نشریه پژوهش های علوم و فنون دریایی
سال نهم شماره 1 (بهار 1393)

Molecularly imprinted polymers (MIPs) are synthetic polymeric materials with specific recognition sites complementary in shape, size and functional groups to the template molecule, involving an interaction mechanism based on molecular recognition. In this study, we have prepared a novel ion imprinted polymer (IIP) for removal of aluminium ions in solution sample. The imprinted polymer was prepared by copolymerization of allyl glycidyl ether/ iminodiacetic acid (AGE/IDA) as functional monomers in the presence of N,N′-Methylenebisacrylamide as crosslinker. The polymerization was carried out in bulk with free radical initiation using 2,2′-azobisisobutyronitrile (AIBN). The polymer particles were characterized by Fourier transform infrared (FT-IR) and elemental analysis. The effect of various experimental conditions, like pH, adsorption and desorption time and type of eluent were investigated and optimized. The optimum pH for quantitative aluminium retention was 4.5, while elution was completed with 5mL of 0.5M nitric acid. The total capacity of IIP was found to be 62.4mg g-1in 20ºC. The method was applied to the recovery and determination of aluminium in real samples. The imprinted polymers exhibited good characteristics for adsorption and preconcentration of target aluminium.

This paper presents the effective processes on the oil slick after spill accidents in sea. Processes include advection, evaporation, dissolution, photo-oxidation, sedimentation and biodegradation which are described by analytical methods. The processes can influenc and change the initial parameters of oil, including density, water content and viscosity. Spreading process play a governing role during a period of several hours after spill accidents, while the process of transforming oil slick may occur during a period of several days. Estimation of evaporation, advection and the thickness of the oil layer is used in calculating the ratio of the natural dispersion by numerical models. The evaporation and the thickness determine the lifetime of oil slick on the sea surface by many models. In addition, estimates of the layer area of ​​the slick can be used to evaluate efficiency of oil spill control methods and evaluation of their environmental impacts. The study was performed in the Assalouyeh marine region on the northern coasts of Persian Gulf, for effective processes on the fate of gas condensate slick. The results show that after spill accidents, the gas condensates transfer into the atmosphere due to evaporation and atmospheric and marine conditions, and also penetrate in the water column. Due to wind velocity, gas condensates move away from the coast in the winter and in summer due to higher stability at sea, gas condensate particles can accumulate on the surface (especially for larger particles).

The Demospongiae was used in Kish Island of Persian Gulf as the biologic absorptive with nano fovea for removing magnesium action and the effect of density, contact time and the size of the absorptive particle was studied in absorption capacity. The absorption capacity of magnesium ion in 10, 30, 50 and 300 mg /l was tested on shaker and the capacities of 0.7, 3, 6.6, 80.3 mg/g were obtained respectively which showed that the absorption capacity increases with density. In addition, the absorption of magnesium ion in the densities of 10, 30 and 50 mg/l, in contact time of 1 hour without shaker, were 1.2, 4.2, 11 and in 3 hours, 0.2, 4.6 and 14.5 mg/g, which showed that the absorption capacity does not increase with contact time. The absorption capacity in absorbent size of 70 meshes and 120 meshes were 80.3, 64.6 and 74.2 mg/g respectively, which showed that the absorption capacity is more when used in pieces. The results of the present research showed that the absorption capacity of magnesium ion by Persian Gulf sponge is 80.3 mg/g and the reported ratio is higher compared to other natural absorbents and is now the highest capacity.

Nutritional needs are important in successful breeding process of the fishes. Aloe vera gel having beneficial compounds such as the eight essential amino acids, monosaccharides and polysaccharides, vitamins C, B12, B6, B2, B1, A, E and minerals, can be used as a valuable supplement and food rations used in natural aquatic environment. Effect of prescription of this crude extract of plant Aloe vera in Oscar (Astronotus ocellatus) with an average weight of 17.57 ±2.56 g were studied in this research. Therefore, 54 fish in three treatments, each with 3 repeats were used in this research. Two treatments included a concentration of 2 and 5% crude extract of Aloe vera plant which were added to the Biomar feed size of 0.8 mm used for Carnivore fishes. Samples were fed for 60 days with the fortified feed. The control sample feed were not fortified. The results indicated that feed fortification with plant extracts of Aloe vera makes a significant difference (p<0.05) in weight gain, growth factor and coefficient of obesity and reduced food conversion factor compared with controls, and increase in fortification showed an increased effect. No mortality was observed in both treatments. Fortified feed at 5% showed a better result as a whole.

Anzali Lagoon is an internationally protected lagoon located in west-south of Caspian Sea which has special ecologic, economic, social importance with vast diversity of plants and animals. According to entrance of contaminants into this lagoon, concentration of several heavy metals in muscle of Esox lucius fish have been investigated in this study. First stage of sampling from three stations of lagoon, have been fulfilled at dry season of September and second stage have been implemented at rainy season of November 2010. In each season nine samples of fish have been collected and transported to laboratory in freezed condition. Evaluation and measurement of heavy metal concentration has been fulfilled by Graphite furnace atomic absorption equipment. Maximum mean concentration of Hg, Ni, Se, Zn, Al, and Fe have been detected in the summer and maximum mean concentration of Cu has been detected in the winter. Maximum mean value of Hg, Ni, Zn,Al in Abkenar, maximum mean value of Se in Siah Darvishan and maximum mean value of Cu, Fe in Komeh Aghajani have been detected, while concentraton of Mo, Cd, V and Pb are equal in the three above mentioned stations. Statistical analysis of this study has been fulfilled by SPSS, V14 software. Pearson correlation test, showed a positive strong correlation between temperature and the amount of Fe (r=0.83, P<0.05). Only significant difference in concentration of Fe has been obtained between summer and winter seasons (P=0.016, df=16, P<0.05). Significant difference in concentration was detected only for Hg between Abkenar and Komeh Aghajani stations (P=0.05).This study shown that, the concentration of Ni, Hg, and Cd in the muscle of Esox lucius are high and it is considered as a serious warning.

To review the diet of Malabar trevally (Carangoides malabaricus) in the waters north of the Persian Gulf (Bandar Abbas area), fishing gillnet was used for fishing seasonally, from spring 2012 to winter 2012. 188 samples were taken randomly evacuated fishing. Samples of frozen fish were packed in polystyrene and were flown to Tehran and were transferred to the laboratory at the faculty of Marine Science and Technology of Islamic Azad University North Tehran Branch. Stomach contents analysis of 188 samples indicated that the fishes were main food in both females and males of this species %85 and %86 respectively and followed by subsidiary food which included crustaceans, %15 and %14 respectively. Among fishes, Leiognathidae were the main food (%53) , which followed by Engraulidae (%41 ), Mullidae (%3 ) and Gobiidae (%3 ). Among crustaceans, shrimp (%39) and crabs (%61) were found in stomach contents. Statistical analysis on the preference feeding showed no significant difference between male and female fish. This species of fish is considered as low food consumption type and the highest percentage of empty stomach is found in spring and autumn.

The aim of the present study was to evaluate Pb, Cu and Cd contamination of the amphipod species, Pontogammarus maeoticus in southwestern coasts of Caspian Sea. Sampling was done in two seasons, spring (March 2014) and summer (June 2014) in 3 sites of the southwestern coasts of Caspian Sea (from Ramsar to Anzali). Results showed that Cu concentrations were much more than the other two metals, and there was no significant difference among sites in this regard (P>0.05). However, Chamkhaleh possessed the least amount of heavy metals in the body of the gammarid species; and Anzali had the most concentration in the coastal amphipod species body.Concentration of lead, copper and cadmium in the body of P. maeoticus was 1.02, 95.61 and 0.81 µg/g in spring and 1.46, 93.91 and 0.74 µg/g in summer, respectively. The results were compared with EU, US and Australian standards. According to these standards Cooper concentrations were at target values and is not considered polluted. Lead in P. maeoticus passed standard level according EU standard for edible cephalopods and Australian standard for fish flesh. This was not the case for Pb in spring in Anzali station, accouding to EU cephalopod standard only. Lead was in acceptable concentration if compared with EU standard set for edible bivalve molluscs, Australian standard for edible molluscs, and US standard of AET. Also cadmium concentrations were more than maximum allowable in edible lobster as stated by EU standards. While other standards AET of US, Australian standard for edible molluscs, and EU standards for edible cephalopods, bivalves and fish consider the concentration of Cd in the P. maeoticus within standard limits. Considering the Pb and Cd contamination levels in P. maeoticus and international standards, it can be concluded that these two heavy metals can be at threatening level. Especially that this species is consumed by fish fingerlings of some popular teleost fishes of Caspian Sea, such as Kutum and Mullet. They might be able to pass to fish flesh and cause health hazards for fish consumers. It is suggested that further study be conducted on possible transfer roots of Pb and Cd from P. maeoticus to fish flesh, and also there is a strong reason to control heavy metal pollution of the Caspian environment.

Heavy snowfall and its aftermath is an example of atmospheric phenomenon which can cause serious harm to many parts of the natural and human environment. In order to identify the effective synoptic characteristics and patterns at the events of heavy snow in Tehran in the present study, the snowfall data are collected from the Mehrabad airport weather station archives over the years 2000-2009. From the total number of 150 snowy days that had been recorded, synoptic maps have been created for 19 February, 2003, using data from the GFS, with an accuracy level of 1.0o×1.0o, by GrADS software. Temperature advection maps have also been created using CFSR data. Studying the synoptic maps at different atmospheric levels revealed that during the period of heavy snowfall in February, 2003, the formation of low-pressure over the Mediterranean Sea and on the other hand the formation of high-pressure and its ridge over Caspian Sea are visible and the transition of the two systems causes intensive pressure gradient over the area under the study. Simultaneously at the level above, a low and trough forms that the transition of this trough to the aforementioned area leads to the creation of snowfall. Analyzing the amounts of absolute vorticity and the vertical motion reveals advection of absolute vorticity and the negativity of the vertical motion () which imply the instability and ascending air mass that will eventually result in the occurrence of heavy snowfall. Studying the amounts of temperature advection at 200 hPa also represents warm advection.