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Forty-two different dinoflagellate cyst types were found in recent sediment samples collected between July 1999-September 2002 from 44 stations along the eastern coast of Russia. This represents the first survey of recent dinoflagellate cysts in Russian marine waters. Forty cysts were identified to the species level, representing 17 genera. The most common cysts were those of ellipsoidal Alexandrium spp., Protoceratium reticulatum, Gonyaulax spp., Polykrikos kofoidii, P. schwartzii, Protoperidinium americanum, P. minutum, P. conicoides, P. subinerme, P. conicum and Scrippsiella trochoidea. Fifteen of the dinoflagellate species have not previously been recorded as motile cells in Russian marine waters: Alexandrium cf. minutum, Cochlodinium cf. polykrikoides, Diplopsalis cf. lebourae, Fragilidium mexicanum, Gonyaulax elongata, G. membranaceae, Gymnodinium cf. catenatum, Pentapharsodinium dalei, P. tyrrhenicum, Protoperidinium americanum, P. cf. avellanum, Scrippsiella cf. lachrymosa, S. cf. precaria, S. cf. rotunda and Warnowia cf. rosea. Cysts of the potentially toxic species Alexandrium cf. minutum, A. tamarense and Gymnodinium cf. catenatum were also found in this survey. Ellipsoidal Alexandrium tamarense type cysts were widely distributed and dominated many localities in the study area. These data suggest that additional cyst surveys should be conducted in areas of the eastern Russian coastline not yet investigated, and that the potential for paralytic shellfish poisoning toxicity as a result of blooms of toxic species may be more widespread than previously documented.

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Preliminary studies on dinoflagellates epiphytic on macrophytes in a bight of Peter the Great Bay, Sea of Japan revealed the presence of two species of the genus Ostreopsis, O. cf. ovata and O. cf. siamensis. Morphometric features, such as the length of the pore plate, and thecal ornamentations were used for species identification. The two species differed from each other in cell size and the length of the pore plate. Cells of O. cf. ovata were smaller in length and width, with a dorsoventral diameter of 36-60 mm and a width of 24-45 mm, in comparison with the cells of O. cf. siamensis, which were 63-78 mm in dorsoventral diameter and 36-54 mm in width. Cells of O. cf. siamensis are slightly flattened in comparison with O. cf. ovata; the dorsoventral to anteroposterior diameter ratio varied from 1.9 to 2.7 for O. cf. ovata and from 1.8 to 3.5 for O. cf. siamensis. The length of the pore plate in O. cf. ovata (6.3-8.3 mm) is shorter than that in O. cf. siamensis (11-13 mm), while the diameter of the thecal pores in O. cf. ovata and O. cf. siamensis overlapped markedly (0.12-0.25 mm and 0.16-0.20 mm, respectively). The two species were presentfrom August to October at water temperatures of 7-258C on almost all macrophytes collected. The maximum abundance of Ostreopsis spp. reached 10,970 cells g -1 dry weight in late September at a water temperature of 98C. This is the first occurrence of the genus Ostreopsis in Russian waters, which are characterized by cold temperatures during the winter season.