Week of May 6 - 12, 2012
Fixed Site Network
Phillipsdale: With the onset of warmer weather, surface temperatures began to increase this week averaging 14.7oC, increasing nearly 2oC from the previous week, and ranging from 12.5oC – 18.0oC. Chlorophyll concentrations were similar to the prior week averaging 7.4µg/L over the entire week but began decreasing towards the end of the week. Dissolved oxygen (DO) concentrations were also similar to the previous week and averaged 9.1 mg/l and ranged from a high of 12.6 mg/l to a low of 7.4 mg/l. With the spring tides surface salinity fluctuated greatly at the beginning of the week, but became less variable around the 10th. Bottom temperatures were similar to the surface averaging 14.2oC and ranging from 12.6oC to 16.8oC. Bottom salinity fluctuated depending on the tide, ranging from a maximum of 28.7 ppt to a low of 3.6 ppt. Dissolved oxygen at the bottom was slightly lower than surface DO, averaging 7.9 mg/l and ranging from 4.9 mg/l to 12.3 mg/l.
Bullock’s Reach: The Bullock's Reach buoy is being deployed on Tuesday May 15th. Sondes are expected to be in place by the end of the week.
Week of May 6 - 12, 2012
Water Column Profiles
On May 9th, six water column profiles were collected throughout the Upper Bay, from Phillipsdale Landing south to Conimicut Point. A very well mixed water column was evident in the three stations visited in the morning (9:30 – 10:30 am), Conimicut Point, Bullock’s Reach and Pomham Rocks. The depths at these stations are relatively deep (7 – 12 m) and the dissolved oxygen (DO) concentrations remained approximately 8 mg/L throughout the water column. Later in the afternoon (1:00 – 2:00 pm), water column profiles were collected at the remainder of the stations, Edgewood Yacht Club, India Point Park, and Phillipsdale Landing. At the two shallower stations, Edgewood and Phillipsdale, the water column remained relatively well mixed with DO concentrations of 7.5 mg/L, slightly less than other stations. At India Point Park, the water column was slightly stratified at 4.5 m, with increasing salinity and decreasing temperature in the bottom layer of water. The DO concentrations remained at 8 mg/L until 7 m in depth where it decreased to 7.5 mg/L at the bottom (9 m).
Week of May 6 - 12, 2012
R/V Monitor's Blog
On Wednesday, May 9th, the R/V Monitor was out on the Bay collecting nutrients and chlorophyll samples, taking Secchi Disk and Par senor water clarity measurements, conducting water column profiles using the Seabird instrument, and conducting real-time surface mapping of water quality paramters, including dissolved oxygen, chlorophyll, water temperature, salinity, and pH, all in an effort to monitor water quality. Captain Sara was with monitoring professionals Bekki and Marcos this day. It was raining and the water was choppy, but manageable. There was not much activity at all observed on the Bay this day. Below is a photo of Field's Point as seen from the East.
Week of May 6 - 12, 2012
Water Column Clarity
On May 9th, six water clarity measurements were collected throughout the Providence River estuary. The weather was rainy with a light wind. Moderate precipitation on the days leading up to the sampling date caused a decline in water clarity at all but one of the measurement locations (Bullock’s Reach rose from 1.50m to 1.70m). The greatest decline in clarity was at India Point Park, with measurements falling from 1.37m to 0.98m. Pomham Rocks and Phillipsdale Landing also experienced substantial declines in clarity, each falling by 0.25m to 1.15m and 0.87m, respectively. This Phillipsdale Landing measurement was also the lowest water clarity reading recorded on May 9th. The Edgewood Yacht Club, which last week was the only location to show a decline in clarity, continued to fall from 1.42m to 1.28m. Finally, the smallest drop in clarity was at Conimicut Point, where the measurement fell from 1.60m to 1.47m.
Week of May 6-12, 2012
Surface Mapping
Data was collected on May 09, 2012 while the R/V Monitor was underway collecting nutrient samples in the Seekonk River and Providence River estuaries. Chlorophyll concentrations ranged between 0.5 and 35.5 ug/l. Raw chlorophyll concentrations measured by the YSI sonde indicated the average chlorophyll concentration was 12.5 ug/L. The chlorophyll was highest in the southern portion of the Providence River. The chlorophyll data from this date is presented in the map below:
