Choghakhor Wetland Research Articles

Removal of Natural Organic Matter (NOM) from Aqueous Solutions by Multi-Walled Carbon Nanotube Modification with Magnetic Fe3O4 Nanoparticles

Backgroundand Aim. Natural organic matter (NOM) has become one of the most serious environmental problems due to its persistence in aqueous solutions and the risk of carcinogenesis. In this study, the removal efficiencies of real and synthetic humic acid (HA) by multi-walled carbon nanotubes (MWCNTs) coated with iron oxide were evaluated. Materials and Methods. The MWCNs were synthesized and coated with iron oxide. In addition, the effects of pH, contact time, mixing speed, and adsorbent dose on the removal efficiency of NOM by MWCNTs-Fe3O4 were studied. Then, the removal efficiency of NOM from real samples was investigated at optimal conditions. The MWCNT-Fe3O4 was characterized by scanning electron microscopy (SEM) test and X-ray diffraction (XRD), respectively. Data analysis was performed using Minitab software based on the Taguchi method. Results. The results showed that MWCNTs were coated with Fe3O4. The SEM test shows particle (MWCNTs-Fe3O4) size in the range of 48–143 nm, and the particles have uniform spherical shapes. Enix software was used to identify the phase in this sample. The conditions including p H = 3 , mixing speed = 120 rpm, adsorbent dosage = 1.5 g·L−1, and contact time = 90 minutes were selected as optimal for NOM adsorption. The mean removal efficiencies of NOM in synthetic samples at 5, 10, and 20 mg·L−1 concentrations were 86.6%, 84.87%, and 95.41%, respectively. In addition, the mean removal efficiency of NOM in Choghakhor Wetland was 77%. Conclusion. Our findings demonstrated that the MWCNTs-Fe3O4 can be potentially used as an adsorbent for removing natural organic matter (HA) from aqueous solutions.

Length-mass relationships for macroinvertebrates in the Choghakhor international wetland, Iran

This study investigates length-mass relationships for 17 families of freshwater macroinvertebrates collected in the Choghakhor Wetland (Central Iran). Body length, head width, distance between eyes and mass (dry weight and wet weight) were used to estimate biomass with linear, log-linear and exponential models. The results show better performance of the log-linear model (ANOVA, p = 0.03), as compared to the other two (ANOVA, p > 0.05). A cross-validation test demonstrated that all three models performed reasonably well, in terms of both statistics and the accuracy of prediction. However, for more than 60% of the relationships the p value for the log-linear model was greater than for the other two, suggesting that the accuracy of this model is in general superior. Body length was generally demonstrated to be a good indicator to estimate biomass. However, for some taxa, the measurement of sclerotized structures (i.e., the distance between the eyes and the head width) were also found to be suitable biomass indicators. The latter is beneficial for the estimation of biomass with individuals that have been kept for a long time under laboratory conditions and/or those that show damaged parts of their bodies. The present study provides the first set of length-mass relationships for macroinvertebrates in the Middle-East region, and its findings are expected to contribute to the estimation of biomass in aquatic environments that are affected by semi-arid conditions and different degrees of anthropogenic stress.

Detection and Prediction of Water Body and Aquatic Plants Cover Changes of Choghakhor International Wetland, Using Landsat Imagery and the Cellular Automata–Markov Model

The quantitative and qualitative study of wetland ecosystems is the main base for their sustainable use. In arid and semi-arid regions such as Iran, importance of wetlands is more obvious. Providing new information of changes in wetlands during several decades help us finding the reasons of alteration and making programs and policies. One of the most effective techniques in this field is remote sensing. Choghakhor international wetland, one of the most important wetlands in Iran. In this study, satellite images of MSS, TM, ETM +, and OLI were used during 1976–2017 to identify changes within the wetland. Also, the distribution of aquatic plants has been evaluated with NDVI index as an environmental indicator due to their key role on these aquatic ecosystems. After mapping the changes in wetland patterns over times, a cellular automata model (CA) was used to simulate changes up to the 2030s. The results of the time processing map data of the maps show the gradual decrease of the area (water body) of the wetland in the spring and more in the autumn season, which is more evident in recent years. However, the aquatic plants of the wetland in recent years has been. In general, three life periods for the Choghakhor wetland could be defined: “natural period”, “developmental period” and “dehydration period”. According to the CA model, the water body of the wetland shows a decreasing trend by 2030. On the other hand, aquatic plants growing in the wetland and its surroundings, which could be due to the high nutrient and organic load in future. Therefore, having an integrated strategy and program to improve the status of this unique ecosystem is necessary more than ever.

Cd and Pb bioaccumulation in Eurasian watermilfoil (Myriophyllum spicatum) in relation to the role of metal contents in wetland sediments.

The Choghakhor Wetland in Chaharmahal and Bakhtiari Province (Iran) has a significant role in maintaining water and sediment quality, because the wetland acts as a sink for contaminants that can pollute the aquatic ecosystem and affect human health. The present study uses a simple geostatistical technique to investigate the spatial variability of Cd and Pb in the Choghakhor Wetland to link the spatial variations of sediments to heavy metal contents in Myriophyllum spicatum. It was hypothesized that the heavy metal contents in the Choghakhor Wetland sediments impacted the concentration values in macrophytes. The value of heavy metals in sediments ranges from 0.54- to 1.84-μg/g dry weight (dw) for Cd, and from 1.32- to 2.46-μg/g dw for Pb, with a mean value of 1.12- and 1.82-μg/g dw, respectively. The mean value of Cd and Pb was 1.14- and 1.67-μg/g dw, respectively, in the aquatic macrophyte Myriophyllum spicatum, with corresponding ranges of 0.9-1.83-μg/g dw and 1.33-1.95-μg/g dw. There was a spatial structure in the Cd and Pb contents in the wetland sediments, with lower contents in the northern zone despite the values quantified in the south. We observed a direct spatial relationship between the Cd content in sediments and the Cd concentration in M. spicatum, and confirmed an effect of plant uptake for Cd. However, there were no significant differences between Pb in sediments and Pb in samples of M. spicatum, which implied that other factors like discharged industrial waste could also affect the accumulation of metals in plants. It can be concluded that spatial patterns indicated differences in the territory of the sediment Cd content at the Choghakhor Wetland localization in association with sediment enrichment. However, it was surprising that Pb did not show this pattern despite anthropic pressure.

DNA barcoding of Aphanius vladykovi from different habitats in Chaharmahal va Bakhtiari Province, Iran

This study was aimed to reveal the possible cryptic diversity of the Aphanius vladykovi populations in the Chaharmahal va Bakhtiari Province, Iran using mitochondrial cytochrome-c oxidase subunit I (COI). A total of 30 specimens from the Beheshtabad River, Choghakhor and Gandoman Wetlands, and Brovi, Shalamzar, and Balagholi springs from the Chaharmahal va Bakhtiari Province were collected. The maximum within-population genetic distance based on K2P was 0.28% and this distance was 0.22% between populations of Gandoman and Brovi with Shalmazar, whereas the least genetic distance was observed between Choghakhor and Beheshtabad (0.09%). A total of six haplotypes were observed between the studied specimens. Maximum Likelihood (ML) and Neighbor-Joining (NJ) trees reconstructed and all haplotypes from A. vladykovi specimens collected from non-type localities nested in one group with A. vladykovi from Choghakhor wetland i.e. type locality. The results of this study detected no cryptic diversity in A. vladykovi inhabiting different habitats in the studied region. Hence, it is proposed to consider all the studied populations in conservation measures related to A. vladycovi .

Monitoring spatiotemporal variability of water quality parameters Using Landsat imagery in Choghakhor International Wetland during the last 32 years

Use of Landsat is of importance in monitoring and assessment of long-term changes of water quality in freshwater ecosystems, especially in small water bodies. In this study, over a 32-year period (1985–2017), the changes in water surface temperature (WST), secchi disk transparency (SDT), and chlorophyll-a (Chl-a) concentration were estimated at the Choghakhor wetland using Landsat imagery. Based on WST three detectable temperature zones can be observed within the wetland aquatic environment where the highest amount was observed in thermal strips. The results showed Chl-a concentration volatility in different periods in the wetland as well as its long-term increasing trend. The western part of the wetland, as compared to other areas, was affected by these changes, which could be due to the human activity concentrated in this area. In contrast (SDT) showed a decreasing trend during this period that was consistent with the observed changes in Chl-a concentration. This could be due to an increase in organic matter load and suspended solids in the water body of wetland during this time. Comparison of the extracted satellite data with the field data showed the least RMSE and high R2. Also, ANOVA results showed significant spatio-temporal differences between the studied parameters in Choghakhor wetland (p < 0.05). The present study can help to detect long-term changes in Choghakhor wetland and help toward moving to optimal management and protection of this wetland.

Environmental vulnerability assessment of Choghakhor International Wetland during 1985 to 2018

AbstractAs of natural constraints, and the specific climate of Iran, as well as the increasing importance of international water resources in the socio‐economic development of societies, studies on surface water resources, especially wetlands, merit special attention. Accordingly, the TM, ETM+ and OLI satellite images of 1985, 2000 and 2018 were used in the present study to detect changes in the Choghakhor international wetland. Classifying the images with a supervised method, and using maximum likelihood algorithms, the distinct land use/land cover classes of waterbody, aquatic plants, pasture and forest, agricultural lands, bare land and human built lands were ranked. Selected landscape metrics information on the spatial pattern of the Choghakhor wetland was quantitatively determined, using Fragstats software, and the spatial composition and vulnerability of the wetland were evaluated. The vulnerability assessment of wetland contamination was investigated using the WRASTIC index based on the catchment area scale. Time processing of the data obtained from the maps indicated a 26.63% decrease in the pasture and forest area, and a 12.1% increase in the area of human built lands and agriculture lands during the period from 1985 to 2018. Further, in spite of the waterbody area expanding during 1985 to 2000, it subsequently shrunk in size from 2000 to 2018, with the area of aquatic plants lands increasing during the same period. Analysis of landscape metrics generally indicated the natural wetland cover has been changing during this period along with increasing anthropogenic impacts. Degradation, rotation and replacement of natural land cover such as pastures and forests with human built areas can be considered undesirable development effects on the Choghakhor wetland. The results of the WRASTIC index calculation indicated a major impact of Choghakhor wetland components from water pollution. The results of the present study place an emphasis on more sustainable land use and prevention of land destruction in the Choghakhor wetland basin.

Wetland water quality assessment in cold and dry regions (Case study: Choghakhor wetland, Iran)

Abstract Wetlands are among the most productive ecosystems in the world. They provide numerous beneficial services for people and wildlife. The most important services are improving water quality and wildlife habitats. The complex, dynamic relationships between the organisms inhabiting the wetland environment are called food webs. Both water quality and high levels of nutrients are crucial for improvement of the food web. Many bird species rely on wetlands for food, water and shelter, especially during migration and breeding. The water quality of Choghakhor Wetland was evaluated from April 2010 to March 2011, by measuring some physicochemical parameters and doing benthic macroinvertebrate analysis. Sampling was done in 3 replicates with alternation of 45 days. The resolute was divided into more than 25 identified macroinvertebrate families which belonged to 5 classes and 12 orders. The correlation between biological indices and water quality parameters showed that bioindicators and community indices could be used for the evaluation of water quality in this wetland. The water quality of Choghakhor Wetland was classified as average or in the severe pollution class, according to these indices. It can be concluded that bird migration is at risk due to the decline in the overall health of the Choghakhor Wetland ecosystem.

Effects of nutrients on the primary production and determination of the restricting factors in primary production in the international wetland of Choghakhor (Iran)

Limitations in nutrients and physicochemical parameters play a key role in aquatic ecosystems. The present study aimed to determine the influential physicochemical factors in the chlorophyll-a content for wetland management by identifying the restricting factors in primary production. Sampling was conducted during March 2017-February 2018. Factors such as water salinity, temperature, pH, nitrate and phosphate concentrations, biochemical oxygen demand, total dissolved solids, electrical conductivity, total suspended solids, and dissolved oxygen were measured in triplicate at each station. In addition, the trophic state index (TSI) was used to determine the trophic state of the wetland. No significant difference was observed in chlorophyll-a contents in different seasons (P>0.05), with the highest values reported in spring and autumn, and the lowest values reported in summer. The maximum and minimum chlorophyll-a content were observed in stations A and C, respectively. Station A had a significantly higher value compared to the other stations (P 0.05). The highest (5.9 mg/l) and lowest water nitrate levels (4.1 mg/l) were observed in spring and autumn, respectively (mean nitrate level: 4.84 mg/l). The highest (2.1 mg/l) and lowest water phosphate levels (0.47 mg/l) were observed in spring and autumn, respectively (mean nitrate level: 1.04 mg/l). Moreover, TSI indicated that the wetland is oligotrophic in spring and winter, while it is mesotrophic in summer and autumn. Overall, the nitrate level in water was the main restricting factor in the management of Choghakhor wetland.

Vulnerability assessment of wetland landscape ecosystem services using driver-pressure-state-impact-response (DPSIR) model

Wetlands exist in complex ecological conditions that are changeable in time and space in terms of function and structural diversity. In recent decades, wetlands have been exposed to a wide range of threats. Assessment of these threats is essential to develop an understanding of the state of a wetland ecosystem and to develop a suitable management strategy. This paper discusses wetland vulnerability in terms of analysis of human and environmental systems from application of the driver-pressure-state-impact-response (DPSIR) framework. This assessment presented a systematic methodology for assessment of wetland vulnerability in a social-ecological approach applying broad-scale ecosystem services and vulnerability functions. The method combined the hydro-geomorphic approach with estimations of vulnerability indicators and DPSIR analysis. The aim of this paper was to assess vulnerability of wetland ecosystem services and to characterize the threat indicators according to importance, severity, and probability of occurrence. Quantitative and qualitative methods were applied to characterize values for these three indicators. The Multi Criteria Decision Making (MCDM) method was used to prioritize threats and impacts of the wetland on the basis of experts’ opinions. The proposed methodology was applied to the Choghakhor international wetland landscape in south-western Iran. Vulnerability assessment revealed that water requirement of the lowland and the water transfer system were the most important factors threatening the wetland. Agricultural activities, settlements and urban areas, drought, tourism, population growth, and mining activities in the upland were the next most important priorities, in that order. Hydrological balance was determined as the most vulnerable function and was considered as the most important function in the Choghakhor wetland. The DPSIR model was used to determine a management strategy to reduce vulnerability of ecosystem services in response to drivers, pressures, states and impacts indicated by modelling.

Potential ecological risk assessment, enrichment, geoaccumulation, and source identification of metals in the surface sediments of Choghakhor Wetland, Iran

This study reported the first comprehensive research on identification of metal concentrations (Fe, Mg, Mn, Pb, Cd, Cr) in order to provide baseline data for future studies, identify possible sources, determine degree of pollution, and identify potential ecological risks of metals in surface sediments from Iran’s Choghakhor Wetland. The order of metal concentration was as follows: Fe > Mg > Mn > Pb > Cd > Cr, with mean concentrations of 6140.35, 1647.32, 289.03, 1.10, and 0.45 µg/g of dry weight, respectively. These results reveal that Choghakhor Wetland is not heavily polluted compared to other regions. The results of enrichment factor (EF) and geoaccumulation index (I geo) showed that Fe, Pb, Mg, Cr, and Mn presented low levels of contamination and probably originated from natural sources. On the other hand, the results of EF and I geo indices suggested that Cd concentrations in sediments of Choghakhor Wetland originated from anthropogenic sources. Based on the results of three sets of sediment quality guidelines, only Cd concentration in sediments of Choghakhor Wetland is a threat for aquatic organisms of Choghakhor Wetland. The results of multivariate analysis such as principal component analysis and cluster analysis showed that Fe–Mn, Cr–Mg, and Pb groups originated from natural sources, while Cd concentrations in sediments of Choghakhor Wetland originated from both natural and anthropogenic sources (mainly chemical fertilizers). To our knowledge, this is the first study about metal concentrations in sediments of Choghakhor Wetland, and because of low levels of these metals, these concentrations can be considered background levels for future investigation.

Water quality assessment in Choghakhor Wetland using water quality index (WQI)

The Choghakhor International Wetland plays an important role in preserving and protection of part of the plant and animal species in the Iranian plateau. Since the water of this wetland is utilized for different human purposes, complete periodic chemical and physical quality assessment of its water seems necessary. Water quality index (WQI) was calculated using the following eleven parameters: Nitrate, Nitrite, Ammonium, Alkalinity, Hardness, Turbidity, Conductivity, Dissolved Oxygen, Total Dissolved Solid, pH and Biochemical Oxygen Demand (BOD5). For this purpose, the relative weight assigned to each parameter ranged from 1 to 4 based on the importance of the parameter for aquatic environment and human health. The analyses of variance (ANOVA) of data revealed significant differences between different periods of sampling (p<0.01). Therefore we assigned the results in two categories: very poor and inappropriate, which make it not suitable for human uses such as drinking. The most important factor in assessment of water quality in this study was BOD5. The result of this research demonstrated that this method can be used for assessment of water quality in wetlands.

Assessing the Condition of Macrobenthoses and Water Quality in Choghakhor Wetland through BMWP Index

Assessing the Condition of Macrobenthoses and Water Quality in Choghakhor Wetland through BMWP Index

New records and geographical distribution of Alburnus hohenackeri Kessler, 1870 (Teleostei: Cyprinidae) in Iran

The distribution of the Persian bleak, Alburnus hohenackeri Kessler, 1870 in Iran is described. During a survey from 2009 to 2012, we captured 30 specimens of A. hohenackeri from Choghakhor Wetland in Tigris River basin and Kardeh Dam in Harirud River basin of Iran. This is the first report of the occurrence of this species in these localities. The main distribution range in Iran is the southern part of the Caspian Sea from where it has been translocated to the other Iranian basins along with exotic Chinese carps.