Effects of Kaduna Refining and Petrochemical Corporation Effluents on the Abundance and Distribution of Phytoplankton Community along River Rido, Kaduna, Nigeria

The effects of effluent discharged from Kaduna Refining and Petrochemical Corporations (KRPC) on the Phytoplankton species distribution and abundance was studied along river Rido for a period of twelve months from February 2013 to January 2014. A total of Ninety-three (93) species of phytoplankton distributed in five divisions were recorded from four different study stations (A, B, C and D) along the river. Random sequential sampling was employed for selecting a sampling station. Physicochemical parameters were determined in accordance with the standard procedure for wastewater assessment guidelines of American Public Health Association (APHA). Phytoplankton identification was done using appropriate reference materials. The phytoplankton community was dominated by Bacillariophyta9 constituting 78.98% with 41 species, followed by Chlorophyta (6.67%) having 25 species, and then Cyanophyta (6.46%) having 12 species, while 10 species of Dinophyta and 5 species of Euglenophyta constituting 5.42% and 2.49% respectively were observed. The results from the study revealed low density of phytoplankton in station B, while high density of phytoplankton was observed in stations A and D. The physicochemical parameters showed both seasonal and spatial variations. Values of some parameters studied were observed to be above Federal Environmental Protection Agency (FEPA) limits at station B. Thus, effluent from KRPC is a source of contamination of water quality and adversely affects phytoplankton community along river Rido. Therefore, effluent retention facility should be established for long term treatment of effluent before discharge into the river

Seasonal nitrogen fluxes of the Lena River Delta

The Arctic is nutrient limited, particularly by nitrogen, and is impacted by anthropogenic global warming which occurs approximately twice as fast compared to the global average. Arctic warming intensifies thawing of permafrost-affected soils releasing their large organic nitrogen reservoir. This organic nitrogen reaches hydrological systems, is remineralized to reactive inorganic nitrogen, and is transported to the Arctic Ocean via large rivers. We estimate the load of nitrogen supplied from terrestrial sources into the Arctic Ocean by sampling in the Lena River and its Delta. We took water samples along one of the major deltaic channels in winter and summer in 2019 and sampling station in the central delta over a one-year cycle. Additionally, we investigate the potential release of reactive nitrogen, including nitrous oxide from soils in the Delta. We found that the Lena transported nitrogen as dissolved organic nitrogen to the coastal Arctic Ocean and that eroded soils are sources of reactive inorganic nitrogen such as ammonium and nitrate. The Lena and the Deltaic region apparently are considerable sources of nitrogen to nearshore coastal zone. The potential higher availability of inorganic nitrogen might be a source to enhance nitrous oxide emissions from terrestrial and aquatic sources to the atmosphere.

Distribution, diversity and abundance of some insects around a telecommunication mast in Ilorin, Kwara State, Nigeria

Background The preponderant use of wireless telecommunication in the twenty-first century has enabled ease and efficient communication and a pervasive occurrence of electromagnetic fields (EMFs) that has significantly impacted the ecosystem. This study looks at the effect of radiations from wireless telecommunication EMF on the distribution, diversity and abundance of some insects in Nigeria. The study was undertaken in Ilorin, Kwara State, which is located in the Guinea Savannah belt of Nigeria. The chosen choice of study area was one with a telecommunication mast devoid of residential and human interference within a 10 km radius. Five sampling stations were selected around the mast and a control station. EMR intensity levels and pollinating insect number were monitored daily for 22 weeks using an acoustimeter and malaise traps. Collected insects were identified morphologically using appropriate keys. Results The mean electromagnetic radiation (EMR) intensity was significantly (P < 0.05) highest (1.58 ± 1.52 V/m) at sampling station B, and there was an increase in EMR intensity as the radius reduced around the mast. A total of 1878 insects were recovered from the study with the dominant species in terms of abundance of insects collected from the study being Musca domestica (0.39) followed by Apis mellifera (0.31) and Locusta migratoria (0.30), while the least dominant species Tetramorium caespitum (0.23). Conclusions Indeed, EMR intensity has an effect on the distribution, diversity and abundance of insects and there is a need to reduce the number of masts in use in the environment by encouraging telecommunication service providers to jointly use the same mast in an area for broadcast.

Study on the Stability of Antibiotics, Pesticides and Drugs in Water by Using a Straightforward Procedure Applying HPLC-Mass Spectrometric Determination for Analytical Purposes

The stability of analytes is a critical point in chemical analysis, especially in the field of trace levels residue analysis. Nowadays, due to advances in analytical technology and in separation sciences, the analyses of water have been improved. Unfortunately, in this context, one of the most critical issues in water analysis include compound stability from sampling station to laboratory procedures. This study was carried out to explore the stability of several compounds in water from sampling to analysis concerning analytes reported in implementing decision 2018/840—Watch List. During method development and validation, the stability of compounds was investigated to detect the best operating conditions concerning sampling, extraction and analysis. In this paper, we report a study on the stability of antibiotics, pesticides and drugs in water determined using a straight-forward procedure applying mass spectrometric detection for analytical purposes. The laboratory tests were performed in Milli-Q water and surface water by analyzing samples through direct injection, solvent mixture (Water/ACN) and solid phase extraction system from time 0 to 168 h. All the analytes of the WL are stable in aqueous solutions with the addition of at least 25% ACN even after 168 h, and the analytes have shown a matrix effect on recovery of some analytes such as Famoxadone from sampling results (recovery in surface water 72%). For all the analytes investigated, recoveries were between 70 and 130% by using SPE procedures before UHPLC-MS/MS analysis, which is in good agreement with method validation procedures.

Physico-chemical Factors an Phytoplankton as Indicators of the Water Quality in Two Periurbans Lakes of a Natural Protected Area in Mexico City

The protected natural area (ANP), Ejidos de Xochimilco and San Gregorio Atlapulco (SGA), is a priority area of ecological conservation in Mexico City (CDMX), that still have remnants of the ancient lake system of the Valley of Mexico watershed that have been modified for decades due to the impact of human activities and that threaten their continuity, despite been declared as a RAMSAR site and historical and cultural heritage of CDMX. Given the above, the present study aimed to compare the spatial-temporal variability of physical-chemical factors and phytoplankton as indicators of anthropogenic impact to diagnose the current state of this locality and propose possible alternatives for sustainable management in the study area. The research design considered comparing the area of channels and lagoons of the SGA wetland in two contrasting climatic seasons: dry and rainy. Eleven sampling stations were delimited: three in the channels area and eight in the lagoons, during the months of March and July. Nine physical-chemical variables were measured: temperature, pH, total solids, conductivity, dissolved oxygen, as well as the concentrations of ammonium, nitrites, nitrates, and soluble phosphorus in surface and bottom samples from each sampling station. The statistical design took into account a factorial design of fixed effects (epochs - locations and strata), with Tukey's "post hoc" test to delimit subsets and various multivariate analysis techniques. Phytoplankton samples were taken in both localities, which were identified down to the genus level, evaluating the relative frequency of the various taxa, as well as their association through the saprobity and diversity indexes. The water quality variables indicated that both the area of channels and the lagoons of the wetland are sites with hypereutrophic characteristics, but the wetland due to its semi-isolation is an area that presents on average levels of nitrates 2.4 times lower than in the channel zone, nitrite concentrations are almost imperceptible, and ammonia is within tolerable limits for the existing biota. It also presents space-time homogeneity in its physical-chemical dynamics, in contrast to the area of channels. The composition of species indicating saprobity also differed between both sites, denoting a lesser impact on the wetland area, so it is suggested to use this site for reintroduction activities of species removed from the channel area and preserve the remaining biota in the lake system.

Quantitative assessment of multiple fish species around artificial reefs combining environmental DNA metabarcoding and acoustic survey

Since the early 1970s, many artificial reefs (ARs) have been deployed in Japanese coastal waters to create fisheries grounds. Recently, researchers began to use environmental DNA (eDNA) methods for biodiversity monitoring of aquatic species. A metabarcoding approach using internal standard DNAs [i.e., quantitative MiSeq sequencing (qMiSeq)] makes it possible to monitor eDNA concentrations of multiple species simultaneously. This method can improve the efficiency of monitoring AR effects on fishes. Our study investigated distributions of marine fishes at ARs and surrounding stations in the open oceanographic environment of Tateyama Bay, central Japan, using qMiSeq and echo sounder survey. Using the qMiSeq with 12S primers, we found higher quantities of fish eDNAs at the ARs than at surrounding stations and different fish species compositions between them. Comparisons with echo sounder survey also showed positive correlations between fish eDNA concentration and echo intensity, which indicated a highly localized signal of eDNA at each sampling station. These results suggest that qMiSeq is a promising technique to complement conventional methods to monitor distributions of multiple fish species.

Abundance and Diversity of Snails in Relation to Physicochemical Parameters along Kwadom Stream, Gombe State, Nigeria

Aims: The aim of the study is to investigate the abundance and diversity of snails along Kwadom stream, Gombe state, Nigeria. Study Design: Snails were collected using a benthic scoop net with mesh size of 0.2 mm and hand picking from three sampling stations (home, farmlands, and fishponds sites) along Kwadom stream; between 6:30 am to 11:00 am weekly. In addition, physicochemical parameters (temperature, dissolved oxygen, conductivity, alkalinity, water depth and pH) were measured fortnightly to determine their effect on the diversity of snail species. Place and Duration of Study: The study was conducted along Kwadom stream in Yamaltu Deba Local Government Area of Gombe State, Nigeria from March to July 2021. Methodology: Snails were collected from each of the three stations and identified to species level using hand lens and taxonomy keys. Water physicochemical parameters: temperature, dissolved oxygen, conductivity, alkalinity, water depth and pH were measured using standard method. General linear models (GLM) were used to compare the abundance and diversity of the snails across the sampling station, as well as the effect of physicochemical parameters on the diversity of snails. Results: 160 individual snails were recorded from 11 species, including Biomphalaria pfeifferi– the intermediate host of Schistosoma mansoni. The result showed there was a significant difference in the abundance of snails (p<0.01) across the three study sites – home site 68 (42.5%), farmlands site 56 (35%) and fishpond site 36 (22.5%). The home site had a higher diversity of snail species (p<0.01) relative to the farmlands and fishponds sites. Temperature, conductivity, and alkalinity had a significant effect on the diversity of snails. Conclusion: Overall, Kwadom stream harbors many individual snail species, suggesting the need for educating the public on the mode of transmission of diseases that are caused by these snails.

Habitat heterogeneity facilitates coexistence of two syntopic species of Peromyscus in a temperate forest of Central México

An essential topic in ecology is to understand how the structure of the habitat and its changes in space and time (i. e., habitat heterogeneity) affect the frequency and interactions between cohabiting species. Here, we assessed the effect of the biotic and abiotic components that configure the microhabitat heterogeneity and its temporal shifts (dry and rainy seasons), on the frequency (total and by sex) of two congeneric species, Peromyscus difficilis and P. melanotis, that co-occurs in a temperate forest of Central Mexico. To address this, an experimental plot composed of 120 sampling stations was placed within a temperate forest in the National Park Desierto de los Leones, Mexico City. In each sampling station, we set Sherman traps to capture mice of two syntopic Peromyscus, and we also evaluated six variables related to the spatial heterogeneity of the habitat during two rainy seasons. Our results revealed differential effects of habitat heterogeneity on the frequency of each species. Moreover, habitat heterogeneity also had a different effect on male and female frequencies of each Peromyscus species. While P. difficilis was captured more frequently in sampling stations with high presence and coverage of logs in the soil, P. melanotis was regularly captured in sampling stations with high vegetation cover and plant species richness. Thus, it seems that the different requirements and habitat preferences of these two Peromyscus species facilitate their spatial and temporal coexistence in this mid-latitude temperate forest. In general, we provide evidence of the importance of studying the heterogeneity of the habitat to better understand the interactions between syntopic species, offering new insights into the spatial and temporal mechanisms that could determine its coexistence at local scale.

Application of Gravity-Assisted Wellbore Segregation to Wireline Sampling Operations. A Low Permeability Case Study

A common challenge in exploration in the North Slope of Alaska is the formation evaluation of low-permeability formations when near-wellbore damage is caused by water-based muds (WBM). This study describes the novel application of existing technology to collect high-quality hydrocarbon samples efficiently in these challenging conditions. The concept was tested with a wireline formation tester in a well with severe formation damage caused by WBM. The procedure and hardware used are discussed and an example of the effectiveness of the proposed technique is shown. Due to the unfavorable mobility ratio, WBM filtrates tends to move preferentially while attempting oil sampling in low permeability rock leading to long station times during wireline formation testing operations. To overcome this challenge, a target sampling interval was subjected to high drawdown using a 3D radial probe to move the target phase closer to the wellbore. Once hydrocarbon was detected in the fluid analyzer, the 3D radial probe was retracted, and the string repositioned to cover the same interval with a straddle packer assembly. Straddle packers provide wellbore annular space for filtrate and hydrocarbon to segregate after the flow period is resumed. When hydrocarbons are again seen in the fluid analyzer, a simultaneous two-pump flow is used to collect them and discard the filtrate. The combination of 3D radial probe and straddle packer assists with displacing the mud filtrate, bringing the target hydrocarbons to the wellbore, and enables the collection of segregated samples with exceptional quality. After pumping at one sampling station using the 3D Radial probe, the maximum hydrocarbon fraction observed was 5%. When the straddle packer was positioned at the same interval, the fluid analyzer showed that the low velocity in the annular space between tool's mandrel and wellbore enabled hydrocarbon segregation from the filtrate due to the existing density contrast. When the hydrocarbon in the wellbore reached the straddle packer inlet, the lower pump was used to flow most of the filtrate in the down direction at high rate. Meanwhile, the hydrocarbon was "skimmed off" and placed in sample containers at a much lower rate using the upper pump. Laboratory results confirmed that the samples collected with the traditional sampling method contained 95% filtrate whereas the samples collected with our technique contained 90% hydrocarbon. Downhole fluid segregation using single-inlet, wireline straddle packer and dual-pump action has not been found in the literature. Recent developments in wireline formation testing use dual inlets in straddle packer modules to enable downhole segregation. We consider that the technique described here innovatively uses the capabilities of current formation testers to collect high-quality hydrocarbon samples in low permeability conditions. With minor adjustments, this technique can also be applied in gas or water sampling in wells drilled with oil-based muds.

Assessment of the Level of Some Selected Heavy Metals and Physicochemical in Abzana Water Samples, Kibet Woreda, Ethiopia

Background: This study was conducted to investigate the contamination level of Abzana water in Asano district. A total of five water samples were collected from different point of Abzana water. Some parameters of water were analyzed like temperature, pH, electrical conductance and total dissolved solids (TDS) and four heavy metal (Cd, Pb, Cr, and Mn) concentration using standard procedures and the results were compared with WHO guideline values. Result: The results of the present study have shown the temperatures of all sampling station range between 18.9 and 19.2°c. The pH was found to be of range from 6.54 to 7.11 whereas, the electrical conductance was 174.5 to 206(µS/cm). In addition, the lowest value of TDS was 131.4 and the highest was 140.1 ppm. In contrast, heavy metals (Pb, Cd, Cr and Mn) were analyzed and compared with standards of drinking water. The results indicate that the mean concentration of Cd (0.00664mg/l) exceeded the standards, although the mean concentration of Mn, Pb and Cr were found within the standard limit at 0.076082, 0.00810 and 0.035442 mg/l respectively. Conclusion: The concentrations of the investigated metal (Cr, Pb and Mn) and all physico-chemical result of Abzana water from Asano kebele were found below the guidelines for drinking water given by the World Health Organization. But the concentration of Cd in Abzana water sample was found above the permissible limit of WHO standards. Therefore, it was not safe for drinking and health effect according metals what we have studied here.