To establish if highly eutrophic lakes generate higher N 2 O emissions than non‐eutrophic aquatic environments in New Zealand, we monitored N 2 O emissions from hypereutrophic Lake Horowhenua, near Levin, and the oligotrophic Turitea dam reservoir, near Palmerston North, used as control. Based on more than 12 months of monitoring data, N 2 O emissions from Lake Horowhenua were estimated to −0.05–6.93 mg‐N 2 O·m −2 ·d −1 ( n =...