JOURNAL OF MARINE BIOLOGY
Year:2020 | Volume:12 | Issue:45|Papers Count:8

Tuna fish from the order Perciform and the scombridae family, with 15 genera and 52 species, it has been an important economic fish for most countries and the most valuable economic aquatic are in industrial catch in the world. The rate of overfishing in the southern waters (from 1997 to 2016) in 2019 was based on CMSY model and R software and Bayesian status approach (Problem solving based on basic information) and Monte Carlo simulation. The average catch of tuna fish (tuna fish, seer fish and billfish) in the southern waters for the period studied was 167260 tons with 95% confidence interval of 167367-167152 tons and the average catch increased significantly during the last two decades (R = 0. 94, P <0. 05) and the average catch of tuna fish (tuna fish, seer fish and billfish) in Sistan and Baluchestan province (Yi) for this period was 94505 tons with 95% confidence interval of 94414-94595-9595 tons and the average catch increased significantly during the last two decades. (R = 0. 83, P <0. 05). Overall overfishing rate (weight of tuna) in the southern waters of the country and Sistan and Baluchestan province for the study period were 43% and about 47%, respectively, and in the case of overfishing rate (number of tuna) in the southern waters of the country and in Sistan and Baluchistan province reached about 16 percent and more than 7 percent, respectively. According to the terms and situation mentioned, it seems with regard to sustainable fishing requirements, it is possible to increase the catch of tuna and large pelagic fish in the south of the country.

This study was conducted to determine growth parameters and mortality of sharp nose mullet (Cheloc saliens). A total of 442 specimens collected using small beach siene in Gorgan bay from June to October two successive years of 2016 and 2017. The samples included 210 males and 232 females. Growth parameters calculated using Gulland and Holt method, and the length frequency analysis done using ELEFAN and Shepherd methods in FISAT software. Observed length-weight relationship was W=0. 0084L 3. 018 for males and W=0. 010L 2. 954 for females. After fitting the regression using least squares method, the non-linear relationships were W=0. 009L 2. 977 and W=0. 013L 2. 855 for males and females, respectively. The results showed that there are two cohorts (with mean values of TL 7. 34 and 17. 06 cm) in males and three cohorts (with mean value of TL 6. 84, 15. 28, 20. 76 cm) for females. Fitted K and L∞ of VBGF were 0. 270 year-1 and 32 cm for males, and 0. 235 year-1 and 34 cm for females. Total mortality rate which calculated using linear catch equation, was 1. 39 and 1. 07 year-1 for males and females respectively. In general, this species inhabiting the Gorgan Bay has population dynamics characteristics similar to those of the r-selection strategy.

Dust is a natural process in the desert areas. Strong winds on the dry soil surface make the particulate matter suspended in the air near the ground. In recent years, the influence of several natural factors has led to the further spread of dust in the western and southwestern parts of Iran. A storm take placed in the Khuzestan province and the northwest of the Persian Gulf, in February 17-19, 2017. The purpose of this study was to determine the source of dust as well as to study the conditions of the wind speed and direction and role of Low Level Jet in dust formation and transfer to Khuzestan and Persian Gulf. For synoptic analysis meteorological data provided from the ECMWF website. The horizontal distribution of dust investigated by MODIS satellite image and DREAM model. The HYSPLIT model also determined the dust trajectory. A coincidence survey showed that the northwest winds in eastern Syria and northwest of Iraq (the northern wind) were formed at the height of the fissure between east to west of Iran and a stack of compression from Turkey to north of Arabia. The synoptic analysis showed that northwest winds (Shamal) in eastern Syria and northwest of Iraq (northern wind) were formed between the pressure trough which is extended from east to west ward of Iran and pressure ridge from Turkey to north of Saudi Arabia. The northwest winds at the 925 reached 14 to 16 (28 to 32 Knt). The increase in the wind speed in the low altitudes of the atmosphere led to an increase in wind speed of 10 meters by 9 (18 Knt), which resulted in the release of dust particles into the atmosphere. During February 18 in southeastern Iraq and southwestern Iran, the LLJ developed. The result was an increase in turbulence and the vertical extension of the dust in the lower layers of the atmosphere. The synoptic north wind direction corresponded to the HYSPLIT model and Windrose. All of them represented the northwest wind direction and confirmed the transfer of dust from Iraq to the Persian Gulf. Satellite imagery and the DREAM model determined the deserts of Iraq and eastern Syria as the origin of the Persian Gulf dust. The MODIS imagery and the DREAM model showed the deserts of northwestern of Iraq and eastern Syria as the source of Persian Gulf dust storm.

Population structure of sea cucumber Holothuria parva in the coasts of Bushehr and Halileh from Persian Gulf was determined by 16S rRNA of mitochondrial genome sequencing in autumn and winter seasons of 2019. In Bushehr and Halileh populations, 2 and 4 haplotypes were identified out of 374 nucleotide sites, respectively, and haplotype 2 was the most abundant in Bushehr population and was observed as a common haplotype with Halileh population. The average haplotypes diversity on the coasts of Bushehr and Halileh was 0. 5 and 1, respectively, but nucleotide diversity in the above two populations was 0. 0013 and 0. 0053, respectively. Due to the high gene flow in the studied populations and the low genetic distance, gene differentiation in both populations was-0. 111. Therefore, based on the above and common of the haplotype, it is possible that H. parva collected from the cost of Bushehr and Halileh was the same population.

Shipping is among the most important ways to transfer the non-native species. In the present study, the transferability of the plankton species by the ballast water of 10 ships entering the Bushehr Port in the Persian Gulf has been investigated. The values of physicochemical parameters measured in the ballast waters showed that the average temperature, pH, salinity and TOC, were 26. 2 0C, 8. 17, 37. 90 ppt and 34. 73 ppm, respectively. In total, 3 phylum, 3 classes, 18 orders, 23 families, 39 genera and 53 species of phytoplankton were identified. The Ochrophyta with 18 families (78. 73%), Myzozoa with 4 families (20. 32%), and Haptophyta with 1 family (0. 94%) were the highest to the lowest phylum found inside the tanks. Zooplankton species were from 7 phylum, 11 classes, 15 orders, 33 families, 38 genera and 48 species. Arthropoda comprises 57. 25% of the species (the highest density) with 23 families and 38 species and Chordata with two families and two species, 1. 52% of species (the lowest density). No invasive species were also identified among the species indicating that they pose no threat for the coastal ecosystem of the Bushehr Port due to the transfer of invasive species through the waters of the northern India Ocean. The process of ballast water exchange can be applied as an appropriate managerial technique to alleviate the risk of transferring the non-native species to the Bushehr Port.

One of the pollutants produced by gas and petrochemical industries in Assaluyeh region is heavy metals which, by entering of these industries into the Persian Gulf, has caused water and aquatic pollution. Therefore, in the present study were investigated the concentration of non-carcinogenic hazard quotient index (NHQI) of heavy metals (Fe, Cr, Pb, Cu, Zn, Cd, Se, Ni) in Persian Gulf waters and its impact on Scomberomorus guttatus and Brachirus orientalis. A total of 42 water samples and 84 fish species samples were collected from 14 points (three replicates each) and the concentrations of metal elements in fish water and muscle were measured. After normalizing the data, heavy metal pollution index (HPI) was used to determine the amount of heavy metal contamination in fish and water. Finally, kriging method in GIS environment was used to determine the spatial distribution of heavy metals in fish and water. The results of analysis in water samples showed that the maximum values of Cd, Cu, Ni, Pb, Zn, Pb in the samples were 4. 8, 10, 9. 8, 5. 2, 9. 4, 6. 7 mg/l respectively. Given these values, it is clear that near the power plant all elements exceed international standards, indicating high water pollution in the area. The results also showed that the contamination was higher in Brachirus orientalis than in the Scomberomorus guttatus where the two fishes lived where the Scomberomorus guttatus live near the surface of the water, whereas the Brachirus orientalis were live in deeper water. Based on the results of this study, it can be expected that the long-term risk of contamination with heavy metals will continue. As the risk of contamination on the marine waters of the area has a great impact, which leads to their poisoning and enters the food cycle of the people of the region.

Chlorella species are single-celled green algae that have many uses. Chlorella sorokiniana is a green algae that is seen as a single cell and a mass. In this study, which was conducted in 2019 at Payame Noor University of Tehran, Chlorella sorokiniana was cultured in the modified Bold basal medium by modifying phytohormones, 2, 4-D (0. 5-1 mg / l), with BAP(1-2 mg / l), and minerals (double nitrate and phosphate), and growth, lipid content, and water-soluble sugars were measured. The experiments were performed in a completely randomized design. Statistical analysis was performed using SPSS13 software and the comparison of means using Duncan's test was determined. In the treatment of 2. 4 dichlorophenoxy acetic acid (2, 4-D) (1 mg /l) with benzyl aminoporein (2 mg / l), the number of cells (21×107cells per milliliter of algal suspension) was significantly P≤ 0. 05 increased compared to the control (10. 98×107 cells per milliliter of algal suspension). The largest cell masses were observed in the treatment of 2, 4-D (1 mg /l) in combination with Benzylaminopurine (1 mg/l). In 75% of the hormonal treatments, the diameter of the cells and in all the hormonal treatments, the lipid content showed a significant decrease (13. 3%-16%) in P ≤ 0. 05 compared to control (24. 7%). The highest percentage of lipids (32. 63%) was obtained in the Bold medium with twice as much nitrate and phosphate. The content of soluble sugars in any of the treatments (0. 2-3. 9 mg /g dry alga) did not show a significant change compared to the control (2. 1 mg /g dry alga). Overall, the results of the present study showed that the combination of 2, 4-D with Benzylaminopurine hormones in these concentrations increases the growth of algal cell masses but reduces the lipid content of algae. These hormones can only be used to increase of biomass. But adding two fold nitrate and phosphate increases the growth and content of algae lipids, making it the most suitable growing medium for increasing the growth and lipid content of Chlorella sorokiniana.

There are many practical motivations for studying Scorpaenidae, which are among the world's most dangerous venomous fish in tropical waters, especially in the Persian Gulf, because they are biologically very active and therefore researchable. They are useful for biomedical medicines or the drugs and biological products. Second, such biotoxins have significant negative or repulsive effects on living organisms in marine communities. A large number of marine organisms with such biotoxins pose a serious threat to humans. To conduct this study, which was carry out from May to March 2019, 200 black spotted fish (Faryaleh) (Synanceia) were caught from the Persian Gulf and In the laboratory, after extracting the toxin, purification, protein measurement and LD50 determination were performed as the most basic information for the initial examination of the venom of this species of fish (as the aim of this study). The results of these studies showed that Persian Gulf black spot stone fish (Synanceia) poison is one of the most dangerous poisons for human health and hygiene with LD50 equal to 185 and protein percentage is 2. 272 mg/ml.