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Findings of Alona protzi Hartwig 1900 (Branchiopoda: Anomopoda. Chydoridae) in Finland

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Nykanen M. , Sarmaja-Korjonen K.

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2007

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tom Vol. 24

73-77

EN

Alona protzi is a rare species of Cladocera, occurring in lake littoral throughout Europe. However, little is known about this animal, and so far it has not been included in provisional lists of species found in Finland. In this short report we present our findings of Alona protzi, both recent and subfossil material, as well as one previous, unpublished finding site of the species in Finland. We found three subfossil shells of this species in the bottom sediments of two lakes. In a third lake we found intact animals, an ephippial female and a male, while sampling stony bottom of lake littoral.

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Langzeituntersuchungen (1969-2002) zur verbreitung der cladoceren auf den niedersächsischen sandinseln der sudlichen Nordsee, Deutschland

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Hollwedel W.

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2004

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tom Vol. 21

25-36

EN

From 1969 to 2002 the distribution of cladoceran species on ten islands in the southern North Sea was investigated. A total of 50 species was found. The small water bodies in the salt marsh have to be resettled after salt water floods; Macrothrix hirsuticornis and Moina brachiata are two of the pioneer species in the brackish water bodies. Most cladoceran species were found in permanent and temporary dune waters. Some of them were caught only occasionally and in low abundance. A characteristic species of dune waters is Scapholeberis rammneri, which was detected on eight islands. A small group of cladoceran species inhabited concrete basins containing drinking water for cattle and horses. The Hammersee on Juist island, a shallow freshwater lake since a dyke had been built in 1928, was inhabited by 35 species. Within the last decade the species number decreased because of eutrophication and biotopes being filled up by sedimentation. On islands with newly dug water bodies species number increased. The two species, Macrothrix hirsuticornis and Scapholeberis rammneri, characteristic of the islands in the southern North Sea, are endangered due to changes and losses of habitats on all but one (Wangerooge) islands.

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Recent sedimentation and eutrophication of kruklin lake after artificial drop in water-level in the middle of 19th century

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Gąsiorowski M. , Hercman H.

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tom Vol. 22

17-25

EN

Sediments of two short cores collected from two basins of Kruklin Lake were studied by means of 210Pb and Cladocera analyses. The 210Pb allowed to date sediments and was helpful to obtain changes of sedimentation rate during the last two centuries. The CRS model was applied to calculate sediments age. Sedimentation rate differed strongly (from 0.55 cm/yr to 6.25 cm/yr) not only in time, but also between each basin. An accurate chronology of sediments was the basis for tracking of palaeolimnological changes with Cladocera analysis. Cladoceran planktonic:littoral ratio reflects event of artificial drop of lake water-level in the middle of nineteenth century. However, this event was recorded only in sediments of the southern, shallower basin and we suggest, that cladoceran planktonic:littoral ratio is better representative in shallow lakes. Changes of Cladocera assemblage composition suggest also strong eutrophication of lake water during the last century.

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Analysis of zooplankton assemblages from man-made ditches in relation to current velocity

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Czerniawski R. , Sługocki Ł.

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tom Vol. 46, No. 2

199--211

EN

Because of the slow current velocity, man-made ditches may create distinct physical and ecological conditions that are suitable for the growth of zooplankton populations. However, the influence of drainage ditches on zooplankton communities has not been studied yet. This study aims to answer the following questions: i) Are man-made ditches a rich source of zooplankton? ii) What current velocity value leads to abundant zooplankton in man-made ditches? iii) Do zooplankton communities differ between man-made ditches and connected natural streams? In man-made drainage ditches with a water current lower than 0.1 m s-1, the abundance of zooplankton was greater than in the majority of streams. Sometimes this level of abundance was equivalent to the densities of zooplankton in lakes or dammed reservoirs. The presence of zooplankton in man-made ditches may be of great importance to the establishment of food webs, particularly during periods of high water levels or heavy rainfall, both of which may accelerate the water current, causing the dispersion of zooplankton along the ditches and into natural streams.

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Instability of spring environmental conditions as a driver of biotic interactions and crustacean structuring in meteorite crater ponds (Morasko, Poland)

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Świdnicki K. , Basińska A. M. , Kuczyńska-Kippen N.

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2016

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tom Vol. 45, No. 1

66--78

EN

There are 150 meteorite craters worldwide, however, their aggregations are rarely noted. The nature reserve ‘Meteoryt Morasko’ in Poland with fishless meteorite ponds was analyzed as a unique ecosystem for biological analysis of invertebrate interactions. The aim of the study was to recognize the main environmental drivers of cladoceran and copepod community structure from among biotic (competitors and predators) and abiotic factors (i.e. oxygen and pH level) in the spring season. The abundance of small cladocerans (Alonella excisa and Chydorus sphaericus) was the highest at the end of the spring season, i.e. in June, while large species (Daphnia pulex and Simocephalus exspinosus) were most abundant in May. Both size groups of Cladocera were negatively affected by invertebrate predators (Chaoborus crystallinus and carnivorous copepods), which are known to play an important role in structuring cladoceran communities due to the fishless character of the studied ponds. No negative effect of those predators was found for Copepoda, however, nauplii density was reduced by competitors (Aedes communis larvae and ostracods). The temporary character of the examined ponds, oxygen depletion and low pH of water in the shallowest pond resulted in the abundant occurrence of cladoceran males, whose high densities are usually observed in autumn.

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Late holocene water-level changes in lake iso lehmalampi, southern finland, reflected in subfossil cladocerans and chironomids

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Nevalainen L. , Luoto T. P. , Sarmaja-Korjonen K.

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tom Vol. 25

33-42

EN

Analyses of subfossil cladocerans (Crustacea: Cladocera) and chironomids (Diptera: Chironomidae) were applied to examine water-level changes in a small and oligotrophic lake in southern Finland over the past 2000 years. Major changes in the invertebrate communities occurred ca. 400 AD onwards when the littoral cladoceran Alonella nana started to replace the planktonic Eubosmina as the dominant species and chironomids Psectrocladius sordidellus group and Zalutschia zalutschicola increased. These changes were most likely due to a decreasing water level and an enlarging proportion of the littoral area, providing suitable vegetative habitats, e.g. aquatic bryophytes (mosses), for these taxa. The lowering water level reached its minimum just before the Medieval Warm Period, ca. 800-1000 AD, after which the lake level rose again and remained high until modern times. A prominent change in the chironomid assemblages occurred during the 20th century when Ablabesmyia monilis and Chironomus anthracinus type increased, presumably due to changes in water chemistry, caused by anthropogenic load of pollutants.

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Evolution of an Eemian lake based on Cladocera analysis (Konin area, Central Poland)

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Pawłowski D.

Acta Geologica Polonica

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2011

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tom Vol. 61, no. 4

441-450

EN

The succession of Cladocera assemblages in the Eemian Sławoszewek palaeolake (Central Poland) and the inferred environmental parameters are presented. The Cladocera assemblages provide a rich and relatively complete record of the Cladocera succession of the Eemian Interglacial, and are similar to those from other Eemian sites in Poland. The species composition and the variability in frequency of specimens of Cladocera made it possible to distinguish five zones of their development, which correlate well with pollen data. The Sławoszewek palaeolake existed from the early Eemian to the late Eemian Interglacial; at the end of the middle Eemian, the lake dried up temporarily. The cladoceran assemblages show that the initial shallow, oligotrophic status of the lake was followed by an increase to eutrophic status, especially during the interglacial optimum. Based on cladoceran composition, changes in climatic conditions in the mid-pollen zone E1, the late pollen zone E5 and in pollen zone E7, were recognized. It appears that cladoceran development was due mainly to climate changes, but also to changes in the locally prevailing conditions within the water body. The high frequency of cladocerans and the presence of cladoceran taxa preferring warmer water in mid-pollen zone E1 show an increase in temperature. The appearance of cold-tolerant Cladocera species at the end of pollen zone E5, suggests unfavourable conditions, probably cooling. Changes in Cladocera patterns in pollen zone E7 show that warm conditions still obtained in this area.

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Two climatic oscillations during the eemian interglacial : preliminary results of multi-proxy researches of palaeolake at solniki, Ne Poland

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Kupryjanowicz M. , Ciszek D. , Morosław-Grabowska J. , Marciniak B. , Niska M.

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tom Vol. 16

53--57

EN

Lake series from the Eemian Interglacial and Early Vistulian has been discovered at Solniki in the Białystok Upland region, north-eastern Poland. Preliminary results of interdisciplinary researches (pollen, diatom, Cladocera, isotopic and magnetic susceptibility analyses) were used to illustrate the changes of the Eemian climate. At present stage of investigations, there are found signs of two abrupt climatic oscillations - first with very humid climate took place at middle part of the regional Carpinus pollen zone (E5 R PAZ), and second with cold and dry climate at middle part of the regional Pinus zone (E7 R PAZ).

PL

W Solnikach na Wysoczyźnie Białostockiej (północno-wschodnia Polska) odkryto serię osadów jeziornych reprezentujących interglacjał eemski i wczesny vistulian. Wstępne wyniki badań interdyscyplinarnych (analiza pyłkowa, okrzemkowa i Cladocera, pomiary podatności magnetycznej osadów oraz zawartości izotopów stabilnych tlenu i węgla) wykorzystano do zilustrowania zmian klimatu podczas interglacjału eemskiego. Udokumentowano dwie gwałtowne oscylacje klimatu - pierwsza z ciepłym i bardzo wilgotnym klimatem (?opady) miała miejsce w środkowej części poziomu pyłkowego E5 Carpinus, druga z klimatem suchym i bardzo zimnym - w środkowej części poziomu E7 Pinus.