Ritzrau, W, Thomsen, L, Lara, RJ and Graf, G (1997) Enhanced microbial utilisation of dissolved amino acids indicates rapid modification of organic matter in the benthic boundary layer. Marine Ecology Progress Series, 156 . pp. 43-50. DOI https://doi.org/10.3354/meps156043.

Text Lara.pdf - Published Version Download (742kB)

Abstract

Recent information on activity, abundance, and size of bacteria as well as concentration and composition of particles in the benthic boundary layer (BBL, range of water depths 191 to 479 m) was compared to the distribution of these parameters in 2 layersof the water column, the chlorophyll maximum layer (range of water depths 13 to 25 m) and the intermediate water depth (IWC, range of water depths 136 to 486 m). Microbial activities and concentrations of various biochemical parameters displayed distinctvariation patterns in the BBL, exhibiting higher values compared to their variations in the chlorophyll maximum layer and the IWC. In the BBL the microbial utilisation of 14C-amino acids revealed no correlation with concentrations ofparticulate organic carbon (POC), but was related to chlorophyll a (chl a) equivalents and the ratio of POC and chl a equivalents. The distribution of dissolved free amino acids (DFAA) suggests that not necessarily the concentrationbut alternatively the accessibility (concentration and transport rate) of DFAA to bacteria determines heterotrophic activity. Results indicate that the BBL represents a distinct environment with rapid modification of organic matter prior to its finalincorporation into the sediment.

Document Type:	Article
Programme Area:	PA Not Applicable
Research affiliation:	Ecology > Mangrove Ecology
Refereed:	Yes
Open Access Journal?:	No
DOI:	https://doi.org/10.3354/meps156043
ISSN:	0171-8630
Date Deposited:	05 Nov 2025 11:51
Last Modified:	05 Nov 2025 11:51
URI:	https://cris.leibniz-zmt.de/id/eprint/5949

Actions (login required)

View Item