Half a century of oligochaete research in Estonian running waters (original) (raw)
Related papers
Micro-distribution of oligochaetes in a soft-bottomed lowland stream (Elsbeek; The Netherlands)
Aquatic Oligochaetes, 1999
This study focuses on a low-gradient, soft-bottomed stream which shows strong fluctuations in discharge, partly natural (i.e. due to rainfall) and partly due to agricultural land-use. This dynamic discharge pattern causes silt deposition between discharge peaks which in turn cause the silt to be washed out. This process occurs independently from the height of the peak. The main substrate in the stream is quite homogeneous fine sand. Twenty-three species of oligochaetes were found. Their distribution and abundance varied with season and substrate. Mature tubificids and Lumbriculus variegatus occurred throughout the year. Stylodrilus heringianus occurred in winter and spring. Different naidids occur in different seasons, though half of the species can be collected all year. The micro-habitat of three tubificids, one lumbriculid and eight naidids were be identified. A high number of oligochaete species coexisted in a small stretch of the stream due to a separation in micro-habitat in space and time. The temporal variation in distribution was due to season. Particle size, the mineral and organic component of the substrate, and position in the stream bed influenced the spatial distribution of species. Temporal and spatial distribution of oligochaetes can not be separated.
In order to determine the oligochaeta fauna of Lake Sapanca (Turkey) samples were collected from 5 stations monthly, between September 2000-August 2001. As a result of the study, 13 species, which belong to 9 genera, were determined. These species are Aulodrilus limnobius, Tubifex tubifex, Tubifex ignotus, Tubifex nerthus, Limnodrilus hoffmeisteri, Potamothrix hammoniensis, Potamothrix vejdovskyi, Nais communis, Spirosperma ferox, Psammoryctides barbatus, Ilyodrilus templetoni, Psammoryctides deserticola, Paranais frici. Also some physicochemical parameters of the water (temperature, dissolved oxygen, pH, turbidity and depth) were measured at the sampling site. The average density of total oligochaetes in the benthos of the lake was 1,887 ind m-2. According to Shannon-Wiener index, Lake Sapanca was found had 2.59 richness and, 5 th station were found to have highest diversity (3.87) while 3 rd station to have the lowest (1.59). There are almost no data on the Oligochaeta fauna of this lake so far. Hence, all the determined taxa from the localities are recorded for the first time.
Aquatic Oligochaete Biology VIII, 2001
The species composition of the Scandinavian freshwater oligochaete fauna is strongly influenced by its post-glacial history . Few species are likely to have survived in the core areas of glaciation and the present composition of species has thus been highly dependent upon the immigration rate of 'new' species . Active immigration into new localities has proven to be a very slow process, whereas passive transportation in running water and by rafting is much faster. Exchange of ballast water in harbours is likely to be the single most effective action by man, causing large-scale passive dispersal of the aquatic fauna and flora. Bottom water with stirred-up sediment containing oligochaetes could thereby be sucked into the tanks of ships and later exchanged in nearby and distant ports. Ponto-Caspian species among the Tubificidae, originating in the Black Sea-Caspian Sea region, are continuously dispersing to the west over Central Europe and to the north-west towards the Baltic Sea area adding to the species list of the Tubificidae. Five such species of the genus Potamothrix have quite recently reached eastern Sweden . The dispersal front presently goes obliquely across Scandinavia from the north-east to the south-west. Comparisons with results from previous bottom-sampling series in Lake Mälaren from 1915 to 1916 revealed ongoing colonization, especially in those basins of the lake which were in recent contact with the Baltic Sea and thus had brackish bottom water. One of those species, Potamothrix heuscheri, which is particularly tolerant to anoxic conditions and high salinity and is likely to have reached Scandinavia in ballast water possibly via indirect sources from the Mediterranean Sea. Its uneven distribution in Scandinavia is well correlated with historic water-ways for heavy transport, for instance via cargoes of wood pulp from Lake Munksjön to the south of Lake Vättern and to and from other cellulose industries on the Baltic coast. It is speculated that distant occurrences of P. heuscheri in Africa and South America may have been reached through passive transport in the plumage of migrating wading-birds.
Springer eBooks, 2001
In most soft-bottomed, lowland streams in the Netherlands discharge regimes largely follow the precipitation pattern. Winter discharges are higher and much more dynamic then summer discharges, although rain storms throughout the year cause unexpected peak flows. Minimal precipitation, reduced stream flow and droughts can occur during the summer months. Lowland stream habitat, particularly in The Netherlands, is hydrologically dynamic, with substrates frequently moved or disturbed. Differences in discharge patterns in Dutch soft-bottomed lowland streams are expected to affect distribution patterns of macroinvertebrates and thus oligochaetes. Ten small to medium sized lowland streams, differing from one another in hydrological regime, were studied. Five major habitats in each stream were assessed on three occasions over a 15-month period. Each habitat sampled with a micro-macrofauna shovel; during each sampling period, several environmental parameters, especially hydrological and substrate parameters, were measured. Ordination (CANOCO) (Ter Braak, 1989) and statistical tests (chisquared test) (Lindgren & McElrath, 1970) were used to determine the major oligochaete distribution patterns between streams as well as between habitats within each stream. Each stream was characterized by its oligochaete assemblage; general distribution patterns and individual oligochaete-substratum relationships were documented. Hydro-morphological parameters together explained the differences in major distribution patterns. Preferences of oligochaetes for specific structural habitats are discussed.
Aquatic Oligochaete Biology VIII, 2001
The oligochaete fauna of 57 small streams of the Morava and Odra River basins, Czech Republic, was studied during 1997 and 1998. TWINSPAN and CCA (CANOCO) were used to characterize the relationship between oligochaete species, habitat diversity and environmental variables. Chemical oxygen demand (COD), water hardness, NO 3 −-N, Ca 2+ , Mg 2+ , altitude, and substrate type were found to be the primary factors influencing the distribution of aquatic Oligochaeta.
Distribution and diversity of aquatic Oligochaeta in small streams of the middle taiga
Turkish Journal of Zoology
Th e goal of the present study was to describe the fauna, community structure, distribution, diversity, abundance, and ecology of Oligochaeta in small streams of the Komi Republic. Th e work was performed in 13 streams located in the Vychegda River basin during the month of July, 2005-2008. During the study, 48 taxa from 7 families were collected. Th e habitat of each study stream was determined with respect to chemical water composition (Na + , Mg 2+ , Ca 2+ , Cl-, and total phosphorus (P tot), among others) and some environmental factors: bottom structure (hard or soft), water temperature, depth, fl ow velocity, moss or algae cover, etc. Th e species composition, diversity, and determination of the small streams' aquatic Oligochaeta as well as the infl uence of diff erent ecological factors on these characteristics were analyzed and discussed. Th e number of species, their composition, and the average abundance and biomass of Oligochaeta were found to depend upon bottom texture, current velocity, moss or algae cover, water temperature, and changes in the water chemicals (Na + , Mg 2+ , and P tot concentrations), as well as the nitrogen, carbon, and humus contents in the bottom sediments.
Estonian Journal of Ecology, 2008
According to the EU Water Framework Directive, benthic macroinvertebrates are considered a biological quality element required for typology and classification of the ecological status of freshwaters. The effects of habitat, season, and sampling effort on three common quality metrics were studied in Estonian streams. More than 900 macroinvertebrate samples from minimally disturbed sites, collected in 1985-2002, were analysed. All metrics were significantly influenced by stream size, bottom substrate, flow velocity, and geographical location. The biological quality was the best 30-50 km from the stream source. The geographical distribution of the values of ASPT (mean sensitivity of a taxon) and DSFI (level of organic pollution) was markedly different from the geographical distribution of the values of NTAXA (taxa richness). All metrics also revealed lower quality for sandy than for stony bottom, and for low than for high flow velocity (except NTAXA). Unlike the other two metrics, ASPT did not depend on sampling season and depended much less on sampling method. Hence it could be recommended as a tool for transforming the biological quality derived from historical non-standard samples into modern terms.
The biology of Oligochaeta from Dorset chalk streams
Freshwater Biology, 1971
Fewer species and more individuals of Tubificidae were present in the soft sediments of a polluted ditch than in the relatively unpolluted Bere Stream. Changes in width frequency of natural populations of Tubifex tubifex and Limnodrilus hoffmeisteri throughout the year were similar at both the sites investigated. In laboratory experiments larger populations of Tubifex tubifex developed in fine sediments than coarse. By means of a width-<lry-weight relationship it was possible to estimate the weight of the experimental populations.
Oligochaete assemblages of Swiss Alpine lakes
Italian Journal of Zoology, 2014
Th e profundal oligochaete fauna is mostly formed of species present also in shallower waters. Endemic taxa have developed only in ancient rift lakes like Lake Baikal. "Common" lakes, mostly of glacial or volcanic origin, are too ephemeral for speciation. In the profundal of larger European oligotrophic lakes, there can occur about 10 tubifi cid and lumbriculid species. With a decline in dissolved oxygen in water, only 1-2 of them will remain, Tubifex tubifex oft en being the last survivor. In eutrophic lakes, Potamothrix hammoniensis is the climax species. In the Far East, the profundal is also inhabited by a small assortment of oligochaetes from surrounding waters. In the eutrophic lakes of Honshu (Japan), the widely distributed species Limnodrilus hoff meisteri and T. tubifex dominate, while more species occur in the northern oligotrophic lakes. In the eutrophic lakes in China, L. hoff meisteri or Branchiura sowerbyi dominates. Th e zoogeographical origin of the commonest profundal oligochaetes is discussed.