PROSTORNA I VREMENSKA RASPODJELA DINOFLAGELATNIH CISTA U RIJEČKOM ZALJEVU

Encystment of dinoflagellate cysts is driven by two major factors: (1) species life cycle and (2) a resistant stage to overcome unfavourable conditions. The main vector for spreading of the cysts is by ships' ballast water. In the Rijeka Bay area five stations have been selected for sampling, which was carried out in 2011, 2014 and 2015. In total, 32 species of dinoflagellate cysts, sorted in five orders were identified. A seasonal pattern in the total abundance was observed along with the seasonal pattern of several species. The cysts with higher abundancies are believed to be formed from the vegetative stages, thus considered autochthonous, in the water column, or have been introduced by ballast water and subsequently spread, thus considered alochthonous. The cysts with lower abundancies and the ones that have been recorded desultorily are believed to be introduced by ballast water. In order to 70 further understand the composition and dynamics of cyst populations in Rijeka Bay additional research needs to be conducted in conjunction with experiments on cysts in regards to biotic and abiotic factors characterising the area.