Station S1 Research Articles

Monitoring structural and functional responses of the macroinvertebrate community in a resilient stream after its depollution (Casablanca, Morocco).

This study evaluates the changes in the structure of the macroinvertebrate functional feeding groups (FFGs) of the Hassar Stream (northeast of Casablanca) following the installation of Mediouna's wastewater treatment plant (WWTP). Data on water quality and the macroinvertebrate fauna were collected at seven sample points from November 2013 to October 2014. Macroinvertebrates were used to assess the impact of physicochemical and hydromorphological properties on the FFG organization and resilience. Redundancy analysis (RDA) was employed to examine the distribution of FFGs along this stream. Based on the FFGs' relative abundance, collector-gatherers account for 39.06% of the macroinvertebrates' assemblage, followed by shredders (28.41%), collector-filters (18.76%), scrapers (7.16%), and predators (6.6%). The FFG ratios revealed that the environment was highly heterotrophic (P/R < 0.75), and all studied stations had relatively stable substrates. In addition, the ratios indicated that the studied stations had a functional riparian zone (CPOM/FPOM > 0.25), except for stations S1 and S2. Simultaneously, the RDA model revealed that the distribution of the FFGs closely followed fluctuations in the water quality (BOD5, NH4+, PO43-, EC, and Cl-) and hydromorphic properties (flow and depth). These findings highlight the importance of studying macroinvertebrate FFGs as a complementary way to assess the aquatic ecosystems' ecological integrity and resilience following anthropogenic impact reduction.

Microalgae colonization and trace element accumulation on the plastisphere of marine plastic debris in Monastir Bay (Eastern Tunisia).

In this study, we examined the toxicity potential of the epiplastic microalgal community that developed on low-density polyethylene (LD-PE) plastic debris found in two distinct regions of the Monastir Bay (Tunisia): the coast exposed to anthropogenic discharges and the open sea in front of the Kuriat Islands. Concentrations of potentially toxic elements (PTEs) accumulated in sediments and plastisphere were compared in order to determine their toxicity potential to biological life. The collected plastispheres were predominantly composed of cyanobacteria, chlorophytes, and diatoms. Diatoms display a relatively high diversity (25 species). At all stations, potentially harmful microalgae (PHM) were more abundant in the plastisphere than in seawater and the coastal zone seems to harbour increased number of potentially harmful cyanobacteria within the plastisphere. At the offshore station S1, the PHM community was dominated by the potentially harmful diatoms belonging to the genus Pseudo-nitzschia. Phormidium sp. was the main potentially harmful cyanobacterium identified in the plastisphere of S1. PTEs concentration in the plastisphere was higher than in sediment and ranking with very high contamination factors at all sites according to the sequence Pb > Cu > Cd > Ni > Zn. The highest accumulation of PTEs in the plastisphere was recorded near harbors and industrial zones with important human interference. This work shows that plastisphere can be a threat to vulnerable species not only because it can contain PHM but also because it can accumulate PTEs.

Evaluation of the water quality of a highly polluted stream with water quality indices and health risk assessment methods

The water quality of Çorlu Stream, located in the Thrace region of Türkiye, and exposed to intense industrial pressure, was evaluated by monitoring 10 toxic metals and 13 other water quality variables in the dry and wet seasons of 2021. Seven different water quality indices were applied to determine the pollution level at the sampling stations in the stream. In addition, human health risks from exposure to toxic metals in stream water via ingestion and dermal contact were evaluated. The results showed that the water quality at stations S2 and S3 of Çorlu Stream receiving domestic and industrial discharges are seriously polluted by NH4–N, PO4–P, COD, BOD5 and suspended solids according to surface water quality standards. In addition, these stations were highly polluted and had poor water quality according to the results of the water quality indices. The average Cr level at station S3 exceeded the permissible levels set for the protection of aquatic life due to effluent discharges from the leather factories. Considering the results of the health risk assessment methods, non-carcinogenic risks from ingestion of combined metals in stream water can be expected at station S3 for both children and adults and at station S2 for children. Also, it was estimated that Cr and As at station S3 may cause carcinogenic health risks for residents.

Distributional patterns of two sympatric blue crabs (Callinectes) and the implications for conservation management at the South-west Atlantic subtropical shelf

ABSTRACT Changes in species distribution patterns allow managers to monitor the conservation status of species. This study investigated the distribution and segregation in the blue crabs Callinectes danae and Callinectes ornatus in the South-west Atlantic subtropical shelf. We characterized the crabs’ abundance and related it to environmental factors. Abundance expressed as catch per unit effort estimates deviated significantly from crabs’ abundances assessed by years: in Year 1, station S7 showed the highest abundance for C. danae and the lowest for C. ornatus. In Year 2, the abundance of species only differed significantly in station S2. Summer was the season with the highest abundance of C. danae and spring of C. ornatus. Temperature was the environmental factor that modulated the distribution of blue crabs. The crabs presented different spatial and temporal distribution patterns, although there was no evident segregation between species. This ecological study indicates a potential site in the South-west Atlantic subtropical shelf to maintain the reproductive viability of the population.

DISTRIBUTION OF BENTHIC FORAMINIFERA IN THE CORAL REEFS ECOSYSTEM OF PULAU BIDONG, TERENGGANU, SOUTHERN SOUTH CHINA SEA

A study on the distribution of benthic foraminiferal species in the surface sediments of coral reefs was carried out in Pulau Bidong in the southern South China Sea (SCS). Samples were collected at 12 sites around Pulau Bidong at water depths ranging from 5 m to 30 m. Live (rose bengal stained) and optimally preserved empty tests of benthic foraminifera were analysed based on their chamber and apertural characteristics observed under binocular microscope (Leica Zoom 2000). The results revealed that 32 genera of benthic foraminifera were found in the coral reefs sediments. Amphistegina was the most abundant genus with relative abundance of 68% and frequently recorded at depths of between 10-15 m and 25-30 m. Other common genera that were found were Calcarina, Elphidium, Heterolepa, Heterostegina, Quinqueloculina, Peneroplis and Triloculina. These genera showed depth distribution preference in the shallow water zone (5 m depth). The highest diversity index (2.3) and number of taxa (26 genera) were recorded at station W2, located at the western part of Pulau Bidong. The lowest diversity index (0.2) and number of taxa (seven genera) were recorded at station S3, located at the southern part of Pulau Bidong. The frequency distribution and diversity of benthic foraminifera in the study area were related to water depth.

Multivariate statistical methods and GIS based evaluation of the health risk potential and water quality due to arsenic pollution in the Kızılırmak River

The Kızılırmak River is Turkey's longest (1,355 km) river and it is important since it constitutes the drinking and irrigation water source of the Central Anatolia Region. In the current study, the spatial distribution, effect on irrigation water quality, environmental pollution status, ecotoxicological and health risks as well as possible sources of 12 potential toxic elements' (PTEs) (manganese (Mn), aluminum (Al), arsenic (As), chromium (Cr), zinc (Zn), iron (Fe), nickel (Ni), cadmium (Cd), cobalt (Co), copper (Cu), mercury (Hg), and lead (Pb)) concentrations from surface water samples in the Kızılırmak River were analyzed by using geographical information systems (GIS) software, ecotoxicological indices, and multivariate statistical analysis. As a result of the current study, it was determined that the As concentration is above the World Health Organization (WHO) limit values, and, in terms of the 12 PTEs, there is slight heavy metal contamination in the river according to the Heavy Metal Pollution Index (HPI) and Heavy Metal Evaluation Index (HEI) values and there is a low level of pollution. The Hazard Quotient for ingestion (HQingestion) and Hazard Index (HI) values indicate that non-carcinogenic effects may occur. Exposure to river water is likely to result in a low level of carcinogenic risk (CR) in adults, mainly due to the As concentration. The water at Sampling Station S3 (131.79) cannot be used for drinking and is not suitable for consumption. According to the sodium percentage (Na%), Sodium Absorption Ratio (SAR), and Magnesium Hazard (MH) index results, river water is suitable for agricultural use.

Investigation into spatiotemporal characteristics of coastal winds around the Taiwan Island

Temporal and spatial variation characteristics of winds and their relationship with terrain environment in the Taiwan Island were investigated in this research. Based on the empirical orthogonal function (EOF) analysis, the monthly-averaged wind speed and direction at eight observation stations around Taiwan island from 1980 to 2015 were analyzed. Then the temporal and spatial variation characteristics of wind direction and wind speed as well as the abrupt change characteristics of wind speed were studied. Main results are: (1) The first EOF modal variance contribution rate of wind speed reaches 43%, and its spatial distribution numerical center shows that the positive value center is at S10, and the negative value center is at S1. The value at other areas does not change significantly. The contribution rate of the second EOF mode is 22%, which is also reflected in the positive center at S10, and the variance contribution rate of the third EOF mode is 16%. At the same time, the analysis of the wind direction EOF results shows that the first EOF modal variance contribution rate is 35%, which is lower than that of wind speed. Only stations S1 and S12 are positive but have small values, while S5 and S8 have the maximum negative value. In combination with the local terrain, it shows that wind speeds are significantly affected by topography. The wind speed is stable, but the wind direction is unstable near the plain along the Taiwan Strait. Additionally, the wind speed is less stable and the wind direction is more stable at the north and south of Taiwan Island due to the influence of the central mountains. (2) Analysis on the main contribution modal time coefficient of wind speed EOF indicate that the value is mostly negative in winter and positive in summer, which shows that the wind speed around Taiwan Island has significant variation at a seasonal scale, with a strong northeast wind in winter significantly affected by the northeast monsoon and a weak southwest wind in summer affected by the southwest monsoon.

Use of Quality and Organic Pollution Indices in the Physico-Chemical Quality Assessment of Kébir Wadi East Surface Waters (Region of El Taref, Extreme North East Algeria)

Surface water is subject to strong anthropogenic pressures caused by the development and the extension of the agricultural activities and also by the industrial and domestic activities. Pollution is a major environmental problem due to discharges into rivers and the excessive use of agricultural fertilizers add to that the discharges from urban and industrial sources. The aim of this study is to assess the quality and the state of the organic pollution of surface water in the Kébir wadi east, based on the Water Quality Index (WQI) and the Organic Pollution Index (OPI) during six sampling campaigns carried out between April and September of the year 2011. Seven stations were studied along the Kébir wadi east downstream from the Mexa Dam. The results are visualized by the use of GIS through making thematic maps. They revealed that half of the stations show excellent to good water quality and moderated organic pollution except the stations S3, S6 and S4, that have poor water quality and high pollution at S3 and S6 respectively, and non-potable water with very high organic pollution at S4. The anthropogenic environmental deterioration recorded in the wadi is the result of the use of nitrogen and phosphate agricultural fertilizers and especially, the discharge of untreated domestic and industrial wastewater from neighbouring agglomerations. The seasonal variation remains discrete and reflects a slight tendency to the deterioration of the waters of El Tarf region during the low waters of the summer period.

Spatial distribution of physicochemical-bacteriological parametric quality and water quality index of Gomti River, India.

Surface water bodies are vital source of water for human consumption, domestic needs, agriculture, industrial activities, and also for aquatic life and ecosystems. In this study, a stretch of river Gomti was studied at 5 sites in Lucknow for two consecutive seasons during 2019. The physicochemical-bacteriological parameters of water and sediment samples were analyzed, followed by multivariate statistics. Mean values of pH, turbidity, EC, TS, TDS, TSS, DO, BOD, COD, nitrate, phosphate, sulfate, total alkalinity, total hardness, chloride, and fluoride during the pre-monsoon period were 7.4 ± 0.2, 5.2 ± 3.3 (NTU), 444.4 ± 97.4 (µS/cm), 274.6 ± 61.6, 254.3 ± 50.2, 21.9 ± 11, 5.4 ± 1.6, 10.2 ± 5.9, 31.2 ± 13.3, 1.2 ± 0.5, 1.7 ± 1.1, 25.9 ± 3.7, 204 ± 41.8, 146.2 ± 11.5, 15.5 ± 8.7, and 0.5 ± 0.1mg/l, respectively. The corresponding values during the post-monsoon season were 7.5 ± 0.2, 5.5 ± 3.2 (NTU), 436 ± 75.1(µS/cm), 273.7 ± 124.2, 209.7 ± 82.5, 63.9 ± 43.4, 5.6 ± 1.6, 15.8 ± 8.9, 39.2 ± 23.5, 5.4 ± 4.6, 1.4 ± 0.9, 25.5 ± 5, 199.2 ± 36.6, 134 ± 8.6, 20.2 ± 8.9, and 1.7 ± 0.2mg/l, respectively. Concentration of pollutants significantly increased by 5-15% from sampling station S1 (upstream) to S5 (downstream). Enumerations of fecal coliform and Escherichia coli bacteria were low at S1 but significantly higher at the S5 site. WQI ranged from 88 to 345 during pre-monsoon and 159 to 422 during post-monsoon period, indicating poor water quality which was unsuitable for drinking purposes. Strong positive correlations (≥ 0.9) were observed among pH, chloride, phosphate, sulfate, turbidity, conductivity, TS, TDS, BOD, and COD for water samples during both seasons. The data reveals that pollution load increases gradually from upstream to downstream due to the increasing discharge of raw sewage. Regulatory bodies should formulate strict regulations and ensure their implementation for the protection and management of river water quality.

A Study of Benthic Macroinvertebrate Fauna in a Tributary of Himalayan River Bhilangana, Uttarakhand, India

The present study is focused on structural and functional composition of benthic macroinvertebrate fauna in the river Nailchami, a tributary of Bhilangana River. The seasonal samples were collected during March 2018 to February 2019 at three different stations (S1, S2, and S3) by lifting of stones and sieving of soft substrate (0.5 mm mesh size) from marked area (1ft square). Standard procedures were adopted to identify and analysis for preserved samples. The physico-chemical parameters varied among the stations. The total mean density varied seasonally at each station and found significantly different. The highest density was found in winter season followed by summer and monsoon. Fifty-eight invertebrate families were recorded among all the stations. Simulidae was most abundant family at all stations during summer season (S1-17.5%, S2-6.8%, S3- 11.3%). However, in the monsoon season, chironomidae was abundant at S1 (22.8%) and S3 (10.6%), while limnephilidae (16.2%) at S2. In winter season, stations S1, S2 and S3 were dominated by chironomidae (48%), limnephilidae (12.4%) and simulidae (16.7%), respectively. PCA ordination techniques identified characteristic benthic macroinvertebrate taxa at different stations. Gathering collectors were most abundant functional feeding groups at all stations as well as seasons. Thus, river indicated heterotrophic status along the river length.

Structure of Benthic Macroinvertebrate Assemblages in Azagny Channel (Côte d’Ivoire)

The Azagny Channel is an estuarine ecosystem connecting Ebrié Lagoon to Bandama River estuary and it is adjacent to Azagny National Park. The aim of this study was to provide the first data on diversity and structure of macroinvertebrates in this estuarine area. Physicochemical parameters were measured monthly in three sampling stations S1, S2 and S3, and the benthic Macroinvertebrates was collected using a Van Veen grab. A total of 28 taxa distributed among 20 families and 11 orders belonging to Annelida, Mollusca, Crustacean and Insecta were collected. The taxonomic richness and diversity were higher in S1 compared to S2 and S3, probably due to its proximity to Bandama estuary. The relative abundance revealed that mollusks represented mainly by Pachymelania aurita (16.04%), P. fusca (15.83%), Anodonta anatina (13.02%) dominated the species assemblage; followed by crustaceans with Macrobrachium vollenhovenii (31.87%) and Potamon sp. (5.01%). Canonical correspondence analysis revealed that the main factors that influenced macroinvertebrates distribution in Azagny Channel were conductivity, salinity and Total Dissolved Solids (TDS). There is a strong correlation between these three abiotic factors and their influence on species assemblage would be linked to proximity of study area to Atlantic Ocean. These findings provide valuable information that can be used to establish biotic indices to monitor the water quality of Azagny Channel.

Assessment of the effects of seasonal changes, urban discharges and leachates on the parasitological and bacteriological qualities of soil and water from Oued Larbaâ (North-eastern, Morocco)

The objective of this study is to evaluate the parasitological and bacteriological qualities of the soil and water of the Oued Larbaâ, through nine stations covering the part of the Oued crossing the Taza city of Morocco (7km of length). This study was conducted during two dry periods (2017 and 2018) and one wet period (2018). Soil parasitological studies revealed high contamination by helminths belonging to the species Enterobius vermicularis and Toxocara sp., which recorded the highest concentrations in stations S2 and S8, respectively, with values of 11.41 and 29.26 eggs/g. Concerning water, the majority of stations indicated contamination mainly by Ascaris lumbricoides, which reached concentrations of 56.49, 37.39, and 56.15 eggs/l in stations S3, S6, and S8, respectively. Bacteriological examination of the soil showed very high concentrations of bacteria, especially Streptococcus, due to the high retention of this type of bacteria in the soil. The water analysis indicated that stations S3, S4, and S8 are the most impacted, with total coliform and Streptococcus concentrations in station S3 of 2.45 105 and 0.20 107CFU/ml, respectively, Fecal coliforms and Staphylococci are detected in high concentrations in station S8 with values of 1.35 104 and 8.92 106CFU/ml, respectively, and total aerobic mesophilic flora in station S4 with a concentration of 1.89 109CFU/ml. During the study periods, influences of sampling season, nature of discharge existed (wastewater or leachate) on the parasitological and bacteriological composition of the river were established with high concentrations during the dry period and in the stations in which large amounts of liquid discharge were observed.

+Study of metallic contamination of Oued Sebou sediments, Morocco

The water of Oued Sebou has known for several years, an alteration in its quality. This is due to the discharge of pollutants of different natures and origins, which come from domestic, agricultural or industrial activities. In this study, we will try to carry out a spatiotemporal evaluation of the contamination of the sediments of the river in question by metallic trace elements. This assessment will focus on zinc, chromium, lead, copper, mercury, cadmium and nickel. To carry out this study, we selected a set of twelve sampling sites. Thanks to the ICP-MS method, or analysis by mass spectrometry coupled to an inductive plasma, the results obtained allowed us to quantify the degree of pollution by the aforementioned elements. We found an increase during the dry period in the concentrations of TME compared to the winter period. This applies to all metals except chromium. Indeed, the concentrations of this element obtained during the dry period are lower than those which concern the winter period. The acceleration of work at the tanneries in the city of Fez after Aïd al-Adha (August) in 2018 seems to us a logical explanation for this observation. In the evaluation of the pollution index of Cr, values between 6.65 in August and 9.1 in December were observed, thus indicating contamination by this element. The pollution indices which concern the other TME vary between 0.38 and 2.5 indicating a normal situation in relation to the reference station S1.

Distribution Levels of Particulate Matter Fractions (10 µm) at Seven Primary Schools in a European Ceramic Cluster.

This study addresses the concentration of particulate matter and their size using a statistical analysis of data obtained inside seven schools located in the towns of Castellón (S1, S2, and S3), Alcora (S4, S5, and S6) and Lucena (S7) in northeast Spain. Samples were taken for five to eight hours, depending on school hours, to obtain a monthly sample for each school. The main goal of this study is to assess the differences depending on the type of location and the sampling point to be able to design corrective measures that improve the habitability and safety of the teaching spaces analyzed. The lowest concentrations of fine particulate matter, less than 2.5 µm, were registered at the rural location. The values of these particles found in industrial and urban locations were not substantially different. In the case of particulate matter between 2.5 and 10 µm, significant differences were observed between the three types of locations. The lowest concentrations of particles larger than 10 µm were registered at the rural location, and the highest concentrations were found at the industrial locations. Among the urban stations, the particle concentration of this fraction in station S2 was significantly higher than that in stations S1 and S3, which had similar concentrations. These values are also similar to those registered at school S6, which is at an industrial location. The resuspension of particles from both indoor sources as well as those transported from the outside is an important factor in the concentrations of particles inside classrooms.

Objective structured clinical examination (OSCE) to assess the clinical skills of physical therapy students when using physical agents

Introduction: The use of physical agents in physical therapy (PT) requires clinical reasoning, as well as knowledge of their risks and contraindications; however, deficiencies may be observed when used in clinical practice. Objective: To implement the Objective Structured Clinical Evaluation (OSCE) method for the assessment of clinical skills among physical therapy specialty students when using physical agents. Materials and methods: A pilot, non-experimental, cross-sectional study was conducted in 114 physical therapy students enrolled during the first semester of 2019 in a physical agents course offered at the Universidad Andres Bello, Santiago, Chile. The OSCE consisted of 7 peer-validated stations, in which various skills were implemented in simulated clinical scenarios to achieve learning outcomes associated with the use of physical agents, namely: S1: connective tissue flexibility; S2: muscle relaxation; S3: analgesia; S4: drainage; S5: muscle strengthening; S6: parameter interpretation; and S7: equipment installation. Observers at each station assessed students’ clinical skills and decision-making using a checklist. OSCE scores were described using medians and interquartile ranges, representing the data dispersion between the 25th and 75th percentile (P25-P75). Station scores by sex were compared using the Mann-Whitney U test. Results: Median scores were higher than the minimum passing score in stations S1 (66, IQR: 52-70), S2 (55, IQR: 45-60), S3 (60, IQR: 50-69), S4 (65, IQR: 55-73), and S7 (40, IQR: 33-45), but they were below the passing score in stations S5 (54, IQR:46-65) and S6 (10, IQR: 9-13). In addition, 101 (88.59%) students had a global passing score in the OSCE. Conclusion: The OSCE scores obtained by the participants show their attainment of clinical skills when using physical agents since most of them obtained a global passing score; however, reinforcing the clinical skills for parameter interpretation is necessary, considering that the lowest mean score was obtained in said station.

Assessing the Chemical Composition of Wastewater Released from Hawassa Castel Brewery Plant and its Impact on Groundwater

Brewery plants have been known to cause pollution if they have no proper environmental safety systems by discharging effluent into the receiving stream, ground water and soil. The study aims to assess the physicochemical composition of wastewater generated from Hawassa Castel brewery plant and its impact on the surrounding environment particularly on the quality of ground-water. Thus, the study was conducted on samples taken from effluents of Hawassa Castel brewery plant and ground water from the nearby areas. Physicochemical parameters such as pH, temperature, DO, BOD, COD, TDS, TSS, EC, turbidity, nitrate, phosphate, sulphate, NH3-N, chloride, TN and TP were analyzed both for effluent samples and groundwater samples. Brewery effluent samples were collected from three sampling stations S1 (brewery effluent discharge point), S2 (50 m from brewery effluent discharge point downstream), and S3 (100 m from brewery effluent discharge point downstream) and four groundwater samples namely G1, G2, G3, G4 were also collected from near Hawassa Castel brewery plant. Groundwater samples G1 and G2 were collected approximately 30 m away from effluent discharge point and groundwater samples G3 and G4 were collected 100 m away from the stream. The parameters monitored for the quantitative analysis of brewery wastewater and ground water. The values of BOD (70.9 ± 7.69 mg/L), COD (178.5 ± 42.8 mg/L), TDS (135.5 ± 34.3 mg/L), turbidity (7.44 ± 0.77 NTU), and phosphate (9.08 ± 4.6 mg/L) were found to be above the permissible industrial effluents discharge limits. Moreover, the presence of high levels of TDS (462.8 ± 216.8 mg/L), TSS (143.7 ± 62.7 mg/L), EC (2370.9 ± 595 μS/cm), nitrate (43.5 ± 21.3 mg/L), phosphate (0.61 ± 0.13 mg/L), and chloride (931.9 ± 42.7 mg/L) in the ground-water samples were immensely polluted by anthropogenic activities and making it unsuitable for drinking purpose. Thus, the concerned bodies should act to prevent further deterioration of the quality of groundwater.

Assessment of the water quality of Oued El Kell by physicochemical and bacteriological approach

Aquatic ecosystems continue to be threatened and the impacts of anthropization on biodiversity and human health are unprecedented following untreated wastewater discharges. Our study consists of the analysis of organic pollution parameters (dissolved oxygen, forms of nitrogen, ortho phosphates, and COD) and microbiological indicators of faecal pollution of the waters of Oued El Khell. The latter receives municipal and domestic wastewater from the Ain Salma tourist complex that is poured directly onto the bed of Oued Bou-Iddar tributary of Oued el Kell that is use for the irrigation of vegetable crops. The results obtained show that the water from the study stations is classified as municipal wastewater after biological purification since the COD value varies between 80 and 100 mg / L. The Organic Pollution Index (OPI) shows the waters’ quality of stations sampled from a bacteriological point of view, the ratio (R: FC / FS) total coliforms (CF) and faecal streptococci (SF) show that the origin of faecal contamination is animal and human with a human predominance for S1 and S3 and human origin for station S2. According to Moroccan standards, the waters of the study are not suitable for irrigation and can affect human health.

Effect of Water Quality on Caddisflies (Trichoptera) in Kallada River, Kerala, India

The caddisflies (Trichoptera) constitute a significant water quality marker group because of their taxonomic richness, ecological diversity, and abundance in virtually all freshwater ecosystems. In this study, caddisflies were collected for an evaluation of the water quality in Kallada river, South, India. Samples collected during the pre-monsoon season were identified at the family level. In total, more than 4500 specimens were identified as belonging to five different taxa. These sensitive species have typically been restricted to non-polluted water bodies. The dominant family at stations S1, S2, S3 and S4 was determined to be Hydropsychidae, whereas the dominant family at S5 was found to be Philopotamidae. The upstream, midstream and downstream sites of Kallada River show drastic differences among caddisfly assemblages. The lack of caddisflies in the midstream and downstream areas is due to anthropogenic interferences and mixing of seawater with freshwater within these low-altitude regions. Other sources of pollution, including bridge construction, urbanization and fishing both midstream and downstream are likely reasons for the fundamental changes in the composition of caddisfly assemblages observed in these areas.

Physico-chemical evaluation of soil resources in different regions of Taza – Taounate, Morocco

&lt;p&gt;The area studied Taza-Taounate is a vast mountain range in north-central Morocco, characterized by a variation in bio-geographical factors that encourage a vibrant and diversified vegetation cover with a remarkable rate of endemism compared to Moroccan flora. Our work involves the physicochemical analysis of soils at seven stations in the study area. Three surface soil samples (0-15 cm) were collected and analyzed for physical and chemical parameters using standard laboratory techniques at each station.&lt;/p&gt;&lt;p&gt;The results showed the clay fraction's dominance in S2 and S3 and the silt fraction in stations S1, S4, S5, S6, and S7. The studied soils have low levels of organic carbon (0.97% to 2.29%), high levels of CaCO&lt;sub&gt;3 &lt;/sub&gt;(10.1% to 24.9%), and neutral and slightly alkaline pH (7.01to 7.81). The most dominant element in all stations is calcium exchangeable, with values ranging from 51.52 to 74.91 cmol+/kg. The other exchangeable basic cations (Mg&lt;sup&gt;2+&lt;/sup&gt;, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;) have relatively low levels. CEC values vary between 36.12 and 81.13 cmol+/kg, indicating that our soil type is heavy to organic.&lt;/p&gt;

Spectral characteristics of dissolved organic matter in sediment pore water from Pearl River Estuary

As key parts of land-sea transition zones, estuary ecosystems play a very important role in the ocean carbon cycle processes. The sources, degradation, and preservation of dissolved organic matter (DOM) in estuaries have long been the subject of intense study. To examine the aforementioned issues, this study examined three-dimensional fluorescence spectroscopy and ultraviolet-visible absorption spectroscopy to determine the spatial distribution and sources of DOM in the pore water of three sedimentary cores from the Pearl River Estuary (S1, S2 and S3, with increasing salinity). Using the parallel factor analysis (PARAFAC) method to analyze the three-dimensional fluorescence spectrum data, five fluorescent components were obtained—three humic-like components (C1, C3, and C4), and two protein-like components (C2 and C5). C2 exhibited a significant positive correlation with the sediment microbial deoxyribose nucleic acid (DNA) concentration (R2=0.69, P < 0.01), indicating that the protein-like component C2 might be derived from the catabolism of in situ microbes. C5 displayed a relatively weak correlation with DNA concentration (R2=0.40, P < 0.05), presumably due to the incorporation of phenolic compounds, which have a fluorescence peak very similar to that of protein-like components. The source of humic-like fluorescent components is extremely complex. The content at station S1 was relatively high (1.45–8.83 R.U.), which implies that terrestrial inputs had a significant influence. The three humic-like components showed similar distributions at S2 and S3, and the fluorescence intensity was rather low; this result indicates that the DOM at these two stations was more likely affected by the metabolism of algae and microorganisms. The humification index (HIX) and the fluorescence intensity of protein-like components increased and decreased, respectively, with depth. There was a significant positive correlation between the relative content of protein-like components and the spectral slope ratio (SR), which indicates that DOM transitioned from low-molecular-weight protein-like components in the surface sediment to high-molecular-weight humic-like components in the subsurface. This study provides valuable information for understanding the pore water size/reactivity (PWSR) model of DOM and its biochemical processes occurring in estuary sediments.