Transplanting macrophytes as a rehabilitation technique for lowland streams and their influence on macroinvertebrate assemblages.

Lowland streams are usually affected by river engineering works that produce the loss of habitat heterogeneity. Our aim was to assess the transplantation of macrophytes with different complexity into a lowland stream which was dredged and widened. Stuckenia pectinata and Hydrocleys nymphoides were collected at an extraction site and installed at a transplant site.

Chironomid genera distribution related to environmental characteristics of a highly impacted basin (Argentina, South America).

The objective of the present study was to investigate the responses of the chironomid communities (Diptera: Chironomidae) to environmental variables in four moderately and highly disturbed rivers located in one of the most degraded watersheds in South America. Sampling campaigns were carried out during 2014-2016 in four sites of the Matanza-Riachuelo basin. The physical-chemical and hydrological variables were measured and, the ecological indices were calculated and evaluated by ANOVA.

Assessing the sensitivity of leeches as indicators of water quality.

The objective of this work was assessing the sensitivity of leeches to several water quality attributes in lowlands streams. We used occupancy modelling that account explicitly for detectability, to estimate the influence of four variables (dissolved oxygen, 5-days biochemicals oxygen demand, conductivity, and dissolved inorganic nitrogen) affecting nine species. We described the sensitivity as a change in the occupancy along the range of water quality attributes.

Ecology of the non-native snail Sinotaia cf quadrata (Caenogastropoda: Viviparidae). A study in a lowland stream of South America with different water qualities.

Sinotaia quadrata is a snail native from Asia recorded for the first time in South America in 2009 in central Argentina. In 2015, this species was also found in a lowland stream with different water qualities. Our aims were to contribute to the knowledge of its population ecology and to compare the individuals from the two locations anatomically.

Macrophytes, epipelic biofilm, and invertebrates as biotic indicators of physical habitat degradation of lowland streams (Argentina).

Our objective was to assess the effect of the physical habitat degradation in three lowland streams of Argentina that are subject to different land uses. To address this matter, we looked into some physical habitat alterations, mainly the water quality and channel changes, the impact on macrophytes' community, and the structural and functional descriptors of the epipelic biofilm and invertebrate assemblages. As a consequence of physical and chemical perturbations, we differentiated sampling sites with different degradation levels.

In situ tests for water quality assessment: a case study in Pampean rivers.

Two invertebrate species (Hyalella curvispina and Palaemonetes argentinus) and one macrophyte (Egeria densa) from a naturally high nutrient content system (Pampean rivers of La Plata, Argentina) were evaluated for their potential use in situ assays aiming to assess changes in water quality. Invertebrates were individually placed in cylindrical chambers in polluted sections of rivers and in reference upstream sites. Mortality after 48 h was high in polluted and reduced in control sites.