Limnological studies of lake Norrviken, a eutrophicated Swedish lake

Ahlgren, Ingemar

doi:10.1007/bf02502198

Cited by 34 publications

(37 citation statements)

References 15 publications

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“…The values are sufficiently close to the maximum possible proposed of 300-500 mg m -2 chla (e.g. Ahlgren 1970;Talling 1970) to support the above evidence for a primary light rather than nutrient limitation. However, the exceptionally high chla value for Bogoria could be an artifact of sampling only between 0 and I m rather than the whole mixed layer.…”

Section: Discussionsupporting

confidence: 77%

Phosphorus limitation in some tropical African lakes

Kalff

1983

Hydrobiologia

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Two of three Kenyan lakes studied between November 1979 and October 1980 have very short 33PO 4 turnover times, indicating a high phosphorus (P) demand throughout the year. The P turnover time in Lakes Oloidien and Sonachi is as rapid as in the most P deficient temperate zone lakes. The third lake, Lake Naivasha, has a lower overall P demand and a wide seasonal range, with lowest demand between November 1979 and February 1980 when a P deficiency was unlikely. On an annual basis the Lake Naivasha status is, however, not statistically different from that recorded during the summer in Lake Memphremagog, a generally P-limited temperate zone lake. Lake Naivasha and Lake Oloidien fit well to the line of best fit for the Dillon-Rigler relationship relating total phosphorus (TP) and chlorophyll a derived in temperate zone lakes. Thus, temperate zone models predicting aspects of lake behaviour on the basis of TP may also be applicable to these two tropical lakes. Saline lake Sonachi had not only a short P turnover time but also responded dramatically to the fertilization of enclosures with P. However, it does not fit the TP-chla or the total nitrogen-chla plots from the temperate zone. This suggests that, in this saline lake at least, much of the TP is unavailable to the algae, with some of it in a particulate form that is readily extracted with boiling water. The epilimnetic N:P ratios also characterize lakes Oloidien and Sonachi lakes as highly P deficient and lake Naivasha as more moderately P limited. A single set of measurements in Winam Gulf (Lake Victoria) also showed a rapid P turnover time and thus P limitation, but as in lake Sonachi much of the TP was in a non-algal particulate form. Occasional measurements in three other hypertrophic and saline lakes suggest them to be primarily light limited on the basis of their very high photosynthetic cover. These findings support the hypothesis of a primary P limitation for those lakes not light limited, and contradicts literature suggestions that nitrogen is the primary limiting element in tropical lakes.

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Section: Discussionsupporting

confidence: 77%

Phosphorus limitation in some tropical African lakes

Kalff

1983

Hydrobiologia

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“…In Neusiedlersee, both the average (0.89%) and the maximal (almost 4%) values were very high. Light limitation can result in increased cellular chlorophyll a (Ahlgren, 1970;Pork & Milius, 1978;Desortova, 1981;Hunter & Laws, 1981) which, at least to some extent, explains our high values. Another, perhaps more important factor, is the underestimation of phytoplankton biomass when picoalgae are not included in routine phytoplankton countings.…”

Section: Ur~l~imentioning

confidence: 75%

Meroplankton dynamics in a saline, turbulent, turbid shallow lake (Neusiedlersee, Austria and Hungary)

Padis�k

Dokulil²

1994

Hydrobiologia

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Phytoplankton species composition, horizontal distribution, seasonal-and long-term dynamics are investigated in relation to some environmental factors, based on about 700 samples taken between 1968 and 1992 in the shallow, turbid, turbulent, saline Neusiedlersee (Austria/Hungary). We deduced:1. The phytoplankton is relatively poor in species which is attributable to high salinity and turbidity. Blue-green algae of picoalgal size, meroplanktonic diatoms, green algae either with gelee or elongated form are the most important groups in the plankton; 2. No consequent horizontal differences in the distribution of phytoplankton biomass were found; the high contribution of diatoms (69%) and green algae (22%) is characteristic;3. Despite the low percentage contribution (0.54%) of phytoplankton dry weight in total seston, the two variables correlate closely because of simultaneous resuspension after wind actions. The prevalence of both low phytoplankton/seston ratio and significant correlation between these two variables is indicative to the presence of a meroplankton; 4. Phytoplankton biomass, especially that of diatoms, varies within wide limits in the short term as a combined effect of growth/loss, transport by horizontal water currents and periodic resuspension from the sediment surface. Diatoms like Fragilaria, Surirella and Campylodiscus are involved especially. Parameters of population dynamics (growth rate, annual cycles, length of stationary phases, standing crop) were estimated based on moving averages. Growth rates were smaller than those of 'normal' planktonic species; however, the similarities of seasonal pattern suggest that the carrying capacity of the lake is very constant; 5. Picoalgal biomass is very high in the lake; its contribution to total biomass can exceed 75 %, especially in spring. The large cellular chlorophyll a content of Neusiedlersee's phytoplankton can most probably be explained by this high picoalgal standing crop, which is not included in the routine biomass estimations;6. Concerning long-term changes of phytoplankton, periodic appearances and disappearances are very characteristic. Annual average biomass of most species is growing for several (3-5) years, then declining with a similar rate and these periods are recurrent. Climatic drying-out periods, during which water level lowers, conductivity increases, nutrients and their ratios change following trend-like periodicities, and they are supposed to be responsible for the observed longterm periodicity of dominant species. An increased nutrient load in the seventies was superimposed on this cyclicity; 7. Most of the species can be found in smaller or larger amounts in the littoral microhabitats (canals, inner ponds) of the lake in periods when they are absent or very rare in the open water. Thus, these littoral microhabitats play a very important role in the survival and recruitment of planktonic populations to the open water.

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“…14). However, it does not fall below 1.6 mg/l, and should therefore not limit diatom growth (see for example Ahlgren 1970;Bailey-Watts 1976). The low Si/P ratio, perhaps in combination with high metal concentrations, is probably the reason for the abrupt decline of the diatom population in Lake Ala Lombolo (mainly Diatoma tenuis Agardh), being replaced primarily by the green alga Tetraëdron minimum (A. Braun) Hansgirg.…”

Section: Fig 14mentioning

confidence: 99%

Interpretation of Si concentrations in lake sediments: three case studies

Peinerud

2000

Environmental Geology

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The biogenic Si concentration in a sediment can be determined as the non-detrital Si concentration by normalization of the total Si concentration with Al. This procedure is based upon the assumptions that (1) that Al exists predominantly in detrital, i.e. minerogenic, particles and (2) that biogenic Si (mainly diatom frustules) is the dominating non-detrital Si phase. This paper focuses on the reasons for the variations of the non-detrital Si concentration in these lake sediments. Data from three lakes are presented, representing three principally different cases regarding the Si concentration. The processes controlling the concentrations of detrital and non-detrital Si are discussed.

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Limnological studies of lake Norrviken, a eutrophicated Swedish lake

Cited by 34 publications

References 15 publications

Phosphorus limitation in some tropical African lakes

Phosphorus limitation in some tropical African lakes

Meroplankton dynamics in a saline, turbulent, turbid shallow lake (Neusiedlersee, Austria and Hungary)

Interpretation of Si concentrations in lake sediments: three case studies

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