Study on biological characteristics, sexual maturation and reproduction of Liza abu in the water of Khozestan Province

As the most of the fish resources are known and exploited, protecting their generation is of the greatest importance. Aquaculture is one of the efficient procedures in protecting and reviving fish resources and knowing about the reproductive cycle and gonads development has an important role in approaching this aim. Liza abu belongs to the family Mugilidae that according to its resistance to the environmental condition and its fast growth , can be introduced as a fish with economical value. As there is no scientific data on the reproductive biology of this species , study on the reproductive biology and gonad development is considered as the aim of this research . For this purpose , 360 samples of this species were investigated during the period from February 2007 to January 2008 in Khozestan Province . After studing morphological and histological characteristics of gonad specimen , they were prepared through histological method. Samples were prepared through usual histological method and studied under light microscope. According to the results, the maturity stages of male and female Liza abu were separated to six different successive stages. In ovaries , these stages were as follow : In stage І, the oocytes were small , this stage was observed from July to October . In stage ІІ, considerable growth was observed in the oocytes . This stage was observed from October to January . In stage III, due to vitellogenesis, the maximum growth was observed and three layers of theca, granullosa and follicle cells were visible. This stage was observed during January and February . In stage IV, migration of germinal vesicle was observed and due to hydration of the oocytes , their diameter was increased. The ovaries were yellowish and in maximum size and ovules could be easily observed with naked-eye . This stage was observed in February and March . In stage V, spawning occured. This stage was observed in April . In stage VI, ovaries consisted of immature and atretic oocytes and also empty follicles. This stage was observed in May and June. In testes , these stages were as follow : In stage I , the testes were small in size and contained the spermatogonia which were the only cellular components.This stage was observed in August and September . In stage II (maturing virgin ) , the spermatogonia and the primary spermatocytes were visible. This stage was observed in October . In stage III (developing), intensive spermatogenesis was occured and the primary and the secondary spermatocytes were the most visible cells during this stage .This stage was observed from November to January. In stage IV(developed), cells of all stages of spermatogenesis could be seen but the secondary spermatocytes and spermatids were in large number. This stage was observed from January to March. In stage V , the testes were filled with sperms. This stage was observed in March and April .In stage VI, residual spermatozoa and the spermatogonia were visible in the testes. This stage was observed from May to August. According to cyclic changes in GSI, sexual maturation in breeding begins in January and spawning occurs in April. The ova diameter ranged from 30.75 μ in stage I to 472.19 μ in stage IV. In this study , the sex ratio was 1:2.7, and male and female percentage were 27.02% and 72.98% respectively. This means that females predominate males. In this study absolute fecundity was calculated and changing between 30805.44 to 431247.3 was observed and absolute fecundity was calculated 111275.3 in average.

Technical report on the environmental monitoring of the cage area at the Source of the Nile (SON) Cage Fish Farm for quarter 4: October-December 2015

Source of the Nile (SON) Cage Fish farm is located at Bugungu in Napoleon Gulf, northern Lake Victoria, near the headwaters of the River Nile. NaFIRRI has, through a Public-Private collaborative partnership with SON management, undertaken quarterly monitoring of the cage fish farm since 2011. The objective of the environment monitoring is to track possible environment and biological changes as a result of fish cage operations in the area. The agreed study areas cover selected physical-chemical parameters i.e. water depth, transparency, column temperature, dissolved oxygen, pH and conductivity; nutrient status; and biological parameters i.e. algae, zooplankton, macro-benthos and fish communities. The fourth quarter survey, which is the subject of this report was undertaken during December 2015. Results/observations made are presented in this technical report along with a scientific interpretation and discussion of the results with reference to possible impacts of the cage facilities to the water environment and aquatic biota. The present report presents field observations made for the fourth quarter survey undertaken in December 2015 and provides a scientific interpretation and discussion of the results with reference to possible impacts of the cage facilities to the water environment and the different aquatic biota in and around the fish cage site.

A study on stock enhancement/restocking of the Kyoga basin lakes

Increased management attention to the fisheries tn Uganda is fuelled by five major factors:socio-economic demands, human population increase,stock depletion, biodiversity loss and,environmental degradation.Fish exports from Uganda to overseas and regional markets have rapidly increased since the mid 1990s and it is estimated that total exports are worth at least US$ 200m three quarters of the value due mostly to Nile perch exports to overseas markets.Exports to regional markets are dominated by variously processed tilapia "mukene" (Rastrineobo/a argentea),Nile perch "angara"(A/estes baremose) and cat fishes.Virtually all major water bodies contribute to this trade. A combinatilm of exports and an increased human population has seen the per capita fish consumption in Uganda drop from 15kg in the early 1990s to almost 10kg by 2005.this figure is below the WHO recommended fish protein intake of 17kg. the apparent fish gap in a liberalised economic framework has stimulated interest in commercial fish farming

Environmental priorities in strategic product development

This paper reports some results from a major research project on the integration of environmental issues into design in the electrical and electronic industry. Product development practice and ecodesign methods were examined along with qualitative data from 19 manufacturers, using interviews and an action research methodology. A four-stage framework for ecodesign practice resulted: first, to make an environmental assessment from a life cycle viewpoint; then to communicate the analysis and collect feedback; thirdly to prioritize the environmental issues and finally to complete the design using relevant tools and methods. This 'ARPI' framework (analyse, report, prioritize, improve) applies to both strategic and operational levels. Initial testing of the framework in collaborating companies highlighted difficulties with communication with design teams; the role of 'ecodesign champions' is explained. Other challenges are the development of customized tools and the training of designers. The study concludes that the prioritization step is critical, as it simplifies and clarifies the tasks in design that take place after formulation of the specification. Copyright (C) 2000 John Wiley and Sons, Ltd. and ERP Environment.

Civil and Environmental Engineering Challenges for Data Sensing and Analysis

The objective of this study was to identify challenges in civil and environmental engineering that can potentially be solved using data sensing and analysis research. The challenges were recognized through extensive literature review in all disciplines of civil and environmental engineering. The literature review included journal articles, reports, expert interviews, and magazine articles. The challenges were ranked by comparing their impact on cost, time, quality, environment and safety. The result of this literature review includes challenges such as improving construction safety and productivity, improving roof safety, reducing building energy consumption, solving traffic congestion, managing groundwater, mapping and monitoring the underground, estimating sea conditions, and solving soil erosion problems. These challenges suggest areas where researchers can apply data sensing and analysis research.

Climate resilience of schools: a case study

Social and political concerns are frequently reflected in the design of school buildings, often in turn leading to the development of technical innovations. One example is a recurrent concern about the physical health of the nation, which has at several points over the last century prompted new design approaches to natural light and ventilation. The most critical concern of the current era is the global, rather than the indoor, environment. The resultant political focus on mitigating climate change has resulted in new regulations, and in turn considerable technical changes in building design and construction. The vanguard of this movement has again been in school buildings, set the highest targets for reducing operational carbon by the previous Government. The current austerity measures have moved the focus to the refurbishment and retrofit of existing buildings, in order to bring them up to the exacting new standards. Meanwhile there is little doubt that climate change is happening already, and that the impacts will be considerable. Climate scientists have increasing confidence in their predictions for the future; if today’s buildings are to be resilient to these changes, building designers will need to understand and design for the predicted climates in order to continue to provide comfortable and healthy spaces through the lifetimes of the buildings. This paper describes the decision processes, and the planned design measures, for adapting an existing school for future climates. The project is at St Faith’s School in Cambridge, and focuses on three separate buildings: a large Victorian block built as a substantial domestic dwelling in 1885, a smaller single storey 1970s block with a new extension, and an as-yet unbuilt single storey block designed to passivhaus principles and using environmentally friendly materials. The implications of climate change have been considered for the three particular issues of comfort, construction, and water, as set out in the report on Design for Future Climate: opportunities for adaptation in the built environment (Gething, 2010). The adaptation designs aim to ensure each of the three very different buildings remains fit for purpose throughout the 21st century, continuing to provide a healthy environment for the children. A forth issue, the reduction of carbon and the mitigation of other negative environmental impacts of the construction work, is also a fundamental aim for the school and the project team. Detailed modelling of both the operational and embodied energy and carbon of the design options is therefore being carried out, in order that the whole life carbon costs of the adaptation design options may be minimised. The project has been funded by the Technology Strategy Board as part of the Design for Future Climates programme; the interdisciplinary team includes the designers working on the current school building projects and the school bursar, supported by researchers from the University of Cambridge Centre for Sustainable Development. It is hoped that lessons from the design process, as well as the solutions themselves, will be transferable to other buildings in similar climatic regions.

Thermogravimetric study on the hydration of reactive magnesia and silica mixture at room temperature

The synthesis of magnesium silicate hydrate (MSH), which has wide applications in both construction and environmental fields, has been studied for decades. However, it is known that the characteristics of magnesia (MgO) vary significantly depending on their calcination conditions, which is expected to affect their performance in the MgO-SiO2-H2O system. This paper investigated the effect of different MgO and silica sources on the formation of magnesium silicate hydrate (MSH) at room temperature. The hydration process was studied by mixing commercial reactive MgO and silica powders with water and curing for 1, 7 and 28 days. The hydration products were analysed with the help of X-ray diffraction (XRD) and thermogravimatric analysis (TGA). The results showed the continuous consumption of MgO and the existence of MSH and brucite and other minor phases such as magnesite and calcite. It is found that the Mg and Si sources have significant effect on the hydration process of MgO-SiO2-H2O system. The reaction degree is controlled by the availability of dissolved Mg and Si in the solution. The former is determined by the reactivity of MgO and the latter is related to the reactivity of the silica as well as the pH of the system. © 2013 Elsevier B.V. All rights reserved.

Mechanism study on the frequent variations of cell-bound microcystins in cyanobacterial blooms in Lake Taihu: Implications for water quality monitoring and assessments

Although Microcystis-based toxins have been intensively studied, previous studies using laboratory cultures of Microcystis strains are difficult to explain the phenomenon that microcystin concentrations and toxin variants in natural blooms differ widely and frequently within a short-term period. The present study was designed to unravel the mechanisms for the frequent variations of intracellular toxins related to the differences in cyanobacterial colonies during bloom seasons in Lake Taihu, China. Monitoring of Microcystis colonies during warm seasons indicated that the variations in microcystins in both concentrations and toxin species were associated with the frequent alteration of Microcystis colonies in Lake Taihu. High concentration of microcystins in the blooms was always associated with two Microcystis colonies, Microcystis flos-aquae and Microcystis aeruginosa, whereas when Microcystis wesenbergii was the dominant colonial type, the toxin production of the blooms was low. Additionally, environmental factors such as temperature and nutrition were also shown to have an effect on the toxin production of the blooms, and may also potentially influence the Microcystis species present. The results of the present study provides insight into a new consideration for quick water quality monitoring, assessment and risk alert in cyanobacterium- and toxin-contaminated freshwaters, which will be beneficial not only for water agencies but also for public health. (C) 2009 Elsevier Ltd. All rights reserved.

Factors affecting leaf morphology: a case study of Ranunculus natans C. A. Mey. (Ranunculaceae) in the arid zone of northwest China

In order to examine the role of environmental factors affecting foliar morphology, we performed a case study of leaf morphological variation of Ranunculus natans found in the arid zone of northwest China. We found that foliar phenotypic variation differed significantly between populations. We described substantial positive correlations between altitude and leaf area (LA) as well as leaf perimeter (LP), and also between longitude and number of teeth, along with dissection index (DI). The pH, conductivity, and salinity of the environment caused a significant decrease in both LA and LP. Ranked in terms of their impacts on leaf morphology, the six selected factors were: altitude > pH > conductivity > salinity > longitude > latitude. We found that foliar morphological variations are functional responses to water-quantity factors (e.g., altitude and longitude at regional scales) and water-availability relation factors (e.g., pH, conductivity, and salinity at local scales), rather than to temperature-relation factors (latitude). Therefore, altitude and longitude, along with pH, conductivity, and salinity, are the main factors that significantly influence foliar morphology in the arid zone of China. We found that main factors played major roles in plant phenotypic plasticity in a complex ecosystem, although different combinations and interactions of environmental and geographical factors in each local environment may obscure the general trends in trait changes along environmental gradients.

Digital elevation models and GIS for watershed modelling and flood prediction-A case study of Accra Ghana

Geographical Information Systems (GIS) and Digital Elevation Models (DEM) can be used to perform many geospatial and hydrological modelling including drainage and watershed delineation, flood prediction and physical development studies of urban and rural settlements. This paper explores the use of contour data and planimetric features extracted from topographic maps to derive digital elevation models (DEMs) for watershed delineation and flood impact analysis (for emergency preparedness) of part of Accra, Ghana in a GIS environment. In the study two categories of DEMs were developed with 5 m contour and planimetric topographic data; bare earth DEM and built environment DEM. These derived DEMs were used as terrain inputs for performing spatial analysis and obtaining derivative products. The generated DEMs were used to delineate drainage patterns and watershed of the study area using ArcGIS desktop and its ArcHydro extension tool from Environmental Systems Research Institute (ESRI). A vector-based approach was used to derive inundation areas at various flood levels. The DEM of built-up areas was used as inputs for determining properties which will be inundated in a flood event and subsequently generating flood inundation maps. The resulting inundation maps show that about 80% areas which have perennially experienced extensive flooding in the city falls within the predicted flood extent. This approach can therefore provide a simplified means of predicting the extent of inundation during flood events for emergency action especially in less developed economies where sophisticated technologies and expertise are hard to come by. © 2009 Springer Netherlands.

Phosphorus in suspended matter and sediments of a hypertrophic lake. A case study: Lake Dianchi, China

From June 2004 to December 2004, Lake Dianchi, which had large scale of cyanobacterial blooms was investigated in order to study P-fractionation in the suspended matter and the sediment. The investigation improves our understanding of phosphorus in Lake Dianchi and the relationship between phosphorus and cyanobacterial blooms. It contributes to the available literature on the behavior of P in hypertrophic lakes. The distribution of P-fractions in Lake Dianchi was not uniform from northwest to south, but was closely related to the trophic status of the whole lake. The concentrations of total phosphorus, labile P (NH4Cl-P), Organic P (NaOH-NRP) and loss on ignition in suspended matter were positively correlated with the strength of cyanobacterial blooms. Total phosphorus in suspended matter was relatively stable for almost half an year and closely related to Chl. a concentration. The main content of organic phosphorus is in the cyanobacterial blooms. The concentrations of phosphorus bound to metal oxides and carbonates (NaOH-SRP and HCl-P) in sediment were similar to NaOH-SRP and HCl-P in the corresponding suspended matter. The latter two forms of P in suspended matter were not affected by cyanobacterial blooms, indicating that the inorganic phosphorus is derived from the sediment after resuspension from the sediment due to wind and wave action. The contribution of the different P-fractions to TP in sediment and in suspended matter indicates that NH4Cl-P in the suspended matter is an important buffer for maintaining dissolved phosphorus in water.

THE RESPONSES OF Microcystis TO SEDIMENT ENVIRONMENTS AND THE ASSESSMENT FOR ITS OVERWINTERING - A SIMULATION STUDY IN A NOVEL DEVICE

A novel multi-cell device made of organic glass was designed to study morphological and physiological characteristics of Microcystis population trapped in simulated sediment conditions. Changes of colonial morphology and antioxidant activities of the population were observed and measured over the range of 31-day incubation. During the incubation, the antioxidant enzyme activities fluctuated significantly in sediment environments. The activities of catalase (CAT), glutathione peroxidase (GPx) and malondialdehyde (NIDA) reached the highest on the 11(th) day, 6(th) day and 6(th) day. respectively, and then dropped down remarkably in the following days. The ratios of Fv/Fm and the maximal electron transfer rate (ETRm) declined during the initial days (1 similar to 11(th) day), but rebounded on the 16(th) day, which were consistent with the variations of total protein. In the end of incubation. gas vacuoles were hard]), observed and the gelatinous sheath was partly disappeared in the population of Microcystis. Nevertheless, the remaining populations. upon transferred to culture medium, were able to grow though experiencing a longer lag phase of nine days. The results indicated that the sediment environments were able to cause negative effects on M. aeruginosa cells. The cells, however, responded to against the possible damage afterwards. It is thus proposed the acute responses in the population during the early stage of sedimentation could be of importance in aiding the long-term survivor of Microcystis and recruitment in lake sediments. The present study also demonstrated the utility of the device in simulating the sediment environments for further investigation.

Hydroacoustic study of spatial and temporal distribution of Gymnocypris przewalskii (Kessler, 1876) in Qinghai Lake, China

Gymnocypris przewalskii (Kessler 1876) is an endangered and state-protected rare fish species in Qinghai Lake, China. To further understand the life history and distribution of this fish, five surveys were carried out in Qinghai Lake between 2002-2006. Results of these surveys indicate that fishes were predominantly distributed about 2 m under the surface. In July, significant differences in fish density were found between surface and bottom layers (P = 0.001), and/or between middle and bottom layers (P = 0.025). Fish density was the greatest in the surface layer. In August and October, no significant differences were found between the different layers, but the bottom layer had a greater fish density. Furthermore, there were very large differences among different zones in fish distribution density. Differences in horizontal distribution were not significantly correlated to factors such as water depth and inshore distance, possibly because of very low and uniform fish density. Feeding, changes in water temperature, over-wintering and spawning appeared to influence fish distribution. Hydroacoustic estimates of G. przewalskii biomass in Qinghai Lake increased significantly between 2002 and 2006. We attribute this increase to the management measures put in place to protect this species.

Kinetic study of the 2-methyl-3-methoxy-4-phenylbutanoic acid produced by oxidation of microcystin in aqueous solutions

Microcystins (MCs) are a family of related cyclic hepatotoxic heptapeptides, of which more than 70 types have been identified. The chemically unique nature of the C20 beta-amino acid, (2S, 3S, 8S, 9S)-3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca4,6-dienoic acid (Adda), portion of the MCs has been exploited to develop a strategy to analyze the entirety. Oxidation of MCs causes the cleavage of MC Adda to form 2-methyl-3-methoxy-4-phenylbutanoic acid (MMPB). In the present study, we investigated the kinetics of MMPB produced by oxidation of the most-often-studied MC variant, MC-LR (L = leucine, R = arginine), with permanganate-periodate. This investigation allowed insight regarding the influence of the reaction conditions (concentration of the reactants, temperature, and pH) on the conversion rate. The results indicated that the reaction was second order overall and first order with respect to both permanganate and MC-LR. The second-order rate constant ranged from 0.66 to 1.35 M/s at temperatures from 10 to 30 degrees C, and the activation energy was 24.44 kJ/mol. The rates of MMPB production can be accelerated through increasing reaction temperature and oxidant concentration, and sufficient periodate is necessary for the formation of MMPB. The initial reaction rate under alkaline and neutral conditions is higher than that under acidic conditions, but the former decreases faster than the latter except under weakly acidic conditions. These results provided new insight concerning selection of the permanganate-periodate concentration, pH, and temperature needed for the oxidation of MCs with a high and stable yield of MMPB.