This review examines the role of soil and sediment organisms as bioindicators in environmental pollution assessment. As fundamental elements of terrestrial ecosystems, soils harbour a rich and diverse biodiversity that plays a key role in regulating ecological processes. The use of bioindicators provides a sensitive and specific approach to detecting the effects of chemical, biological, and physical pollutants on soil health. The review presents a detailed analysis of the types of contaminants commonly encountered, the soil organisms used as bioindicators, and the criteria for selecting the most appropriate bioindicators. It also discusses assessment methods, including soil sampling and analysis techniques, and the biological and ecological indices used to measure contamination. Regional case studies illustrate the practical application of bioindicators for assessing soil quality in different geographical contexts. The review also highlights current challenges to the use of bioindicators, such as technical limitations and the variability of organism responses, and suggests perspectives for future research, including technological innovation and the integration of bioindicators into environmental policy.

Thoughts on Water Beetles in a Mediterranean Environment | InTechOpen, Published on: 2017-04-12. Authors: Touaylia Samir

Synthesized Mn-doped ZnS nanoparticles, with 10% of Mn dopant, were used to investigate their environmental toxicity. Mn-doped ZnS quantum dots (QDs) stabilized by 3-mercaptopropionic acid (MPA) were synthesized in a basic aqueous solution using the nucleation doping. The optical properties and structure of the obtained Mn (10%):ZnS QDs have been characterized by X-ray diffraction, UV–vis, photoluminescence spectroscopies and transmission electron microscopy. The brain, gills and liver stained sections from Gambusia affinis were dissected. Antioxidant enzyme activities (acetylcholinesterase and catalase), as well as malondialdehyde and H₂O₂ levels, were determined after exposure (94 h) to 14 and 28 mg/L of nanoparticles. The obtained nearly monodisperse Mn(10%):ZnS@MPA QDs have an average diameter of ca. 2.8 nm and a zinc-blende crystal structure. Mn-doped ZnS acts differently on the activities of the biomarkers in a dose-dependent manner. The recorded alterations varied between organs. Such findings provide information on the biological target of nanoparticles and their behaviour within the environment.

Summary. The understanding of community structuring factors is a fundamental issue in community ecology. We investigate the biodiversity of the water beetle in the Ichkeul Lake stream system located in Northern Tunisia, with emphasis on the effect of several environmental variables on their assemblage structure. This area is of a great importance since it was included in the list of preserved waterbodies by RAMSAR convention on wetlands, MAB (Man And Biosphere), UNESCO (United Nations Educational, Scientific and Cultural Organization). Consequently, the study of its biodiversity constitutes a required way to better conduct this protection aim. Special attention must be paid to species endemic to North Africa, as all of them require conservation measures. Sampling was carried out over the course of a year. Dissolved oxygen, conductivity, pH, temperature and turbidity were measured for each study site. Water permanence, velocity, aquatic vegetation and substrate type were considered. The investigated streams showed a spatial heterogeneity in water depth, water velocity, turbidity, mineralization and substrate type, but homogeneity in temperature and dissolved oxygen. A total of 68 coleopteran species were identified from the investigated area, belonging to different chorotypes and phenological categories. The coleopteran assemblage was assessed in terms of four community parameters: abundance, richness (S), diversity (Shannon–Wiener index: H′), and evenness (Pielou index: J′). Species composition was analyzed by multivariate analysis. Sites were arranged into two groups based on their species affinity by non-parametric multidimensional scaling (MDS) ordination on the basis of Bray–Curtis similarity at a similarity of 50%. Principal component analysis (PCA) highlighted the species response to the environmental variables. It revealed the distribution profile of sampled species; on the first axis, F1, a maximum number of variables are projected. Its positive pole is defined by the majority of species, with tolerance of high salinity. On its negative pole only three species are present. Its positive pole is defined by lentic phytophagous species, showing a preference for well vegetated waters. Its negative pole is marked by the species L. orientalis, associated with the majority of water parameters.

Metal pollutants are widespread in air, soil and water causing a decline in invertebrates worldwide. The increase of environmental pollution by heavy metals has a negative impact to organisms and influence their diversity, distribution, physiology and behavior. Contrary to other pollutants, metals are non-degradable and can potentially bio-accumulate and be biomagnified in the trophic chain. Because soil invertebrates tend to be strongly affected by environmental disturbances, high concentrations of these metals can become hazardous to invertebrates. Noxious effects can affect all biological levels, and toxins affect all ecological interactions. In this brief chapter, we have tried to develop a comprehensive understanding of the influence of metal contamination on ecosystem disturbance. We give examples of studies on the effects of pollutants on invertebrates.