Shahmir Eghtesadi; Rafieh Zahedi
Volume 10, Issue 3 , September 2012, Pages 4-13
Abstract
One of the most striking phenomena in the Caspian Sea is the sea level rise. Sea level fluctuation is due to climatologically changes, regional precipitation, water evaporation, temperature, wind stresses, surges and geomorphology changes in the sea bed, alteration in atmospheric transport pattern as ...
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One of the most striking phenomena in the Caspian Sea is the sea level rise. Sea level fluctuation is due to climatologically changes, regional precipitation, water evaporation, temperature, wind stresses, surges and geomorphology changes in the sea bed, alteration in atmospheric transport pattern as well as human activities such as construction of dams on the major rivers. More meteorological studies of Caspian Sea region as well as advanced watershed and ocean modeling must be used in order to predict the sea level fluctuation with acceptable results. In this research the variation of evaporation and precipitation in five coastal stations of south Caspian Sea from 1993 to 2008 has been studied and determines what are the effects of precipitation and evaporation in Caspian Sea fluctuation during this pried. The mean calculated evaporation in this period is about 922.9 mm. It is less than the mean calculated evaporation for long term period that is about 1007 millimeter/year. Mean calculated precipitation in this period is about 1292.6 mm. It is higher than mean calculated precipitation for long term period that is about 1221 millimeter/year. So in southern Caspian Sea, the increase of precipitation and the decrease of evaporation have an important role in sea level rise in recent years. The statistical index and correlation between atmospheric parameters are also determined and discussed in this research.
Homayoon Hosseinzadeh Sahafi; Hossein Abdolhai1; Mohammad Hossein Toloee; Javad Sayadfar
Volume 10, Issue 3 , September 2012, Pages 14-22
Abstract
Morpholine as retrieving agent has been used by many researchers for homing of fish.Brooders were selected from Khoshkrud River and breeding was done in Shahid Ansari hatchery, Rasht in 2005. To determine the critical period for imprinting of morpholine 10450 kutum fish were exposed to 10×5-5 mg/lit ...
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Morpholine as retrieving agent has been used by many researchers for homing of fish.Brooders were selected from Khoshkrud River and breeding was done in Shahid Ansari hatchery, Rasht in 2005. To determine the critical period for imprinting of morpholine 10450 kutum fish were exposed to 10×5-5 mg/lit of morpholine in different stages(yolk sac fry ,active fry, 2-3-g fingerlings , 4-5 g fingerlings )and released into Khoshkrud river.The return rate of released fish were studied and recorded in2008 .Results showed significant difference between kutum return rate in active fry stage(1 %) compare to other stages i.e. , yolk sac fry (0.23%) , 2-3- g. fingerling(0.23%) , 4-5 g. fingerling (0.26%) and control(0.13) during the tree years of study period(P<0.001). There was significant difference in sex ratio [M(1.42): F(1)] in recaptured fish in Khoshkrud river( x2=6.4 α= 0.05 df= 1).Higher recapturing rate of 6.7 % recorded in the present study compared to recapture rate of 5% reported during last 5 years, revealed that morpholine can be used for return rate enhancing of kutum fish.
Ali Azimi; Alireza Safahieh; Ali Dadollahi Sohrab2; Hossein Zolgharnein1; Ahmad Savari
Volume 10, Issue 3 , September 2012, Pages 23-32
Abstract
Heavy metals are major group of dangerous contaminants in marine environment. Due to their persistence, they may enter aquatic food chains and transfer from one trophic level to another. They also may be harmful for human being which is placed at the top of the food chain. Imam Khomeini’s Port ...
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Heavy metals are major group of dangerous contaminants in marine environment. Due to their persistence, they may enter aquatic food chains and transfer from one trophic level to another. They also may be harmful for human being which is placed at the top of the food chain. Imam Khomeini’s Port is located in the north west end of Persian Gulf and ships traffic and several industries especially petrochemical industries around of the port, discharge various organic and non-organic contaminants such as heavy metals into this ecosystem. In this study in order to investigate the levels of heavy metals (Hg, Cd, Pb and Cu) in soft tissue of oyster Crassostrea gigas from Imam Khomeini port, oysters of the same size were sampled on March 2010 from 5 different locations including harbors of Petroshimi, Doc Sorsoreh, 15, 28 and 33 in the Imam Khomeini port. The samples were freeze dried and acid digested in order to determine their heavy metal content with atomic absorption spectrophotometry. Results indicated that the content of Hg, Cd, Pb and Cu in the oysters’ soft tissue were 3.12±2.97, 7.56±3.62, 7.1±3.30 and 440.57±66.17 µg/g of dry weight, respectively. The highest level of Hg, Pb and Cu were recorded in harbor of Petroshimi while the highest level of Cd was measured in harbor no 15.The concentration of Hg, Cd, Cu and Pb in bivalve soft tissue was more than standard limits. This can be dangerous for public health therefore regular monitoring of heavy metals in the area is recommended.
Kamran Lari *; Majid Abrehdary; Alireza Sudkolaei
Volume 10, Issue 3 , September 2012, Pages 33-39
Abstract
One of the most important hydrographic operations is the chart datum determination and reduction of measured depth to this surface. For selecting this surface, sea water undulations frorm tide and other factors should be measured.Today coastal tide gauge observations is popular and finally the chart ...
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One of the most important hydrographic operations is the chart datum determination and reduction of measured depth to this surface. For selecting this surface, sea water undulations frorm tide and other factors should be measured.Today coastal tide gauge observations is popular and finally the chart datum determination is illustrated on lowest sea water level. Due to high differential between tidal range and phase in variation points, this method is not suitable offshore, therefore other methods should be used.In this study the satellite altimetry was collected using Jason-1 satellite altimetry data of 2002-2008 in the Persian Gulf and Oman Sea. Chart datum was calculated according to reference ellipsoid WGS84.
Sara Sara Rastegar1; Abdolali Movahedinia; Zahra Yarahmadi
Volume 10, Issue 3 , September 2012, Pages 40-47
Abstract
The present study carried out to assess the effects of Benzo-α-Pyrene (BaP) as a serious member of Polycyclic Aromatic Hydrocarbons (PAH) on the plasma levels of cortisol and triiodothyronine (T3) hormones in male Seabream, Acanthopagrus latus (Sparidea). To assess the acute effects of BaP on the ...
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The present study carried out to assess the effects of Benzo-α-Pyrene (BaP) as a serious member of Polycyclic Aromatic Hydrocarbons (PAH) on the plasma levels of cortisol and triiodothyronine (T3) hormones in male Seabream, Acanthopagrus latus (Sparidea). To assess the acute effects of BaP on the endocrine system, a group of fish was injected with dissolved BaP in sunflower oil (50mg/kg BaP in 2µg/l oil according to the body weight). Other fishes were injected with 2µg/l body weight as controls. Blood samples from both groups collected 3 hours after injection. In another protocol, the chronic effects of BaP on the plasma levels of cortisol and T3 were assessed. For this reason a group of fish was implanted with 50mg/kg BaP in 10µl/g coconut oil in respect to each fish body weight. As the previous protocol a control group was implanted with the same amount of oil without the BaP. Blood samples collected from both implanted groups (treatment and control) after 72 hours. According to the results, plasma levels of cortisol in yellowfin Seabream increased during both short time and long time exposure but T3 levels in the plasma decreased during the chronic stress of BaP exposure. It seems the cortisol levels are elevating to provide more energy requirement under the acute and chronic stress conditions by direct effect on glyconeogenesis and fast blood sugar level to be consumed by cells. T3 levels may be affected by inhibitory effect of Aryl hydrocarbon receptors (AhRs) which decreased it during long term exposure.
Omidvar Farhadian; Mohammad Hossein Khanjani
Volume 10, Issue 3 , September 2012, Pages 48-56
Abstract
Temperature and photoperiod are important parameters in zooplankton culture, particularly in cladoceran culture due to their significant effect on growth and reproduction. Effects of temperature and photoperiod on the growth and fecundity of a cladoceran, Moina macrocopa was examined by culturing and ...
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Temperature and photoperiod are important parameters in zooplankton culture, particularly in cladoceran culture due to their significant effect on growth and reproduction. Effects of temperature and photoperiod on the growth and fecundity of a cladoceran, Moina macrocopa was examined by culturing and feeding it with green algae Scenedesmus quadricauda in 500 ml conical flasks. Treatments used for temperature (0C)and photoperiod were 25, 30, 35 (0C) and 12:12, 24:0 and 0:24(light:dark hours), respectively. The maximum population density (310.5 individuals/flask), maximum specific growth rate (SGR) (0.387 individuals /day), shortest population doubling time (Dt) (1.79days) and highest fecundity (8.5 offsprings/ female) obtained at 30(0C). Correspondingly, the maximum population density (320.7 ind/flask), maximum SGR (0.538 ind/day), shortest Dt (1.28 days) and highest fecundity (7.54 offsprings/ female) determined at 24:0 light:dark photoperiod. Overall, this research showed that growth and reproduction of M. macrocopa at 30 (0C) and 24:0 light:dark photoperiod gave significant performance (P<0.05) compared to other examined treatments. Mass culture of this species under the mentioned conditions of temperature and photoperiod could provide suitable live food for use in fish larvaiculture.
Sepideh Khatib Haghighi; Hojjat Khodaparast
Volume 10, Issue 3 , September 2012, Pages 57-68
Abstract
For this survey, eight stations were selected in the Anzali Lagoon based on vicinity to the urban area, agricultural fields, in lets and out lets of the rivers. Sampling was carried out seasonally and in each season triplicate water samples were taken from surface layer of each station. Totally 96 water ...
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For this survey, eight stations were selected in the Anzali Lagoon based on vicinity to the urban area, agricultural fields, in lets and out lets of the rivers. Sampling was carried out seasonally and in each season triplicate water samples were taken from surface layer of each station. Totally 96 water samples were collected during one year period in sterile condition.Samples were transferred to the laboratoray at 4ºC temperature using ice box. The pollution by Coliform was examind using standard technigue of MPN and for count of bacteria differential, specific test and pourplate method isolate was used. In this survey different genus of bacteria were isolated and identified as: E.Coli (%19.65), Shigella (%18.21), Klebsiella (%17.86), Proteus (%13.21), Enterobacter (%11.07), Morganella (%9.65), Salmonella (%3.92), Serratia (%2.5), Providencia (%2.14) and Citrobacter (%1.79) which belonged to family Enterobacteriacea. Also the most important isolated genus of Vibrionacea were Vibrio (%47.55), Aeromonas (%28.67) & Plesiomonas (%4.9) and nonfermented-bacilli containg Suedomonace (%18.88). There was significant differences in the bacterial pollution between stations (P<0.05). The highest Coliform count was recorded during summer amounting to (147.71±171.36) ind. 100 cm3 and also the highest Fecal Coliform count was observed in summer (135.125±173.19) ind. 100 cm3 in the water. Generally the pollution in summer was higher in comparison to rest of the year due to increasing temperature and decreasing water flow of rivers.Higher bacterial pollution during autum in comparison to winter was attributed to heavay rain, erosion of the soil, flooding of the rivers and run off of the waste waters. Pirbazar river, Psikhan and Shambe Bazaar Roga drained high volume of urban agricultural and animal waste waters.The western area of the lagoon which is the bigest part of the Anzali lagoon had the least pollution.
Ahmad Shadi; Ahmad Savari; Preeta Kochanian; Simin Dehghan Madiseh; Yaseman Gandomi
Volume 10, Issue 3 , September 2012, Pages 69-78
Abstract
During one year survey (January to December 2007), Khouzestan coastal waters in the north west of Persian Gulf were examined to investigate juvenile fishes distribution, density and biomass. Monthly juvenile fish samples were caught using a 360 hp research vessel towing a 24 mm mesh size bottom trawl. ...
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During one year survey (January to December 2007), Khouzestan coastal waters in the north west of Persian Gulf were examined to investigate juvenile fishes distribution, density and biomass. Monthly juvenile fish samples were caught using a 360 hp research vessel towing a 24 mm mesh size bottom trawl. Trawling was carried out at 10 randomly selected stations. Distribution map for dominant species was prepared and biomass and CPUA was estimated in the study area. Highest and lowest CPUA was observed in October and December, repectively.Biomass fluctuations showed increasing trend during warm seasons.Significant correlation was recorded between environmental parameters (water temperature and salinity) with biomass and number of species per month in the study area.