Iranian National Institute for Oceanography and Atmospheric Science
Journal of Oceanography
1562-1057
9
36
2019
1
1
Evaluating the Pattern of Monsoon Wind Generated Waves in the Northwest of the Persian Gulf using Coupled Atmospheric and Wave Model
1
11
FA
Mohammad
Pakhirehzan
University of Hormozgan
Maryam
Rahbani
University of Hormozgan
Hossein
Malakooti
University of Hormozgan
This research has been conducted to simulate the wind and wave pattern due to the winter Shamal Wind, which is a local systematic wind with the duration of 3 to 7 days, normally occurs in cold months of December to March. For simulating this phenomenon, the Coupled Ocean–Atmosphere–Wave–Sediment Transport (COAWST) model has been employed. In this model, the Weather Research and Forecasting (WRF) model was coupled with the Simulating WAves Nearshore (SWAN) model via the Model Coupling Toolkit (MCT). Simulated results of weather showed a cyclonic low pressure system in the middle of Iran’s plateau, which is accompanied with a deep upper-level trough and polar front jet system. Simulated results showed an increase of about 1.1 m in significant wave height right after beginning of Winter Shamal Wind. It was also shown that the direction of wave propagation due to this wind was deviated to North and Northwest. Calculating statistical parameters, it was found that wind and wave results derived from COAWST could better represent the actual situation in the area comparing with the simulated results of WRF (for wind), and of SWAN (for wave). It could be concluded that for simulating wind and wave, specifically for stormy condition, COAWST is a reliable model.
Iranian National Institute for Oceanography and Atmospheric Science
Journal of Oceanography
1562-1057
9
36
2019
1
1
Antagonistic Effect of Various Dietary Levels of Aflatoxin B1 and Zearalenone on Digestive Enzymes Activity of Fingerling Rainbow
Trout (Oncorhynchus mykiss)
13
21
FA
Behrooz
Daghestani
Urmia University
Ahmad
Imani
Urmia University
Farzaneh
Noori
Urmia University
Mohsen
Farzaneh
Shahid beheshti University
Kourosh
Kourosh Sarvi Moghanlou
Urmia University
The formation of mycotoxins in feedstuffs is a worldwide issue affecting digestive physiology of aquatic animals and resulting in lower animal performance. In the study, 540 rainbow trout (Oncorhynchus mykiss) with an average body weight of 3±0.2 g were treated in 9 distinct groups with various dietary levels of aflatoxin B1 (0, 25 and 50 ppb) and zearalenone (0, 200 and 400 ppb) for 4 weeks. At the end of the experiment, pyloric ceaca samples were taken for determining alkaline protease, lipase and amylase activity. Results revealed that feeding on diets contaminated with aflatoxin B1 and zearalenone for 4 weeks did not significantly affect alkaline protease activity (P<0.05), however, significantly affected lipase and amylase activity (P<0.05). The highest lipase activity was recorded in control group (feeding on diet devoid of any mycotoxins) and in treatment group that was co-contaminated with containing 25 ppb aflatoxin B1 or 200 ppb zearalenone. However, the lowest lipase activity belonged to treatments contaminated with only 400 ppb zearalenone or 25 ppb aflatoxin B1. The highest amylase activity was assayed in group fed on diet without any mycotoxin contamination in comparison with those fed diet contaminated with any levels (25 or 50 ppb) of aflatoxin B1 (P<0.05). It can be concluded that cocontamination with both aflatoxin B1 and zearalenone can reduce their negative effects on lipase activity of fish.
Iranian National Institute for Oceanography and Atmospheric Science
Journal of Oceanography
1562-1057
9
36
2019
1
1
Antimicrobial Activity and Molecular Identification of Nocardiopsis sp. AHA2 from Deylam Nearshore Sediments
23
29
FA
Hassan
Alijani
1- Department of Marine biology, Faculty of Marine Science, Khoramshahr University of marine science and technology, Iran.
Soheila
Matroodi
1- Department of Marine biology, Faculty of Marine Science, Khoramshahr University of marine science and technology, Iran.
Ali
Sharafi
Zanjan University of Medical Sciences, Zanjan, Iran
Isac
Zamani
Department of Marine biology, Faculty of Marine Science, Khoramshahr University of marine science and technology, Iran.
The aim of this study was identification and antimicrobial activity examination of Nocardiopsis sp. isolated from Deylam nearshore sediments. Samples were collected from Deylam nearshore sediments on the late September 2014. Identification was done using 16Sr RNA analysis. Antimicrobial assay of the bacterial extracts was performed using standard well diffusion assay. Nocardiopsis was isolated and identified according to amplification and sequencing of 16Sr RNA gene. Differential analyses results for catalase and Gram test were positive and for other tests were negative. Antimicrobial assays showed that the sample had more antifungal activity than antibacterial activity against tested pathogenic microbes. Antibacterial activity results showed that the metabolites extracted from samples were active against Salmonella sp. (inhibition zone, 8.86 mm) and Bacillus cereus (inhibition zone, 7.9 mm). Antifungal activity analysis demonstrated that more inhibition zone was observed against Aspergillus flavus (14.4 mm). The results of this investigation revealed that Deylam nearshore sediments were a rich source of rare actinomycetes which produced bioactive compounds.
Iranian National Institute for Oceanography and Atmospheric Science
Journal of Oceanography
1562-1057
9
36
2019
1
1
Numerical Simulation and Experimental Study on Tsunami Propagation and Run-up and the Influence of Submerged Breakwater on Run-up
31
38
FA
Masih
Honarmand
University of Isfahan
Ahmad
Shanehsazzadeh
University of Isfahan
Mahdi
Zandi
University of Isfahan
Arman
Vahida
University of Isfahan
Tsunami threatens the lives and property of millions of people who are living in coastal areas. The southern coasts of Iran are also exposed to tsunami waves due to Makran subduction zone. Therefore, understanding the propagation and run-up of tsunami waves through numerical simulation and experimental studies is vital. In this research, applying OpenFOAM computational fluid dynamics open source Software, propagation and run-up of tsunami waves in different conditions were estimated and the results of numerical simulations were compared with experimental data. Solitary waves were considered as the model for tsunami waves. Initially, the propagation of non-breaking and then the breaking solitary wave as two-dimensional numerical simulation were investigated. The effect of submerged obstacle on the decreasing run-up was studied numerically and experimentally. Results showed that the submerged obstacle could reduce the tsunami run up to 19.7 percent. The results showed that OpenFOAM software was able to precisely model the propagation phenomena and predict the wave run-up with acceptable level of accuracy in numerous wave conditions.
Iranian National Institute for Oceanography and Atmospheric Science
Journal of Oceanography
1562-1057
9
36
2019
1
1
Investigation of Antibacterial, Antifungal and Antioxidant Activity of Marine Limpet Siphonaria carbo
39
46
FA
Ahmad
Shadi
Amir
Vazirizadeh
Fatemeh
Afridon
Khanomnaz
Ebadi
This study was performed to evaluate the antibacterial properties of different (wet and dry ethanolic and aqueous) extracts of Siphonaria carbo on Escherichia coli, Staphylococcus aureus, and Saprolegnia parasitica using well method as well as antioxidant activity using MDA method. The
results revealed that ethanolic extracts from dry tissue showed minimum lipid peroxidation 30.54±0.49 (±SD), and thus the highest autoxidation (44.45±0.74) activity. The results of antibacterial analysis of the examined extracts showed no significant antibacterial property (P<0.05). This study revealed some antioxidant activities of Siphonaria carbo extracts. Detailed biochemical studies are recommended for identification of compounds causing this property.
Iranian National Institute for Oceanography and Atmospheric Science
Journal of Oceanography
1562-1057
9
36
2019
1
1
Modeling of Scouring around Submerged Pipes by Group Method of Data Handling
47
56
FA
Ebrahim
Shahbazbeygi
Department of Water Engineering, College of Agriculture, Islamic Azad University, Kermanshah Branch, Kermanshah
fariborz
yosefvand
Department of Water Engineering, College of Agriculture, Islamic Azad University, Kermanshah Branch, Kermanshah
Behrouz
Yaghoubi
Department of Water Engineering, College of Agriculture, Islamic Azad University, Kermanshah Branch, Kermanshah
In this study, scour pattern around submarine pipelines which were located on an erodible bed was simulated using Group Method of Data Handling (GMDH). Also, to assess the performance of hybrid models, the Monte Carlo simulations (MCs) were applied. In the study, the k-fold Cross Validation (k=6) was used for examination of the models ability. Then, using the effective parameters on scour, six various GMDH model were developed. By analyzing the numerical models, the superior model was introduced. The model predicted the experimental results with reasonable accuracy. For instance, correlation coefficient, scatter index and root mean square error were calculated 0.914, 0.160 and 0.141, respectively. For a superior model, some relations were obtained in order to predict the scour around submarine pipelines. In addition, by sensitivity analysis, the most influential parameter was identified. Finally, GMDH 4 model and the ratio of the distance between pipe and erodible bed to diameter pipe (e/D) were introduced as the superior model and the most effective input variable, respectively.
Iranian National Institute for Oceanography and Atmospheric Science
Journal of Oceanography
1562-1057
9
36
2019
1
1
Continuous Monitoring of Tidal Bores Using Acoustic Tomography Technique
57
64
FA
Masoud
Bahreinimotlagh
Water Research Institute
Reza
Roozbahani
Water Research Institute
Mortaza
Eftakhari
Water Research Institute
Hamid
Kardan Moghaddam
Water Research Institute
Seyyed Amirmohammad
Hasanli
Tehran University
Salinity intrusion to the upstream of estuaries has become a major issue in the coastal areas. This phenomenon intensifies in lack of river discharges. The result is salinity increment in agricultural lands located near the estuaries. In this study, the tidal currents, as well as the river discharges were measured using an Acoustic Tomography Technique. Two acoustic stations were deployed on both sides of Kyu Ota Estuary and measured the variations of stream flow affected by tidal currents for 42 hours. The results of measurement showed that the river discharge was between 20 to 50 m3/s. Whereas, the stream flow direction changed abruptly to the upstream at the time of passing tidal bores. The maximum stream flow was approximately 20 m3/s to the landward. Therefore, acoustic tomography technique can be introduced as an appropriate instrument to monitor the estuary stream flows.