Description: A new organic-walled dinoflagellate cyst species, Spiniferites multisphaerus sp. nov., is described from Late Quaternary sediments of Guaymas Basin, Gulf of California (Mexico). This species is characterized by a pronounced apical protuberance and bubble-like elements that comprise the central body wall, sutural septae and processes. The central body wall is ~1.0–2.1 μ m thick and appears pseudoreticulate in transmitted light microscopy. Processes are generally stubby and have blunt or furcated tips. Tabulation is expressed by low to moderate sutural septae, and is typical of the genus. Spiniferites multisphaerus sp. nov. has been found in low abundances throughout the Late Quaternary in Guaymas Basin with maximum abundances of 6% or 1670 cysts g –1 , and is rare in the Holocene, including modern sediments.

Description: Absolute abundances (concentrations) of dinoflagellate cysts are often determined through the addition of Lycopodium clavatum marker-grains as a spike to a sample before palynological processing. An interlaboratory calibration exercise was set up in order to test the comparability of results obtained in different laboratories, each using its own preparation method. Each of the 23 laboratories received the same amount of homogenized splits of four Quaternary sediment samples. The samples originate from different localities and consisted of a variety of lithologies. Dinoflagellate cysts were extracted and counted, and relative and absolute abundances were calculated. The relative abundances proved to be fairly reproducible, notwithstanding a need for taxonomic calibration. By contrast, excessive loss of Lycopodium spores during sample preparation resulted in non-reproducibility of absolute abundances. Use of oxidation, KOH, warm acids, acetolysis, mesh sizes larger than 15 μm and long ultrasonication (N1 min) must be avoided to determine reproducible absolute abundances. The results of this work therefore indicate that the dinoflagellate cyst worker should make a choice between using the proposed standard method which circumvents critical steps, adding Lycopodium tablets at the end of the preparation and using an alternative method.

Description: We establish the cyst-theca relationship of the dinoflagellate cyst species Trinovantedinium pallidifulvum Matsuoka 1987 based on germination experiments of specimens isolated from the Gulf of Mexico. We show that the motile stage is a new species, designated as Protoperidinium louisianensis. We also determine its phylogenetic position based on single-cell polymerase chain reaction (PCR) of a single cell germinated from the Gulf of Mexico cysts. To further refine the phylogeny, we determined the large subunit (LSU) sequence through single-cell PCR of the cyst Selenopemphix undulata isolated from Brentwood Bay (Saanich Inlet, BC, Canada). The phylogeny shows that P. louisianensis is closest to P. shanghaiense , the motile stage of T. applanatum , and is consistent with the monophyly of the genus Trinovantedinium. Selenopemphix undulata belongs to a different clade than Selenopemphix quanta (alleged cyst of P. conicum) , suggesting that the genus Selenopemphix is polyphyletic. Trinovantedinium pallidifulvum is widely distributed with occurrences in the Gulf of Mexico, the North Atlantic, the northeast Pacific and southeast Asia. In addition, we illustrate the two other extant species, Trinovantedinium applanatum and Trinovantedinium variabile , and two morphotypes of Trinovantedinium. Geochemical analyses of the cyst wall of T. pallidifulvum indicate the presence of amide groups in agreement with other heterotrophic dinoflagellate species, although the cyst wall of T. pallidifulvum also includes some unique features.

Description: The first online modern organic-walled dinoflagellate cyst determination key has been launched at www.marum.de/dinocystkey.html . This key is based on easily recognisable morphological features of dinoflagellate cysts that can be observed using standard transmitted light microscopy. To date, the key includes 96 cyst species that can be found in late Quaternary marine sediments. This key is free of charge to users, and will be continuously updated and improved by the authors. For each individual species of dinoflagellate cyst, the website provides information on its defining morphological characteristics and the cyst–motile stage relationship. It gives a comparison with other morphologically similar taxa, links to publications with original cyst descriptions and outlines their modern global distribution where this information is available. All species descriptions are illustrated by line drawings showing their most distinctive characteristics, and accompanied by high-quality bright-field photomicrographs. The key is compatible with all major computing platforms (including smartphones) and software.

Description: Continuous multiyear records of sediment-trap-gained microorganism fluxes are scarce. Such studies are important to identify and to understand the main forcings behind seasonal and multiannual evolution of microorganism flux dynamics. Here, we assess the long-term flux variations and population dynamics of diatoms, coccolithophores, calcareous and organic dinoflagellate cysts, foraminifera and pteropods in the eastern boundary upwelling ecosystem of the Canary Current. A multiannual, continuous sediment trap experiment was conducted at the mooring site CBeu (Cap Blanc eutrophic; ∼20∘ N, 18∘ W; trap depth is ca. 1300 m) off Mauritania (northwest Africa), between June 2003 and March 2008. Throughout the study, the reasonably consistent good match of fluxes of microorganisms and bulk mass reflects the seasonal occurrence of the main upwelling season and relaxation and the contribution of microorganisms to mass flux off Mauritania. A clear successional pattern of microorganisms, i.e., primary producers followed by secondary producers, is not observed. High fluxes of diatoms, coccolithophores, organic dinoflagellate cysts, and planktonic foraminifera occur simultaneously. Peaks of calcareous dinoflagellate cysts and pteropods mostly occurred during intervals of upwelling relaxation. A striking feature of the temporal variability of population occurrences is the persistent pattern of seasonal groups contributions. Species of planktonic foraminifera, diatoms, and organic dinoflagellate cysts typical of coastal upwelling, as well as cooler-water planktonic foraminifera and the coccolithophore Gephyrocapsa oceanica, are abundant at times of intense upwelling (late winter through early summer). Planktonic foraminifera and calcareous dinoflagellate cysts are dominant in warm pelagic surface waters, and all pteropod taxa are more abundant in fall and winter when the water column stratifies. Similarly, coccolithophores of the upper and lower photic zones, together with Emiliania huxleyi, and organic dinoflagellate cysts dominate the assemblage during phases of upwelling relaxation and deeper layer mixing. A significant shift in the “regular” seasonal pattern of taxa relative contribution is observed between 2004 and 2006. Benthic diatoms strongly increased after fall 2005 and dominated the diatom assemblage during the main upwelling season. Additional evidence for a change in population dynamics is the short dominance of the coccolithophore Umbilicosphaera annulus, the occurrence of the pteropod Limacina bulimoides and the strong increase in the flux of calcareous dinoflagellate cysts, abundant in warm tropical oligotrophic waters south of the study area after fall 2005. Altogether, this suggests that pulses of southern waters were transported to the sampling site via the northward Mauritania Current. Our multiannual trap experiment provides a unique opportunity to characterize temporal patterns of variability that can be extrapolated to other eastern boundary upwelling ecosystems (EBUEs), which are experiencing or might experience similar future changes in their plankton community.

Description: As part of the activities of the Global Ecology and Oceanography of Harmful Algal Blooms (GEOHAB)programme, Open Science Meetings (OSMs) have been organized to discuss and synthesize research efforts on various aspects of harmful algal blooms (HABs), and to plan future collaborative activities relevant to the research theme. Within this framework, the steering committee of the GEOHAB Core Research Project on HABs in Fjords and Coastal Embayments has organized two OSMs. The first OSM was held in 2004 in Santiago, Chile; the major goals were to identify the primary research priorities and to initiate an agenda to further our understanding of HAB dynamics in these small-scale coastal systems. The second OSM was held in May 2012 in Victoria,Canada to highlight the progress accomplished since the first OSM and to focus attention on the importance of a comparative approach in conducting ecosystem studies to improve our understanding of HABs. This second OSM addressed four major themes for which significant advances have been made in recent years, with particular focus on their application to semi-enclosed basins linked to coastal ecosystems: (1) Life history of HAB species; (2) Chemical ecological and toxin interactions; (3) Genetic diversity and (4) Transport and mixing of blooms in small-scale, mesoscale and semi-confined systems. This Report presents the major outcomes of this OSM, followed by recommendations for future collaborative studies. These recommendations include the maintenance of international activities on the ecology and oceanography of HABs after the end of the GEOHAB programme in December 2013. A future agenda should focus on a few key questions with clearly identifiable deliverables. These questions should include the development of (i) improved methods to determine the rates of cyst formation and germination in the field, and (ii) coupled biological-physical-chemical models more appropriate to small-scale environments and which incorporate the role of allelochemicals and toxins, as well as the pelagic and benthic coupling components. Research devoted to life history stages should be continued, particularly with respect to fish-killing algal species that cause particular damage in coastal environments. The influence of aquaculture activities on the development of HABs is poorly understood and should be of greater concern in future research on HABs. The influence of climate change, which may be exacerbated in coastal environments, also should be a focus of future research. Long-term ecological research should be encouraged in this respect, in order to make better predictions in the future concerning the development of HABs in coastal environments.