Lake nutrient experiment

Matched enclosures receive 0, 5, or 20 mg/L added nitrate. Mean algal chlorophyll is 8, 21, and 62 units; dissolved oxygen at dawn is 8.2, 6.4, and 2.9 mg/L.

1. More nitrate corresponds to more algae.
2. High algae aligns with low dawn oxygen.
3. Respiration and decomposition can consume oxygen.