scholarly journals Preliminary Observations on the Family Mormyridae in Oyan Dam Lake (Nigeria)

2013 ◽  
Vol 15 (1) ◽  
pp. 33-48 ◽  
Author(s):  
Olaniyi Alaba Olopade
Keyword(s):  
Condition Factor ◽  
Mesh Size ◽  
Mean Value ◽  
Dry Season ◽  
Wet Season ◽  
Wiener’S Index ◽  
Ogun State ◽  
The Family ◽  
Fish Species Composition ◽  
Mormyrus Rume

ABSTRACT This study was carried out to investigate the abundance, distribution, diversity and condition factor of Mormyrids in Oyan Dam lake, Abeokuta North Local Government Area of Ogun State, Nigeria. The fish were sampled from the catches of the fishermen in Oyan Dam lake, which used gillnets of 30-80 mm laterally stretched mesh size. The fish were sampled monthly between February and September 2011, at two different sites (Imala and Ibaro). The results revealed that a total number of 100 fishes of six species belonging to the family Mormyridae were collected. Numerically, catches were dominated by Mormyrus rume (34%), Hyperopisus bebe (30%) and Petrocephalus bane (24%). Together, these species comprised 88% of all collected individuals. Marcusenius ihuysi was rare and least in number representing 1% of the fish caught. The results showed that only four species were recorded in the dry season, namely Mormyrus rume, Hyperopisus bebe, Petrocephalus bane and Mormyrus deliciosus while five species were recorded in the wet season particularly in September. Mormyrus deliciosus, was not recorded in the wet season. In terms of body weight, the highest mean value was recorded for Mormyrus deliciosus (435.71 ± 95.71), followed by Mormyrus rume (143.82 ± 5.55) and Hyperopisus bebe (123.5 ± 5.26) while Petrocephalus bane was the least one (95.00 ± 8.56). The results also showed that the condition factor during the wet season (4.18) was higher than the condition factor of the dry season (3.51). Simpson’s index was used to determine the species richness, while Shannon-Wiener’s Index was used to evaluate species diversity; species evenness was equally evaluated using Pielou’s Index. The indices of diversity included (d) = 0.31 and 0.23, H = 1.18 and 1.53 and E = 0.851 and 0.853 respectively for the two sites at Oyan Dam lake. The estimates from these indices indicated a low fish species composition and richness, also unevenness in the population of Mormyrids in Oyan Dam lake. Therefore, it will be advisable to regulate the activities of fishers in the water body to allow future increase in the abundance of this species.

scholarly journals Investigation of Heavy Metals Level in selected Boreholes around the Vicinity of some Cemeteries in Benin City, Nigeria

2021 ◽  
Vol 25 (5) ◽  
pp. 841-845
Author(s):  
C.A.E. Ibhadode ◽  
I.R. Ilaboya
Keyword(s):  
Heavy Metals ◽  
Pollution Index ◽  
Mean Value ◽  
Dry Season ◽  
Wet Season ◽  
Monthly Basis ◽  
Benin City ◽  
Standard Procedures ◽  
The Mean ◽  
Mean Concentration

Groundwater pollution by heavy metals such as lead, copper, nickel and iron is one of the major environmental issues of concern which has developed into a widely studied area. In this study, attempt was made to investigate the level of heavy metals in selected boreholes around the vicinity of cemeteries in Benin City. Seventy-two (72) samples of groundwater were taken from boreholes in 9 stations around the three cemeteries in Benin City on monthly basis. The samples were analysed for 7 heavy metals, in accordance with standard procedures. The heavy metals include; Zinc, Lead Iron, Copper, Cadmium, Nickel and Mercury. From the results of the study, a variation in the mean concentration of zinc was observed. The mean concentration of zinc in site 1 was 0.450mg/l, for site 2, it was 0.140mg/l and for site 3, it was 1.0533mg/l. For iron, mean concentration was 0.072mg/l in site 1. For site 2, mean concentration of iron was 2.140mg/l and for site 3, mean concentration of iron was 0.560mg/l. It was further revealed based on the results that mean value of heavy metals in groundwater around cemeteries in Benin City were generally lower during dry season compared to wet season. In addition, result of computed pollution index (Pi) revealed that the heavy metal with the highest potential to pollute groundwater is Cadmium, with Pi of 0.5333 and 0.400 representing dry season and wet season respectively.

Seasonal variability of evapotranspiration in the central Andes of Peru using eddy covariance techniques and empirical methods

2020 ◽  
Author(s):  
Stephany Magaly Callañaupa Gutierrez ◽  
Hans Segura Cajachagua ◽  
Miguel Saavedra ◽  
Jose Flores ◽  
Joan Cuxart ◽  
...  
Keyword(s):  
Eddy Covariance ◽  
Sonic Anemometer ◽  
Strong Relationship ◽  
Mean Value ◽  
Dry Season ◽  
P Value ◽  
Wet Season ◽  
Peruvian Andes ◽  
Energy Limitation ◽  
Relationship Of

<p>In this study, the real evapotranspiration (ET) obtained using the eddy covariance (EC) technique from field crops located in the central Peruvian Andes (Huancayo Observatory, 12.04° S, 75.32°, 3350 msnm) is analyzed. Data from a sonic anemometer and a krypton hygrometer are used to estimate daily and monthly ET variability and to explore relationships with meteorological and surface variables. The results show that the mean value of daily evapotranspiration is estimated to be 3.45 mm/day during the wet season (January to March) while in the dry season (June to August) the value is 0.95 mm/day. In addition, linear regressions were used in order to evaluate the relationship of meteorological variables with evapotranspiration. As a result, solar radiation is the meteorological variable that has a strong relationship with evapotranspiration during the wet season (r2=0.76, p-value <0.005) and soil moisture during the dry season (r2=0.77, p-value <0.005). These results indicate a clear water-energy limitation depending on the season. Besides, the empirical evapotranspiration equations of FAO Penman-Monteith, Priestley-Taylor and Hargreaves were validated. Where the Priestley-Taylor equation is the empirical equation that best fits the observed data of evapotranspiration by EC (r2=0.70, p-value< 0.005).</p>

scholarly journals Patterns of Fish Assemblage, Growth, and Diet Composition in a Tropical River between Two Cascading Hydropower Dams

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Lee Nyanti ◽  
Chen-Lin Soo ◽  
Afina-Yian Chundi ◽  
Elsa-Cordelia-Durie Lambat ◽  
Alvinna Tram ◽  
...  
Keyword(s):  
Fish Species ◽  
Diet Composition ◽  
Fish Assemblages ◽  
Condition Factor ◽  
Dry Season ◽  
Growth Patterns ◽  
Native Fish ◽  
Wet Season ◽  
Fish Samples ◽  
The Impact

Construction of cascade dams has been shown to have impacts on fish assemblages and biodiversity. Yet, there is no literature on fish assemblages in the Murum River that connects the cascading Bakun and Murum dams in Sarawak, Malaysia. Hence, study on this modified ecosystem is necessitated to better understand the effects of the cascade dam construction on fish fauna. For this, fish samples were caught at five stations located along the river during both dry and wet seasons. Environmental parameters were taken concurrently with fish sampling. Length-weight relationship, condition factors, and diet composition of selected fish species in the river were also determined. The present study demonstrated that there are indications of the impact of cascading dams on the formation of a complex ecosystem in the Murum River, that is, changing from the shallow downstream of the Murum Dam to the deep transitional and inundated zone of the Bakun reservoir. The transitional zone in the Murum River exhibited the lowest fish species diversity, richness, and evenness during the dry season due to low pH and DO coupled with high turbidity. The biological indices improved when the water quality improved during the wet season. On the contrary, the diversity and evenness indices at the inundated tributary station decreased remarkably during the wet season, likely due to the migration of fish during the onset of the rainy season. This study showed that Barbonymus schwanenfeldii has a wider feeding habit which contributes to its higher distribution and abundance in the Murum River. The growth patterns of B. schwanenfeldii, Cyclocheilichthys apogon, Hampala macrolepidota, Lobocheilos ovalis, and Osteochilus enneaporos were better during wet than dry season. Overall, the condition factor of all native fish species in the Murum River was in poor to fair condition, whereas the exotic species, Oreochromis mossambicus, exhibited excellent condition (K value > 2) for both seasons. The increase in the number of O. mossambicus coupled with its high condition factor indicates biological intrusion and a potential threat to the native fish species in the Murum River. Continuous monitoring is essential to detect in-time risk issues associated with environmental degradation and biological invasion in this regulated and inundated river ecosystem.

scholarly journals FACTORS AFFECTING LIVEWEIGHT OF GOAT AND SHEEP IN TWO LOCATION WITHIN OGUN STATE.

2021 ◽  
Vol 23 (1) ◽  
pp. 12-15
Author(s):  
C. O. N. IKEOBI ◽  
O. A. FALETI
Keyword(s):  
Dry Season ◽  
West African ◽  
Wet Season ◽  
The West ◽  
Southwestern Nigeria ◽  
Factors Affecting ◽  
West African Dwarf ◽  
Ogun State ◽  
West African Dwarf Goat ◽  
The Mean

A study was conducted over two years  With the to determine the changes in the liveweight of Yankasa sheep and Maradi goat in goats and sheep in two locations in Ogun State, South-Western Nigeria Factors found to be important included breed of goat, season, location, and sex of the animal. The Maradi goat had a greater variation in its liveweight than the West African' dwarf goat. The mean weekly gain in the liveweight of goats was 0.18±02 dry season and 0.26±0.05 kg in the wet season. Liveweight changes were greater in yearling Yankasa sheep reared in this part of the Southwestern Nigeria than in older ones; these differences were significantly greater in the dry than in the wet season.

scholarly journals Seasonal variation and characterization of effluents of fertilizer factory

2015 ◽  
Vol 26 (2) ◽  
pp. 136-146
Author(s):  
K Fatima ◽  
MK Hossain ◽  
MA Islam
Keyword(s):  
Water Quality ◽  
Water Samples ◽  
Quality Parameters ◽  
Mean Value ◽  
Dry Season ◽  
Chemical Parameters ◽  
Wet Season ◽  
Physico Chemical ◽  
The Mean ◽  
Nitrite Nitrate

The study was carried out to assess the water quality of the Jamuna river affected by effluents discharged from the nearby Jamuna Fertilizer Company Limited and its temporal change over wet and dry seasons due to change of the physico-chemical parameters. Effluents of the factories and water samples were collected from four different selected stations during the period of June to August 2014 and January to March 2015.The results further revealed that the water samples showed a remarkable variation in physico-chemical parameters during the wet and dry season. In wet season the mean value of temperature, pH, EC, TDS, TSS, DO, BOD, ammonium, nitrite, nitrate and chloride were28.63± 3.79 °C, 8.10± 0.85, 664.41± 599.54µscm-1, 370.91± 111.38 ppm, 74.49± 25.90 ppm, 6.11 ± 1.28 ppm, 75.39 ± 140.86 ppm 296.74± 303.03 ppm, 12.31±21.38 ppm,  15.19±24.49 ppm and 15.23±8.72 ppm, respectively In the dry season the mean value of temperature, pH, EC, TDS, TSS, DO, BOD, ammonium, nitrite, nitrate and chloride were31.69 ±3.18°C, 8.44± 0.66, 786.25±551.18µscm1, 338.37± 94.70 ppm, 72.08± 58.83 ppm, 5.45 ± 0.95 ppm, 86.93 ± 159.82 ppm, 347.91± 291.60 ppm, 13.68±23.1 ppm, 18.34± 24.92 ppm and 18.3±9.32 ppm, respectively. The comparative study showed that most of the effluent and water quality parameters were higher in dry season than those of the wet season because in dry season less quantity of water remains in the river and in wet season more water remains in river that has great dilution capacity. For existence and conservation of aquatic resources, it is essential to investigate the water quality and surrounding environment of the river.Progressive Agriculture 26 (2): 136-146, 2015

scholarly journals Estimation of Radio Horizon Distance Using Measured Meteorological Parameters over Some Selected Locations in Nigeria

2019 ◽  
pp. 1-11
Author(s):  
A. T. Adediji ◽  
S. O. Adebusola ◽  
J. S. Ojo
Keyword(s):  
Relative Humidity ◽  
Data Acquisition ◽  
Meteorological Parameters ◽  
Mean Value ◽  
Dry Season ◽  
Wet Season ◽  
Atmospheric Research ◽  
Port Harcourt ◽  
Study Results ◽  
The Mean

In this study, results of the variation of maximum and minimum radio horizon distance derived from the computation of surface refractivity through measurement of temperature, relative humidity and pressureacrosssevenlocations((Akure (7.15°N, 5.12°E), Lagos (6.30°N, 3.20°E), Abuja (7.10°N, 9.25°E), Jos (9.50°N, 8.50°E), Makurdi (7.30°N,8.53°E), Port-Harcourt(4.20°N,7.00°E), and Nsukka (6.90°N,7.67°E)) in Nigeria are presented. Two years (Jan., 2011–Dec., 2012) archived data as provided by Tropospheric Data Acquisition Network (TRODAN) of the Centre for Atmospheric Research Anyigba, Kogi State were utilized for the study. Results showed that the values of surface refractivity (Ns) were low during the dry season months and high during the wet season months and also there was high value of NS at the coastal areas compared with the inland areas. It was also deduced that the mean value of NS for Abuja, Akure, Jos, Lagos, Markurdi, Nsukka and Port-Harcourt is 355, 362, 303, 391, 375, 361 and 399 N-units respectively. Results showed that the Radio Horizon Distance (RDH) values were generally low during the wet season months and high during the dry season months. The variability of radio horizon distance of transmitting antennas is higher in the Northern part of Nigeria than the southern part.

scholarly journals The use of pre-dawn leaf water potential and MODIS LAI to explore seasonal trends in the phenology of Australian and southern African woodlands and savannas

2008 ◽  
Vol 56 (7) ◽  
pp. 557 ◽  
Author(s):  
Anthony R. Palmer ◽  
Sigfredo Fuentes ◽  
Daniel Taylor ◽  
Cate Macinnis-Ng ◽  
Melanie Zeppel ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Water Potential ◽  
Leaf Water Potential ◽  
Mean Value ◽  
Dry Season ◽  
Leaf Water ◽  
Wet Season ◽  
Area Index ◽  
Climate Change Research ◽  
Modis Lai

Trends in global soil moisture are needed to inform models of soil–plant–atmosphere interactions. Predawn leaf water potential (Ψpd), a surrogate for soil moisture and an index of plant water stress, has been routinely collected in Australian forests, woodlands and savannas, but the associated leaf area index (LAI) has seldom been available to enable the preparation of a Ψpd on LAI relationship. Following an analysis of Ψpd and MODIS LAI data from Australian forests, woodlands and savannas, we identified patterns in Ψpd which provide an understanding of the role of soil-moisture status in controlling LAI. In the savanna of northern Australia, the MODIS LAI product had a basal value of 0.96 during the dry season as compared with a mean value of 2.5 for the wet season. The dry season value is equivalent to the LAI of the tree component and corresponds with ground-truthed LAI. Ψpd is lowest (more negative) during the height of the dry season (late October) at −2.5 MPa, and highest (−0.1 MPa) during the wet season (early March). We present two models which predict Ψpd from the MODIS LAI product. These may be useful surrogates for studying trends in soil moisture in highly seasonal climates and may contribute to climate change research.

scholarly journals Spatial Organization of the Kasungu Elephant

1983 ◽  
Vol 53 (2) ◽  
pp. 179-186 ◽  
Author(s):  
Hugo Jachmann
Keyword(s):  
Home Range ◽  
Spatial Organization ◽  
Food Competition ◽  
Dry Season ◽  
Home Ranges ◽  
Wet Season ◽  
Activity Area ◽  
The Social ◽  
The Family ◽  
Extended Area

Using a recognition file that was compiled during the study, information on movements of individually known elephants was collected over two periods, one of three and one of eight months, in 1978 and 1981/82, respectively. There appeared to be a relationship between the number of animals in the family unit and the size of the home range/activity area, probably as a result of food competition between the members of a unit. Since 1978 the size of the home range/activity area had decreased in general, as a result of compression by illegal activity. Dry-season home ranges of family units appeared to be rather stable over longer periods and larger than the wet-season home ranges that were situated along the river Lingadzi. Dry-season home ranges of bulls only lasted throughout a single dry season. During the wet season bulls ranged over an extended area. In the later part of the dry season, elephant movements were determined by salt licks and the remaining water holes with a relatively high conductivity, at a distance of the river Lingadzi. The social structure of the family units that made up a kin-group determined the time spent with each other and also appeared to influence the actual size of the home range.

scholarly journals Seasonal Comparison of Potential Groundwater Aquifer in Ijebu-Ife, South-West, Nigeria, using Dipole-Dipole Array and Electromagnetic Methods

2020 ◽  
pp. 241-249
Author(s):  
J. O. Coker ◽  
H. H. Akpan ◽  
A. O. Atilade ◽  
O. F. Ojo
Keyword(s):  
Geophysical Methods ◽  
Low Frequency ◽  
Dry Season ◽  
Wet Season ◽  
Clayey Sand ◽  
Ogun State ◽  
South West ◽  
Groundwater Aquifer ◽  
Potential Groundwater ◽  
High Depth

Seasonal comparison of potential groundwater aquifer unit using integrated geophysical methods at Ijebu-Ife, Ogun State, South-west, Nigeria was investigated. The fieldwork employed two seasons (dry and wet seasons). The electromagnetic method employed the Very low frequency and its data was acquired during the dry and wet seasons along with five profiles of Dipole-dipole array covering 500 m length using ABEM WADI VLF equipment and was processed using the KAROUS-HJELT software. The 2 – D Dipole-dipole data were also acquired along with five (5) traverse for both seasons making a total number of ten (10) and was processed with DIPROFWIN software. The results of the Integrated Dipole-Dipole and VLF-EM data identified three geoelectric layers based on its electrical resistivity and conductivity distribution. The study identified a clayey sand horizon which constitutes a good aquifer zone. The study reveals in, comparison, that during the dry season, all layer resistivities are high with low depth while during the wet season; all layer resistivities are low with high depth. Also, conductivity during the wet season is high at high depth than conductivity which is low at low depth during the dry season. The study concluded that, in water exploration, drilling of water should be done during the dry season in other to locate the exact depth of water.    

scholarly journals The seasonal changes of the gut microbiome of the population living in traditional lifestyles are represented by characteristic species-level and functional-level SNP enrichment patterns

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xue Zhu ◽  
Jiyue Qin ◽  
Chongyang Tan ◽  
Kang Ning
Keyword(s):  
Gut Microbiome ◽  
Seasonal Changes ◽  
Dry Season ◽  
Urban Setting ◽  
Snp Analysis ◽  
Wet Season ◽  
Human Gut ◽  
Human Gut Microbiome ◽  
Genome Level ◽  
Prevalent Species

Abstract Background Most studies investigating human gut microbiome dynamics are conducted on humans living in an urban setting. However, few studies have researched the gut microbiome of the populations living traditional lifestyles. These understudied populations are arguably better subjects in answering human-gut microbiome evolution because of their lower exposure to antibiotics and higher dependence on natural resources. Hadza hunter-gatherers in Tanzania have exhibited high biodiversity and seasonal patterns in their gut microbiome composition at the family level, where some taxa disappear in one season and reappear later. Such seasonal changes have been profiled, but the nucleotide changes remain unexplored at the genome level. Thus, it is still elusive how microbial communities change with seasonal changes at the genome level. Results In this study, we performed a strain-level single nucleotide polymorphism (SNP) analysis on 40 Hadza fecal metagenome samples spanning three seasons. With more SNP presented in the wet season, eight prevalent species have significant SNP enrichment with the increasing number of SNP calling by VarScan2, among which only three species have relatively high abundances. Eighty-three genes have the most SNP distributions between the wet season and dry season. Many of these genes are derived from Ruminococcus obeum, and mainly participated in metabolic pathways including carbon metabolism, pyruvate metabolism, and glycolysis. Conclusions Eight prevalent species have significant SNP enrichments with the increasing number of SNP, among which only Eubacterium biforme, Eubacterium hallii and Ruminococcus obeum have relatively high species abundances. Many genes in the microbiomes also presented characteristic SNP distributions between the wet season and the dry season. This implies that the seasonal changes might indirectly impact the mutation patterns for specific species and functions for the gut microbiome of the population that lives in traditional lifestyles through changing the diet in wet and dry seasons, indicating the role of these variants in these species’ adaptation to the changing environment and diets.

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