The opportunistic collection of the flocculent layer, over the spring to late summer seasons, has provided information on the seasonal dinoflagellate cyst sedimentation in Koljo Fjord, on the west coast of Sweden. The dinoflagellate cyst assemblages within the flocculent layer can be both diverse and contain many cysts. The cyst assemblages do not remain constant over time but demonstrate seasonality. Our very limited dataset of six samples suggests that the spring bloom is characterised by round, brown Protoperidinium cysts together with subsidiary Pentapharsodinium dalei and Protoperidinium conicum. The early summer assemblage differs in containing higher proportions of P. dalei with fewer round, brown Protoperidinium cysts together with relatively minor amounts of Lingulodinium polyedrum and Polykrikos schwartzii. The late summer cyst flora is co-dominated by Lingulodinium polyedrum and round, brown Protoperidinium cysts, together with minor amounts of P. dalei and Spiniferites spp. including Spiniferites bentorii. Cyst production within the different species occurs at times of the year when the surface water conditions within the fjord are suitable. This probably reflects, all or in part, the stability of the upper water column, the relative availability of nutrients and the overall phytoplankton productivity. (C) 2004 Elsevier B.V. All rights reserved.
