Tatiana Yu. Orlova

Dinoflagellate cysts in recent marine sediments from the east coast of Russia

Abstract 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.

Morphogenetic and toxin composition variability of Alexandrium tamarense (Dinophyceae) from the east coast of Russia

T.Y. Orlova, M.S. Selina, E.L. Lilly, D.M. Kulis and D.M. Anderson. 2007. Morphogenetic and toxin composition variability of Alexandrium tamarense (Dinophyceae) from the east coast of Russia. Phycologia 46: 534–548. DOI: 10.2216/06-17.1 Twenty-seven clones were established from elongate Alexandrium sp. cysts collected in six regions along the Russian Pacific coast. All isolates were identified as Alexandrium tamarense via detailed epifluoresence microscopy of thecal plates. Morphological differences of both cultured and wild cells from the study regions mainly occurred in the shape of the cell (length/width ratio), degree of development of the sulcal list, and the shape of the posterior sulcal (S.p.) and second antapical (2″″) plates. Cells were divided into two cell types: ‘short’ (isodiametrical or wide) and ‘tall’. Each cell type exhibits specific features of tabulation, mainly the shape of the S.p. and 2″″ plates and was dominant in each particular region of the study. The short type, with a wide S.p. and reduced length in the dorsoventral 2″″ plates, was characteristic of A. tamarense from Primorye and southern Sakhalin Island. The tall cells, i.e., with cell length exceeding width, and having and elongate S.p. and dorsoventrally elongate 2″″ plates, prevailed in Avachinskaya Guba Inlet and in the Bering Sea. The differences reported here between the two types are within the range of morphological variability of A. tamarense sensu Balech, 1995. The D1–D2 fragment of the large subunit nuclear ribosomal DNA was analyzed for 24 clones. Alexandrium tamarense from the Russian Pacific coast compose three genetically distinct populations that correspond to the Japanese temperate Asian, eastern North American, and western North American ribotypes of the ‘tamarensis’ complex. The presence and distribution of eastern and western North American ribotypes along the Russian Pacific coast suggest that dispersion to the temperate Asian region occurred long ago via natural currents and processes, and not through human-mediated introductions, as has been proposed. No strict correlation was observed between different morphological types of cells and ribotypes. High-performance liquid chromatography toxin analyses showed that all isolates were toxic and demonstrated variability in toxin content and composition among different populations. These data document the significant and previously uncharacterized risk of shellfish contamination with paralytic shellfish poisoning toxins from blooms of A. tamarense in Russian marine waters.

The genus Chaetoceros (Bacillariophyta) from Peter the Great Bay, Sea of Japan

Abstract Several studies in the Sea of Japan have dealt with the taxonomy, morphology and ecology of Chaetoceros species. In this study, a total of 33 Chaetoceros taxa was recorded between 1991 and 2004 from the phytoplankton of Peter the Great Bay, in the northwestern part of the Sea of Japan. This investigation was based on light and electron microscopy. Chaetoceros minimus is a new record for the Pacific Ocean, C. compressus var. hirtisetus is a new record for the seas of Russia, and C. socialis f. radians is a new record for the northwestern Sea of Japan. Diagnostic descriptions, illustrations and distribution are provided for all 33 Chaetoceros taxa from the study area.

Toxicity, morphology and distribution of Pseudo-nitzschia calliantha, P. multistriata and P. multiseries (Bacillariophyta) from the northwestern Sea of Japan

Toxicity, morphology and distribution patterns of three bloom-forming species of the diatom genus Pseudo-nitzschia (potential producers of the neurotoxin domoic acid and causative organisms of amne ...

Diversity of Pseudo-nitzschia H. Peragallo from the western North Pacific

A survey focusing on species belonging to the diatom genus Pseudo-nitzschia was conducted in the western North Pacific (the northwestern Sea of Japan and the Sea of Okhotsk). Light and electron microscopic examination of 314 phytoplankton field samples collected from 1995 to 2006 revealed the presence of 11 Pseudo-nitzschia species: P. americana, P. cf. caciantha, P. calliantha, P. delicatissima/arenysensis, P. fraudulenta, P. cf. heimii, P. multiseries, P. multistriata, P. obtusa, P. pungens and P. seriata. Detailed morphological descriptions and illustrations as well as distributional data are provided for all 11 Pseudo-nitzschia taxa. The study presents a taxonomical baseline investigation of Pseudo-nitzschia from the western North Pacific and provides distributional data from an area otherwise not thoroughly examined earlier. Morphological deviation from the current description of P. cf. heimii, P. obtusa and P. caciantha is presented. It is established that P. calliantha, P. multistriata, P. multiseries and P. pungens occur in bloom proportions and are widely distributed in the Sea of Japan and the Sea of Okhotsk. In the literature, P. seriata is characterized as being restricted to the northern hemisphere where it occurs in the North Atlantic Ocean exclusively. The current study, however, documents that P. seriata is found in the North Pacific and hence is widespread in the northern hemisphere. One species, P. cf. caciantha, is a new record for the western North Pacific, whereas two others, P. cf. heimii and P. multistriata, are new records for the Sea of Okhotsk. The geographical distribution of P. cf. caciantha, P. multistriata and P. obtusa in the North Pacific is expanded by the current study.

Attheya ussurensis sp. nov. (Bacillariophyta)—a new marine diatom from the coastal waters of the Sea of Japan and a reappraisal of the genus

I.V. Stonik, T.Yu. Orlova and R.M. Crawford. 2006. Attheya ussurensis sp. nov. (Bacillariophyta)—a new marine diatom from the coastal waters of the Sea of Japan and a reappraisal of the genus. Phycologia 45: 141–147. DOI: 10.2216/04-48.1 A new species of the mainly sand-dwelling marine diatom genus Attheya is described from the Sea of Japan. Of the seven species of the genus, Attheya ussurensis most closely resembles Attheya decora in its valve and girdle structure and in its plastid form and number, but it also possesses features found in one or other of the remaining species (presence of a rimoportula, pores in the girdle bands and horn morphology). Keys are provided to aid ide.gification of all known Attheya species.

Diarrhetic Shellfish Toxins in Primorsky Krai, Russia

ABSTRACT Mariculture and recreational zones are expanding rapidly along the coast of Primorsky Krai in the Russian Far East, increasing the pressing need for monitoring of toxin-producing algae and seafood poisoning. One poisoning syndrome, diarrhetic shellfish poisoning has not been reported in this region, but its expansion to other subarctic waters has been observed. To our knowledge, the research here shows the first measures of diarrhetic shellfish toxins (DST) on the east coast of Russia. Mussels contained DST concentrations above the recommended regulatory level of 16 mg/100 g shellfish at almost all sites sampled in the Primorsky Krai region, with maximum concentrations of 56.3 mg/100 g. The primary DST isoform was dinophysistoxin-1 (DTX-1; 94%-100%) but minor amounts of okadaic acid (0%-6%) also were detected. Other lipophilic toxins measured in shellfish were yessotoxin , pectenotoxin-2 (PTX-2), and azaspiracid-2; the last two toxins observed in Russian water for the first time. Phytoplankton samples dominated by Dinophysis acuminata contained DST, indicating that it was likely responsible for shellfish toxicity. Particulate seawater samples with Dinophysis contained 2.1–10.2 ng DTX-1/l and 6.5–101.8 ng PTX-2/l, corresponding to cellular concentrations of 3.1–5.6 pg DTX-1/cell and 9.6–46.7 pg PTX-2/cell. These findings provide a foundation for a Federal Monitoring Program for harmful algal blooms and phycotoxin control in seafood in Russia, and suggest that appropriate methods for both rapid screening and regulation of shellfish toxins should be established to ensure safe harvest in Russia.

Phytoplankton and Primary Production

The northern part of the East Sea (Japan Sea) is dominated by the cold waters of the Liman Current, whereas in the southern part, the dominant current is the Tsushima Warm Current. Together with these major current systems, subpolar fronts and mesoscale eddies that form in the region exert a strong influence on the phytoplankton ecosystem in the East Sea. These conspicuous physical forcings are manifested as often clearly discernible features in temporal and spatial distributions, composition, abundance, biomass and production of phytoplankton. In short, diatoms and dinoflagellates are found to be the most diverse phytoplankton groups and are occasionally responsible for blooms in coastal waters. Diatoms are also abundant in frontal areas and in the rings of warm core eddies. Picophytoplankton groups are also found to be important phytoplankton in the East Sea, especially in warm seasons, and photosynthetic picoeukaryotes and Synechococcus show distinct seasonal and vertical distribution patterns. Recent field measurements indicated that the spatial distribution of primary productivity in the Ulleung Basin (UB) of the East Sea ranged from 172 to 358 g C m−2 year−1. This range of primary productivity is relatively higher than in other regions in the East Sea. The East Sea is a body of dynamic “non-oceanic” water with its own particular oceanic characteristics. Coastal upwelling and mesoscale eddies over a wide range of horizontal scales contribute to the high primary productivity in the UB. This vibrant primary production provides the foundation for a biological “hot” spot and strong support for an energetic biological pump cycle in the East Sea. Despite much progress in expanding knowledge of phytoplankton ecology in the East Sea, more studies on diversity, productivity, niche, and physiological adaptation to dynamic environments should be conducted to better understand ecological roles of phytoplankton in changing oceans.

Morphology and molecular phylogeny of Pseudohaptolina sorokinii sp. nov. (Prymnesiales, Haptophyta) from the Sea of Japan, Russia

Abstract: An under-ice brown water discolouration in coastal waters of Vladivostok, the northwestern Sea of Japan, during March 2013 was caused by a bloom of haptophyte algae initially identified as Chrysochromulina sp. Seawater samples collected near the edge of the ice hole contained aggregations of haptophytes with concentrations up to 7.4 × 107 cells·l−1 (99.8% of the total density of phytoplankton). Detailed morphological studies conducted by light microscopy and transmission electron microscopy methods and molecular analyses based on nuclear-encoded small-subunit [18S ribosomal (r)DNA] gene sequences were performed on an environmental isolate (PB2013) to determine its systematic position. The characteristic structure of the covering body scales of our specimens was similar to Chrysochromulina birgeri found earlier from Finland and Japan. However, the scale morphology of our specimens and C. birgeri was not identical, and the sequence of C. birgeri was not known. The molecular signature indicated the systematic position of our specimens as belonging to the genus Pseudohaptolina. The value of rDNA divergence (p) between PB2013 and P. arctica, a single known species of Pseudohaptolina, was 0.011 (1.1%); this value falls within the same order of magnitude used to distinguish species-level differences in other Prymnesiales. On this basis, we proposed the new species Pseudohaptolina sorokinii sp. nov.

Scrippsiella trochoidea cysts in recent sediments from Amur Bay, Sea of Japan: distribution and phylogeny

Abstract A study of vertical distribution of dinoflagellate cysts in recent sediments was conducted for the first time in the Far Eastern seas of Russia. Dinoflagellate cysts were studied in sediment cores retrieved from five stations in Amur Bay (Peter the Great Bay, Sea of Japan) in 2010 and 2013. The Scrippsiella trochoidea complex was the dominant type of cyst, the average proportion of which (in the entire sediment cores) reached 39% of the total cyst abundance. The maximum abundance of S. trochoidea complex reached 5513 cysts g-1 dry sediment. Cysts of the S. trochoidea complex were found to remain viable in the sediments after exposure to sub-zero temperatures. The identification of S. trochoidea in the Far Eastern seas of Russia was first confirmed by using biomolecular genetic analyses. The study of vertical distribution showed that cysts of this species dominate the upper sediment layers (0–10 cm). A tendency for abundance to increase from the shore toward the middle part of the bay was observed in the spatial distribution of cysts.