Sezonska dinamika autotrofne zajednice u Limskom kanalu (Sjeverni Jadran)

This work describes the dynamics of the autotrophic plankton community in Lim Bay in the north-eastern part of the Adriatic Sea from June 2008 to September 2009. There was an evident shift between microphytoplankton and picophytoplankton domination in summer and autumn periods, while nanophytoplankton contributed negligibly. Picophytoplankton dominated in June 2008 and September 2009 (contributing up to 84 % of the total phytoplankton biomass), while the micro- fraction dominated in September 2008 and June 2009 (contributing up to 97.2 % of the total biomass). The pico- fraction was dominated by Synechococccus in terms of abundance and biomass, with the highest abundances in September of 2009. Picoeukaryotes were not that prominent in terms of abundance or biomass, but they exceeded Synechococcus in terms of biomass in November 2008 and February 2009, and proved to be an important and consistent component of the Lim Bay phytoplankton community. Our results indicate that seasonal variability in the community structure was more affected by specific environmental perturbations occurring in Lim Bay than by availability of nutrients.
Ovaj rad opisuje dinamiku autotrofne zajednice u Limskom kanalu, u sjevero-istočnom dijelu Jadranskog mora od lipnja 2008 do rujna 2009. Tijekom ljeta i jeseni jasno je uočena promjena u dominaciji biomase između mikrofitoplanktona i pikofitoplanktona, pri čemu je doprinos nanofitoplanktona bio zanemariv. Pikofitoplankton prevladavao je u lipnju 2008 i rujnu 2009 (do 84% doprinosa ukupnoj fitoplanktonskoj biomasi), dok je mikro-frakcija prevladavala u rujnu 2008 i lipnju 2009 (do 97.2% doprinosa ukupnoj biomasi). Unutar piko-frakcije prevladavale su cijanobakterije roda Synechococcus, kako brojnošću tako i biomasom, s najvećim vrijednostima u rujnu 2009. Međutim, u studenom 2008 i veljači 2009 pikoeukarioti su biomasom premašili populaciju cijanobakterija Synechococcus, čime su se pokazali kao važna komponenta zajednice fitoplanktona Limskog kanala. Rezultati ovog istraživanja su pokazali da je sezonska varijabilnost u strukturi zajednice podložnija utjecaju određenih perturbacija u okolišu nego dostupnosti nutrijenata.