LI Sound Water Quality: Not Bad for August
Bottom water dissolved oxygen concentrations were below 4.8 mg/L at 27 stations with 3 of those stations falling below 3.5 mg/L and none falling below 3.0 mg/L compared to 2009 when 34 stations were below 4.8 mg/L, 24 of those stations were below 3.5 mg/L and 15 stations were below 3.0 mg/L. The lowest concentration was observed at Station D3 (3.12 mg/L). In 2009 the lowest concentration was at A4 (1.49 mg/L).
The area of bottom water affected by hypoxia (DO <3.5 mg/L) is 33.9 square miles (87.9 sq. km). The area of bottom water with DO values below 3.5 mg/L was 33.9 square miles (87.9 sq. km), well below the ten year average of 217.6 sq mi (563.7 sq km), and no stations were observed to have values below 3.0 mg/L. Cooler than average temperatures and an east wind the week prior to our survey helped dissolved oxygen levels rebound, preventing the severe hypoxia normally observed this time of year. The average area affected by hypoxia from 1999-2010 was 217.6 sq mi (563.7 sq km).