New contribution on spatial and seasonal variability of environmental conditions of the Golfo San Jorge benthic system, Argentina

Author(s):  
Mónica Fernández ◽  
José Mora ◽  
Ana Roux ◽  
Daniel A. Cucchi Colleoni ◽  
Juan C. Gasparoni

A new contribution on spatial and seasonal variability of physico-chemical parameters of the Golfo San Jorge benthic system from autumn 2001 through summer to 2002 is presented. Temperature, salinity, density, oxygen content and chlorophyll-a in bottom water as well as concentration of total organic matter, total organic carbon, total nitrogen, total phosphorus, chlorophyll-a and phaeopigments in sediments were analysed. The origin and nutritional value of the deposited organic matter were also assessed. The results reflect the existence of: (1) a typical temperate water seasonal cycle; (2) a bimodal cycle in the phytoplanktonic production; and (3) seasonal variations in the chemical variables and in organic matter origin in sediments.Three sectors which geographically correspond with those identified in previous studies were defined: (1) the inner area of the gulf; (2) the areas next to the north and south extremes; and (3) the coastal and south-east part.

2020 ◽  
Vol 7 (3) ◽  
pp. 378-382
Author(s):  
Santoshkumar Jayagoudar ◽  
Pradeep Bhat ◽  
Ankita Magdum ◽  
Duradundi Sakreppagol ◽  
Laxmi Murgod ◽  
...  

Algae are the diverse group of organisms in the soil and aquatic environment. The role of them in soil fertility enhancement has been extensively studied worldwide. Belagavi is a tropical agricultural belt in the North Karnataka region with highly fertile soil. Water and soil samples were collected randomly from the paddy field of 15–20 well-distributed spots in 4 selected locations viz Kusumali, Jamboti, Kinaye and Piranwadi. The identification revealed the presence of 94 species and 71 genera in the investigated sites. Among all, 62 species belonged to Bacillariophyceae, 14 species to Chlorophyceae, 10 species to Cyanophyceae, 3 to Xanthophyceae, followed by Trebouxiophyceae and Zygnematophyceae (2 species each) and one species of Ulvophyceae. The maximum number of 62 species was recorded from Kusamali, followed by 49 species in Kinaye, 44 in Jamboti and 35 in Piranwadi. The month of February had the highest number of species (61), decreased to 45 in March, 42 in April and 37 in May. Among the physicochemical parameters analysed for the soil samples, it was found that the pH of the soil is slightly acidic in all the study sites ranged between 5.03–5.85. Further, the electrical conductivity (EC) varied from 0.27–0.345 dS/m, found to be in a good range. Estimation of available micro and macronutrients of soil were measured, and it was found to be at low to moderate levels. The present study indicates the extensive distribution of different classes of algae in the rice fields of four study locations in Belagavi.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Fella Hamaidi-Chergui ◽  
Mohamed Brahim Errahmani ◽  
Fatouma Benouaklil ◽  
Mohand Said Hamaidi

The present study was carried out to determine the monthly variations of physico-chemical parameters in water samples from Chiffa river at Blida, North West of Algeria from April to August 2006. Water samples were analyzed for physico-chemical parameters and the results showed their monthly variations as follows: pH 7.5-7.6, electrical conductivity 0.87–1.06 mS·cm−1, nitrate 0–7.00 mg·L−1, nitrite 0–0.28 mg·L−1, ammonia 0–0.03 mg·L−1, phosphate 0–0.94 mg·L−1, sodium 19.3–47.0 mg·L−1, chloride 35.7–52.0 mg·L−1, calcium 90.3–104.7 mg·L−1, magnesium 27.3–37.7 mg·L−1, organic matter 0.4–3.9 mg·L−1, chlorophyll a 0.7–132.3 mg·L−1, and bicarbonate 219.3–248.7 mg·L−1. The analyzed physico-chemical parameters were almost not exceeded the maximum permissible limit of WHO and Algerian Water Quality Guidelines. A total of 53 taxa belonging to 4 divisions have been identified, including Chlorophyta (52.83% of taxa), Bacillariophyta (28.30%), Cyanophyceae (16.98%), and Charophyta (1.89%).


Author(s):  
Cam Nguyen

The objective of this study was to treat biological ammonium and organic matter from milk manufacturing wastewater in Binh Dinh using combined biofilter and plant process. The treatment efficiency of biofilter-plant method in section biosysterm was higher than that of individually biofilter and plant method to be observed. The obtained experiment results showed that the outflowing physico-chemical parameters as COD, NH4+ of milk production wastewater after treatment by the combined use of biofilter and plant treatment reached QCVN 40: 2011/BTNMT for industrial wastewater sort A.


2010 ◽  
Vol 7 (4) ◽  
pp. 1357-1373 ◽  
Author(s):  
N. Greenwood ◽  
E. R. Parker ◽  
L. Fernand ◽  
D. B. Sivyer ◽  
K. Weston ◽  
...  

Abstract. This paper presents new results from high temporal resolution observations over two years (2007 and 2008) from instrumented moorings deployed in the central North Sea, at the Oyster Grounds and on the northern slope of Dogger Bank (North Dogger). The water column was stratified in the summer at both sites, leading to limited exchange of the water in the bottom mixed layer. Data from these moorings revealed the variable nature of summer oxygen depletion at the Oyster Grounds. The combination of in situ and ship-based measurements allowed the physical and biological conditions leading to decreasing dissolved oxygen concentrations in bottom water to be examined. In 2007 and 2008, the concentration of dissolved oxygen in the bottom water at both sites was observed to decrease throughout the summer period after the onset of stratification. Depleted dissolved oxygen concentration (6.5 mg l−1, 71% saturation) was measured at the North Dogger, a site which is not significantly influenced by anthropogenic nutrient inputs. Lower oxygen saturation (5.2 mg l−1, 60% saturation) was measured for short durations at the Oyster Grounds. The seasonal increase in bottom water temperature accounted for 55% of the decrease in dissolved oxygen concentration at the Oyster Grounds compared to 10% at North Dogger. Dissolved oxygen concentration in bottom water at the Oyster Grounds was shown to be strongly influenced by short term events including storms and pulses of particulate organic matter input. In contrast, dissolved oxygen concentration in bottom water at the North Dogger reflected longer seasonal processes such as a gradual temperature increase over the summer and a more steady supply of particulate organic matter to the bottom mixed layer. The differences between the study sites shows the need for an improved understanding of the mechanisms driving these processes if the use of oxygen in marine management and ensuring ecosystem health is to be meaningful and successful in the future. These high frequency observations provide greater understanding of the nature of the depletion in bottom oxygen concentration in the North Sea.


2013 ◽  
Vol 39 (2) ◽  
pp. 3-16 ◽  
Author(s):  
Aleksandra Ibragimow ◽  
Barbara Walna ◽  
Marcin Siepak

Abstract The occurrence of heavy metals (Cd, Cr, Cu, Ni, Pb, Zn) has been determined in the fluvial sediment samples collected along three transects in the Middle Odra River (western Poland) with a width of 360 m. The total concentrations of the metals were obtained after HNO3 microwave digestion and the available fractions of heavy metals were determined by single extraction procedures using two extractants: 0.01M CaCl2 and 0.05M EDTA. The measurement of physico-chemical parameters was also performed. The determination of total and available fractions of heavy metals, except potential available fractions of Cr, revealed high concentrations of studied elements detected in the sediment samples characterized by high content of coarse and very coarse-grained sand fraction and high content of organic matter. It was found that the concentrations of total and available fractions of metals could increase along with the content of organic matter, Eh values and concentrations of H+. Apart from the above, those concentrations become the lowest, the higher the content of medium grain size fractions is. Furthermore, the amounts of CaCl2 and EDTA extractable metals increase in the sediments samples characterized by the lowest total and available concentrations of heavy metals.


Author(s):  
N’Doufou Gnosseith Huberson Claver ◽  
Kouadio Koffi Hypolithe ◽  
De Lasm Omer Zephir ◽  
Zogoury Eddie Constant Fabrice

This work focuses on analyzing of physico-chemical properties of sediment affected by frequent floods along the eastern shore of the Bandama River in the department of Niakaramadougou. Sampling was from 4 excavated graves at two positions of studied area, one near the stream and the other one far away from the stream.. Samples collected were analyzed, including texture with granulometric analysis made by the Robinson pipette, and standard sediment analysis methods for measuring organic carbon (OC), nitrogen (N), and other chemical properties including pH, organic matter (OM), and C/N ratio. Statistical analyses were carried out to assess the differences between the physico-chemical parameters at different sampling areas. Differences are significant when comparing areas that are highly affected by floods and areas that are less affected by floods, especially for concentrations of OM, OC and nitrogen. Results show that successive floods are influencing directly the dynamic of physico-chemical properties of the sediments along the shore.


2021 ◽  
Vol 58 (3) ◽  
pp. 233-247
Author(s):  
M. E. El-Zeiny ◽  
A. M. Ghoneim ◽  
O. A. Abu Samak ◽  
A. A. Khidr

Summary In addition to being a good food source, freshwater snails are considered one of the positively and negatively influencing invertebrates on the environment. Several biotic and abiotic factors are thought to affect the distribution and the dynamics of these snails. Freshwater snails are the most dominant and conspicuous individuals of the freshwater biota in Damietta Governorate. In this study, freshwater snails were collected monthly from 5 geographically and environmentally different sites at Damietta Governorate at the north of Egypt during June 2017-May 2018. Seven snail species; Lanistes carinatus, Lanistes varicus, Pila wernei, Segmentorbis angustus, Melanoides tuberculata, Biomphalaria alexandrina, and Gabbiella senoriansis, were identified. Lanistes carinatus was the most abundant species (56.4%) in the collection sites. Besides, Al-Inaniyyah village had the highest snail species abundance and variety. The abundance of the most recorded species varied seasonally; the highest abundance was recorded during summer while the lowest was during winter. The abundance of some snail species correlated positively or negatively with some physico-chemical parameters; water temperature, dissolved oxygen, conductivity, total dissolved salts, and electrical conductivity. Two types of trematode cercariae; gymnocephalus cercariae and xiphidiocercariae, were harvested from Lanistes carinatus. The highest prevalence of both cercarial types was detected during summer. The correlation between the prevalence of both cercarial types and the physico-chemical parameters were determined. Xiphidiocercariae were the most predominant cercarial type in Damietta Governorate. Our findings suggest that the invasion of some freshwater snails is likely to be the cause of the low prevalence or complete absence of some medically important intermediate snail hosts. We recommend further characterization of the distribution of freshwater snails and the interrelationships among them in Egypt, and suggest a controlled use of selected snail species to combat their medically important analogues.


2013 ◽  
Vol 20 (1) ◽  
pp. 64
Author(s):  
Marly Azevedo Saraiva ◽  
Gilberth Silva Nunes ◽  
Ivone Garros Rosa ◽  
José Malheiros Silva ◽  
Carlene Reis Peixoto ◽  
...  

O mel é um alimento muito apreciado e de excelente valor nutritivo, constituído por uma mistura complexa de carboidratos, enzimas, aminoácidos, ácidos, minerais, substâncias aromáticas, vitaminas, pigmentos, cera e grãos de pólen. O produto pode apresentar alterações devido a formas inadequadas de armazenamento e conservação. Tais procedimentos ocasionam sua deterioração, comprometendo seriamente o alimento. Quando os méis de abelha são submetidos a condições de temperatura e luminosidade intensa podem sofrer algumas modificações nas suas propriedades físico-químicas. A proposta deste trabalho é verificar a presença e o grau de deterioração dos méis de abelha comercializados em São Luís do Maranhão. Foram realizadas as análises físico-químicas: umidade, acidez, atividade diastásica e hidroximetilfurfural em 30 amostras de méis de Apis mellifera e os valores foram analisados segundo a Instrução Normativa n.º 11 de 2000 do MAPA. As amostras em estudo apresentaram valores fora dos padrões estabelecidos pela legislação, em relação à determinação de atividade diastásica e teor de hidroximetilfurfural, parâmetros físico-químicos que fornecem indicações sobre o grau de conservação e superaquecimento, o que indica que as amostras apresentaram deterioração.Palavras-chave: Mel. Apis mellifera. Deterioração.STATE OF DETERIORATION OF BEE'S HONEYS (APIS MELLIFERA) COMMERCIALIZED IN SÃO LUIS- MARANHÃOAbstract: Honey is a very appreciated food and has excellent nutritional value, constituted by a mixture of a complex carbohydrates, enzymes, amino acids, minerals, flavorings, vitamins, pigments, waxes and pollen. The product may undergo changes due to inadequate forms of storage and conservation. These procedures may cause their deterioration, severely compromising the food. When the honeys of bee are submitted to conditions of temperature and intense light may undergo some modifications in their physicochemical properties. The purpose of this study is to verify the presence and degree of deterioration of honeys of bee commercialized in São Luis do Maranhão. Physico-chemical analyses were done: moisture, acidity, diastase activity and hydroxymethylfurfural in 30 honey samples of Apis mellifera and the values were analyzed according to Normative Instruction No. 11 of 2000 of MAPA. The samples studied showed values outside the standards established by legislation in relation to the determination of diastase activity and hydroxymethylfurfural content, physico-chemical parameters that provide indications about the degree of conservation and overheating, which indicates that the samples showed deterioration.Keywords: Honey. Apis mellifera. Deterioration.ESTADO DE DETERIORO DEL MIEL DE ABEJA (APIS MELLIFERA) SE COMERCIALICEN EN SAO LUIS DO MARANHÃOResumen: La miel es un alimento muy popular y el valor nutritivo excelente, compuesto de una mezcla de hidratos de carbono complejos, enzimas, aminoácidos, minerales, vitaminas, aromatizantes, colorantes, ceras y polen. El producto puede sufrir cambios debido a métodos inadecuados de almacenamiento y conservación. Estos procedimientos causan su deterioro, comprometiendo severamente los alimentos Cuando las abejas están sujetas a condiciones de temperatura y luz intensa pueden sufrir algunas modificaciones en sus propiedades fisicoquímicas. El objetivo de el presente estudio es verificar la presencia y el grado de deterioro de la miel de abeja negocian en São Luís do Maranhão. Los análisis se realizaron con propiedades físicoquímicas: La humedad, acidez, actividad de la diastasa y el hidroximetilfurfural en 30 muestras de miel de Apis mellifera y los valores fueron analizados de acuerdo a la Instrucción Normativa N º 11 de 2000 MAPA. Las muestras estudiadas mostraron valores fuera de los estándares establecidos por la legislación en relación con la determinación de la actividad de la diastasa y el contenido de hidroximetilfurfural, parámetros físico-químicos que proporcionan información sobre el grado de conservación y el sobrecalentamiento, lo que indica que las muestras mostraron deterioro.Palabras clave: Mel. Apis mellifera. Deterioro.


2021 ◽  
Vol 44 ◽  
pp. 102435
Author(s):  
Luan de Souza Leite ◽  
Maria Teresa Hoffmann ◽  
Fábio Simões de Vicente ◽  
Danilo Vitorino dos Santos ◽  
Luiz Antonio Daniel

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