scholarly journals Seasonal Larval Abundance of the Blackfly, Simulium damnosum Complex and the Physico-chemical Properties of their Breeding Sites in Oji River System, Enugu State, Nigeria

2021 ◽  
Vol 4 (3) ◽  
pp. 59-68
Author(s):  
Josephine C.O. ◽  
Ethel-Doris N.U. ◽  
Victor S.N.

Seasonal larval abundance of the blackfly, Simulium damnosum complex, and the physico-chemical properties of their breeding sites in Oji river system was carried out, with the aim of finding out the season that promotes the breeding of S. damnosum complex and the effect of the physico-chemical properties of the breeding sites of S. damnosum complex on larval abundance. Larvae of S. damnosum complex were collected monthly from forty-eight (48) breeding sites in four sampling units for three years, in dry and wet seasons. The physico-chemical properties of the breeding sites of S. damnosum complex studied were copper, dissolved oxygen, magnesium, nitrate, pH, phosphate, potassium, temperature, and water velocity. A total of six hundred and ninety one (691) larvae of S. damnosum complex were collected in the Oji river system in both seasons. Wet season catch was more and comprised 82% of the total catch, while dry season catch comprised 18% of the total catch. Dry and wet seasons catches in the sampling units were found to differ statistically. All the physico-chemical properties of the breeding sites of S. damnosum complex determined showed positive correlations with total larval abundance in both seasons, except copper which showed no correlation with total larval abundance in the dry season. Wet season promotes larval abundance of S. damnosum complex, and the physico-chemical properties of the breeding sites of S. damnosum complex play some roles (in varying degrees) in larval development.

2016 ◽  
Vol 5 (10) ◽  
pp. 4927
Author(s):  
Emily Chirchir* ◽  
Samuel Lutta ◽  
Jackson Cherutoi

The noxiousness of pesticides as well as their harmful environmental effects have generated interests in the identification and quantification of organophosphate in borehole water. These contaminants can move from agricultural land or poorly managed sewerage systems and get into drinking water by surface runoff or by leaching into groundwater. The study sought to analyze the organophosphates contaminants of borehole water of Maili-nne a residential area and Sosiani an agricultural area. This was through detection of organic contaminants in borehole water; quantification of the detected organochemicals of borehole water of Maili-nne and Sosiani areas. Fifteen boreholes, five at Maili-nne (MB1-MB5) and ten at Sosiani (SB6-SB15) were systematically selected and water sampled during the dry and the wet seasons. Organic contaminants were analysed by detection and quantification of organic pesticides based on retention times by High Performance Liquid Chromatography (HPLC) and Gas Chromatography–Mass Spectroscopy (GC-MS) in correlation to computed element libraries for quantification. Diazinon was detected in boreholes SB9, SB12 and SB13, with highest level of 2.21 mg/L during the dry season and 1.52 mg/L in the wet season. Fenitrothion was detected in MB1 (0.145 mg/L and 0.191 mg/L) during the dry and the wet season, respectively. Malathion was found in SB6 and SB15 at 0.207 mg/L and 0.940 mg/L, respectively only during the dry season. Chloropyrifos was present in both Mailli-nne and Sosiani areas in borehole number MB1, SB9 and SB13 only during the dry season. Sulfotep was only detected during dry season in water samples obtained from SB9 and SB13. Dimethoate was only detected in Sosiani (SB7) during the wet season. It can therefore be concluded that residues of some organophosphate contaminants were above the WHO standards leading to decrease of water pH during the dry season beyond WHO limits (pH 6.5). The study also established that there was a positive significant correlation between presence of organic contaminants and deviation of physico-chemical properties (p=0.016, rho=0.68) in Maili-nne and Sosiani. In this regard the borehole water in the study areas should be treated and awareness be made on the impacts of pesticides use.


2021 ◽  
Vol 4 (3) ◽  
pp. 69-78
Author(s):  
Josephine C.O. ◽  
Ethel-Doris N.U. ◽  
Victor S.N.

Identification of the sibling species of the blackfly, S. damnosum complex using their polytene chromosomal banding patterns in Oji river system was carried out with the aim of accurately identifying the particular sibling species of S. damnosum complex involved in the transmission of onchocerciasis in Oji-river LGA and environ. Simulium damnosum complex larvae were collected monthly in forty eight (48) breeding sites in four sampling units for three years in the Oji river system in wet and dry seasons. Collected larvae were preserved in cold Carnoy’s solution prior to processing. Salivary gland chromosomes were extracted, processed and analyzed microscopically for polytene chromosomal banding patterns. Three sibling species of Simulium damnosum complex that breed in the Oji river system were identified in varying degrees. They included S. squamosum, S. yahense and S. damnosum sensu stricto (s.s.). Variation in the occurrence of the sibling species was statistically significant. Dry and wet season catches for all the sibling species in the sampling units were found to differ statistically. The identified sibling species of S. damnosum complex are known to be vectors of Onchocerca volvulus, the causative agent of onchocerciasis, a disease highly prevalent in Oji-river LGA and environ.


2015 ◽  
Vol 27 (1) ◽  
pp. 118-129 ◽  
Author(s):  
Ludmilla Cavalcanti Antunes Lucena ◽  
Thaís Xavier de Melo ◽  
Elvio Sergio Figueredo Medeiros

Aim:The objective of the present work is to present a list of species of zooplankton (Rotifera, Cladocera and Copepoda) from the Parnaíba River. Additionally, we provide comments on their distribution along the river, and between dry and wet seasons.MethodsZooplankton was collected with a plankton net (60 µm mesh) and concentrated into a volume of 80 mL for further analysis, during the dry (October 2010) and wet (April 2011) seasons. Sampling was restricted to the marginal areas at depths between 80 and 150 cm.ResultsA total of 132 species was recorded among the three zooplankton groups studied. During the dry season a total of 82 species was registered and 102 species was registered for the wet season. Rotifera contributed with 66.7% of the species, followed by Cladocera (26.5%) and Copepoda (6.8%).ConclusionsThe richness of species observed was high compared to other large rivers in Brazil. In the context of current policies for water management and river diversions in northeastern Brazil, the present study highlights the importance of this river system for biodiversity conservation.


2021 ◽  
Vol 14 (1) ◽  
pp. 347
Author(s):  
Kuan-Nan Lin ◽  
Chiu-Wen Chen ◽  
Chih-Feng Chen ◽  
Yee Cheng Lim ◽  
Chih-Ming Kao ◽  
...  

The Fengshan River system is one of the major rivers in Kaohsiung City, Taiwan. This study investigated the concentration of eight phthalate esters (PAEs) in sediments of the river and the impact of potential ecological risks during the dry and wet seasons. The potential risk assessment of sediment PAEs was evaluated by adopting the total risk quotient (TRQ) method. The total PAEs concentrations (∑PAEs) in the sediments of the Fengshan River system are between 490–40,190 ng/g dw, with an average of 8418 ± 11,812 ng/g dw. Diisononyl phthalate (38.1%), bis(2-ethylhexyl) phthalate (36.9%) and di-isodecyl phthalate (24.3%) accounted for more than 99.3% of ∑PAEs. The concentration of ∑PAEs in sediments at the river channel stations is higher during the wet season (616–15,281 ng/g dw) than that during the dry season (490–1535 ng/g dw). However, in the downstream and estuary stations, the wet season (3975–6768 ng/g dw) is lower than the dry season (20,216–40,190 ng/g dw). The PAEs in sediments of the Fengshan River may have low to moderate potential risks to aquatic organisms. The TQR of PAEs in sediments at the downstream and estuary (TQR = 0.13) is higher than that in the upstream (TQR = 0.04). In addition, during the wet season, rainfall transported a large amount of land-sourced PAEs to rivers, leading to increased PAEs concentration and potential ecological risks in the upper reaches of the river.


Author(s):  
Tres Tinna B. Martin ◽  
Gerald G. Lobredo ◽  
Emmanuel P. Leaño ◽  
Maximo C. Aljibe ◽  
Edna P. Oconer

Healthy riverine systems provide ecological services that can be translated into human use and consumption. However, human activities cause environmental degradation limiting available pristine water supply and raising public health concerns. In the present study, four tributaries surrounding Mt. Matutum Protected Landscape (MMPL) were selected (Glandang, Linan, Kawit, and Amlok) for evaluation of their physicochemical and microbial characteristics between wet and dry season. The pH and total dissolved solids (TDS) of the river waters ranged from 6.75-8.68 and 55.96-221.89 ppm, respectively, with a pronounced pH fluctuation and TDS increase in Glandang and Linan tributaries from upstream to downstream stations. All tributaries showed varying dissolved oxygen (DO) levels upstream but become relatively stable downstream. All DO values, however, are below the standard limit set for freshwater quality. In terms of microbial load, total coliform ranged from 51-275 cfu/ml while E. coli showed absence (0 cfu/ml) to as high as 77 cfu/ml. Higher total coliform counts were observed on Kawit and Amlok tributaries which are situated in areas that are relatively more forested than the other two rivers. Presence of E. coli was also detected in the water samples from all tributaries. Temporal variation is significant indicating increased pH, TDS and microbial load during the wet season and DO during the dry season. The present microbial load of the four tributaries would restrict the utilization of water resource and necessitate proper treatments prior to domestic use. Read full article here.


2016 ◽  
Vol 28 (1) ◽  
pp. 9-16
Author(s):  
Md Rakib Hasan Sarker ◽  
Asadul Islam ◽  
Ariful Islam ◽  
Md Mahbubul Hoque ◽  
Shimul Roy

Water samples were collected from three points of Louhajong river (Dighulia, Kagmari Bridge and Oloa) to see the seasonal variation in physico-chemical parameters. The results revealed that some of the parameters such as TDS, alkalinity and acidity have exceeded the standard level in dry season in all of the points, which are unsuitable for different purposes including fish culture. During dry and wet seasons the highest concentrations of BOD was recorded as 2.0 and 0.8 ppm at Kagmari Bridge (point-2) respectively. DO ranged from 1.4 to 3.1 and 2.4 to 3.8 ppm during dry and wet seasons. Maximum and minimum EC was recorded as 890 and 130 ?s/cm at Dighulia (point-1) during dry and wet seasons. The results suggest that at wet season Louhajong river may be suitable for fish culture and other purposes.Bangladesh J. Sci. Res. 28(1): 9-16, June-2015


Author(s):  
Md. Billal Hossain ◽  
Md. Nurul Islam ◽  
Mohammad Shamsul Alam ◽  
Md. Zakir Hossen

This study was conducted to explore the present trend and pattern of industrial growth with spatial distribution of industries and seasonal extent of physicochemical characteristics of wastewater at Sreepur of Gazipur, Bangladesh. The wastewater samples were collected from 5 locations in three seasons viz. pre-monsoon, monsoon and dry season. A total of 120 medium to large industries were surveyed, among those 52 were in red category, 53 were in orange-B category, 13 were in orange-A and only 2 were in green category. In 1995, there were only three industries, which gradually increased to a total of 29 in 2005. Among them, 11 were in red category and 18 were in orange-B category. But from 2006-2010, a total 59 industries were developed and most of them were in red and orange-B categories. Similarly, during the period of 2011 to March 2013, a total 16 industries were developed, among them 8 industries were in red and 3 were in orange-B category. Major types of wastewater discharging industries were textile, dyeing, washing and printing. Among the surveyed industries about 33% didn’t have any effluent treatment plant (ETP). The mean value of pH, EC, DO, BOD, COD and TDS of wastewater were 7.28, 2.64, 1.62 mg L-1, 82.0 mg L-1, 217.31 mg L-1 and 1380 mg L-1, respectively during pre-monsoon; 6.7, 1.15, trace, 8.0 mg L-1, 152.4 mg L-1 and 539.58 mg L-1, respectively during monsoon and 7.7, 1.82, 0.74 mg L-1, 48.8 mg L-1, 204.8 mg L-1 and 993.6 mg L-1, respectively during dry season. Average DO concentrations in all seasons and sites were significantly low, while BOD and COD contents were higher in pre-monsoon and dry seasons than the DoE permissible limit. The study concluded that the area is now a hub of polluting industries which are mostly liable to pollute the surrounding environment.


2017 ◽  
Vol 15 (1) ◽  
pp. 42-56
Author(s):  
S A ISHOLA ◽  
V MAKINDE ◽  
I C OKEYODE ◽  
F G AKINBORO ◽  
H AYEDUN ◽  
...  

Pollution of wells and borehole water, either from point or non-point sources, has become a matter of health concern both in urban and rural areas. Groundwater is tapped for domestic uses through the con-struction of hand dug wells and boreholes. However, while providing an alternative to the public water supply sources; most of the boreholes are often located too close to possible contamination sources. Various land use and human activities such as solid waste landfills, cemetery and animal wastes, among others can result in ground water contamination. In an open or buried dumping solid waste or sanitary landfill, the organic and inorganic by-products resulting from the decomposition of wastes are leached out by the infiltration of rainfall. A release of leachate to the surrounding soil without proper collection and treatment could contaminate groundwater resources. Many of the wells and boreholes in the study area were found to be indiscriminately located and scattered among such impairing lands/features. This study was therefore aimed at assessing the pollution hazards and vulnerability of groundwater resource in Abe-okuta North Local Government Area (LGA) by sampling some boreholes from selected locations in the area. Water samples were collected and analyzed for water quality parameters using standard proce-dures. The parameters determined were Turbidity, Temperature, Electrical Conductivity (EC), pH, Total Dissolved Solids (TDS) Total Suspended Solids (TSS), Total Solids (TS), Total hardness, cations {Potassium (K), Sodium (Na), Calcium (Ca), Magnesium (Mg), Manganese (Mn), iron (Fe)}, anions {Chloride (Cl-), Nitrate (NO3-), Sulphate (SO42-), Phosphate (PO43-)}, and heavy metals {lead (Pb2+), Zinc (Zn2+), Copper (Cu2+)}. Results were subjected to statistical evaluations using SPSS 18.0 for descriptive statistics and Analysis of Variance (ANOVA). It was observed that the elemental parameters in the bore-holes sampled have mean values of the concentrations of Fe2+, Na+, Cl- , SO42-, Pb2+, Mn2+, Cu2+ and Zn2+ higher during the wet season relative to dry season. For the physico-chemical parameters, it was equally observed that parameters such as EC, TDS, TS, TSS were higher during the wet season than dry season while turbidity, temperature, pH and total hardness were higher during dry season than in the wet season. Water quality parameters such as Fe2+, Pb2+, NO3-, and EC have mean values greater than World Health Organization and NESREA maximum permissible standards for drinking water. Elevated values of these parameters are of great concern to public health when the water from these boreholes is consumed without treatment by people. It is recommended that well and borehole waters in this area be adequately treated before consumption using advanced inorganic removal techniques such as Nano-filtration and Reverse Osmosis to safeguard human health in the study area.Keywords: Boreholes, pollution, water quality, public health, physico-chemical


1965 ◽  
Vol 56 (1) ◽  
pp. 1-16 ◽  
Author(s):  
A. M. Jordan

Observations, largely based on regular catches along a fly-round, were made over the five years 1959–64 on a population of Glossina morsitans submorsitans Newst. in the Northern Guinea Savannah of Nigeria. The results showed that the largest numbers of flies were caught in the early dry season (November–January) and that, as the climate became progressively drier and more severe, fly numbers declined to reach their annual minimum at the end of the dry season or in the early rains (March–May). These results are tentatively interpreted in terms of the true density of the flies and their activity. Differences occurred between the various years, some of which could be explained by climatic differences.Of the 7,412 flies caught over the five years, 1,128 (15·2%) were females; the percentage of females was highest in the dry season, rising to a peak of 24·1 per cent, in February, and was below 10 per cent. during the wet season. Many more females were caught on the bodies of the catching team than on vegetation or the ground near the team.The flies rarely fed on civet cat (Civettictis civetta) or duiker (Cephalophus rufilatus, Sylvicapra grimmia), which were the potential hosts most frequently observed in the experimental area, but fed mainly on wart-hog (Phacochoerus aethiopicus) and man, the next most commonly observed potential hosts.During the heavy rains, males of G. m. submorsitans were evenly distributed over the fly-round, but at all other seasons they were concentrated to some extent in areas of thicker vegetation. During the dry season, pupae were found in the dry soil of forest islands and riverine vegetation in the savannah; the wet season breeding sites were not discovered. Previously published data on the resting sites and trypanosome infection rate of G. m. submorsitans in the area are summarised.The results are discussed and compared with the conclusions reached by other workers from earlier more extensive studies on G. m. morsitans Westw. in Tanganyika and on G. m. submorsitans in the Sudan Savannah vegetation zone of Northern Nigeria.


2006 ◽  
Vol 73 (3) ◽  
Author(s):  
D.M. Pfukenyi ◽  
S. Mukaratirwa ◽  
A.L. Willingham ◽  
J. Monrad

During the period between January 1999 and December 2000, the distribution and seasonal patterns of Schistosoma mattheei infections in cattle in the highveld and lowveld communal grazing areas of Zimbabwe were determined through monthly coprological examination. Faecal samples of cattle were collected from 12 and nine dipping sites in the highveld and lowveld communal grazing areas, respectively. Patterns of distribution and seasonal fluctuations of the intermediate host-snail populations and the climatic factors influencing the distribution were also determined at monthly intervals from November 1998 to October 2000, a period of 24 months, in six dams and six streams in the highveld and nine dams in the lowveld communal grazing areas. Monthly, each site was sampled for relative snail density, the vegetation cover and type, and physical and chemical properties of the water. Mean monthly rainfall and temperature were recorded. Snails collected at the same time were individually examined for shedding of cercariae of S. mattheei and Schistosoma haematobium. A total of 16 264 (5 418 calves, 5 461 weaners and 5 385 adults) faecal samples were collected during the entire period of study and 734 (4.5 %) were positive for S. mattheei eggs. Significantly higher prevalences were found in the highveld compared to the lowveld (P < 0.001), calves compared to adult cattle (P < 0.01) and the wet season compared to the dry season (P < 0.01). Faecal egg output peaked from October/ November to March / April for both years of the study. Bulinus globosus, the snail intermediate host of S. mattheei was recorded from the study sites with the highveld having a significantly higher abundance of the snails than the lowveld (P < 0.01). Monthly densities of B. globosus did not show a clearcut pattern although there were peaks between March / May and September / November. The mean num ber of snails collected was positively correlated with the water plants Nymphaea caerulea and Typha species. Overall, 2.5 % of B. globosus were shedding Schistosoma cercariae. In the highveld, 2.8 % of B. globosus were infected with schistosome cercariae and 1.5 % in the lowveld, with the figures at individual sites ranging from 0-18.8 % in the highveld and from 0-4.5 % in the lowveld. The cercariae recorded here were a mixture of S. mattheei and S. haematobium since they share the same intermediate host. The transmission of Schistosoma cercariae exhibited a marked seasonal pattern, being more intensive during the hot, dry season (September / November).


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