Walkers Point
Overall, the water quality at Walkers Point was good to fair this week. Weather conditions included light rain events this week, with 2.09 inches of precipitation recorded at T.F. Green. Surface salinity averaged 20.5 ppt and ranged from 10.0 ppt to 27.5 ppt. At the bottom, salinity averaged 20.5 ppt and ranged from 10.0 ppt to 27.5 ppt. Temperatures averaged 22.4°C at the surface and 21.3°C at the bottom. Surface temperatures ranged from 20.8°C to 25.7°C, while bottom temperatures ranged from 20.1°C to 22.6°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 depths. The longest periods of hypoxic conditions spanned 20.25 hours, occurring at the bottom depth from the night of June 24th to the afternoon of June 25th. During this period, the DO averaged around 2.46 mg/L. Surface DO averaged 7.0 mg/L and ranged from 3.5 mg/L to 12.8 mg/L. Bottom DO concentrations averaged 3.0 mg/L and ranged from 1.2 mg/L to 5.2 mg/L. Chlorophyll readings averaged 10.34 µg/L at the surface and 3.43 µg/L at the bottom. Maximum chlorophyll at the surface reached 37.45 µg/L on the afternoon of June 27th.
Bullock Reach
Sondes were swapped this week on the morning of June 24th. Overall, water quality was good to fair at Bullock Reach this week. Salinity averaged 28.8 ppt, 30.0 ppt, and 20.6 ppt at the surface, middle, and bottom sondes, respectively. Surface salinity ranged 26.6 – 30.1 ppt, middle salinity range 28.1 – 31.6 ppt, and bottom salinity ranged 30.52 – 32.8 ppt. Surface temperature averaged 22.1°C and ranged from 20.8°C to 24.7°C. Middle temperature averaged 21.4°C and ranged from 19.6°C to 23.4°C. Bottom temperatures averaged 19.3°C and ranged from 18.1°C to 22.1°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 depths. The longest periods of hypoxic conditions spanned 1 hours, occurring at the bottom depth from the night of June 28th. During this period, the bottom DO averaged around 2.82 mg/L. Surface DO averaged 7.5 mg/L and ranged 5.8 – 10.2 mg/L. Middle DO averaged 6.2 mg/L and ranged 4.1 – 8.2 mg/L. At the bottom, DO averaged 4.5 mg/L and ranged 2.6 – 8.1 mg/L. Chlorophyll readings ranged from low to elevated throughout the week. Readings averaged 10.7 µg/L at the surface, 13.3 µg/L at the middle, and 12.7 µg/L at the bottom. The maximum bottom chlorophyll was 45.7 µg/L on the morning of June 26th.