Nitrous oxide emissions from sea animal colonies in the maritime Antarctic

Little is known about nitrous oxide (N 2 O) emissions from wild animal colonies. N 2 O fluxes were measured from a penguin colony on Ardley Island, a seal and skua colony on Fildes Peninsula in the maritime Antarctic using a static chamber technique. Mean fluxes from penguin, skua and seal colonies were 856, 132 and 189 μ g N 2 O‐N m −2 h −1 , respectively. The deposition of sea animal excreta controls spatial variations of N 2 O fluxes from the colonies. The highest fluxes (2559, 2836 and 2081 μ g N 2 O‐N m −2 h −1 for penguin puddles, seal wallows and skua puddles, respectively) occurred during the freezing‐thawing period. Laboratory experiments showed that the freezing‐thawing cycle induced a flush of N 2 O from the soils sampled from the colonies and denitrification was the predominant process for the N 2 O source. We proposed that sea animal colonies represent the strong point sources of N 2 O in the maritime Antarctic.