Effects of environmental parameters and nutrients on phytoplankton communities around the shrimp farm complexes in Bushehr Province, in the Persian Gulf

The aim of this work was to be informed and aware of the red tide conditions before the entering of algal blooms in seawater supply canals of the shrimp farm and hatchery complexes in Bushehr Province. Field investigations and monthly samplings have been carried out to determine environmental parameters, nutrients, chlorophyll–a and phytoplankton in the southern part of the input water channels of Mond, Delvar and Heleh farmed shrimp complexes from April to December 2011. The identified phytoplankton belonged to three classes of Bacillariophyceae, Dinophyceae and Cyanophyceae. 12 genera belonging to Dinophyceae, 25 genera to Bacillariophyceae and two genera to Cyanophyceae were observed during the study. The highest average density of total phytoplankton was recorded at Heleh station at 18374 cells/lit. The maximum density of phytoplankton was at Delvar station in December. The highest density of Dinophyceae was observed in August. Alexandrium sp., Ornithocercus and Prorocentrum sp. were the predominant species of Dinophyceae class. Bacillariophyceae are thermo-tolerant and halo-tolerant while Dinophyceae and Cyanophyceae are thermo-intolerant and halo-intolerant. Bacillariophyceae are silica limited while Dinophyceae are phosphorus limited phytoplankton

Monitoring of Cochlodinium polykrikoides blooms as a harmful phenomenon in the Persian Gulf (2010-2011)

The monitoring of the harmful bloom of Cochlodinium polykrikoides in the northern Persian Gulf was studied during 2010 to 2011. The results revealed that in the waters of Hormozgan Province, the Diatoms and Dinoflgellates had the highest frequency. No significant difference was found for amount of nutrients in three sub- regions. The bloom of C. polykrikoides was higher in central sub-region in spring and was occurred in the eastern sub-region in summer, but no mortality of fishes was recorded. In Bushehr Province, four classes of Bacillaryophyceae, Cyanophyceae, Dynophyceae and Prymnesiophyceae were determined. Furthermore significant different values of nutrients were recorded. In waters of Khuzestan Province, different values of NH4 were measured for different months. In total, the measured ratio of N: P in all months was lower than Redfield Ratio (16:1) in which subsequently the environmental condition was not suitable for bloom of C. polykrikoides

The monitoring of hydrology and hydrobiology stydies of the Persian Gulf in the Bushehr region

This study has been carried out in waters of Bushehr province in the Persian Gulf covering Nayband bay to Bahregansar between 26° 45 N to 30° 00 N and 49° 45 E to 52° 45 E, 15 main and 5 sub- stations, by R/V Ferdows 1 in winter 2004, summer 2004 and winter 2005. The physico - chemical parameters, nutrients (silicate, phosphate, nitrate and nitrite), phyto, zooplanktons, sediments and macrobenthoses were collected from water layers and sea bottom, and then analysed. The parameters were compared and evaluated with the results of the previous work, conducted in the same area. Termocline, halocline, oxycline and picnocline layers were formed in summer. These clins disappeared due to water column mixing in winter. The values of temperature, conductivity and pH in summer were higher than those of in winter, while the salinity and density values of surface and subsurface layers in winter were higher than those of in summer. The temperature and conductivity have been decreased from surface to depth, from coastal rigions to offshore and from southern waters to northwern waters, while salinity, density and turbidity have been increased. The dissolved oxygen is decreased by increasing the values of temperature, salinity and depth and it is observed that D.O. has increased in correlation with chlorophyl a in mean and subsurface layers. The pH was rather decreased from surface to depth while turbidity was increased. Orthosilicate (Si_SiO44), nitrate (N_NO3), and nitrite (N_NO2 ) concentration have increased from surface to depth while orthophostate (P_PO43) decreased. Among the phytoplanktons, Dinophycea had most abundance in winter 2004 and Diatoms had most abundance, variety and distribution in summer 2004 and winter 2005. Among the zooplanktons, Copeopda had most abundance, variety and distribution. The intensity of phytoplanktons in summer was more than those in winter; it decreased from surface to depth and from coastal rigions to offshore, at first increased and then gradually decreases. Intensity of zooplanktons in summer was more than those in winter and decreased from surface layers to depth and from coastal waters to offshore. The abundance of benthoses in summer was more than that in winter while their biomass in winter was more than that in summer. The abundance decreased from southern to northwern waters, but the rate of decrease in biomass was more than that of abundance. The mainly texture of sediments was loamy or muddy and the grain size in southeastern and northwestern areas were coarser than those in middle area. Compared with the previous study, the trend of physico chemical, silicate, nitrate and nitrite were the same but in spite of the past, the values of pH in summer were more than those in winter and also phosphate concentration had been decreased frome surface layer to depth. The overall trends of phyto and zooplanktons densities are almost similar to previous observation, but cyanophyceae significantly decreased, in comparison with spring and summer abundance. It is also observed that the zooplanktons average density has been in reverse order compared to previous observations. Average concentration of phosphate in the entire region was seven times more than that of the former study and its maximum value has rised more than 26 times in the petroleum and gas industries areas. On the other hand, the abundance and diversity of phyto and zooplanktons and also the ratio of biomass to abundance of benthoses were decreased

A study on the diversity and abundance of ichthyoplankton in coastal waters of the Kharg and Dylam (Persian Gulf)

The present investigation was undertaken to identify fish larva and estimate their abundance, diversity and evenness indices. Twelve stations were sampled monthly during daytime hours by Bongonet in the kharg and khargoo regions of Persian Gulf from January 2005 through December 2006. Forty family of fish larva were identified, Families of Silaginidae, Clupeoidea, Blenidae and Athrinidae consisted of more than 61 percent of all specimen; The abundance of specimen were more during spring through fall months and least during winter. The number and abundance of identified families varied from cruise to cruise and station to station; the average amount of diversity, Species Richness and evenness in investigated region were computed 1.93, 12 and 0.68, respectively. Temperature and salinity of water during this study were between 16-34°C and 35-42 gr/lit. There weren’t any significant correlation between fish larva indices and above factors

Identification of local microalgae & their evaluation as live food in aquaculture from Oman Sea

Microalgae are very important organisms in aquaculture as major live food in all growth stages of bivalve, some larval stages of crustaceans, some fishes and zooplankton. In this project with the knowledge that local algae can provide better nutritional balance for local animals. Microalgae were isolated, identified and evaluated for their nutritional value for the first time. Another aim of this research was to create phytoplankton culture collection (Bank) in the south of Iran. Water was sampled from Sistan and Baluchesta coasts, then isolation and purification process were carried out in the lab. Species identification was based on morphology and molecular analyses. rDNA was extracted from each strain after PCR, partial LSU-rDNA region were sequenced and compared with similar sequence from GenBank. In order to evaluate their nutritional properties, relative growth, fatty acids composition, total lipid, carbohydrate, protein, and some vitamins of each purified strain were determined. Totally 25 species were isolated and purified, of which 12 strains were recorded in GenBank and their nutritional potential were assessed. Dunaliella cf. bardawill, Isochrysis sp. Cheatoceros sp. Clorella cf. volgaris, Ochromonas sp. and Synechococcus sp. were the most important species research. Iranian strains were varied in their amount of protein (27-40%), carbohydrate (221%) and lipid (8-13%). Proportions of SFA (21-48%), MUFA (33-53%) and PUFA (11-28.5%) were varied among strains. The highest amount of PUFA and B3 vitamin were found in Clorella cf. vulgaris. The highest content of protein (40.12% dry wt) and total fatty acid concentration (30% dry wt) were found in Dunaliella cf. bardawil and Ochromonas strain(CHPO2) respectively. The maximum content of total fatty acid was observed in Ochromonas sp. (CHPO2). Cheatoceros sp. had higher relative growth rate in comparison with other species

Environmental impact assessment (EIA) on cultivation of the nile tilapia (Oreochromis niloticus) with brackish water in Dashtestan

EIA is a worthy tool for identifying and assessing potential impacts and control them.it compatibles environmental aspects with sustainable development. In order to predict the effects of tilapia culture activities on regional we gathered physical, biological, and social information to quantify the activities effects on them. We addressed 42 impacts consist of 31 positive, and 11 negative. These affect half of social, 33% of physical, and 17 of biological elements. This equivalent with -42, +304, and+36 when puts in the charts.in order to have a good and comprehensive assessment of activities Leopold matrices was employed. Based on summarized values from this we have +380and -82 results +298. This means that this activity has a great positive result especially on socio-economic environment. These kinds of studies are highly recommended for other parts of the Bushehr province e.g Dashtestan county that most of their water resources are brackish and not suitable for agriculture

Environmental risk assessment of the activity of specific pathogen free shrimp production centers

This study is a part of the national and technology master plan entitled "Attain to technical knowledge of specific pathogen free shrimp production and cut off to dependence on foreign products". The goals of this work were to assess and analysis the risk factors of production of specific pathogen free Litopenaeus vannamei shrimp in its all stages (broodstocking, laravl production, shrimp farming, feeding and water quality), determining the pattern of outcomes monitoring, management and control of outcomes from April 2012 to September 2015 in Bandargah research station and Persian Gulf SPF Shrimp research station and their environment, belonging to Shrimp Research Center, located in Bushehr. Identification and screening of risk factors have been done based on Environment Aspect and Effect Analysis method, (EA)2, using a fine statement questionnaire and quantification of risks. The number of identified risk factors in Bandargah research station was 15 while it was 13 in Persian Gulf SPF Shrimp research station. The more number of risk factors in Bandargah station in respect to its number in Persian Gulf station is might due to lower level of biosecurity, physical structure and aging of Bandargah station and existence of two possible source of contamination, the Bushehr nuclear power plant pollutants and Bandargah fishing harbor, near to the station. On the basis of results, the maximum values of APN in Bandargah station was 42 while it was 30 in Persian Gulf station. These results revealed that the level of risk in Bandargah station is lower than that in Persian Gulf station. The most probable risks in both studied research stations are related to transmission of pathogens in shrimp feeding and water intake pollution

Impact assessment of master plan of "attain to technical knowledge of specific pathogen free shrimp production and cut off to dependence on foreign products" on Bushehr city environment: A case study, Shoghab research station

This study is a part of the national and technology master plan entitled "Attain to technical knowledge of specific pathogen free shrimp production and cut off to dependence on foreign products". The goals of this work were to assess the environmental effects of Specific Pathogen Free shrimp production complex on surrounded region in Persian Gulf (Shoghab) research station in Bushehr city. The environmental impacts were assessed in Persian Gulf (Shoghab) research station in Bushehr city by usage of simple checklist for impacts prediction, and scaling check list for assessment during Feb 2012 till Sep 2014. Flushing the effluents to the sea is the biggest concern of this project that can resulted in health impacts on aquatic and human communities that can be avoided by treatment. Low diversity in activities beside lack of environmental sensitive elements in the region leads us to use of scaling check list for impact assessment. Environmental grade of each activity can be achieved by stratification of them according to their intensity, significance and scale. We reached +320 and -198 for positive and negative points respectively that sounds a clear yes for execution choice

Auxeticity effect on crushing characteristics of auxetic foam-filled square tubes under axial loading

This paper treats energy absorption and crushing characteristics of auxetic foam-filled square-section tubes under axial loading condition. The influence of auxeticity effect on the structural collapse was experimentally investigated to quantify the interaction effect between Poisson's ratios of foam (ranging from −0.31– 0.03) and square tube walls under quasi-static and dynamic loadings. The validated computer simulation technique was employed to conduct a series of parametric study in order to evaluate the influence of tube parameters on the energy absorption responses. It is evident that negative Poisson ratio effectively influences the crushing response and energy absorption capability of auxetic foam-filled square tubes. Moreover, it was found that increasing the auxeticity level of foam filler enhances crashworthiness performance of foam-filled structures under both quasi-static and dynamic loading conditions. The primary outcome of this study is a design guideline for the use of auxetic foam in different ranges of Poisson's ratio as a core for an energy absorber device where impact loading is expected

Influence of auxetic foam in quasi-static axial crushing

This paper treats the influence of auxetic foam on the crush response and energy absorption response of square-section tubes when subjected to uniaxial quasi-static loading. The study aims at quantifying the energy absorption capability of auxetic foam-filled square tubes for variations in wall thickness, initial height, aspect ratio and slenderness ratio of the tube. The capability of simulating the crush response of auxetic foam-filled tubes using the validated numerical models is also presented. Based on the experimental results, the influence of the auxetic foam in the thin-walled square tubes was quantified in terms of energy absorption capacity, specific energy absorption and crush force efficiency. It is evident that a thicker tube filled with auxetic foam is preferable if the energy absorption level is the primary goal, yet this compromises the crush force efficiency. The outcome of this present study is the establishment of empirical models for estimating the quasi-static crushing response of auxetic foam-filled tubes with varying slenderness ratio and aspect ratio