Benthic community ecology for Algerian river Seybouse

The Seybouse is the second largest river basin in Algeria, hosting an important biodiversity and providing various ecosystem services. This watershed is highly influenced by agricultural and industrial activities, which threaten its biodiversity and ecosystem integrity. The use of benthic macroinvertebrates as biological indicators has a long tradition in developed countries and integrated into all assessments of the ecological quality of river systems. However, the macroinvertebrates of many North African regions are still not well studied, including those of the Seybouse river. The aim of this study is to assess the inventory and ecological role of benthic macroinvertebrates in inland waters of the Seybouse River and determine the impact of pollution on their spatial distributions. We sampled the benthic macrofauna of Wadi Seybouse and its affluents using regular surveys in three sites, of which one was in the upper Seybouse Bouhamdane in Medjez Amar and two in the middle Seybouse. Between December 2019 and May 2020, 10 physico-chemical parameters (pH, EC, OD, water speed, NO3, Salinity, NO2, MES, turbidity, depth) were measured in order to establish a health state diagnosis of these aquatic ecosystems. The complementary biological approach by the analysis of populations of macroinvertebrates identified 7482 individuals and 40 taxa divided into five classes: Crustaceans which were the most dominant, insects with the main orders (Ephemeroptera, Diptera, Trichoptera, Heteroptera and Odonata), Molluscs, Nematodes and Annelids. The physico-chemical analyzes and the application of the organic pollution indices indicated a strong to excessive pollution for all sites, especially in Seybouse upstream

Structural Identification of Metalloproteomes in Marine Diatoms, an Efficient Algae Model in Toxic Metals Bioremediation

The biosorption of pollutants using microbial organisms has received growing interest in the last decades. Diatoms, the most dominant group of phytoplankton in oceans, are (i) pollution tolerant species, (ii) excellent biological indicators of water quality, and (iii) efficient models in assimilation and detoxification of toxic metal ions. Published research articles connecting proteomics with the capacity of diatoms for toxic metal removal are very limited. In this work, we employed a structural based systematic approach to predict and analyze the metalloproteome of six species of marine diatoms: Thalassiosira pseudonana, Phaeodactylum tricornutum, Fragilariopsis cylindrus, Thalassiosira oceanica, Fistulifera solaris, and Pseudo-nitzschia multistriata. The results indicate that the metalloproteome constitutes a significant proportion (~13%) of the total diatom proteome for all species investigated, and the proteins binding non-essential metals (Cd, Hg, Pb, Cr, As, and Ba) are significantly more than those identified for essential metals (Zn, Cu, Fe, Ca, Mg, Mn, Co, and Ni). These findings are most likely related to the well-known toxic metal tolerance of diatoms. In this study, metalloproteomes that may be involved in metabolic processes and in the mechanisms of bioaccumulation and detoxification of toxic metals of diatoms after exposure to toxic metals were identified and described.

Community structure of benthic invertebrates in the Allipén River basin, North Patagonia, Araucania region (38º S, Chile)

One of the biological indicators most used to determine the health of a fluvial ecosystem are the benthic macroinvertebrates. The presence of recurrent species in a wide gradient of latitudes, dominates the biogeographic pattern of the benthic macroinvertebrates in Chilean fresh waters, nevertheless the knowledge on the communitarian ecology of these in the Chilean rivers continues to be scarce. Null models became a powerful statistical tool for describing the ecological mechanisms that drive the structure of an ecological community and the underlying patterns of diversity. The objective of this study was to determine the community structure of benthic invertebrates in the Allipén River by describing their composition, richness and abundance of species through richness models and null models based on presence/absence. The results reveal a high family richness and low diversity, three phyla, five classes, 11 orders and 28 families were identified in the study area during the four seasons of the year. The Arthropoda phylum was the most representative in abundance and richness. Regarding to richness, Trichoptera (7 families) and Diptera (6 families) followed by Ephemeroptera (3 families) were the orders that showed the greatest diversity of families, however, a low diversity with a H’≤ 1.5 nit was registered in the study area. We demonstrated through the null models, the randomization in the species associations corresponding to the three analyzed sites. The information provided here contributes to the understanding of the ecological patterns of the invertebrate communities in the Allipén River, establishing the basis for more complex ecological studies.

The structure community of zooplankton and environmental conditions of the Kalimireng River estuary, Gresik, East Java

Water quality monitoring is a key component in the management of these important water resources and ecosystems. Biological indicators can be monitored continuously and are easy instructions for monitoring the occurrence of pollution. One of the biological parameters that can be used as a marker of environmental conditions is plankton. zooplankton can be used as study material to determine the quality and water productivity. The method used in this research is descriptive to determine the water quality condition in the estuary of the Kalimireng river biologically through the identification and characterization of zooplankton. Observations of plankton identification, plankton abundance, dominance index, and characterization of zooplankton were analyzed by fluorescence microscope observation. Three species of zooplankton were found in the waters of the Kalimireng estuary, Leptodiaptomus sp., Canthocamptus staphylinus, and Diaphanosoma bracyurum. Zooplankton is more abundant in water conditions at high tide compared to water conditions at low tide. At high tide, the highest abundance value was obtained at the station I at week 3, 843 ind/mL. At low tide, the highest abundance value was obtained at the station I at week 2,251 ind/L. The highest Dominance Index (D) at tidal water conditions is shown at station 2. This indicates that there is a community that dominates at that station.

Effect of hydrogen peroxide solutions on growth of micromycetes Saprolegniaceae on egg membranes of beluga (Huso huso) embryos and on indicators of its embryonic development during incubation

The article describes the data of the experimental works on assessing the influence of hydrogen peroxide so-lutions (0.05, 0.10, 0.20, 0.30, 0.40%) in different concentrations on the growth of the micromycetes Saprolegniaceae on egg membranes of beluga embryos and its embryonic development. In conditions of increasing intensification of aquacultures there is an acute problem regarding to the shortage of approved drugs for treating a common disease in fish farming - saprolegniosis. This disease is caused by species of different genus, the most common of which are the genus Achlya and Saprolegnia belonging to the biological kingdom Chromista (Stramenopila), the Oomycota phylum, the Oomycetes class, the Saprolegniales order, the Saprolegniaceae family. The impact of experimental hydrogen peroxide solutions on the beluga embryonic development and infection with saprolegnial micromycetes was assessed by fish-breeding biological indicators: the number of inseminated oocytes, number of survived embryos and hatched prelarvae, number of embryos infected with the micromycetes Saprolegniaceae and abnormally developing fish. Histological analysis of embryos at different stages of development was also carried out. The experimental works were carried out under production conditions in an incubation apparatus of “Sturgeon” type. The experimental groups were formed in accordance with the experimental solutions’ concentrations. Upon the result of the studies it has been inferred that using a 0.05% hydrogen peroxide solution with a 10-minute-exposure proves effective. This solution sup-pressed growth of micromycetes Saprolegniaceae without any negative impact on the embryonic development. Other experimental solutions had a negative impact on beluga (Huso huso) embryonic development of in most cases, causing the increased mortality and, as a consequence, the increased infection rate.

Physical-chemical properties of the surface water from shallow lakes of the Matita-Merhei Unit, Danube Delta, Romania: current state and environmental significance

This study aimed to assess the water quality of certain lakes (Bogdaproste, Trei Ozere and Radacinos) belonging to the Danube Delta, Romania. Deltaic ecosystems are subject to natural and man-made environmental stressors. If in the past these ecosystems were largely threatened by eutrophication and organic/inorganic pollution, nowadays, we must focus on hydro morphological impact. This refers to the physical character and water content of the aquatic environment, impoundment (dams and flood gate), channelization and embankments, as well as clog/siltation of lakes. Environmental parameters are those physical, chemical and biological indicators used to characterize a freshwater body, and, which vary in time and space. In this regard, 44 water samples were collected in the dry season from the three lakes, for analysis of physical-chemical quality indicators. A series of physical (T, EC, TDS, turbidity, TSS, transparency) and chemical parameters (pH, DO, nutrients, SiO2, TOC, SO42-, ORP, technophilic elements) were considered. The results obtained in the physical-chemical analyses revealed that the majority of parameters were found in line with enforcing environmental regulations. Despite that, P-PO43- and Cd concentration results of some samples were found above certain permissible limits set by the normative. Probably, these inadvertences can be associated with local conditions of the transitional deltaic environment. Further analysis is required conducting repeated measurements with the same question, meaning a routine monitoring, especially P-PO43- and Cd. Finally, it was concluded that the results of this study showed a good quality of water in investigated lakes that did not pose potential health and environmental problems related to the biota.

Biological Indicators of Soil Condition on the Kabanyolo Experimental Field, Uganda

Soil biological activity is an integral characteristic reflecting the state of soil fertility, biodiversity, and the activity of soil processes carried out by soil organisms. In Africa, studies of soil biological properties are few compared to the agrochemical research. In this paper, we present an assessment of multiple biochemical and microbiological properties of soil from an agricultural field located in the African tropical savanna. We determined basal respiration, substrate-induced respiration, C of microbial biomass, the potential activity of denitrification, nitrogen fixation activity, and estimated prokaryotic components in the soil microbial complex by quantitative PCR. Basal respiration of soils ranged from 0.77 ± 0.04 to 1.90 ± 0.23 μg C-CO2·g−1·h−1, and substrate-induced respiration ranged from 3.31 ± 0.17 to 7.84 ± 1.04 μg C-CO2·g−1·h−1. The C reserves of microbial biomass averaged 403.7 ± 121.6 μg C·g−1 of soil. The N2O emission from the upper layer on average amounted to 2.79 ng N-N2O·g−1·day−1, and the potential denitrification activity reached 745 ± 98 ng N-N2O·g−1·h−1. The number of copies of bacterial genes varied from (0.19 ± 0.02) × 108 to (3.52 ± 0.8) × 108 copies·g−1, and of archaea—from (0.10 ± 0.01) × 107 to (0.29 ± 0.01) × 107 copies·g−1 of soil. These results were in good agreement with the studies in other seasonally wet tropical regions: the biological activity was relatively low. The difference between biological indicators of the experimental field and the reference profile were insignificant except for nitrogen loss, which was higher in the ploughed field. Biological indicators strongly varied in space; we explained their heterogeneity by non-uniform management practices in the course of agrochemical field experiments in the past. The use of organic fertilisers may cause the release of climatically active gases due to intensive microbial respiration and denitrification, but the intensity of emission would strongly depend on the cultivation and management method.