engleski

Reorganization of the microbial food web structure associated with the rise in temperature: a case study of the Adriatic Sea

Along the eastern Adriatic coast sea surface temperature (SST) increased by an average of 1.03 °C during the period from 1979 to 2015, while in the recent period, starting from 2008, a strong upward almost linear trend of 0.013 °C/month was noted. During this period, SST increased by 1.25 oC. In the present study, Self-Organizing Map (SOM) procedure was used in analyzing time series (1997-2015) of a number of microbial parameters at two stations with different trophic status in the central Adriatic Sea. The rise in temperature was associated with: (1) the increasing importance of microbial heterotrophic activities and (2) the increasing importance of autotrophic picoplankton (APP) in the MFW. The temperature increase was accompanied with increase of bacterial growth, bacterial biomass turnover, bacterial predator abundances (particularly HNF) and grazing on bacteria, suggesting strong top-down control and increase in the proportion of bacterial carbon channelled to higher trophic levels. Simultaneously, autotrophic picoplankton (APP) biomass (including Synechococcus, Prochlorococcus and picoeukaryotes) significantly increased with temperature, suggesting that APP have a great potential as an additional carbon biomass that can be channelled towards higher levels in the warming conditions.

Microbial food web ; Global warming ; Long-term data ; Self-Organizing Map Analysis ; Adriatic Sea

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