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A new marine woloszynskioid dinoflagellate Dactylodinium pterobelotum gen. et sp. nov., collected from a southern Vietnamese estuary, was described on the basis of LM, SEM, and TEM, and molecular phylogeny inferred from rDNA sequences. This species had the smallest number of amphiesmal vesicles (5 latitudinal series) in woloszynskioid dinoflagellates assigned to the Suessiaceae and Borghiellaceae. The eyespot was of type B, composed of osmiophilic globules and brick-like material, located in- and outside of the chloroplast respectively. An apical structure comprised a pair of elongate anterior vesicles (PEV). A large peduncle was conspicuous, located in the sulcal extension in the epicone, and supported by a microtubular strand of ~140 microtubules. Ultrastructural features of trichocysts represent a novel type in the Dinophyceae, bearing lateral hairs besides anterior fibers. The molecular phylogeny based on partial LSU rDNA showed the species in a basal position in the family Suessiaceae; this indicates the eyespot type B and PEV of the Borghiellaceae are ancestral states of the eyespot comprising brick-like material (type E) and an elongate apical vesicle of the Suessiaceae.

Proceedings of the Horiba International Conference "New Direction of Ocean Research in the Western Pacific" : Past, Present and Future of UNESCO/IOC/WESTPAC Activity for 50 years and the JSPS Project "Coastal Marine Science", Section I: Research Articles/Harmful microalgae

Proceedings of the Horiba International Conference "New Direction of Ocean Research in the Western Pacific" : Past, Present and Future of UNESCO/IOC/WESTPAC Activity for 50 years and the JSPS Project "Coastal Marine Science", Section I: Research Articles/Harmful microalgae

Author Posting. © Elsevier B.V., 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Marine Pollution Bulletin 56 (2008): 1049-1056, doi:10.1016/j.marpolbul.2008.03.010., The proposed plan for enrichment of the Sulu Sea, Philippines, a region of rich marine biodiversity, with thousands of tonnes of urea in order to stimulate algal blooms and sequester carbon is flawed for multiple reasons. Urea is preferentially used as a nitrogen source by some cyanobacteria and dinoflagellates, many of which are neutrally or positively buoyant. Biological pumps to the deep sea are classically leaky, and the inefficient burial of new biomass makes the estimation of a net loss of carbon from the atmosphere questionable at best. The potential for growth of toxic dinoflagellates is also high, as many grow well on urea and some even increase their toxicity when grown on urea. Many toxic dinoflagellates form cysts which can settle to the sediment and germinate in subsequent years, forming new blooms even without further fertilization. If large-scale blooms do occur, it is likely that they will contribute to hypoxia in the bottom waters upon decomposition. Lastly, urea production requires fossil fuel usage, further limiting the potential for net carbon sequestration. The environmental and economic impacts are potentially great and need to be rigorously assessed., This paper was developed under the Global Ecology and Oceanography of Harmful Algal Blooms (GEOHAB) core research project on HABs and Eutrophication and the GEOHAB regional focus on HABs in Asia. GEOHAB is supported by the International Oceanographic Commission (IOC) of UNESCO and by the Scientific Committee on Oceanic Research (SCOR), which are, in turn, supported by multiple agencies, including NSF and NOAA of the USA.

Pyrodinium bahamense var. compressum (Pbc) is one of the causative species of Paralytic Shellfish Poisoning (PSP). Incidents of PSP and red tides caused by Pbc are increasing, as well as the geographic distribution of Pbc expanding in Southeast Asia, where it has recently occurred in several areas that previously have not experienced blooms, such as Ambon Bay and Lampung Bay in Indonesia. Five factors including anthropogenic activities, natural activities, visual realization with red tide discoloration, development of techniques like RNA sequence and ELISA toxin kits, and the establishment of a regular monitoring system have been suggested to have led to the increase in reports of dinoflagellate blooms. Occurrence of dinoflagellate cysts in sediments has been used as evidence to which species of vegetative cells occurred in the water column. In this study, the vertical distribution of dinoflagellate cysts in sediments was investigated to confirm the first occurrence of Pbc cysts and to examine the floral changes of dinoflagellate cysts in Ambon Bay and Hurun Bay, Indonesia. In Ambon Bay, Pbc cysts first occurred in ca. 1850 and the cysts were continuously observed since ca. 1870. In Hurun Bay, Pbc cysts were found at 50-52 cm depth, and also at 42-44 cm depth. Cysts of Pbc first occurred at least in 1883, using depositional age calculated from the historical eruption of Mt. Krakatau. Cysts of Pbc have continuously occurred since ca. 1910, and the cyst densities rapidly increased in ca. 1960. Based on these findings, we consider that anthropogenic activities such as ballast water and transportation of shellfish seeds probably did not cause the introduction of Pbc in both bays., Plankton and Benthos Research, 2(4), pp.163-174; 2007