Combination of water quality, pollution indices, and multivariate statistical techniques for evaluating the surface water quality variation in Can Tho City, Vietnam

Assessment of macrozoobenthos baseline diversity for monitoring the ecological quality of Finima Nature Park Lake

The scarcity of pristine, intact ecosystems limits opportunities to learn about succession and ecosystem evolution under conditions of limited human impact. Finima Nature Park (FNP) has been identified as a possible RAMSAR site. Its protected lake-"FNP Lake" (also known locally as "Bonny Lake")-is an unusual habitat that enables monitoring of aquatic ecological succession in the Niger Delta, where pristine and near-pristine ecosystems are becoming scarce. Macrozoobenthos are one of the best-known bio-monitors of ecological health integrity because they are widespread and long-lasting, with moderate mobility and high diversity, among other valuable characteristics. Monthly data of the community structure of macrozoobenthos and some of the FNP Lake's priority abiotic factors were collected in 2018, which provided a baseline for identifying future water quality changes and succession in the lake. Except for temperature and dissolved oxygen (DO), which were spatially uniform, the physico-chemical parameters varied spatio-temporally. The diversity indices values were low. According to the canonical correspondence abundance (CCA) plot, taxa distributions were influenced mainly by pH, DO, and temperature, which explains the prevalence of oxygen-insensitive species.

The effect of organic pollution on the seasonal dynamics of water quality in a semi-arid zone: case of the Hammam Boughrara Dam, Tlemcen (Algeria)

The present study aims to assess the impact of human activities on the water quality of the Hammam Boughrara dam. It also highlights the crucial importance of sustainable management of water resources in the face of persistent challenges related to various forms of pollution. The study is based on an exhaustive database covering a period spread over 16 years, with monthly measurements of organic pollution indicator parameters, namely BOD5, COD, [Formula: see text],[Formula: see text], [Formula: see text], [Formula: see text], Organic Matter (OM), TDS, Dissolved Oxygen (DO) and pH. The box plots showed an asymmetric distribution of almost all the parameters, with significant seasonal variations in the interquartile (IQR) range. The IQR ranges for [Formula: see text] extends from 0.575 mg/l (summer) to 4.445 mg/l (spring), and for [Formula: see text] from 1.3075 mg/l (autumn) to 1.8625 mg/l (spring). This led to the use of the Spearman method for the analysis of correlations between different parameters. The seasonal study of the five categories of water quality, according to the Organic Pollution Index (OPI), revealed considerable organic pollution. At the 1% significance level, the seasonal correlation between OPI and [Formula: see text] varies between -0.71 and -0.85, while that with [Formula: see text] fluctuates between -0.69 and -0.86. During the period analyzed, the COD/BOD Ratio (CBR) reveals two dominant categories with seasonal variations, i.e. the Moderately Biodegradable Effluents (MBE), with 96 cases, reaching 29 in autumn and 20 in spring. The Difficult to Biodegrade or Non-Biodegradable Effluents (DBE or NBE) category records 94 cases, with a maximum frequency of 26 in winter and minimum of 21 in autumn. These results therefore show the persistence of organic pollution, which had an impact on water quality over the four seasons and throughout the period studied. The results indicate persistent organic pollution affecting water quality. Therefore, prompt actions and sustainable strategies are deemed necessary to mitigate these harmful impacts and to ensure the sustainability of the water resource.