Rates of Nitrogen Regeneration in the Water Column

Here we review published rates of NH4 regeneration and DON release in the water column. In general, these rates were measured in small volume incubations ( 4 L) run for 1—24 h and could represent release due to many of the mechanisms discussed above for phytoplankton, bacteria, zooplankton, viruses and detritus. There have been two recent reviews of DON release rates in the field (Bronk, 2002 and Berman and Bronk, 2003) and so here we focus on the literature of the last ten years. There have been no similar reviews for NH4 regeneration, however, and so we extend coverage back to the 1980s, when the isotope dilution technique to measure NH4 regeneration was introduced (Glibert et al., 1982). 

Rates of NH4 regeneration generally exceed DON release as observed in studies in Chesapeake Bay (Bronk et al., 1998 Ward and Bronk, 2001), Monterey Bay (Bronk and Ward, 1999 Ward and Bronk, 2001), the Gulf of Lions (Diaz and Raimbault, 

Total DON release Log-Total DON release Log-DON release (from NH4 Log-DON release (from NH4 Log-DON release (from NOs DON release (from NH4+) DON release (from NH4+) DON release (from NOs ) DON release (from NOs ) 

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