Field and laboratory investigations were conducted to study competition between the planorbid Anisusspirorbis and the lymnaeid Galba truncatula when these two species live in bispecific communities on sedimentary soils. In presence of adult G. truncatula, the survival of juvenile and pre-adult planorbids significantly diminished while the number of egg-masses laid by adult planorbids showed a significant decrease.

Coregonine catches declined in 67% of the 27 lakes studied across three continents in the Northern Hemisphere during the first two decades of the 21st century, with 44% showing significant trends. The analysis showed that lakes with significant catch declines were larger and nutrient-poor. The rate of change in catch appeared to be related to the trophic state of the lake, with oligotrophic and ultra-oligotrophic lakes experiencing the largest declines. While local factors such as nutrients, invasive species and fishing practices contribute to declines, the study suggests a global link between trophic state and coregonine catch trends, influenced by climate change and lake size. The results highlight a potential conflict between water quality management objectives and coregonine fisheries productivity. Efforts to achieve pristine water conditions in developed countries may reduce the productivity of coregonine fisheries. The study highlights the need for collaboration between water and fisheries managers to establish lake-specific management objectives that address the needs of all lake users, particularly in the face of increasing climate change impacts and the introduction of invasive species.

Spatiotemporal variation and stock assessment studies in Tunisian reservoirs revealed unbalanced status in Lahjar and Siliana, with high and low yields, respectively. Kasseb reservoir was found to be overexploited. These findings provide critical insights for improved management and conservation of these vital freshwater ecosystems.

Fish communities in seasonally isolated lagoons showed remarkable seasonality with the highest values of species richness and abundance in the rainy season. Higher species richness was found in environments with the largest area and amount of macrophyte species. Global fish diversity was high due to heterogeneous environmental conditions.

In the study, Sander luciopercais reported for the first time in the Euphrates-Tigris Basin (Keban Dam Lake - eastern Anatolia). Local fish species throughout the entire basin, from Anatolia to the Persian Gulf, are under threat due to predatory extreme characteristic of the S. lucioperca.

Schellencandonarhodanensissp. n. is a stygobite species collected in the interstitial habitat of the Rhône River and its tributaries. It can be distinguish of S. triquetra by its morphological and ecological characteristics and can be used as an indicator of high sediments stability and groundwater upwelling zones.

Amphibious plant species successfully thrivein water and on dry land. Outstanding phenotypic plasticity at structural and functional levelsenables optimal performance in contrasting environments.They have great potential to colonise aquatic ecosystemswherethe hydrological regime isaltered by climate changes.

Changes in GPx activity emerged as the most sensitive biomarker to the trout farm's effluents, showing higher sensitivity compared to macrozoobenthos indices (SI, BMWP, and MBMWPPO). The data collected during this study provides a more detailed analysis and improved insight into the conditions of natural habitats and the organisms living there.

Fertilization and early development of coregonines were affected by sulfate in toxicity tests. The sulfate tolerance of brackish water forms of vendace and whitefish was higher than freshwater forms. The lethal concentrations of sulfate toxicity determined in this study provide valuable information for the construction of species sensitivity distributions, and further formulation the water quality guidelines for both brackish and freshwater environments.

There was no association between water level variables and the density of newly hatched whitefish larvae or egg survival. Neither was the average larval density in the regulated lakes generally lower than that in the non-regulated lake. Thus, moderate water level regulation does not drive whitefish population dynamics directly by negatively affecting the life stage from spawning to hatching.