The spatial heterogeneity of a river bottom: a key factor determining macroinvertebrate communities

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Rapport V.12 Impact des aménagements sur la zone infralittorale méditerranéenne

Impact of managements on the mediterranean infralittoral zone Littoral managements (full-ground, dikes, harbours, artificial beaches) gained on the sea, destroy non reversiblely their own surface of submarine life and particularly complex ecosystems as the big marine phanerogams meadows.Les aménagements littoraux (terre-pleins, digues, ports, plages alvéolaires) gagnés sur la mer détruisent irréversiblement leur propre surface de vie sous-marine et notamment les écosystèmes complexes comme les grands herbiers de phanérogames marines. Mais il en est plus difficile d'en évaluer les impacts indirects qui s'étendent à l'extérieur des zones aménagées. Ces perturbations entrainées par les ouvrages varient selon la technique de construction utilisée et vont de simples modifications hydrodynamiques induisant une réosion de l'herbier de Posidonies jusqu'à sa destruction par ennoyage, sous la sédimentation des argiles et par une augmentation de la turbidité.Astier Jean-Marie, Tailliez Philippe, Moreteau Jean-Claude, Vicente Nardo. Rapport V.12 Impact des aménagements sur la zone infralittorale méditerranéenne. In: L'hydraulique et la maitrise du littoral. Problèmes côtiers posés par le mouvement des sédiments et la pollution. Dix-huitièmes journées de l'hydraulique. Marseille, 11-13 septembre 1984. Tome 5, 1984

Assessing Changes in Community Structure by Dominance Indices: A Comparative Analysis

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The role of salinity in the selection of biological traits of freshwater invertebrates.

Salinity exerts significant pressure on freshwater faunas living in slightly salted water (i.e. water with salinity < 3g L-1). Changes in seven biological and physiological characteristics of freshwater taxa belonging to natural invertebrate communities observed along a salinity gradient wer investigated. Benthic macroinvertebrates were sampled from four stations on the Meurthe River, a six-order stream in northeastern France with a gradient ranging in concentrations from 0.21 g L-1 to 2.60 g L-1 of total dissolved solids over a distance of only 19 km

A Comparative Analysis of Evenness Index Sensitivity

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Effects of mesohabitat sampling strategy on the assessment of stream quality with benthic invertebrate assemblages

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Changes in functional biodiversity in an invaded freshwater ecosystem: the Moselle River

International audienceThe spread of non-indigenous species and the decline of autochthonous ones are leading to a homogenization of freshwater fauna in terms of systematic units, but the functional consequences are poorly documented. We studied the peculiar case of the lower, French section of the Moselle River where 20 invertebrate species have been introduced since 1854, with a rate increasing exponentially with time. Dredge sampling performed in 1994, 1996, 2000 and 2001 at four sampling stations allowed for an evaluation of faunal changes in terms of composition, structure and function. During this period, no structural changes were recorded in spite of multiple, new and successful introductions. The evaluation of functional modifications was based on a typology of taxa exhibiting homogeneous biological/ecological traits. Functional diversity, measured as the diversity of taxa distribution among functional groupings, revealed a significant increase between 1994/1996 and 2000/2001 because those species that were over-represented during the former period reached more equilibrated densities during the latter. The major, indirect implications of these functional changes are discussed

Stream community structure in relation to spatial variation: the influence of habitat characteristics.

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