The study of transparent exopolymer particles (TEP) in the Mediterranean Sea is particularly relevant as they can be promoters of mucilage events, a frequent phenomenon there. We assessed the influence of bacterioplankton on TEP distribution and dynamics across the west-east axis of the Mediterranean Sea. We performed an extensive study of TEP, dissolved carbohydrates, and their relationships with bacterial abundance and bacterial production (BP). A significant and positive relationship was observed between BP and TEP in the study region (r2 = 0.51, p < 0.001). The direct release of TEP by bacteria was experimentally corroborated using regrowth cultures where increases in TEP tracked bacterial growth in abundance and production. These TEP increases were positively related to the increases in BP (r2 = 0.78, p < 0.05). The consistency (similar slopes) of the regression lines between BP and TEP in natural conditions and between the increases of BP and TEP in the experiments underlines the relevant role of bacteria in the formation of TEP in this area.
Bibliographical noteFunding Information:
We thank the captain and crew of R/V “García del Cid” and the Marine Technology Unit for their help in the sampling and experimental setup. We thank R. Santiago for the TOC and chl a analyses. We also acknowledge R.A. Reynolds for improving the English and the anonymous reviewers for the insightful comments to a previous version of this manuscript. This work was funded by the Spanish Ministry of Science and Technology (THRESHOLDS complementary action ref. CTM2005-24238-E to CMD and DISPAR CGL2005-00076 to IR). E.O.-R. was supported by fellowships from the Spanish Ministry of Science and Education and the University of Granada.
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Soil Science