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Water quality in freshwaters is declining worldwide due to increases in human populations, expansion of agricultural activities, and climate change. There are quite a number of regions of the world, Africa inclusive, that are understudied, and little to no baseline information exists related to water quality. This study was focused on the Bua River in Malawi, which supports sustenance fishing and basic needs for local communities. A portion of the river has elevated levels of protection because it is found within the Nkhotakota Wildlife Reserve. The focus of this study was to understand the spatial-temporal variations of water quality at five sites in the Bua River from May 2018 to June 2020 capturing the three main seasons (warm wet, cool dry, and hot dry). Although other water quality parameters did not vary spatially. Spatially, the Bua River mouth registered the highest values of Soluble reactive phosphorus and the Bua River upstream had the lowest. However, there were greater temporal differences across seasons for water temperature, water pH, and chlorophyll a. For instance, chlorophyll-a was higher during the hot dry season (3.28 µgL-1) compared to the cool dry season (2.10 µgL-1) and warm wet season (1.91 µgL-1). Water transparency, as measured by secchi depth was lowest during the warm wet season, which coincides with higher concentrations in SRP. All measurements of salt content, Electrical Conductivity (EC), Total Dissolved Solids (TDS), and salinity) were higher during the hot dry season and correlated negatively with SRP. Similarly, bicarbonate and alkalinity were also higher during the hot dry season. Principle Component Analysis indicated that the parameters responsible for variations of Bua River water quality are mainly related to soluble minerals, water temperature, and surface runoff associated with agricultural activities and domestic waste accounting for 78.49 % of the total variance in the data set.

This paper discusses threats of standing water habitats of high importance to the European Community in the Continental Biogeographical Region (CBR) of Europe, specifically in Poland, as a reference. The study covers five standing water habitats types distinguished in Natura 2000: 3110, 3130, 3140, 3150, 3160, occurring in 806 Special Areas of Conservation (SACs) in Poland. The most significant threats to standing water habitats in the Continental biogeographical region, result from human-induced changes in hydrological conditions that have modified whole natural systems. Based on multivariate analysis, we found that significant differences in the conservation status of the standing water habitats resulted from a variety of threats, pressures, and activities, among which the most significant are decreased and unstable water resources (3110, 3130, 3140, 3150, 3160), fishing and harvesting aquatic resources (3110, 3130, 3140, 3150, 3160), pollution from use of the catchment (3130, 3140, 3150), improper management and use of the agricultural catchment (3110, 3130, 3140, 3150, 3160) and forest catchment (3110, 3140, 3160), urbanisation, residential and commercial development (3150, 3140), transportation and service corridors (3140> 3160 > 3110, 3150), including parking areas (3140), changes in biocenotic evolution, succession, plant species composition (3110, 3130, 3140, 3150, 3160), succession of invasive species (3130), and more intense touristic exploration (3110, 3130, 3140, 3150, 3160). Only in the case of habitats 3110, 3130, 3140 changes in their conservation status have been associated with climate change.

Many bacteria drastically change their cell size and morphology in response to changing environmental conditions. Here, we demonstrate that the freshwater bacterium Caulobacter crescentus and related species transform into filamentous cells in response to conditions that commonly occur in their natural habitat as a result of algal blooms during the warm summer months. These filamentous cells may be better able to scavenge nutrients when they grow in biofilms and to escape from protist predation during planktonic growth. Our findings suggest that seasonal changes and variations in the microbial composition of the natural habitat can have profound impact on the cell biology of individual organisms. Furthermore, our work highlights that bacteria exist in morphological and physiological states in nature that can strongly differ from those commonly studied in the laboratory., All living cells are characterized by certain cell shapes and sizes. Many bacteria can change these properties depending on the growth conditions. The underlying mechanisms and the ecological relevance of changing cell shape and size remain unclear in most cases. One bacterium that undergoes extensive shape-shifting in response to changing growth conditions is the freshwater bacterium Caulobacter crescentus. When incubated for an extended time in stationary phase, a subpopulation of C. crescentus forms viable filamentous cells with a helical shape. Here, we demonstrated that this stationary-phase-induced filamentation results from downregulation of most critical cell cycle regulators and a consequent block of DNA replication and cell division while cell growth and metabolism continue. Our data indicate that this response is triggered by a combination of three stresses caused by prolonged growth in complex medium, namely, the depletion of phosphate, alkaline pH, and an excess of ammonium. We found that these conditions are experienced in the summer months during algal blooms near the surface in freshwater lakes, a natural habitat of C. crescentus, suggesting that filamentous growth is a common response of C. crescentus to its environment. Finally, we demonstrate that when grown in a biofilm, the filamentous cells can reach beyond the surface of the biofilm and potentially access nutrients or release progeny. Altogether, our work highlights the ability of bacteria to alter their morphology and suggests how this behavior might enable adaptation to changing environments.

Global data sets are essential in macroecological studies. File formats of the few available data sets of freshwater ecosystems, however, are either incompatible with most macroecological software packages, incomplete, or of coarse spatial resolutions. We integrated more than 460 million geographical coordinates for freshwater habitats in the FRWater data set, partitioned into seven different habitats (lentic, wetlands, reservoirs, small rivers, large rivers, small ditches, large ditches, small channels, large channels, small drains and large drains) in ModestR (http://www.ipez.es/ModestR). A comprehensive collection of geospatial rasters was assembled, one for each of the seven freshwater habitats, with the area in km2 occupied by each habitat presented in cells of 5 arc-minute resolution. The utility of FRWater was evaluated using hierarchical partitioning via the identification of the contribution of the seven different freshwater habitats to both species richness and rarity. To this end, we used a data set of 836,123 geographical records of the 16,216 species of freshwater fishes recognized as valid by systematists at the end of 2014. Areas in North America and Europe are the most detailed in the FRWater data set, evidencing the higher quality of data sources in those regions. The number of geographical coordinates is much lower for Africa, Asia, Australia, and South America where many water bodies remain unmapped. In light of the variation in information quality at continental levels, we performed and present comparative analyses for Europe versus South America at local (5ʹ × 5ʹ grid cells) and regional (5° × 5° grid cells) scales. The relative contribution of small rivers to both species richness and rarity was highest under almost all analyses, followed by lentic habitats and large rivers. The areas of different habitats moreover explained a relatively high proportion of the observed variance in geographic rarity. Our findings corroborate previous findings that the greater contribution of small rivers to species richness is probably due to these habitats promoting geographical rarity. Hence, species richness is favored by the isolation resultant from, and the refuges associated with, small river basins and via the diversification processes promoted by such isolation., his work was supported by the ENDESA [110/02168].

Matching the trend seen among the major large rivers of the globe, the Amazon River and its tributaries are facing aquatic ecosystem disruption that is affecting freshwater habitats and their associated biodiversity, including trends for decline in fishery resources. The Amazon’s aquatic ecosystems, linked natural resources, and human communities that depend on them are increasingly at risk from a number of identified threats, including expansion of agriculture; cattle pastures; infrastructure such as hydroelectric dams, logging, mining; and overfishing. The forest, which regulates the hydrological pulse, guaranteeing the distribution of rainfall and stabilizing seasonal flooding, has been affected by deforestation. Flooding dynamics of the Amazon Rivers are a major factor in regulating the intensity and timing of aquatic organisms. This study’s objective was to identify threats to the integrity of freshwater ecosystems, and to seek instruments for conservation and sustainable use, taking principally fish diversity and fisheries as factors for analysis.

Neonicotinoid pesticides were first introduced in the mid-1990s, and since then, their use has grown rapidly. They are now the most widely used class of insecticides in the world, with the majority of applications coming from seed dressings. Neonicotinoids are water-soluble, and so can be taken up by a developing plant and can be found inside vascular tissues and foliage, providing protection against herbivorous insects. However, only approximately 5% of the neonicotinoid active ingredient is taken up by crop plants and most instead disperses into the wider environment. Since the mid-2000s, several studies raised concerns that neonicotinoids may be having a negative effect on non-target organisms, in particular on honeybees and bumblebees. In response to these studies, the European Food Safety Authority (EFSA) was commissioned to produce risk assessments for the use of clothianidin, imidacloprid and thiamethoxam and their impact on bees. These risk assessments concluded that the use of these compounds on certain flowering crops poses a high risk to bees. On the basis of these findings, the European Union adopted a partial ban on these substances in May 2013. The purpose of the present paper is to collate and summarise scientific evidence published since 2013 that investigates the impact of neonicotinoids on non-target organisms. Whilst much of the recent work has focused on the impact of neonicotinoids on bees, a growing body of evidence demonstrates that persistent, low levels of neonicotinoids can have negative impacts on a wide range of free-living organisms.

Cystoviridae is a family of bacteriophages with a tri-segmented dsRNA genome enclosed in a tri-layered virion structure. Here, we present a new putative member of the Cystoviridae family, bacteriophage ϕNN. ϕNN was isolated from a Finnish lake in contrast to the previously identified cystoviruses, which originate from various legume samples collected in the USA. The nucleotide sequence of the virus reveals a strong genetic similarity (~80 % for the L-segments, ~55 % for the M-segments and ~84 % for the S-segments) to Pseudomonas phage ϕ6, the type member of the virus family. However, the relationship between ϕNN and other cystoviruses is more distant. In general, proteins located in the internal parts of the virion were more conserved than those exposed on the virion surface, a phenomenon previously reported among eukaryotic dsRNA viruses. Structural models of several putative ϕNN proteins propose that cystoviral structures are highly conserved.

The current synopsis reviews the types of aquatic habitats, that are located in the city of Plovdiv and analyses their importance for the biodiversity. Studies of the biodiversity in urban landscapes are of particular importance because they are still scarce. Several plant and animal groups are studied in the city of Plovdiv – mosses, mollusks, fish, amphibians, reptiles, birds and mammals. Their distribution among habitats is presented, as well as specific threats and conservation problems.