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Cell count time series of Azadinium spinosum, Azadinium poporum and Amphidoma languida at Cuxhaven, Helgoland, Sylt, Wilhelmshaven and Scapa Flow between 2015 and 2019

The data represent species counts (cells L-1) of the three AZA-producing dinoflagellate species Azadinium spinosum, Az. poporum and Amphidoma languida (all members of the taxonomic family Amphidomataceae) of water samples taken during in total six different field expeditions on several research vessels (RV Heincke, RV Uthörn, RV Polarstern) and on in total five stationary sampling stations (Scapa Flow/Scotland, Cuxhaven/Germany, Helgoland/Germany, Wilhelmshaven/Germany, Sylt/Germany) between 2015 and 2019. The water samples have been taken using Niskin bottles (on research vessels attached to a CTD). After DNA extraction, the species cell numbers have been calculated by quantitative PCR (qPCR) analysis using respective standard curves. These samples gained from different geographical areas in the eastern North Atlantic have been analyzed as part of the RIPAZA Project (funded by the German BMBF; in cooperation with the Third Institute of Oceanography, Xiamen/China) and the results are presented and discussed in the doctoral thesis of Stephan Wietkamp (Suppl.Tab.S6, Suppl.Tab.S7). Aim of the project and especially of this data set was to provide first reference data on the biogeography (geographical distribution and seasonality) of toxigenic Amphidomataceae in the eastern North Atlantic.

Cell counts of Azadinium spinosum, Azadinium poporum and Amphidoma languida during POLARSTERN cruise PS92, UTHÖRN cruise UTH16 and various HEINCKE cruises to the eastern North Atlantic between 2015 and 2019

The data represent species counts (cells L-1) of the three AZA-producing dinoflagellate species Azadinium spinosum, Az. poporum and Amphidoma languida (all members of the taxonomic family Amphidomataceae) of water samples taken during in total six different field expeditions on several research vessels (RV Heincke, RV Uthörn, RV Polarstern) and on in total five stationary sampling stations (Scapa Flow/Scotland, Cuxhaven/Germany, Helgoland/Germany, Wilhelmshaven/Germany, Sylt/Germany) between 2015 and 2019. The water samples have been taken using Niskin bottles (on research vessels attached to a CTD). After DNA extraction, the species cell numbers have been calculated by quantitative PCR (qPCR) analysis using respective standard curves. These samples gained from different geographical areas in the eastern North Atlantic have been analyzed as part of the RIPAZA Project (funded by the German BMBF; in cooperation with the Third Institute of Oceanography, Xiamen/China) and the results are presented and discussed in the doctoral thesis of Stephan Wietkamp (Suppl.Tab.S6, Suppl.Tab.S7). Aim of the project and especially of this data set was to provide first reference data on the biogeography (geographical distribution and seasonality) of toxigenic Amphidomataceae in the eastern North Atlantic.

Elemental and biochemical contents of the copepod Temora longicornis

Elemental and biochemical contents of the diets of the copepod Temora longicornis

Fatty acid contents of the diets of the copepod Temora longicornis

Fatty acid contents of the copepod Temora longicornis

Elemental, biochemical, and fatty acid contents for the copepod Temora longicornis (and its diets) fed under laboratory conditions with different nutrient regimes

The two experiments for which data is presented in this record were conducted in the context of RMFS' PhD work. The objective of the experiments was to quantify and qualify the effects of diet quality, herein manipulated in terms of different species (the diatom Conticribra weissflogii and the dinoflagellate Oxyrrhis marina) grown under different nutrient regimes (nutrient replete and Nitrogen-depleted), on the fatty acid (FA) assimilation and turnover of the copepod Temora longicornis. Experiments used field-collected copepods; sampling for experiments I and II took place on May 17th and 30th, 2016, respectively, with a 500 µm mesh-size CalCOFI net which was towed horizontally for 15 minutes at 5 m depth off the German island of Helgoland (54o11'N, 07o54'E), in the southern North Sea. Samples were immediately taken to the laboratory, where intact and active adult females were sorted under an Olympus SZX16 stereoscopic microscope. A total of 1260 females were sorted for each date, 1080 for the feeding experiment and 180 for the determination of in situ elemental and biochemical compositions. This study was conducted concomitantly with that from Franco-Santos et al. (2018). The feeding experiment was initiated after sorting, and lasted for five days. Females were distributed between triplicate 3L plastic beakers (75 females L-1), which were fitted with a 300 µm meshed-bottom cylinder, and kept in a dark, temperature-controlled room (10 ± 0.3oC, a temperature similar to that recorded in the surface water during sampling). Batch cultures of C. weissflogii were started on a daily basis (prior to starting the experiment) for five consecutive days; a stock solution was diluted with fresh f/2 medium (with and without nitrate additions, modified from Guillard, 1975), which contained 13C-enriched sodium bicarbonate (NaH13CO3, 4 mg L-1), and was grown for five days before being used to feed copepods (details in Franco-Santos et al., 2018). The same protocol was followed to culture the cryptophycean Rhodomonas salina, but bicarbonate was added to a concentration of 12 mg L-1. The algae were then used to feed the cultures of O. marina and, thus, create its different nutrient treatments. The dinoflagellate batches were cultured with the same protocol as the diatoms, except that the stock solution was diluted on a daily basis with labelled food (i.e., R. salina) rather than once at the start of the culture with isotopically-enriched medium. Cryptophycean cell quantities given to dinoflagellates were adjusted so that the former was depleted from the cultures on day 5. Diatom and dinoflagellate diets were provided for copepods ad libitum (> 350 µg C L-1; 8 and 2 * 103 cells mL-1, respectively) on a daily basis for five days. Cell density in the cultures was determined with a BD Accuri C6 Flow Cytometer. Beakers were gently stirred three times a day in order to resuspend dietary cells. Immediately before feeding copepods, a partial (approx. 65%) water exchange was conducted, which removed most of the food from the previous day. Copepods were sampled on days 1 (in situ composition, t0h), 3 (t48h), and 6 (t120h) of the experiment. Females were pooled into 10 and 50 individuals per replicate for elemental (body carbon (C) and nitrogen (N) contents and molar C:N ratio) and biochemical (total FA content and profile, and FA-specific content and 13C isotopic signal) analyses. Sampled copepods were gently washed in distilled water, then placed into pre-weighed tin capsules (5x9 mm, IVA Analysentechnik) or pre-combusted lipid vials (for elemental and FA analyses, respectively). Cultures were sampled daily during the experiment (after food was provided to copepods) for determination of cell elemental (C and N contents and molar C:N ratio) and biochemical (total FA content and profile, and FA-specific content and 13C isotopic enrichment) compositions. Subsamples of 5.2 and 0.4 *106 cells (for diatoms and dinoflagellates, respectively) were filtered through pre-combusted (500oC for 24h) Whatman GF/F filters (0.7 µm pore size, 25 mm diameter). Tin capsules and filters with samples for elemental analysis were dried at 60oC for 48 h; filters were folded inside tin foil, and both capsules and foil were stored in a desiccator until analysis. Filters with samples for FA analyses were placed into pre-combusted lipid vials, and vails containing both copepods and filters were stored at -80oC until analyses. The dry mass (DM) and C and N contents of samples were obtained as per Franco Santos et al. (2018). Lipid extraction (modified after Folch et al., 1957) and subsequent fatty acid methyl ester (FAME) quantification were performed as described in Franco-Santos et al. (2019) (and references therein). Temora longicornis does not have significant energy reserves and exhibits triacylglycerols (TAGs) as its primary neutral lipids (Fraser et al., 1989; Peters et al., 2013). Lipid classes were not separated in this study, and it was assumed that FAMEs were composed of TAGs. The FA-specific 13C isotopic composition of FAMEs was measured according to Boissonnot et al. (2016). Lipid C assimilation and turnover were calculated according to the equations used by Boissonnot et al. (2016) and Franco-Santos et al. (2019). Lipid C assimilation efficiency (AE), the percentage of (isotopically-enriched) dietary content ingested by copepods that was assimilated into FAs, was also calculated for (a) TFA, (b) saturation-specific sums of FAs (saturated, monounsaturated, and polyunsaturated FAs), and (c) each individual FA that was both available from the diet and assimilated by copepods (> 1% TFA in copepods). All the equations necessary for these calculations are described in the data sets contained in this bundled publication.

Die Auswirkung Eintrags von Donau, Dnestr und Dnepr auf den Nordwestteil des Schwarzen Meeres, Die Auswirkung des Donaueintrags auf das Schelfoekosystem im Nordwestteil des Schwarzen Meeres

Ziel des Gesamtprojektes ist die Untersuchung der Auswirkung des Donau-Eintrages auf das Schelfoekosystem im Nordwestteil des Schwarzen Meeres. Das Teilprojekt 'Zooplankton' untersucht die oekologische Rolle der dominanten Zooplankter im Pelagial des nordwestlichen Schwarzen Meeres. Hierbei steht die Erforschung der Bedeutung der ins Schwarze Meer eingewanderten Ctenophore Mnemiopsis leidyi im Nahrungsnetz im Vordergrund. Einen weiteren Schwerpunkt bilden Untersuchungen zur Oekologie der heterotrophen Dinoflagellaten Nocticula scintillans, der zeitweilig zu ueber 90 Prozent zur gesamten Biomasse des Zooplanktons im Schwarzen Meer beitragen kann.

FP5-EESD, Biological Control of Harmful Algal Blooms in European Coastal Waters: Role of Eutrophication - BIOHAB

Objective: Biological control of Harmful Algal blooms in European coastal waters: role of eutrophication (BIOHAB). Problems to be solved: Harmful Algal Blooms (HAB) occur in many European marine waters and have increased in frequency concomitantly with a increased nutrient input from land. HABs have a devastating effect on the ecosystem and/or cause health problems in humans. Species of interest for BIOHAB belong to different taxonomic groups. Various algae belonging to these groups produce substances responsible for e g Paralytic Shellfish Poisoning and Diarrhetic Shellfish Poisoning. Some species are harmful in other ways, e g by creating oxygen deficiency. The success of HABs depends on several biological interactions, which are of a complex nature. The overall objective of BIOHAB is therefore to determine the interplay between (anthropogenic) eutrophication and biological control of the losses and gains of HABs. The ultimate goal is to find ways to manage phytoplankton algal blooms in European coastal waters in such a way that harmful species are avoided or at least that their negative effects are minimised. The co-operation involves several European countries, representing distinctly differing regions (the Baltic, the North Sea, coastal zone of Norway, the Mediterranean). Both the Helsinki (HELCOM) and Oslo Paris Commission (OPARCOM) have been established as intergovernmental organisations with as primary task the protection of the marine environments in the Baltic Sea and North Sea. BIOHAB will provide the necessary knowledge on HABs and their control within these commissions. Scientific objectives and approach: The scientific objectives are (1) To determine the susceptibility of HABs to biological control such as grazing (copepods, ciliates, hetero- and mixotrophic dinoflagellates) and/or infection (virus, bacteria, parasites) when growing under deficient as compared to sufficient nutrient conditions. (2) Investigate the release of infochemicals by HABs into the seawater with the aim to avoid grazing and infection. (3) To examine data sets of the general and unique patterns of growth and decay parameters of HAB-species in various coastal regions. (4) To develop a generic or species-specific model for the development of HABs and their mitigation. (5) To obtain and grow HAB species-specific pathogens (viruses, bacteria, parasites) which could potentially be used to terminate HABs (bio-control). The workplan combines laboratory and field experiments with in situ studies, to be carried out in 4 different European seas. This includes the low saline Baltic, the eutrophic N-controlled North Sea, the oligotrophic Norwegian Sea, and the P-limited Mediterranean Sea. Prime Contractor: Netherlands Institute for Sea Research, Department of Biological Oceanography; Den Burg.

Algenparasiten, Algensymbiose und Plastidenevolution

Zellbiologische und ultrastrukturelle Untersuchung von Protisten, die als Parasiten bei Algen oekologisch oder oekonomisch von Bedeutung sind, von Symbiosen bei Algen als rezentes Beispiel fuer die Evolution von Plastiden und entwicklungsgeschichtliche Untersuchungen an Dinoflagellaten.

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