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1

The freshening history of a brackish water bay described by sediment diatoms

100%
Eloranta P.
Oceanological Studies
|
1999
|
vol. 28
|
issue 1-2
51-57
EN
The Luodonjarvi bay was cut off from the northern part of the Bothnian Bay (Baltic Sea) in 1962 by a dam to provide a supply of freshwater. The bay is fed by river water from small rivers. Monitoring results have indicated a rather fast (ca 2 years) change from brackish to freshwater. According to sediment diatom analyses, the process has lasted much longer. The northern part of the reservoir is affected by acid river waters, but some of the original brackish water is still there. The freshening process is described using different ecological groupings of diatoms.
2

Assessment of river health in Australia by diatom assemblages ? a review

51%
John J.
Oceanological and Hydrobiological Studies
|
2004
|
issue 2
95-104
EN
This paper summarises the findings of two national projects carried out by the author, covering the largest area ever investigated on the use of diatoms for monitoring river health in Australia, as well as to recommend future directions in diatom river monitoring in Australia. The first project (1995 to 1998) involved South-west Western Australia ? well known for its forests and abundance of streams and rivers. Data on environmental variables and diatom taxa were obtained from 136 sites, out of which 117 were used as reference sites and 29 as monitoring (impacted) sites. Some 20 sites were randomly selected from the reference sites and used as ?test sites? to verify internal consistency of the reference sites which were considered to be relatively pristine. The streams and rivers were finally classified into four distinct groups based upon environmental factors and diatom distribution pattern. The second project involved monitoring the health of urban streams around the city of Perth, western Australia. The investigation (1996 to 1999) focussed on classification of the urban streams based on water quality parameters and ?stream conditions? and development of a predictive model using diatoms as biomonitors. Close to 180 sites were sampled with 30 environmental variables measured. All the sites were classified on the basis of seven environmental variables with the highest correlation coefficient with the sites, using the multivariate pattern analysis program PATN. The reference and monitoring sites were mostly separated on the basis of environmental factors and distinct diatom assemblages. Currently, a national protocol for assessing the health of all rivers using diatoms in Australia is being compiled.
3

Microphytobenthos of the shallow littoral of the Southern Baltic

51%
Plinski M., Kwiatkowski J.
Oceanological Studies
|
1996
|
vol. 25
|
issue 4
65-79
EN
The microphytobenthos is the ecological fraction of small plant organisms found in sediments. Hitherto only a few investigations into the microphytobenthos in the southern Baltic have been carried out. The objective of the present study was to determine the species com-position and relative abundance of epipsammic taxa in the shallow littoral zone in the southern Baltic as well as the seasonal fluctuations at selected stations in the Gulf of Gda?sk. The results indicate that three regions of the Polish coastline can be distinguished with respect to the spe-cies composition of microphytobenthic diatoms. The distribution of diatom species is probably related to the environmental conditions occurring in particular regions of the Polish coastline. The percentage of certain diatom species tends to follow a clear seasonal pattern.
4

The bentic diatoms of the Bandar Tawahi (Gulf of Aden, Republic of Yemen)

51%
Bafana C. A., Witkowski A.
Oceanological Studies
|
1995
|
issue 69/10
77-96
EN
Diatoma from the surface sediments of the coastal area of Bandar Tawahi, a small embayment of the Gulf of Aden (Khormaksar), were studied by means of light (LM) and electron microscopes (SEM and TEM).Species analysis revealed the presence of numerous taxa, some of which are rare and little known such as: Mastoneis biformis, Navicula giffeniana and N. platyventris.In the case of each species, the ecological requirements (salinity preferences, life form) and geographical distribution are given.
5

International and European standards for algal-based monitoring

51%
Kelly M.
Oceanological and Hydrobiological Studies
|
2004
|
issue 1
77-81
EN
International and European standards relevant to algal-based monitoring have been developed by the International Standards Organisation (ISO) and the Comite Europeen de Normalisation (CEN). This work has been given new impetus by the publication of the EU Water Framework Directive (2000/60/EC), which requires the use of CEN and ISO standards where available. Standards addressing diatom sampling and analysis, macrophyte survey, algal survey and phytoplankton analysis are all either published or under development by CEN. There is also a standard under development dealing with quality assurance of ecological assessments in the aquatic environment. Together, these standards should ensure that robust data are collected that can be used for intercalibrations between Member States.
6

A diatom record of late Holocene environmental changes in the Gulf of Gdansk

51%
Witak M.
Oceanological Studies
|
2000
|
vol. 29
|
issue 2
57-74
EN
The aim of this study was to analyse fossil and subfossil diatom floras preserved in a sediment core taken from the Gulf of Gdansk, near the eastern end of the Hel Peninsula. The diatom record, supported by lithology and radiocarbon data, indicates environmental changes during the later stages of development of the Baltic Sea. In the Litorina Sea stage the diatom flora developed under marine conditions, whereas during the Post-Litorina stage there was a decrease in salinity. During the Subatlantic period the sublittoral diatom flora was replaced by shallow water diatoms originating from the coastal zone, and were redeposited in the deeper part of the basin. In the surface sediments the change to a presumably anthropogenically-influenced diatom flora can be attributed to the eutrophication of the Gulf of Gdansk.
7

Diatom record of northeast Atlantic circulation changes in marine isotope stages 1 and 5

45%
Witak M., Kuijpers A.
Oceanological Studies
|
2001
|
vol. 30
|
issue 1-2
21-38
EN
Fossil and subfossil diatom floras were analysed in a sediment core taken near the outlet of the Faroe Bank Channel, NE Atlantic. Diatom preservation horizons were found at various levels in the core. The correlation with the oxygen isotope stratigraphy of the core indicates that these horizons correspond to the Marine Oxygen Isotope Sub-Stages 5e (Eemian), 5a and Stage 1 (Holocene). Results of the study show that environmental conditions for the development of diatoms were more favourable in Stage 5 than in the Holocene. At the very beginning of the Sub-Stages 5e and 5a distinct changes in the diatom concentration are indicative of circulation changes probably associated with a marked intensification of the North Atlantic Current. The highest surface water temperature is indicated by the diatom flora from early Sub-Stage 5e.
8

Benthic diatoms in polluted river sections of Central Poland

45%
Rakowska B.
Oceanological and Hydrobiological Studies
|
2004
|
issue 1
11-21
EN
Water quality was investigated in the most polluted sections of three rivers in Central Poland: the Rawka, Jeziorka and Bzura. The estimate was carried out using the Lange-Bertalot indicatory method, which is based on various diatom tolerances to pollution, and by calculating the saprobity index of Pantle & Buck. In the investigated rivers, Cocconeis pediculus, C. placentula, Fragilaria construens, F. pinnata, Gomphonema olivaceum, Melosira varians, Meridion circulare, Navicula lanceolata were the most frequent dominants of species sensitive to pollution. The most frequent tolerant species were Achnanthese lanceolata ssp. frequentissima, Cymbella silesiaca, Fragilaria capucina var. vaucheriae, F. ulna, Navicula capitata var. capitata, N. gregaria, N. pupula, and Nitzschia amphibia. The dominants of the resistant group were Gomphonema parvulum, Navicula saprophila, N. veneta, and Nitzschia palea. On the basis of the methods mentioned above, the water of the Rawka River was assigned to water quality class II/II-III, that of the Jeziorka to class II-III/III and that of the Bzura (at both study sites) to class II-III.
9

Eutrophication of Lake Swiete (Gniezno, Western Poland) as evidenced by succession of algal assemblages in sedimentary record

45%
Machowiak D.
Oceanological Studies
|
1998
|
vol. 27
|
issue 2
83-86
EN
The subject of the study was to the compare results of phytoplankton and the sediment core analyses from several lakes in Wielkopolska (Western Poland). Species composition of algal assemblages occurring in these lakes changed as would be expected for increasing trophic conditions. Along with progressive eutrophication diatom taxa belonging to genera Stephanodiscus and Cyclotella became replaced by green algae and finally by blue-green algae. The dominance of blue-green algae is attributed to hypertrophic conditions.
10

A first ecological evaluation of the diatom flora in Central Europe: species diversity, selective human interactions and the need for habitat protection

45%
Lange-Bertalot H.
Oceanological Studies
|
1998
|
vol. 27
|
issue 2
5-12
EN
The recently revised check-list of diatoms found in Germany contains 1437 taxa (1632 taxa have been recorded for Central Europe). Clear correlations with ecological conditions were established for 1000 taxa (70% of 1437). 267 predominantly marine taxa also occur in inland waters; they penetrate progressively into rivers contaminated with industrial waste waters. 61 taxa are aerophilic and 164 eutraphentic, 91 tolerant to all trophic conditions. Very few species in these ecological groupings are endangered. However, at last 417 oligo- or slightly mesotraphentic taxa are included in the 'Red List'. This strongly indicates that conserving oligo- and dystrophic waters as well as lower mesotrophic habitats can best protect species diversity.
11

Diatom indices and stream typology in Estonia

45%
Vilbaste S., Jarvekulg R., Pall P., Piirsoo K., Trei T., Viik M.
Oceanological and Hydrobiological Studies
|
2004
|
issue 1
3-10
EN
This paper deals with the use of diatom indices in the assessment of streams in Estonia. The problem addressed is how rational it is to determine different types of streams or stream reaches based on diatom research. At the moment, there are five different typologies of running waters in Estonia, two of which are analyzed here. Diatom indices can be employed to assess the ecological quality of water but not the status or type of stream. The most promising diatom indices for such assessment are the Trophic Diatom Index, Watanabe Index, Descy Index, and Schiefele & Schreiner Index.
12

Diatom communities in Moss Creek (King George Island, South Shetland Islands, Antarctica) In two summer seasons: 1995/96 and 2001/02

45%
Noga T., Olech M. A.
Oceanological and Hydrobiological Studies
|
2004
|
issue 4
103-120
EN
This paper focuses on the diatom flora of Moss Creek in Antarctica that was collected during two summer (1995/96 and 2001/02) seasons. Of the 95 taxa identified in Moss Creek, two groups of diatom communities were distinguished. Achnanthes germainii, Eucocconeis ninckei, and Nitzschia homburgiensis, taxa indicative of unpolluted waters, dominated in the upper course of the creek. The other group was found in the lower reaches of the creek and included taxa indicative of eutrophic environments. In this part of the creek Mayamaea atomus associated with Nitzschia gracilis and Planothidium lanceolatum were dominant. In both sampling periods the species composition of the dominant taxa was similar with the distinct predomination of Mayamaea atomus. During the 1995/96 season, Nitzschia gracilis, N. homburgiensis, and Planothidium lanceolatum also occurred abundantly, whereas in 2001/02 the proportions of Nitzschia gracilis and Planothidium lanceolatum showed a slight increase.
13

Holocene environmental instability as recorded in a core from the Slupsk furrow, Southern Baltic

45%
Zgrundo A.
Oceanological Studies
|
1999
|
vol. 28
|
issue 3-4
59-73
EN
The aim of the study was to investigate Holocene history as recorded in a single sediment core taken from the Slupsk Furrow, southern Baltic Sea, with the use of diatom analysis. Diatom stratigraphy and abundance of cysts of Chrysophyceae Pascher enabled the changes in salinity and depth of the Baltic during the last 7500 years or so to be followed. Four developmental stages of the Baltic Sea were distinguished on this basis: the decline of the Ancylus Lake (or the Ancylus/Mastogloia transition), the Mastogloia Sea, the Litorina Sea and the Postlitorina Sea.
14

Applicability of diatom indices for monitoring water quality in coastal streams in the gulf of Gda?sk region, northern Poland

45%
Zgrundo A., Bogaczewicz-Adamczak B.
Oceanological and Hydrobiological Studies
|
2004
|
issue 3
31-46
EN
This aim of this study was to test the applicability of diatom indices developed in Europe for monitoring coastal stream waters in northern Poland. Water, sediment, and diatom samples were taken from streams in the resort town of Sopot that discharge into the Gulf of Gdansk. The physical and chemical measurements taken during the sampling period indicated that the purity of the stream waters had improved, and recently they were classified as I class water purity. This is contrasted by the studied waters? diatom communities, which were dominated by eutraphentic taxa. High abundances of -mesosaprobic and -mesosaprobic taxa were recorded at most of the sites. Diatom indices developed for water quality surveillance were calculated with the Omnidia3 database software. Redundancy analyses (RDA), an ordination technique, was used to determine the indices that best correspond to water pollution in coastal streams. The results of the present study indicate that the pollution indices that follow can be applied successfully to monitor flowing freshwaters in the Gulf of Gdansk area in northern Poland: IDAP (Indice Diatomique Artois-Picardie); SPI (Specific Polluosensivity Index); EPI-D (Eutrophication/Pollution Index based on Diatoms), which integrates organic pollution, eutrophication, and mineralization.
15

Water quality study of the Condor and Capivara streams, Porto Alegre Municipal District, Rs, Brazil, using epilithic diatom biocenoses as bioindicators

38%
Lobo E. A., Callegaro V. L. M., Wetzel C. E., Hermany G., Bes D.
Oceanological and Hydrobiological Studies
|
2004
|
issue 2
77-93
EN
The aim of this work was to evaluate the water quality of two urban streams, Condor and Capivara, in the Municipal District of Porto Alegre, RS, Brazil, by measuring physical, chemical and biological variables. Between May 1999 and August 2000, six field trips were taken to sample five sites distributed along the streams. Multivariate canonical correspondence analysis (CCA) was applied for the complete evaluation of physical, chemical and biological data. It was confirmed that phosphate had the largest impact on ordination and exhibited an evident eutrophication gradient. Mayamaea atomus, Amphora montana, Sellaphora pupula and Cyclotella meneghiniana were extremely abundant under such conditions.
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