Particulate DNA and protein relative to microorganism biomass and detritus in the Catalano-Balearic sea (NW mediterranean) during stratification

Using microscopic and biochemical approaches, the relative contribution of the main groups of pelagic microorganisms (bacteria, heterotrophic nanoflagellates, phytoplankton and ciliates) and detritus (<150 μm) to total particulate protein and DNA was investigated at two stations of the Catalano-Balearic Sea (NW Mediterranean) during the stratified period. The two stations, one located in the shelf break front (S) and the other in the open sea, above the central divergence zone (D), were sampled twice in early summer 1993. Both of them showed a well-developed deep chlorophyll maximum (DCM). Maximum DNA concentrations were observed close to the DCM, while protein concentrations were fairly homogeneous from the surface to 60 m depth in all samplings. In general, the microorganism distribution showed maximum concentrations at or near the DCM depths. At both stations, bacteria were the most important contributors to living particulate DNA (22.5-32.6%), while phytoplankton and heterotrophic nanoflagellates were the main contributors to living particulate protein (3.8-24.4 and 2.9-29.1%, respectively). In addition, an important amount of detrital DNA and protein was estimated to occur at both stations. Detrital DNA accounted for 23.9-42.9% of the particulate DNA, while detrital protein represented from 63.5 to 84.7% of the particulate protein. Because both protein and DNA contain nitrogen and DNA is also a phosphorus source, these results indicate that heterotrophic organisms and detrital particles play an important role in the nitrogen and phosphorus cycles in the open sea waters of the NW Mediterranean

Bibliographic Details

Main Authors:	Arin, Laura, Berdalet, Elisa, Marrasé, Cèlia, Estrada, Marta, Guixa-Boixareu, Núria, Dolan, J.
Other Authors:	European Commission
Format:	artículo biblioteca
Published:	Oxford University Press 1999-07
Online Access:	http://hdl.handle.net/10261/256141 http://dx.doi.org/10.13039/501100000780 http://dx.doi.org/10.13039/501100002809
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