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  • 1
    Electronic Resource
    Electronic Resource
    Why ’very shallow‘ lakes are more successful opposing reduced nutrient loads (1997)
    Springer
    Hydrobiologia 342-343 (1997), S. 269-284 
    Details
    ISSN: 1573-5117
    Keywords: shallow lakes ; eu-hypertroph ; Cyanobacteria ; morphometry ; mixing ; euphotic depth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract There are different approaches for classifying deep andshallowwaters using physically and ecologically derived parameters.Nevertheless, transition states make it difficult to definebordercrossing points between the two types of limnetic ecosystemsand todistinguish more precisely between different types of shallow,especially highly eutrophicated lakes. We contribute adetailedanalysis of different characteristics of shallow waters fromlakesin the Berlin/Brandenburg-region. In the catchment area of theriver Dahme in Eastern Brandenburg (Scharmützelsee-region)wefind mainly shallow and highly eutrophicated lakes, dominatedbyCyanobacteria. ’Very shallow‘ lakes of different morphometry andtopography are compared with ’medium shallow‘ or deeper lakesinthe region with similar loading characteristics for thefollowingproperties: morphometry, topography, theoretical retentiontime,mixing intensity, nutrient dynamics, external and internalloading,underwater light climate, zeu/zmix,phytoplankton development and oxygen budget. We found that’veryshallow‘ lakes in the region are more efficient in convertingtheavailable phosphorus into phytoplankton biomass because of theconstant and sufficient underwater light climate due to thefavourable relation of zeu and zmix. Weconclude that the regular mixing regime guarantees a stableandnear optimum light/dark rhythm as well as higher heterotrophicactivities, stimulating primary production up to the upperlimit ofalgal development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1017012012099
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  • 2
    Electronic Resource
    Electronic Resource
    Chrysophytes and chlamydomonads: pioneer colonists in extremely acidic mining lakes (pH 〈3) in Lusatia (Germany) (1998)
    Springer
    Hydrobiologia 369-370 (1998), S. 315-327 
    Details
    ISSN: 1573-5117
    Keywords: acidic mining lakes ; phytoplankton ; Chlamydomonas ; Ochromonas ; water chemistry ; limiting factors
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Twenty-three extremely acidic (pH between 2.5 and 3.5) mining lakes in Lusatia (Germany) were analysed in order to classify their hydrochemistries and to assist the understanding of phytoplankton colonization of these extreme environments. Neither morphometric nor physical parameters influence phytoplankton composition but determine the extent to which the nutrient supply supports the mass development of Chrysophyceae and Chlorophyceae in certain layers of the water (hypo- or epilimnetic chlorophyll maxima and short mass developments). Conventional trophic classification is not readily applicable to these lakes but a chemical classification on the basis of hydrogen, total iron and acidity is proposed. Species of Ochromonas and Chlamydomonas dominate the phytoplankton in fourteen of the most acid lakes; dinoflagellates occurre additionally in four; a more diverse algal assemblage with diatoms and cryptophytes is found in lakes with moderately acidic (pH 5.7–7.0) or alkaline conditions (pH 7.0–9.4). The lake chemistry is the main determinant for the planktonic composition of the water bodies whereas the trophic state mainly determines the level of algal biomass.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1017010229136
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  • 3
    Electronic Resource
    Electronic Resource
    Success of chrysophytes, cryptophytes and dinoflagellates over blue-greens (cyanobacteria) during an extreme winter (1995/96) in eutrophic shallow lakes (1998)
    Springer
    Hydrobiologia 369-370 (1998), S. 229-235 
    Details
    ISSN: 1573-5117
    Keywords: phytoplankton succession ; chrysophytes ; winter ; ice-cover ; trophic gradient
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phytoplankton succession in three shallow eutrophic and hypertrophic lakes located in the Scharmützelseeregion (East Brandenburg, Germany) is described for the extreme winter of 1995/96 before and during ice-cover. The lakes have been investigated since 1993 and pass along the tophic gradient from eutrophic, Petersdorfer See and Melangsee to hypertophic, Larger See. All lakes are dominated by cyanobacteria from early spring to late autumn. Due to low water temperature and low light intensity before ice-cover a decline of cyanobaterial biovolume initiated which led to the total disappearance of cyanobacteria in Melangsee for the whole ice-covered period, whereas their portion in Langer See with at least 6% (3 mm3 l-1) and in Petersdorfer See with 25% (5 mm3 l-1) of total biovolume was still considerable. The cyanobacterial breakdown was linked to a switch in dominance to flagellates which built up together with diatoms a subsequent peak of biovolume during ice-cover. Maximum phytoplankton biovolume under the ice peak reached 20 mm3 l-1 with chl-a concentrations up to 100 µg l-1. Oxygen saturation increased during ice-cover with a final oversaturation of more than 200% in the upper water column at the end of ice cover. These findings indicate that the winter period is also characterized by intensive photoautotrophic activities. Therefore, this period should be more worthy of note in investigations of phytoplankton succession and ecology.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1017054011389
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  • 4
    Electronic Resource
    Electronic Resource
    Surficial sediment composition as a record of environmental changes in the catchment of shallow Lake Petersdorf, Brandenburg, Germany (1999)
    Springer
    Hydrobiologia 408-409 (1999), S. 185-192 
    Details
    ISSN: 1573-5117
    Keywords: shallow lake ; sediment ; dy ; phosphorus ; calcium ; metals
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A chemical characterization of the surficial sediment (0–20 cm) of type `dy' (org-Cpart/TNpart〉10) of the anthropogenically polluted shallow Lake Petersdorf is presented. Eighty samples were analyzed for a set of parameters, i.e. dry weight, loss on ignition (LOI), total inorganic carbon (TIC), N, S, P, Ca, Si, As, Fe, Al, Mn, Zn, Cd, and Pb. LOI, TIC, N, S, Ca, P, and Zn tend to accumulate at a water depth 〉2 m (70.6% of the lake surface) in contrast to Mn and Fe which are more widely distributed, and Cd and Pb which are accumulated in the lake part close to a road. The enrichment factors of certain elements, e.g. Al (23.9%), Si (31.5%), P (12.2%), and Ca (68.7%) from 20 cm sediment depth up to the surface, are attributed to incisive changes in the immediate catchment. Erosion, fertilization, amelioration, and separation of the peatland north of the lake by a dam within the last 60 yrs resulted in the change of Lake Petersdorf from a dystrophic to a eutrophic stage. This enhanced the mineralization of its meso-humic (LOI/TNpart=20.6) sediment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1017059330528
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  • 5
    Electronic Resource
    Electronic Resource
    Lake Plessa 107 (Lusatia, Germany) – an extremely acidic shallow mining lake (1999)
    Springer
    Hydrobiologia 408-409 (1999), S. 293-299 
    Details
    ISSN: 1573-5117
    Keywords: mining lake ; acidification ; plankton ; phytobenthos ; macroinvertebrates ; food-web
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Lake Plessa 107 is an example of the older, relatively small and often shallow mining lakes of Lusatia which only have groundwater inflow. From a morphological point of view, the lake should be polymictic with short stratified periods. But besides temperature, mixing is also determined by chemical gradients in the water column that can lead up to monomixis. The lake water shows an extreme acidification with high concentrations of calcium, iron, aluminium, manganese and sulphate. Despite low TIC and TP concentrations allowing only a low primary production in the pelagial within the oligotrophic range, anoxic conditions can occur during stratification because of Fe(II) oxidation and anoxic groundwater inflow. The phytoplankton is dominated by phytoflagellates. Chlorophyll concentrations follow a yearly pattern determined by temperature and light availability. The zooplankton consists of two rotifer species, ciliates and heliozoans. Sediment analyses show contrary depth gradients of Fe and P with a very high fraction of Fe in the upper sediment layers (up to 60% of DW) which decreases with depth. Probably due to groundwater inflow, at some sites substantial decreases in redox potential and conductivity can be observed with increasing sediment depth accompanied by increases of pH, DOC, DIC and DIP concentrations. No correlations have been found between the available phosphorus or carbon concentrations in the sediment porewater and the phytobenthic biomass. Euglena mutabilis(Euglenophyceae) and Pinnularia acoricola(Bacillariophyceae) are the dominant phytobenthic species. Lake Plessa 107 has a benthic food-web that consists of benthic algae, chironomids and corixids and a pelagic food-web which is composed of phytoflagellates, rotifers, ciliates and heliozoans. The two food-webs are not coupled because larger prey organisms such as crustaceans are missing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1017038616513
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  • 6
    Electronic Resource
    Electronic Resource
    Spring phytoplankton dynamics in a shallow eutrophic lake (1999)
    Springer
    Hydrobiologia 408-409 (1999), S. 269-276 
    Details
    ISSN: 1573-5117
    Keywords: shallow eutrophic lakes ; phytoplankton ; spring bloom ; carrying capacity ; primary production ; loss processes ; flushing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In contrast to other eutrophic shallow lakes in the Scharmützelsee region, a delayed onset of the phytoplankton succession in Lake Melangsee during spring was regularly observed. Biomasses were opposed to the carrying capacity of the lake (calculated from total-P, total-N and underwater light), indicating further regulating factors in spring. This phase was characterised by high Secchi depths, rising flushing and enhanced oxygen concentrations at the lake bottom. Although silicate concentrations decreased in spring, a typical pelagic diatom or cyanobacterial bloom did not develop. Therefore, we frame the hypothesis that a combination of abiotic factors such as increased losses in spring due to higher flushing and a better light supply suppresses pelagic growth and favours benthic diatoms, which outcompete pelagic diatoms for silicate. The vertical oxygen distribution in this period indicates a shift from pelagic primary production to benthic growth. Considering primary production, flushing, under water light supply and nutrients we tried to find the reasons for the depression of phytoplankton growth during spring.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1017096210578
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  • 7
    Electronic Resource
    Electronic Resource
    On the occurrence of clear-water phases in relation to shallowness and trophic state: a comparative study (1999)
    Springer
    Hydrobiologia 408-409 (1999), S. 251-262 
    Details
    ISSN: 1573-5117
    Keywords: clear-water phase ; cyanobacteria ; Cladocera ; shallow lakes ; seasonal succession ; PEG model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We present a comparative study on the occurrence of spring clear-water phases in six eutrophic lakes (two deep, four very shallow lakes dominated by plankton, TP: 0.06–0.13 mg l-1) in the Scharmützelsee region (Germany). Our aim was to analyse the occurrence and intensity of clear-water phases in relation to shallowness and trophic state. We defined a clear-water phase by a continuous increase of Secchi depth, a corresponding decrease in algal biomass and a shift in phytoplankton species composition during the growth phase of cladoceran zooplankton. For shallow lakes, we used the increase of the euphotic depth up to maximum depth as an additional criterion. Only in two of six lakes a clear-water phase occurred. In two lakes, no spring peak of cladocerans developed. In two other lakes, a high biomass of grazing resistant cyanobacteria was not affected by cladoceran maxima. Daphnia galeatawas an important component of the grazer community in lakes with a clear-water phase, whereas lakes without a clear-water phase were dominated by Bosmina longirostris. Top-down control of grazing by fish predation is discussed as the main factor determining biomass, composition and timing of the cladoceran spring peak. The assumed relative strength of fish predation between lakes corresponds to the response in algal biomass, dominance of cyanobacteria and is inversely related to the potential grazing pressure (ratio of cladoceran and algal biomass). Bottom-up effects (food quality) and additional factors (fungal infection, flushing rate) may also influence growth and timing of cladocerans. Our results support the view that a high biomass of grazing zooplankton is essential for the occurrence of a clear-water phase, but not sufficient to explain variability between lakes. High cladoceran maxima in hypertrophic lakes indicate that food quality seems not to limit grazer biomass. Decoupling of zooplankton and phytoplankton may be the result of early and fast growth of grazing resistant algae. We conclude that shallowness and trophy may indirectly reduce the extent and predictibility of a clear-water phase by enhanced growth of cyanobacteria and increasing predation pressure at least for lakes on this TP level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1017088008761
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  • 8
    Electronic Resource
    Electronic Resource
    Extrem saure Seen in Deutschland (1999)
    Weinheim : Wiley-Blackwell
    Biologie in unserer Zeit 29 (1999), S. 98-109 
    Details
    ISSN: 0045-205X
    Keywords: Life and Medical Sciences
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Seen mit Wasser, so sauer wie verdünnte Essigsäure, so sauer wie manche Kraterseen, gibt es solche Seen in Deutschland? Ja, sie gibt es, und zwar sogar recht zahlreich in den alten und vor allem in den neuen Bundesländern. Alle diese Seen sind künstlicher Natur und treten im Zusammenhang mit dem Abbau von Bodenschätzen auf. Durch diesen Vorgang werden tiefere Schichten des Deckgebirges belüftet und mit Wasser versorgt, so daß eine chemische und vor allem mikrobiologische Oxidation von reduzierten Schwefelkver bindungen (Sulfiden) einsetzen kann. Dieselben Vorgänge laufe auch auf und in den Abraumhalden ab. Sulfide sind sehr häufige Begleiter von Braun- oder Steinkohlevorkommen. Ein wesentlicher Teil der Wasserkontaminationen im mitteldeutschen und Lausitzer Raum ist in der Tat mit der Braunkohleförderung verbunden. Ferner sind die meisten, abbauwürdigen Metallvorkommen ebenfalls in sulfidischen Erzen zu finden, so daß deren Abbau zu denselben Oxidation führt, die international als Als Mine Drainage bezeichnet werden.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/biuz.960290206
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