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Validation of aerosol optical depth using AERONET ground stations in marine areas (Case Study: Persian Gulf)
Get PDFDust prediction such as prediction of wind and rain needs to synoptic information to the earth's surface, upper layers of the atmosphere, the prediction maps of land surface and upper levels as well as using radar and satellites. In the meantime, radar and satellite observations included remote sensing can be useful in prediction accuracy. The purpose of this study, use of remote sensing technology and MODIS images to estimate dust optical depth on the Persian Gulf surface and estimating the linear correlation relationship between the dust measurements in ground and atmospheric. The dust optical depth calculated using the code developed in MATLAB software. Evaluation of extracted data conducted using Pearson correlation coefficient, RMSE and RMSD index. In this study, optical depth obtained from image processing compared with the optical depths obtained from AERONET network. The evaluation results showed a high and significant correlation between the obtained optical depth and optical depths obtained from AERONET network (R 2 =0.99). The best and most suitable mode demonstrated for 1.243 and 1.632 bonds. At all stations, AOD value obtained from satellite image is bigger than AOD amount corresponding to the AERONET station and the algorithm used has overestimated. The cause of this more estimate can be use of limited particle's effective radius, because the scope of this effective radius is limited at the distribution of particle size in log-normal. Error resources at the retrieving particulate matter was defined such as sensor calibration error, pollution on the radiation angle, or poor predictor of water reflection
Age, growth and maturity of Hilsa shad (Tenualosa ilisha) in northwestern part of the Persian Gulf
Get PDFIn this study age, growth and maturity of Hilsa shad in Khuzestan province were analyzed. 394 number of fishes from marine habitat (Lifeh-Boseif), estuaries (Bahmanshir and Arvand) and rivers (Bahmanshir and Karoon) from February 2014 to September 2014 were collected using commercial fishing with gill net. Total length and wet weight of each fish were measured with precision of 1 cm and 1 gram. Sagittal otoliths were extracted for age determination of the fish. Since the otoliths were fragile, they were sectioned by polishing with sandpapers 800, 1500 and 2000. Then abdominal cavity of each sample were opened for determining sex and maturity stage. Growth parameters were calculated using von Bertalanffy growth function (L_∞=58.365, K=0.26, t0=-0.16). Phi-prime constant was obtained 2.95. Length and age at first maturity were obtained 27.32cm and 2.4 g respectively using logistic model to fit a and b parameters with observed data in spawning season
What’s new, Webby?: Gender on the agenda in the seafood industry
Get PDFWomen in Seafood Industry (WSI) is an international not-for-profit organization whose aim is to reinforce the voices of women in the seafood industry, amplifying their visibility through projects and collaborations with existing associations, and by supporting relevant initiatives and sharing information on the worldwide web
Toxic metals in Nereis diversicolor Müller, 1776 from inner shores in Sinop peninsula of the Black Sea as bio-indicator species
Get PDFThe concentrations of Cd, Hg and Pb in the whole parts of the worm Nereis diversicolor collected from the Turkish Black Sea coast have been measured by ICP-MS (Inductively Coupled Plasma -Mass Spectrometer) for monitoring metal pollution in 2015. Seasonal differences in the amounts of Cd, Hg and Pb in the sediment were not significant. The amounts of Pb were found to be higher in sediment than those of N. diversicolor. On the other hand Cd and Hg amounts in the worms were higher than the sediment. However, there were significant differences in toxic metal levels between sizes of N. diversicolor. Larger specimen accumulated less toxic metal. Cd had the highest CF mean followed by Hg and Pb showed the lowest CF value. It is concluded that the worm N. diversicolor are suitable biomonitors to assess changes in metal pollution in this coastal area of the Black Sea
A checklist of molluscans inhabiting Bandri Beach along the Jiwani coast, Balochistan, Pakistan
Get PDFMain object of the study was to record the composition and diversity of intertidal molluscan species of the Bandri Beach along the Jiwani coast, Balochistan to develop baseline data information which could be helpful in future conservation perspective. The study revealed the presence of ninety eight (98) species comprising of sixty eight (68) gastropods, twenty six (26) bivalves, two (2) scaphopods, one (1) Polyplacophora and one (1) Cephalopod species at two selected points of the Bandri Beach, Jiwani coast. Among these molluscan species, members of cerithids, trochid Umbonium vestairium, bivalve Branchidontes variabilis and oyster Crassostrea madrasensis were found in abundance. Study presents the first report on the occurrence of molluscan species in the area
Comparison in biodegradable films formulated from two red seaweeds of Karachi coast
Get PDFIn this research a comparative study was made between biodegradable films obtained from two different indigenous red seaweeds collected from Karachi coast. Gracilaria corticata and Melanothamnus afaqhussainii were collected from the Buleji coast of Karachi, Pakistan (24o50’N, 66o48’E). Agar extracted from both the seaweeds was used and incorporated as raw material for the formulation of biodegradable films. Sorbitol was used as plasticizer to increase the tensile strength and elasticity of the films. The results showed that the solubility of M. afaqhussainii was higher than G. corticata. The soil burial test showed that the biodegradability percent of M. afaqhussainii (60%) was higher as compared to G. corticata (40%). The tensile strength and elongation break of G. corticata (9.79±1.21 MPa and 28.72±5.13%) was stronger than the M. afaqhussainii (3.98±1.08 MPa and 16.32±3.80). Results of current study showed that the G. corticata has stronger gelling property as compared to M. afaqhussainii
Acute toxicity of heavy metals to Hyale crassipes (Heller, 1866) in the Black Sea
Get PDFAcute toxicity tests were performed on Hyale crassipes from Karakum shores of Sinop Peninsula in the Black Sea. 24, 48, 72 and 96-h LC50 values were estimated for copper, cadmium and zinc using static bioassay method. This study was the first toxicity study with Hyale crassipes and showed that the species was very sensitive to metals. The results indicated that Cu was more toxic to the amphipods followed by Cd and Zn. Clearly, Hyale crassipes has potential as test species for toxicity studies in Turkish waters
Study on environmental of Litopenaeus vannamei (Boone, 1931) ponds culture with brackish water of Caspian Sea
Get PDFDifferent studies on Litopenaeus vannamei (Boone, 1931) has performed in Iran, but less noted in water quality conditions. Water quality, in addition to creating optimal environment for the growth of vannamei shrimp, as well as cause the live food production and improve economic performance are produced. This study was conducted to evaluate the water quality environment vannamei shrimp in the south of Caspian Sea (Mazandaran province) and in the Caspian Ecology Research Center. The results showed that the enrichment of water out of the ponds, can provide favorable conditions for water quality in the culture of vannamei shrimp with different densities. As a result, Mazandaran province environmental conditions (particularly temperature and salinity of the Caspian Sea) has perfectly suited for optimal growth vannamei shrimp. Therefore, vannamei shrimp (PL12) achieved a final individual weight of 21.1gr in a period culture of 85-day with a density of 35 ind/m^2. Also, The nutrients and water quality parameters (Temperature: 27.4±1.79 ° C, Transparency: 10.7±1.2 cm, Salinity: 10.57±0.78 psu, pH: 8.42±0.38, Dissolved Oxygen 8.04±1.35 mg per liter) were within normal limits during the culture period
Eutrophication trend of southeast Caspian Sea water (Mazandaran-Goharbaran) based on environmental and biotic parameters using single and multiple variables in order to feasibility of marine cage culture
Get PDFThe aim of this project is to study water quality and the trophic status at different months and depths in the southeast Caspian Sea-Goharbaran based on environmental parameters and nutrients during 2013-2014 in order the feasibility of fish cage culture. Results showed that water temperature, transparency, pH, dissolved oxygen, BOD5, COD, total alkalinity and TSS were varied 9.00-29.00C, 0.50-12.00 m, 8.05-8.74, 5.76-12.85, 14-101, 21-195 and 0.00-0.12 mg/l at the different months and depths, respectively. In addition, the values of NH^4+, NH_3, NO^2-, NO^3- and PO^4-3 were 0.007-0.051, 0.001-0.010, 0.002-0.015, 0.043-0.477 and 0.014-0.077 mg/l, respectively. Chl-a concentration was recorded as 0.060-8.02 mg/l. Scaled and unscaled trophic indices were equal to 3.42-5.52 and 2.61-5.85, respectively. The proper temperature for cultivation of salmonids species in this area began from October to March. The range of the standard of pH and dissolved oxygen level for fish farming cage were 7.80-8.50 and >5 mg /l that in current study results of pH and dissolved oxygen which were consistent in the current study. Various forms of nitrogen (ammonium, nitrite and nitrate ) at the different layers were acceptable and less than the threshold limit of Australia and New Zealand. The results of the nutrients concentrations compared with data from the reference years (1996-1996 ) in the Caspian Sea (Goharbaran region) showed that this ecosystem passed from oligotrophic status and shifted to mezotrophic and eutrophic condition. As a conclusion, although nutrients concentrations were acceptable in terms of fish farming cages in this region, some parameters such as chemical oxygen demand and transparency are not suitable for aquaculture industry. Meanwhile, based on various trophic levels, this ecosystem (Gohrabaran region) has a mezotrophic status with a high risk of eutrophication
Isolation, identification and antimicrobial evaluation of marine actinomycetes from Oman sea sediments
Get PDFActinomycetes are gram positive and filamentous bacteria and produce major portion of the bioactive compounds hence play an integral role in the novel drugs development. Recent studies demonstrated that marine habitats inhabiting actinomycetes have unique biodiversity and metabolic activity. For the first time Oman Sea sediments were investigated as a source of antibiotic producing marine actinomycetes in this project. Approximately 84 isolates were obtained from 14 collected sediment samples. Among four culture media and two treatments, Glucose asparagine agar and heat treatment isolated 32 and 47 isolates respectively and exhibited highest efficiency. Evaluation of antimicrobial activity of the isolated actinomycetes by top layer agar revealed that 24, 12, 23 percent of isolates showed antimicrobial activity against S.aureus, E.coli and C.albicans respectively. Determination of Minimum inhibitory concentrations of extracted antibiotics were recorded as 128256, 128-512 and 62-128 µg/ml against S.aureus, E.coli and C.albicans respectively. Preliminary identification studies showed that the potent isolates exhibited typical morphology of Streptomyces genus predominantly. Result of Morphological, biochemical and chemotaxonomical identification revealed that IFSIRI 70 ، IFSIRI 137 ، IFSIRI 145، IFSIRI 193،IFSIRI 214 belonged to Streptomyces genus. Molecular identification by 16s rRNA gene analysis showed high similarity (99%) between IFSIRI 70 ، IFSIRI 137 ، IFSIRI 145، IFSIRI 193،IFSIRI 214 strains with S. chartreusis، S. qinglanensis، S. Cacaoi، S. violaceoruber and S. diastaticus respectively. Phylogenetic analysis showed that isolated producer strains and some commercial antibiotic strains located in a common cluster. These results exhibited high antimicrobial potential of the potent actinomycetes isolates for new antibiotic discovery