Walkers Point
Overall, the water quality at Walkers Point was good to fair this week. Weather conditions were dry this week, except for 1.88 inches of precipitation recorded at T.F. Green on July 25th. Surface salinity averaged 15.9 ppt and ranged from 6.3 ppt to 27.4 ppt. At the bottom, salinity averaged 26.4 ppt and ranged from 21.8 ppt to 29.5 ppt. Temperatures averaged 24.2°C at the surface and 23.7°C at the bottom. Surface temperatures ranged from 22.3°C to 26.7°C, while bottom temperatures ranged from 22.8°C to 24.3°C.
Dissolved oxygen (DO) at Walkers Point remained above the hypoxia threshold (i.e., DO>2.9mg/L) at the surface but dropped below at the bottom depth. The longest periods of hypoxic conditions spanned 49 hours and 46 minutes, occurring at the bottom depth between the evening of July 23rd and July 25th. During this period, the DO averaged around 1.59 mg/L. Surface DO averaged 10.4 mg/L and ranged from 4.7 mg/L to 18.7 mg/L. Bottom DO concentrations averaged 2.6 mg/L and ranged from 0.2 mg/L to 6.0 mg/L. Chlorophyll readings averaged 22.0 µg/L at the surface and 12.4µg/L at the bottom. Maximum chlorophyll at the surface reached 92.6 µg/L on the morning of July 24th.
Bullock Reach
Sondes were swapped this week on the morning of July 23rd. Overall, water quality was good to fair at Bullock Reach this week. Salinity averaged 27.6 ppt, 29.4 ppt, and 30.3 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 24.8 – 29.6 ppt, middle salinity range 26.1 – 31.2 ppt, and bottom salinity ranged 14.5 – 31.7 ppt. Surface temperature averaged 23.9°C and ranged from 22.9°C to 25.5°C. Middle temperature averaged 23.5°C and ranged from 22.0°C to 25.1°C. Bottom temperatures averaged 22.9°C and ranged from 22.0°C to 23.7°C.
Dissolved oxygen (DO) at Bullock Reach remained above the hypoxia threshold (i.e., DO>2.9mg/L) at all the depths. Surface DO averaged 9.3 mg/L and ranged 5.7 – 15.0 mg/L. Middle DO averaged 6.8 mg/L and ranged 4.1 – 11.7 mg/L. At the bottom, DO averaged 5.24 mg/L and ranged 3.79 – 7.22 mg/L. Chlorophyll readings ranged from low to elevated throughout the week. Readings averaged 13.2 µg/L at the surface, 16.5 µg/L at the middle, and 6.87 µg/L at the bottom. The maximum surface chlorophyll was 29.6 µg/L on the night of July 23rd.