboratory shortly after collection. It was a delightful, sunny, and calm day on Narragansett Bay with a strong outgoing tide. Sondes data revealed the surface water temperature was 12.60oC, salinity was 13.89 psu, and chlorophyll a was 5.87 ug/L. The plankton tow net sample was filterable with a 20 micron mesh. The filtrate was a light brown color with a medium filter time. The tow net sample was analyzed qualitatively for microorganisms using 100x phase contrast microscopy. The whole water sample was analyzed quantitatively under 200x phase contrast microscopy. A Hensen Stempel pipette was used to accurately deliver 1ml of sample to a Sedge-wick Rafter chamber. This analysis revealed a total of 415,000 cells per Liter. The most predominant phytoplankton was Skeletonema spp. at 110,000 cells/L. The flagellates were found at 74,000 cells/L. Representative genera include Thalassiosira spp. and Thalassionema spp.
200x phase contrast micrograph of Striatella spp.
Fixed Site Network
Phillipsdale
This week at Phillipsdale, sonde data revealed good water quality. There was about 0.60 inches of rainfall, however, flow from the Blackstone River was greatly above average and peaked on the 28th. This high riverflow had a substantial impact on Phillipsdale water quality keeping both bottom and surface salinities below 1.0 psu until the 29th. Overall, surface salinity increased slightly this week, with an average of 1.2 psu, a minimum of 1 psu, and a maximum of 6.6 psu. Bottom salinity fluctuated with the tides after the 29th when river flow decreased and had an overall weekly average of 7.0 psu and a range of 0.1 psu – 28.1 psu. Surface and bottom temperatures increased slightly over the week with surface temperatures averaging 12.0oC with a range of 10.5oC – 14.3oC; bottom temperatures had an average of 11.4oC and ranged between 9.7oC – 13.0oC. Dissolved oxygen (DO) for the week was very good at both the surface and the bottom; surface DO had an average of 10.7 mg/L and a range of 8.9 mg/L – 12.2 mg/L. Dissolved oxygen in the bottom waters had a weekly average of 9.7 mg/l and ranged from a minimum of 6.5 mg/L to a maximum of 12.2 mg/L. Chlorophyll was very low this week with a weekly average of 0.9 ug/L. Note that tidal fluctuations and Blackstone River flow greatly influence bottom DO, temperature and salinity at this location.
Bullock Reach
The Bullock Reach buoy is expected to be deployed on May 9 with the assistance of RIDEM.
R/V Monitor's Blog
On Wednesday, May 1st, the crew of the R/V Monitor was out on the upper Bay collecting bacteria samples and taking Secchi Disk water clarity measurements in an effort to document water quality improvements associated with NBC construction projects. Par sensor water clarity measurements, water column profiles and real-time surface mapping of water quality parameters were not done due to equipment issues. Sara captained the boat while monitoring professionals Michael and Fern collected the samples and data. It was a cool and mostly cloudy day with no wind and extremely calm waters. The photo below highlights the beautiful skyline and calm waters.
Phytoplankton Sampling
Phytoplankton samples were collected on April 10, 2019 at Bullock's Reach and analyzed in the laboratory shortly after collection. It was an overcast and cool day on Narragansett Bay. Sondes data revealed the surface water temperature was 8.70oC and salinity was 22.89 psu. The plankton tow net sample was filterable with a 20 micron mesh. The filtrate was a tan color with a short filter time. The tow net sample was analyzed qualitatively for microorganisms using 100x phase contrast microscopy. The whole water sample was analyzed quantitatively under 200x phase contrast microscopy. A Hensen Stempel pipette was used to accurately deliver 1ml of sample to a Sedge-wick Rafter chamber. This analysis revealed a total of 1,030,000 cells per Liter. The most predominant phytoplankton was Leptocylindrus spp. at 520,000 cells/L. Representative genera include Chaetoceros spp. and Thalassiosira spp.
200x phase contrast micrograph of Thalassiosira spp.
