MEPS 172:13-24 (1998)  -  doi:10.3354/meps172013

ABSTRACT: Denitrification in the sediments of the open northern Baltic Sea was measured using the isotope pairing method. The highest denitrification activity was found in the central Gulf of Finland, where denitrification varied between 150 and 650 µmol N m^-2 d^-1. The bulk of the denitrification was coupled to the NO₃^- production by nitrification. The mass of benthic fauna was found to be the most significant factor affecting the rate of denitrification. Denitrification rate was highest in late summer and early autumn. Calculated as an average for the Gulf of Finland, the denitrification rate obtained in the present study is 45 kt N yr^-1. This gives a release of ca 30% of the external N input by denitrification.

KEY WORDS: Denitrification · Baltic Sea · Isotope pairing method · Sediment