Walkers Point
Sondes were swapped this week on the morning of July 14th (surface sonde) and 15th (bottom sonde). Overall, the water quality at Walkers Point was good to fair this week. Weather conditions included light rain events this week, with 0.69 inches of precipitation recorded at T.F. Green. Surface salinity averaged 21.6 ppt and ranged from 10.3 ppt to 28.3 ppt. At the bottom, salinity averaged 25.6 ppt and ranged from 20.5 ppt to 28.7 ppt. Temperatures averaged 24.2°C at the surface and 23.8°C at the bottom. Surface temperatures ranged from 22.9°C to 26.5°C, while bottom temperatures ranged from 22.6°C to 24.7°C.
Dissolved oxygen (DO) at Walkers Point remained above the hypoxia threshold (i.e., DO>2.9mg/L) at the surface, but dropped below the hypoxia threshold at the bottom depth. The longest periods of hypoxic conditions spanned 7 hours and 45 minutes, occurring at the bottom depth on the morning of July 16th. During this period, the DO averaged around 2.05 mg/L. Surface DO averaged 6.9 mg/L and ranged from 3.2 mg/L to 14.5 mg/L. Bottom DO concentrations averaged 3.6 mg/L and ranged from 0.1 mg/L to 7.1 mg/L. Chlorophyll readings averaged 13.6 µg/L at the surface and 12.7 µg/L at the bottom. Maximum chlorophyll at the surface reached 94.8 µg/L on the afternoon of July 14th.
Bullock Reach
Overall, water quality was good to fair at Bullock Reach this week. Salinity averaged 28.2 ppt, 29.9 ppt, and 31.0 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 26.1 – 29.9 ppt, middle salinity range 27.6 – 30.9 ppt, and bottom salinity ranged 17.7 – 31.9 ppt. Surface temperature averaged 24.1°C and ranged from 23.1°C to 25.5°C. Middle temperature averaged 23.6°C and ranged from 22.7°C to 24.6°C. Bottom temperatures averaged 22.9°C and ranged from 20.5°C to 24.0°C.
Dissolved oxygen (DO) at Bullock Reach remained above the hypoxia threshold (i.e., DO>2.9mg/L) at the at all depths this week. Surface DO averaged 7.8 mg/L and ranged 5.1 – 11.4 mg/L. Middle DO averaged 6.2 mg/L and ranged 4.4 – 10.2 mg/L. At the bottom, DO averaged 5.2 mg/L and ranged 3.2 – 7.5 mg/L. Chlorophyll readings ranged from low to elevated throughout the week. Readings averaged 13.8 µg/L at the surface, 15.4 µg/L at the middle, and 12.5 µg/L at the bottom. The maximum surface chlorophyll was 30.2 µg/L on the afternoon of July 17th.