Historical News
Nutrients Sampling
Fixed Site Network
Phillipsdale Landing
Water quality was good this week at Phillipsdale Landing. This week was drier than last week, with 0.69 inches of precipitation recorded at TF Green Airport, however, the impact of nearly 2 inches of rainfall occurring on December 14 was evident in the early portion of the week. Surface and bottom salinity generally remained low through December 15 and 16 and began to increase through the remainder of the week. Surface salinity averaged 3 ppt, ranging from 0.2 to 8.1 ppt, while bottom salinity averaged 11.2 ppt, ranging from <1 ppt to 28 ppt.
Water temperatures at both depths continued to cool; surface temperatures for the week averaged 2.8°C, with a maximum value of 5.2°C, and bottom temperatures averaged 4.0°C, with a maximum value of 6.6°C. Flows of cool Blackstone River water (<3°C) continued to influence surface temperatures. Dissolved oxygen (DO) concentrations continue to remain above the hypoxia threshold (> 2.9 mg/L) at both depths. Average DO concentrations were greater than those reported last week, with surface DO averaging 13.5 mg/L, with a minimum of 12.6 mg/L, and bottom DO averaging 11.8 mg/L, with a minimum of 14.1 mg/L. Surface chlorophyll-a remained low this week, averaging 2.7 ug/L with a maximum of 4.9 ug/L. Note that tidal fluctuations and Blackstone River flow greatly influence water column DO, temperature, and salinity at this location.
Bullock Reach
Please note, the Bullock Reach sondes were removed for the 2019 monitoring season on November 19.
Fixed Site Network
Phillipsdale Landing
Water quality was good this week at Phillipsdale Landing. Please note, sondes were changed out for routine maintenance during the morning of December 10. Over the course of the week, 4.53 inches of precipitation occurred, with approximately 1.9 inches of precipitation occurring on December 9 and December 14. In response to the heavy rainfall, surface salinity decreased over the course of the week, hitting a minimum of 0.6 ppt on December 14 and averaging 4.5 mg/L this week. Average bottom salinity was also lower than the previous week, averaging 15.9 ppt and ranging from 1.0 ppt to 30.0 ppt. Water temperatures at both depths remained cool; surface temperatures for the week averaged 4.0°C and bottom temperatures averaged 5.5°C. Inputs of cool Blackstone River water following high-magnitude precipitation events resulted in decreases in surface temperature, and similar surface and bottom temperatures and salinity were observed at various times throughout the week.
Dissolved oxygen (DO) concentrations continued to remain above the hypoxia threshold (> 2.9 mg/L) at both depths. Surface DO averaged 12.9 mg/L, with a minimum of 10.8 mg/L and bottom DO averaged 10.6 mg/L with a minimum of 8.0 mg/L. Surface chlorophyll-a remained low all week, averaging 2.4 ug/L with a maximum of 4.8 ug/L. Note that tidal fluctuations and Blackstone River flow greatly influence water column DO, temperature, and salinity at this location.
Bullock Reach
Please note, the Bullock Reach sondes were removed for the 2019 monitoring season on November 19.
Water Column Clarity
Water clarity was measured at six locations in the Providence River on December 4, 2019. Approximately 1.4 inches of rainfall occurred over the three days prior to the survey. The average Secchi depth increased clarity since the last survey on November 4, from 2.4 m to 3.2 m. India Point Park is the only site that exhibited decreased clarity since the previous survey, down 0.2 m. Four sites exhibited increase clarity, the greatest of which was seen at both Conimicut Point and Ponham Rocks (up 0.93 m). The remaining site (Edgewood Shoals) had not been surveyed recently. Water clarity ranged from 2.5 m at India Point Park to 3.6 m at Conimicut Point. Overall, water clarity in Upper Narragansett Bay increased from north to south.
Fixed Site Network
Phillipsdale Landing
Water quality was good this week at Phillipsdale Landing. During the first three days of the week, 1.2 inches of precipitation occurred, with the daily maximum, 0.76 inches, measured on December 1. Surface salinity generally decreased over the course of the week, particularly following December 3 in response to the early-week precipitation. Surface salinity was lower than the previous week, averaging 8.71 ppt and ranging from 1.9 ppt to 16.1 ppt. Bottom salinity averaged 23.3 ppt and ranged from 5.0 ppt to 30.1 ppt. Water temperatures at both depths continued to cool into the first week of December; surface temperatures for the week averaged 3.6°C and bottom temperatures averaged 6.7°C. Dissolved oxygen (DO) concentrations continued to remain above the hypoxia threshold (> 2.9 mg/L) at both depths. Surface DO averaged 12.2 mg/L, with a minimum of 9.8 mg/L and bottom DO averaged 10.4 mg/L with a minimum of 7.1 mg/L. Surface chlorophyll-a remained low all week, averaging 1.8 ug/L with a maximum of 3.6 ug/L. Note that tidal fluctuations and Blackstone River flow greatly influence water column DO, temperature, and salinity at this location.
Bullock Reach
Please note, the Bullock Reach sondes were removed for the 2019 monitoring season on November 19.
