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  • 1
    Type of Medium: Book
    Series Statement: ICES council meeting papers 1982,6
    Language: Undetermined
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  • 2
    Type of Medium: Book
    Series Statement: ICES council meeting papers 1986(20)
    Language: Undetermined
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  • 3
    Keywords: Hochschulschrift
    Type of Medium: Online Resource
    Pages: Online-Ressource (183 Seiten, 25 MB) , Diagramme, Karten
    Language: German
    Note: Zusammenfassung in deutscher und englischer Sprache
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Helgoland marine research 16 (1967), S. 67-74 
    ISSN: 1438-3888
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung 1. Die im normalen Seewasser recht konstante Ionenrelation kann bei niederen, vor allem aber bei extrem hohen Salzgehalten erheblich gestört sein. Daher ist in diesen Bereichen die Bestimmung der einzelnen Komponenten wünschenswert. Die Bezeichnung S ‰ ist bei sehr großen Salzmengen nur bedingt vertretbar, und übertrieben genaue Angaben sind daher wenig sinnvoll. Deshalb ist für viele Belange ein einfaches Meßverfahren hinreichend. 2. Es wird eine Methode beschrieben, mit deren Hilfe hohe Salzgehalte durch Auswiegen des Inhalts einer Knudsen-Pipette bestimmt werden können. Die Auswertung erfolgt mit Hilfe von Nomogrammen. Die Genauigkeit der Methode dürfte bei ±1 ‰ liegen. 3. Die durchgeführten Dichtemessungen erlauben, bei Gültigkeit der Cl/S-Relation g Cl/l auf S‰ mit einer Genauigkeit von ±0,1‰ umzurechnen.
    Notes: Abstract In the open sea the proportion between the different ions is rather constant with the exception of some elements influenced in their amount and distribution by biological activities (P, N, etc.). This relative constancy is modified if sea-water is diluted near the shores by river water, or concentrated by evaporation, especially in lower latitudes (e. g., Mediterranean, Red Sea). Abnormalities are also found in small isolated bodies of water near the shore. In all these instances the quantitative relation between the different ions is no longer constant; in most cases, calcium shows the first and most pronounced aberrations. It is desirable, therefore, to determine the individual components in such waters, not only its total salinity. In some cases, however, it may be of interest to measure high salinities as such, especially in biological studies. This paper describes a simple method for the determination of salinities between 50 and 275 ‰ via density measurements. The volume of the water sample is then determined by means of a 50 cm3-Knudsen pipette, its temperature measured, and the sample transferred into a clean, dry glass stoppered bottle. Thereafter the pipetted water is weighed and the α value (similar to the well known σt) calculated: TANO In this formula, α and t°C give the resulting salinity. This rather complicated procedure is simplified by the use of nomograms (at the end of this paper). The accuracy is not much better than ±1 ‰. In situations in which it may be assumed that the Cl/S ratio is practically identical with that in normal sea-water, S ‰ can be calculated from the value g Cl/l; in this case the accuracy is ±0.1 ‰.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Helgoland marine research 36 (1983), S. 393-426 
    ISSN: 1438-3888
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phytoplankton blooms have attracted attention since times of old, especially the red tides caused by peridinians. Observed in all regions of the world, red tides occur predominantly in the warmer seas (e. g. West Coast of Florida). An opportunity to study a bloom, caused by the non-toxic dinoflagellateCeratium furca, was provided in North Sea coastal waters of an area ranging from Belgium to Sweden. Its development could be followed from July to October 1981 with the aid of samples taken 5 days a week near the island of Helgoland. A decline in the bloom coincided with a drop in water temperature (increasing turbulence). This condition and the presence, right up to the end, of relatively high amounts of nutrients indicate that nutrient deficiency did not terminate the bloom. Similarly, there was no evidence for a dependence on micronutrients by freshwater input or by the preceding diatom bloom. Longterm investigations indicate that climatic changes coincide with an increase in the phytoplankton stock during all seasons (especially noticeable from July to September) and with a decrease in salinity (there was a minimum in 1981). The stratification of the sea water causes the peridinians to move to depths optimal for their growth which may bring about an aggregation at the surface. There are numerous indications in literature of similar changes of environmental conditions in the North Sea. One example from the Western Baltic Sea demonstrates that the presence of a high vertical density gradient in the sea leads to oxygen deficiency in deeper zones, which, however, is not directly correlated to the coincident phytoplanktonic bloom in the upper layers. It is probable that, under appropriate hydrographical conditions, “red tides” can occur repeatedly in the southern North Sea, produced by non-toxic as well as toxic species.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Helgoland marine research 6 (1957), S. 76-83 
    ISSN: 1438-3888
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Zusammenfassung Es wird ein Verfahren zum oxydativen Nachweis von organischer Substanz im Seewasser beschrieben und seine praktische Bedeutung an einer Untersuchung in der Nordsee erläutert.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Helgoland marine research 6 (1959), S. 239-240 
    ISSN: 1438-3888
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Helgoland marine research 8 (1961), S. 58-67 
    ISSN: 1438-3888
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary 1) A method is described for the direct determination of ammonia in sea water by oxydation with hypobromit in an alkaline solution. 2) It is applicable to concentrations of 0 to 250 µg NH4-N/l with an accuracy of ± 5 µg NH4-N/l. 3) The determination is interfered by amino acids. 4) A given example shows a very complicated situation for the German Bight: One part of the ammonia seems to come from the fresh water respectively from the coast. An other part is formed by reduction of nitrates or by decomposition of organic substances.
    Notes: Zusammenfassung 1) Es wird ein Verfahren zum direkten Nachweis von Ammoniak im Seewasser durch alkalische Oxydation mit Hypobromit beschrieben. 2) Der Meßbereich geht von 0 bis 250 µg NH4-N/l bei einer Genauigkeit von ± 5 µg NH4-N/l. 3) Die Bestimmung wird durch Aminosäuren gestört. 4) Ein Anwendungsbeispiel zeigt für die Deutsche Bucht sehr komplizierte Verhältnisse: Offenbar stammt ein Teil des Ammoniaks aus dem Süßwasser bzw. von der Küste, während ein anderer durch Nitratreduktion oder Zersetzung von organischer Substanz entsteht.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Helgoland marine research 42 (1988), S. 435-467 
    ISSN: 1438-3888
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract During recent decades, phytoplankton stock on the one hand and inorganic nutrients (P and bound N) on the other have increased considerably in the southern North Sea, as demonstrated at a permanent station (since 1962) near the island Helgoland. This correlation between phytoplankton and inorganic P and N need not have anything to do with causality; exceptional algal blooms have been observed and reported in the literature since in the 19th century. Furthermore, these increases (four-fold for phytoplankton and two-fold for nutrients) are in the same range as the fluctuations from year to year under different hydrographical conditions. A detailed investigation carried out in 1981 demonstrated the presence of a slowly growing phytoplankton population. Starting with a considerable stock of flagellates in spring, it reached a peak in cell numbers over a long reproduction period which contrasted with the normal duration of a spring bloom of diatoms. These processes were not related to a limited production by P or N. A considerable concentration of these nutrients was permanently available in the form of inorganic compounds. The total amount of nutrients surpassed by far the portion incorporated in the phytoplankton. This is a consequence of the fact that small organisms have a high metabolic rate. Therefore, the relation between stock and production (daily production ≈stock) is completely different from that known e.g. in agriculture. The nutrients exist during the vegetation period mainly in the form of dissolved organic matter that is accessible to plankton. The great dynamics of this system, including a phase shifting during the year between inorganic P, N, Si, and production, indicates the significance of permanent and fast remineralization. Calculations demonstrate that the natural nutrient content of seawater normally satisfies the demands of phytoplankton present in the North Sea area under study. Only in the more productive coastal region (salinity〈30 associated with fresh water run-offs of low nutrient content — an unrealistic assumption in the German Bight) might some limitation be observed. For diatoms, silicate may represent a critical component, but a high dynamic force exists in the presence of small Si concentrations. Therefore, a lack of silicon must not represent any limitation; however, knowledge on the silicon system is insufficient up to now.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Helgoland marine research 7 (1961), S. 238-251 
    ISSN: 1438-3888
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Summary 1. In August 1959 a station off Helgoland undertook to determine parallels between a great quantity of components in several vertical series during one day. 2. The statistical treatment gave very complicated connections between the different measurements. Usually it was necessary to regard the distribution of one component as being dependent upon some others. That means there is only in a few cases the possibility of drawing a conclusion from one measurement of a component not determined. It is, for instance, not at all possible in this case to give a good description of the distribution of the phytoplankton by means of the chlorophyll measurements. 3. At the moment one should not overlook which relations have a fundamental meaning, which are affected by region or time and which relations are detected only by chance. Fluorescence and Gelbstoff (Kalle) should be connected with the fresh water; the organismic fluorescence (Kalle) seems to be given off by the zooplankton; the turbidity exists in the flat sea with strong tidal currents in the first range of turned-up sediments, while the bacteria are positively connected with the turbidity (settled particles) and with the organic substances.
    Notes: Zusammenfassung 1. Bei Helgoland wurden im August 1959 auf einer Dauerstation zahlreiche Untersuchungsverfahren parallel angewandt. 2. Die statistische Auswertung ergab komplizierte Abhängigkeiten zwischen den verschiedenen Messungen. Es erwies sich durchweg als notwendig, jeweils eine Komponente in ihrer Verteilung als abhängig von mehreren anderen zu betrachten. Hieraus folgt also, daß nur in seltenen Fällen die Möglichkeit besteht, aus einem Meßergebnis auf eine nicht bestimmte Größe rückzuschließen. Z. B. läßt sich in diesem Falle die Phytoplanktonverteilung nicht befriedigend durch die des Chlorophylls beschreiben. 3. Es ist noch nicht zu übersehen, welche Beziehungen grundsätzliche Bedeutung haben, welche regional und welche zeitlich bedingt sind, und welche nur zufällig gefunden wurden. Fluoreszenz und Gelbstoff dürften aus dem Süßwasser stammen; die organismische Fluoreszenz scheint vom Zooplankton abgegeben zu werden; die Trübung besteht in dem flachen Gezeitenmeer weitgehend aus aufgewirbelten Sedimenten; und die Bakterien sind positiv an Trübung (besiedelbare Partikel) und organische Substanz gebunden.
    Type of Medium: Electronic Resource
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