Denitrification in coastal bay sediment: regional and seasonal variation in Aarhus Bight, Denmark

Abstract

The seasonal pattern of denitnfication achmty was studied in sediment from 3 stalons in the Aarhus Bight, Denmark At all 3 stations, a dramahc increase In den~trificat~on activity was found in early spnng coincident wlth sedimentation of the spring phytoplankton bloom The maximum of activity was followed by decllnlng rates in the early summer and low and relatively constant rates throughout the rest of the year For the 3 sedlments the total range of denltrlfication actlvity was <0 05 to 0 5, 0 05 to 0 7 and 0 2 to 1 0 mm01 N m-' d-', respectively, and the total annual activity 35 70 and 180 mm01 N yr stations, throughout the year highest activlt~es were observed in the most organic-nch sediment and lowest were observed in the relatively organic-poor sediment Results ~ndicate that annual denitnflca- bon may increase in response to hlgher nutnent load and primary ploduction in the coastal sea '