Showing 8 results for Qeshm
Volume 1, Issue 2 (6-2013)
Abstract
Concentrations of lead (Pb) were found in the shells of the oyster Saccostrea cucullata and sediments in May 2010. Samples were obtained at four sites on Qeshm Island, at three sites on Hormoz Island, and at three sites in Lengeh Port along the intertidal coast of the Persian Gulf of Iran. The levels of Pb in sediments and shells were analyzed by graphite furnace atomic absorption spectrophotometer.Mean Pb concentrations in the different sampling stations varied between 613.94 and 0.06 µg g-1 in the shells of S. cucullata and 180.78 and 0.86µg g-1 in sediments. Biological effects criteria suggest that Pb concentrations in sediments in three sites from Lengeh Port were higher than ERL (effects range low), but at the all sites were lower than ERM (effects range medium). The present results support the significant differences in shell and sediments’ accumulated concentrations of Pb among sites attributed to input sources of human activities including urban, domestic, industrial, agricultural, shipping and transport, mining activities, and ports and harbors
P. Nourozifard , S. Mortazavi , S. Asad, N. Hassanzadeh ,
Volume 8, Issue 1 (3-2019)
Abstract
toxicology. Considering the specific conditions of the Persian Gulf and the impact of pollutants, the aim of the present study was to evaluation of toxic elements bioavailability from the total amount of surface sediments in the Persian Gulf.
Materials & Methods: In the present study, the total concentration and bioavailability fraction of copper, lead, zinc, cadmium, nickel, and chromium were measured at 14 coastal stations of Hormozgan province and Qeshm island. Nitric acid and perchloric acid were used to measuring the total concentration and K protease enzyme solution was used to measuring the bioavailable fraction.
Findings: Zinc and chromium have the highest mean of total concentration, respectively. Qeshm island has more pollution than Hormozgan. The higher bioavailability and higher percentage of components were observed in lead and chromium than the other elements. With increasing concentrations of lead, chromium, and copper, the bioavailability of these elements also increased. As well as, zinc and nickel showed the lowest bioavailability. The concentration of copper, lead, and nickel was also higher than the sediments world average and the WHO / US EPA maximum, and the nickel concentration was above the ERM, PEL, and SEL.
Conclusion: Due to the low accuracy of determining the total concentration of metals in sediment toxicity for aquatics and the need to pay attention to bioavailability fraction, the probability of ecological risk of lead and chromium elements is higher than the other elements for aquatics of Persian Gulf. Zinc and nickel, have the lowest risk to the environment despite the high total concentration.
Volume 8, Issue 3 (7-2020)
Abstract
Aims: The current study investigated the concentration of Cu, Pb, Zn, Cd, Ni, and Cr in shell and soft tissue of Saccostrea cucullata, water, and sediments of seven stations in Qeshm Island of Persian Gulf.
Materials & Methods: The samples were digested by a combination of nitric acid and perchloric acid and the concentration of elements was measured by atomic absorption spectroscopy.
Findings: The results indicated that the concentrations of Cu and Zn in all samples, Ni in the sediment and Cd in oyster were the highest bio-water accumulation factor were significantly higher than those of bio-sediment accumulation factor. Also, these factors in the soft tissue were higher than in the shell. Furthermore, the macro-concentrators of soft tissue were Cd, Cu, and Zn, while the macro-concentrator of shell was Cd.
Conclusion: The shell can be an appropriate monitoring tool for evaluating Cu and Zn in water and Cu in sediments. Also, the soft tissue can be practical for monitoring Cu and Zn in sediments.
Volume 10, Issue 3 (10-2022)
Abstract
Aims: Monitoring variations in macroalgal assemblages is a crucial issue for the preservation and management program of coastal waters. This study was conducted to determine the seasonal and spatial distribution patterns, and composition of macroalgal communities along the eastern coasts of Qeshm Island, Iran.
Materials & methods: Seasonal sampling was conducted at three different sites of different tidal levels on the eastern coasts of Qeshm Island. Random samples of macroalgae were collected at three stations, seasonally. The species were identified and the dry weight of each species was used to calculate the macroalgae abundance. The Species richness and the Diversity indices were calculated to evaluate the distribution pattern and composition of the macroalgal community.
Findings: As a result, 51 species (4 Chlorophyta, 21 Phaeophyta, and 26 Rhodophyta) were identified. The seasonal and spatial dominant species were found to be Padina sp. and Hypnea sp., and a distribution pattern was seen to have increasing macroalgal biomass from the upper to lower intertidal level. The sampling sites shared more than 50% similarity of their macroalgal species, indicating a relatively homogeneous distribution. The highest (18.1±4.3 gr drywt m-2) and lowest (8.27±2.1 gr drywt m-2) mean of total seaweed biomass were recorded in winter and summer, respectively.
Conclusion: The assemblage composition of macroalgae significantly differs between hot and cold seasons, and there was no substantial compositional variation of seaweeds communities along the tidal gradient. The macroalgal distribution was largely homogeneous with no significant difference among the research areas at sampling seasons.
Gholamali Akbarzadeh Chomachaei, Shiva Aghajary Khazaei, Siamak Darvishi, Siyamak Behzadi, Ramin Karimzadeh,
Volume 10, Issue 4 (12-2021)
Abstract
This study was conducted to investigate the possible effects of cages culture Asian sea bass fish (Lates calcarifer) on the population structure of macrobenthos in the Rigo area of Qeshm Island in Hormozgan province during a breeding period in 1397 were investigated. The average abundance of macrobenthos at the location of the cages culture and the refrences site in this study was equal to (52765 ± 19154 in m2) and (50642 ± 21002 in m2), respectively.The results showed that at the time of the study among the identified the genus of Ammonia sp. With a relative abundance of 73.41 percent at the location of the cages compared to the control station and Archasterope sp., Spirolochulina sp. and Nephtys sp. with a relative abundance of 63.9%, 49.1% and 12.6%, respectively, were more dominant in the control station compared to the location of the cages.The loading rate of organic matter in the bed of the cages was significantly affected by fish farming activities and in some times showed a significant difference with the control station (P<0.05). In general, at the time of the study, activities related to fish farming in cages had no effect on the population structure of macrobenthos in the study area.
Gholamali Akbarzadeh Chomachaei, Fereshteh Saraji, Hadi Koohkan, Siyamak Behzadi, Mohammad Darvishi, Seyedeh Laili Mohebbi-Nozar,
Volume 12, Issue 1 (12-2022)
Abstract
In this study, the possible impact Asian sea bass fish (Lates calcarifer) cages culture on the population structure of phytoplankton in the coastal waters of Qeshm Island.Water sampling was done monthly for a period of six months in three stations from October 2018 to March 2019.The results showed that the mean Variations of total abundance of phytoplankton at the location of fish cages culture compared to the Reference station had a significant increase (P <0.05). At the location of cages culture, the Trophic status level was high (<5), the risk of eutrophication status (<4) and the value of trophic efficiency coefficient were high. According to the analysis of Simper test, Among the Forty-one genera identified, Noctiluca sp. with a relative abundance of % 82.37, contribution rate of 21.8% with high algal bloom at the location of cages in autumn season and then the genera Chaetoceros sp., Nitzschia sp. and Coclodinium sp. with a relative abundance of less than 10 percent in differentiating the population structure of phytoplankton have played a significant role in the dissimilarity of the population structure of phytoplankton between stations In general, in this study, the effects of fish farming activities on the population structure of phytoplankton are ineffective, but it causes the abundance of some species, available nutrients, increases the trophic level, and the probability of harmful algal blooms in the location of the cages culture.
Volume 12, Issue 4 (12-2021)
Abstract
The aim of this study was to isolate and identify a-amylase-producing bacteria present in mangrove ecosystems on Qeshm Island, Hormozgan, Iran. Samples of mangrove leaves and roots were screened for a-amylase activity using Lugol’s solution. Crude extracts were prepared of positive samples, and their a-amylase activity was determined by the Bernfeld method. The two strains with the highest activity were identified by molecular analysis of their 16S rRNA genes. a-Amylase production and activity were optimized by varying temperature and pH. 46 bacterial strains were isolated from mangrove tree leaf and root samples. Of these, 28 strains were capable of producing a-amylase. 16S rRNA gene sequence analysis of two strains with the highest enzyme production identified them as Bacillus sp. strain HR10 and Bacillus sp. strain HR11. The optimum temperature for enzyme production was 35 and 30 °C for strains HR10 and HR11, respectively, and the optimum pH was pH 8 for both strains. The highest enzyme activity was observed at 70 °C and 60 °C for the HR10 and HR11 strains, respectively, and the optimum pH was pH 8 for both strains. In conclusion, we have shown that bacteria isolated from mangrove leaf and root samples are potential source of a-amylases, tolerating a wide range of temperature and pH. Such a-amylases may be of interest for use in environmentally friendly industries.
Volume 18, Issue 2 (9-2011)
Abstract
The first season of survey at Qeshm, carried out during the winter of 2006, resulted in the identification of nine sites from the Parthian and Sasanian periods.
The surface pottery from these sites suggests their trade and cultural relations with contemporary sites in the southern Persian Gulf and other areas. For instance, the Parthian and Sasanian glazed types in Qeshm Island are closely related materials found from Khuzestan as well as northern and southern coasts of the Persian Gulf, including ed-Dur, Suhar, Kush, Failaka and Qalat Bahrain.
Parthian painted ware reveals close similarities to monochrome and bichrome painted pottery of southeastern Iran, Oman coasts and the southern Persian Gulf, specifically ed-Dur, Suhar, Kush and Tel-i-Abrak.
The so-called Indian Red Polished Ware is the other diagnostic type widespread in the northern and southern coasts of the Persian Gulf from the middle Parthian up to the early Islamic period. The material was being widely produced in the Indian region (Gujarat) and Indus, and exported to different places around the Persian Gulf.
The Coarse Black Ware (ceramic noir epaise) with decorative raised bands recorded in Qeshm compares with coarse-black material from the southern Persian Gulf, also occurring at sites such as ed-Dur and Abu Dhabi Islands.
Plain, common Parthian and Sasanian pottery from Qeshm shows parallels with known materials of this period in the northern and southern Persian Gulf.
