engleski

Changes in seasonal pattern of bacteria and heterotrophic nanoplankton in the open Adriatic Sea

Time series of bacterial abundance and production as well as abundance of heterotrophic nanoplankton (HNAN) in the open middle Adriatic Sea were analysed. The time series of studied parameters, consisted of monthly values from 1997-2006 period, were decomposed to obtained seasonal, trend/cycle and irregular components. The relationship between obtained seasonal and trend/cyclic patterns and the fluctuations in a number of environmental factors (temperature, salinity, oxygen saturation, nitrate, ammonium ion, total dissolved inorganic nitrogen, orthophosphate, N/P ratio) was analysed. Comparison between 1997-2001 and 2002-2006 periods showed: (1) marked changes in seasonal components of all studied parameters ; (2) significant changes in contributions of seasonal and trend/cycle components in explaining of the total time series variability ; and (3) changes in environmental factors with which bacteria and HNAN were correlated.

heterotrophic bacteria; heterotrophic nanoplankton; seasonal pattern; Adriatic Sea

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