Dissimilatory nitrate reduction processes in surface sediments of shrimp ponds during the culture period

Intensive aquaculture in estuaries and coasts has resulted several ecological environmental problems. Among various nitrogen transformation pathway, dissimilatory nitrate (NO 3 - ) reduction is considered to be highly important regulating reactive nitrogen. However, there are relatively few studies on the processes contribution of NO x sediment during shrimp pond culture period. Three processes, denitrification (DNF), anaerobic ammonium oxidation (ANA), (DNRA), were surveyed eight ponds across three subtropical using 15 N isotope tracing experiments. The rates DNF, ANA DNRA ranged from 2.87–18.11, 0.10–1.92, 0.21–1.25 nmol g -1 h , respectively. DNF was responsible for 64.2–91.6% total reduction. Regarding factors, C substrates, as well salinity, significantly affected In general, losses approximately 32.43–131.64 m -2 yr 2.38–15.85 this study, indicating that coastal reclamation a nonnegligible way remove Our results provide scientific foundation understanding mechanism cycling artificial aquatic environment ponds.