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The present study was carried out with the aim of determining the concentration of heavy metals (zinc, lead, cadmium, and chromium) in water, sediment, and muscle and liver tissues of Barbus sharpeyi and Barbus xanthopterus of the Karoon River in order to investigate the status of heavy metals. In this river and to determine the health of the water ecosystem of the Karoon River in Bavi City, the evaluation of these two widely consumed fish species as biological monitors of heavy metals should also be done.

This study was conducted in April 1401 in order to investigate the concentration of heavy metals such as zinc, lead, cadmium, and chromium in six stations in the Karun River in Bavi city. The statistical population for the measurement of heavy metals with three replications included 18 water samples, 18 sediment samples, and 40 benny and gotan fish. Then, in order to measure the concentration of heavy metals in water samples, the sediment and tissues of Beni and Gatan fish after acid digestion were injected into the Contra-AA 330 model atomic absorption device. A comparison of heavy metal data from water samples, sediment, and fish tissues was done using SPSS software. The Shapiro-Wilk test was also used to check the normal distribution of the results. The statistical method of one-way analysis of variance was also used for general comparisons, and Tukey's test was used for multiple comparisons, and the differences were significant at the 95% level.

The average concentration of zinc, lead, cadmium, and chromium in water samples was 5.36, 1.80, 0.18, and 0.68 micrograms/liter, respectively, in sediment samples 46.57, 13.31, 2.89, and, respectively, 22.29 μg/g. Regarding the amount of zinc, lead, cadmium, and chromium in the muscle samples of benny fish, respectively, 57.13, 1.60, 0.94, and 0.51 micrograms per gram, and 11.65, 0.91, and 56, respectively, in Gatan fish. 0.0 and 0.41 μg/g were obtained. Also, the amount of these elements in Bani fish liver is 27.33, 3.49, 2.15, and 1.51 micrograms per gram, and in Gatan fish liver it is 23.49, 2.11, 1.40, and 1.32, respectively. µg/g was obtained. Comparing the amounts of elements in the edible muscle tissue of Beni and Gatan fish showed that the amount of zinc in the muscle tissue of two species of fish is lower than the international standards, but lead, cadmium, and chromium in the muscle tissue of Beni and Gatan fish were higher than some international standards. Pearson's correlation test showed that there is a positive and significant relationship between the concentration of metals in water samples, sediment, and tissues of Bani and Gatan fish (p<0.05). The results of calculating the MPI pollution index showed that the value of this index was greater than 1 for all the investigated elements. The BAF index in all samples was less than 1, and the BCF index was greater than 1 for zinc and cadmium elements and less than 1 for lead and chromium. Also, the results of calculating the MLR index showed that the amount of this index for the studied metals is about 0.5.

The concentration of all heavy metals studied in the non-edible tissue of the liver was higher than the edible muscle tissue of Beni and Gatan fish caught from the Karun River located in Khuzestan province. The high levels of the three elements lead, cadmium, and chromium in some international standards indicate the need to pay attention to the possibility of the continuous entry of the sources of these polluting factors, such as the effluents of agricultural poisons, herbicides, insecticides, and residues from fossil fuels. The use in industrial activities depends on the habitat of the mentioned species. Based on the metal pollution index (MPI, BAF, BCF, and MLR), it can be said that among the two investigated fish species, the amount of pollution and health risk of consuming benny fish is much higher than that of gatan fish. The MPI index showed that the level of contamination in the liver is higher than in the muscle. Also, the bioaccumulation factor was higher in Bani fish than in Gatan. The bioconcentration index also shows the high accumulation power of Beni and Gatan fish for zinc and cadmium elements. Therefore, these two species are suitable biological indicators for monitoring the pollution of heavy metals such as zinc and cadmium in the Karun River. Also, considering that the highest bioconcentration index of metals is in Beni fish, Beni fish can be the most indicative species in relation to the accumulation of zinc and cadmium elements in the Karun River. The ratio of muscle to liver also showed that this index can be an important biological index in monitoring heavy metal pollution in aquatic ecosystems. The concentration of heavy metals in the liver and muscle changes with the level of environmental pollution. In polluted places, heavy metals preferentially accumulate in the liver. The results of Pearson's correlation coefficient also showed that there is a significant correlation between the concentration of metals in water and the muscle and liver tissue of Beni and Gatan fish, so it can be concluded that the muscle and liver tissue of Beni and Gatan fish can be a suitable biological monitor for Heavy metals are investigated in the Karun River, and the liver is a more suitable monitor than the muscle. In general, based on the results of this study, it can be seen that the use of fish can give a better picture of the bioavailability of heavy metals such as zinc, lead, chromium, and cadmium. Also, in terms of the health status of the Karun River, using biological monitors, the muscle tissue and liver of Bani and Gatan fish, especially the liver, can be a suitable biological monitor for river health studies. Due to the entry of agricultural, urban, etc. effluents into this area, more periodical investigations and more accurate knowledge of the concentration of pollutants in different foodstuffs such as fish, plants, and agricultural fields are necessary. Also, it is necessary to accurately identify the origin of these pollutants and their input and production sources using chemical fingerprinting techniques so that better control can be done in order to manage these pollutants and finally prevent the penetration of such pollutants into the environment. Values should be avoided.

Soil erosion is a natural process that causes soil loss due to various environmental factors such as climate, soil, topography and vegetation (Abedini et al., 1402: 115). Nowadays, due to the ever-increasing population of the world, the importance of soil erosion studies as one of the most important issues in the sustainable development of agriculture and food production and its environmental effects is more obvious. Due to its environmental and economic effects, soil erosion is a serious global problem that affects many natural and human ecosystems (Abedini et al., 1401: 106).The issue of soil erosion and land degradation is one of the most important issues in natural sciences, the evaluation of its environmental and economic consequences requires quantitative data. In addition, soil erosion has long-term destructive effects on natural and human-managed ecosystems. Soil erosion causes a decrease in soil fertility and productivity, has an adverse effect on the quality and quantity of runoff, and reduces the efficiency of irrigation dams and canals and food production (Abedini, 1400: 100). One of the most important factors in increasing soil erosion is the lack of awareness of the economic value of this ecosystem gift. In recent decades, soil erosion by runoff (WSE) has become a serious problem worldwide, as the ratio of natural resources to population is drastically decreasing. The surface soil is the first part that is exposed to erosion and the amount of nutrients in the soil is greatly reduced. This reduces organic matter (nitrogen, phosphorus and potassium) and other elements needed for the growth of crops (calcium, magnesium, etc.) (Ariafar, 2014: 4).In the Alazarcha basin, the formation is sensitive to erosion, inappropriate use of land, texture, topographical conditions of the area, etc. are factors that cause erosion at the basin level, as an important issue in the development of agriculture and protection of natural resources. In this study, searches using the PSIAC model; The studies of soil erosion in Alazarchai River watershed are carried out and finally, the parts prone to erosion in different parts of the basin are separated and identified.

In order to collect the following data and information from the relevant organizations, necessary measures have been taken:1- Topographic maps of the studied area with a scale of 1:50000. 2- Geological maps of the studied area with a scale of 1:100,000. 3- Meteorological data and statistics of the studied area (climate and meteorology of Ardabil province). 4-Excel software for preparing charts and data analysis.5- Arc GIS and Arc view software for map preparation.In different stages of this research, statistical and graphic software have been used to prepare and draw tables, charts, maps and data analysis. The most basic aspect of the present study was the identification of geomorphological working units of the studied basin. For this purpose, the information in geological and topographical maps was digitized using Arc Map software. In the next step, tectonic, lithology, hydrography, direction and slope maps were prepared using ArcGIS software. Due to the large volume of information and in order to increase the accuracy of work, information layers have been integrated to identify work units using Arc Map software. Other software used in this research include Surfer and Excell graphic software, which were used in the preparation of maps and specifications, tables and data analysis, respectively. The purpose of this study is to evaluate erosion and sediment production in Alazarchai watershed. For this purpose, after identifying the study basins, we estimate the amount of sediment using the PSIAC experimental model. In this method, according to the strength and weakness of each factor, a number is assigned to it. Finally, taking into account the sum of the numbers obtained for different factors, the sedimentation rate of the basin is satisfied. This method using GIS requires that an information layer be prepared for each effective factor in erosion. Therefore, in this research, using arc gis 10.2 software, we divide the watershed into 3 separate hydrological units (Figure 2) and examine the MPSIAC factors according to the hydrological units.

In the assessment of soil erosion and sediment production in Alazarchai basin, among the factors affecting soil erosion in the MPSIAC model, the land use factor with a score of 46.56 is the first priority and the land cover is the last priority with a score of 5.25. Other factors (geology, soil, topography, weather, runoff, current state of erosion and river erosion) are in the next priorities with scores (21.47, 22.18, 18.85, 17.93, 10.65, 44.75, 35.07) respectively. Also, after scoring nine factors affecting soil erosion using calculations, the specific sediment in cubic meters per square kilometer per year was obtained in each of the sub-basins of the study area using PSIAC and MPSIAC models. Finally, the level and intensity of sedimentation of the basin and its sub-basins were determined using Table (3) to determine the level of sedimentation and soil erosion level. The results showed that according to the PSIAC model, the erosion rate of the Alazar watershed is 674.60 cubic meters per square kilometer per year under the Hamza Khan basin, 434.99 cubic meters per square kilometer under the Alilah basin, and 308 cubic meters per square kilometer per year under the Quzlu basin. The main reason for the high amount of sediment in the Hamza Khanlu sub-basin is alluvial defenses and alluvial cones. which caused it to become sensitive to erosion and eventually cause the formation and accumulation of sediment in the area.Also, the results obtained from the two models show that the specific sediment and sediment load of the basin and its sub-basins in the PSIAC model is twice the sediment load and specific sediment of the basin and its sub-basins in the MPSIAC model. The amount of specific sediment of the entire basin in the PSIAC model is 472.53, but in the MPSIAC model, it is 238.47 cubic meters per square kilometer per year. There are differences in the class and intensity of sedimentation of these two models in the entire basin and its sub-basins. In the PSIAC model, Hamze Khan sub-basin is in high sedimentation class (IV) and Alileh and Qozlu sub-basins are in medium sedimentation class (III), while this class in Alazarchai basin and its sub-basins are in sedimentation class III and II in the MPSIAC model, which The intensity of erosion and sedimentation in Hamza Khan sub-basin is moderate and in Alileh and Quzlo sub-basins it is low.

This study was carried out to investigate the concentration of heavy metals of Ni, Cd, Pb, As, Fe, Cr in municipal sewage discharge, urban wastewater and industrial effluent are pumped to the Tembi River. Sampling carried from 10 water and wastewater and 10 sediments. The results of ICP-MMS analysis showed the mean concentration (in ppm) for water sample for As 1/23, Zn 17/71, Cr 0/8, Ni 1.11, Cd 0.09, Pb 6/35, Fe 132/50 and mean concentration of heavy metals in sediment sample for As 0.91, Zn 23/96, Cr 91/50, Ni 56/10, Cd 0/16, Pb 10/40, Fe 14950. Based on the results obtained from the index of enrichment factor, Ni and Cr concentration showed the medium to high pollution level. Based on the molar accumulation land index, Ni and Zn concentration were in the range of moderate to high levels of pollution, and is highly contaminated in all areas with high Fe concentrations. Based on the pollution load factor sediment, It is contaminated with Ni, Cd, Fe and Cr. Based on contamination coefficient at point SA-02 the concentration of Pb and Zn in the sediment is high and As is also contaminated in site C and Ni, Cd, Fe and Cr concentration is high and the sediment is contaminated but there is no heavy metal contamination elsewhere. Tembi River receives untreated municipal and industrial wastewater. According to the results obtained, the Tembi River is in a danger and unsafe area for fishing and swimming purposes.

Sediment samples were collected from 8 sites in the northern areas of Qeshm Island, Iran to determine the total and partial concentrations of heavy metals including copper (Cu), lead (Pb), nickel (Ni), cadmium (Cd), and Iron (Fe), in February 2016. A combination of nitric acid and perchloric acid was used to determine the total concentrations and sequential extraction method was used to analyze the partial concentrations of different geochemical parts of the sediment. Metal concentrations were measured by flame atomic absorption spectrometry. Contamination factor (CF), pollution load indices (PLI), enrichment factor (EF), geoaccumulation index (Igeo), risk assessment code (RAC) and potential ecological risk (PER) were calculated to determine the ecological risk. The results showed that the concentrations of heavy metals were Fe>Ni>Pb>Cu>Cd, respectively. The results of sequential extraction showed that Cd (25.98%) and Cu (21.40%) had the highest bioavailability among the other heavy metals. Most of each element was in the part of reducible (Fe-Mn oxide bound) (F3) and residual (F5). According to the RAC, only Cu and Cd were identified as high-risk at Station 5, and for other stations and other metals, the results showed low, medium or no risk. Evaluation of enrichment factor showed significant contamination for most of the metals tested, including Cd, Ni and Pb, which confirms the results from other indices. Finally, it can be said that the results of various indices that have been measured in relation to the mentioned heavy metals, showed that these elements have low to moderate pollution in the study area.

In the present study, the possibility of using macrobenthos as a biological indicator to assess the level of contamination of the rust estuary with heavy metals has been investigated.

Sampling was performed in 2016 from 4 stations in Zangi estuary at full tide.Sediment was harvested from each station using Van Wen (with a cross section of 0.025 m2) to identify benthos, determine heavy metals in sediment, determine organic matter and granulate sediments. In all 4 stations, clay particles formed the main part of the sediments.

The range of organic matter was 6.90-6.98%, with station 3 having the highest percentage and station 4 having the lowest percentage of organic matter. The identified macrobenthos in Zangi estuary were divided into five categories: Bivalvia, Gastopoda, Polychaeta, Crustacea and Fish and 26 genera and species. Station 1 with 13 species had the highest number of species and Station 2 had the highest number of macrobenthos per square meter and the highest Shannon diversity and uniformity index. Species of Hydroides sp. Polychaeta with 25.97% had the highest frequency in the population of Zangi estuary macrobenthos. Accordingly, Polychaeta with 49.1% and Bivalvia with 37.21% had the most abundant category and fish with 0.86% had the lowest frequency. Polychaeta class in stations 1 and 4 with 63.26 and 56.1% and Bivalvia class in stations 2 and 3 with 44 and 33.06%, respectively, had the highest percentage. Zinc, nickel and chromium had the highest concentrations with averages of 32.41, 23.13 and 19.16 mg/kg.Selenium had the lowest concentration in all 4 stations. The mean concentrations of heavy metals in stations 2 and 3 were significantly less polluted with stations 1 and 4 (p <0.05). Calculation of the degree of pollution in 4 stations of Zangi estuary showed the degree of severely polluted for these stations. Based on the contamination factor, except for vanadium at all stations and lead metal at station 2, which is in the highly contaminated range, other metals were in the low to high contamination range. Thus, the concentration of all metals in the bell ring was in the alarming state.

The results of the present study showed that the first and most important factor influencing the distribution of estuarine macrobenthos was the percentage of bed clay particles, heavy metals such as cadmium, lead, nickel, vanadium, chromium and zinc and then the organic matter in the bed. Also, copper metal had the least effect and correlation with the number of macrobenthos among the studied metals.

One of the recently considered pollutants is microplastic particles. To investigate this contaminant, 15 samples of sediment were sampled from Khor-e-Musa estuary. Samples were transferred to the laboratory in thick plastic bags for extraction and counting of microplastic particles. H2O2 was first used to remove organic matter in the samples. Then, using the condensation separation method, the microplastic particles were separated from the sediment particles and finally identified and counted by using binocular optical microscopy. The average concentration of microplastic particles in the study area was 11.67 per 250 g of sediment and the maximum and minimum concentrations were 22 and 1, respectively. In this study, about 49% of the found microplastics were stringed, 36% multifaceted, and 14% spherical. The predominant color of these particles was white/transparent and black/gray, which accounted for 32% and 36% of the total microplastics, respectively. Also, about 13, 14, and 5 percent of the microplastics were yellow/orange, red/pink, and blue/green, respectively. In general, about 52, 33, 8, 3, and 3% of microplastics are related to microplastic particles with sizes less than 100, from 100 to 250, from 250 to 500, from 500 to 1000, and from 1000 to 1000, respectively. It was 5,000 micrometers. The results of this study showed that microplastic particles are present in the sediments of Khor Musa and most of these particles are filamentous and with dimensions of less than 100 micrometers. This means that the adsorption capacity of these particles is high for pollutants.

In this study, Padina pavonica used as a biological monitor of heavy metals on the coast of Bushehr. For this purpose, four stations of Helileh, Lian, Rafael (burned ship) and Naftkesh were selected as sampling sites and sampling of sediment and Algae were done in the summer and winter of 2016. Powdered samples of sediments and algae were digested and analyzed using Atomic Absorption Spectrophotometer. mean metal levels in sediment and algae decreased in the following order: Ni > Pb > Cu > Cd >Hg and showed that the highest metal concentration in algae was for nickel (mean±SE)12.31±3.9 mg/g at Helileh station in winter and in sediment of Naftkesh 11.45±0.65 mg/g. The lowest metal concentration was for mercury in sediment and algeal samples of Naftkesh in winter, respectively 0.36 ± 0.005 mg/g and 0.39 ± 0.015 mg/g. Also, the highest amount of BSAF belonging to cadmium in Rafael station in winter; that it was 6.23. The results of this study indicated that this species can use as a bio-indicator for heavy metals in the marine environment.

sediment transport is one of the most important coastal processes that most effective environmental factors in relation to it include waves , flows , winds , and changes of the coast environment by man . in this study, the tidal currents and their effect on sediment transport on the dock of 38 Bandar Imam were studied. for this purpose, two stations were selected to measure different parameters such as sediment concentration at 2 km distance in the study area and was measured in two periods of spring and neep. the results showed that the maximum mean sediment concentration (Mmsc) at the first station in spring was 0.42 kg/m3 and the minimum value (mv) was 0.18 kg/m3 and at the second station the Mmsc was 0.43 kg/m3 and the mv was 0.1 kg/m3. also in neep the Mmsc at the first station was 0.37 kg/m3 and the mv was approximately 0.2 kg/m3. at the second station Mmsc was 0.4 kg/m3 and the mv was 0.135 kg/m3.

In this survey, concentration of some heavy metals (Ni, Fe, Cd, Al, Cr, Zn, Pb, and V) in the sediment and bivalve shell of Cerastodema lamarcki were investigated at10 sampling site along the south west coast of the Caspian Sea in Guilan province region in February 2015.After sample preparation and acid digestion, the specimens were analyzed using by ICP-OES.The results showed that the bivalve shells hve suitable potential for accumulation of Cu, Pb, Zn, Cr, and Cd and also can use as a biomonitoring agent at the study areas.Statistical cluster analysis demonstrated that iron and aluminum in sediment samples are independent from the other measured elements.On the base of enrichment factor(EF) calculation, the sediment of the areas classified in mordant enrichment for Cu, Ni and Cd levels. Compression of metal levels with some international standards shows that the sediment quality categorized at the medium level of pollution. By the trend of urbanization, agriculture and industrial development at the region beside the valuable ecological resources of Caspian Sea, overall management of pollutants sources for public health an environmental protection is essential.

Polycyclic aromatic hydrocarbons (PAHs) are classified as an important category of semi-volatile and persistent organic pollutants. They cause environmental problems due to their toxicity and accumulation in sediments. In this research, offshore sediments of 19 stations in 8 transects of the Persian Gulf in Bushehr province were studied to assess the sources of PAHs. The extraction and clean up method were based on pressurized liquid extraction (PLE) with the cleanup by packed silica gel-based column. The compounds were analyzed by GC-MS. Recovery of the compounds was over 70%. The range of total 15 PAHs in sediment was from 6.5 to 35.5 ng g-1 sediment dry weight. The results showed that the levels of PAHs in the sediments were in the category of low pollution sediments. The highest concentrations of PAHs have been recorded in the station number 4 and 15 near the Kharg Island (Abouzar oil field) and Golshan oilfield, respectively. The cross plots of the diagnostic ratios of PAHs have come into common use as a tool for identifying and assessing pollution emission sources. Three cross-plots for the diagnostic ratios were applied in this study. They showed that the PAHs in the area had mixed sources of pyrogenic and pyrolytic. A progressive increase in the levels of PAHs was observed compared to the ROPME Cruise in 2006 that reflected more impact of anthropogenic activities on the sediments in recent years.

Toxicity of trace metals in the environment, bioaccumulation in aquatic environments and in food chains are of great importance.This study concentrates on the distribution patterns of some heavy metals (Pb, Ni, Zn and Fe) in surface sediments of Shoor River estuary. In order to determine the degree of Contamination and environmental quality of region sediments, surface sediment (0-5 cm) samples were collected from 4 stations. At each station, three surface sediment samples were collected and the concentration of heavy metals were measured using a flame Atomic Absorption Spectrophotometer; Then indexes such as the Pollution Load Index (PLI) and Potential ecological risk index (RI) for each of the sampling stations and study area applied. The results of PLI represented the low accumulation of studied metals in the surface sediments of the area. Potential ecological risk was also low. The results indicated that Zn and Ni were mainly from anthropogenic discharge, while a significant portion of Pb and Fe were likely from natural inputs.Overall, frequent adverse effects were expected for Ni and occasional adverse biological effects are expected for Zn, whereas for Pb and Fe rare adverse biological effects are expected. Pearson’s correlation indicated that there was positive correlation betweenNi, Pb, Fe, TOM and fine grain size(p

Mercury (T-Hg), as the most toxic Trace metal, can have adverse effects on the environment. In this study, the concentrations of T-Hg were investigated in surface sediments of higher and lower tidal zones of Hormozgan province coasts including the stations of Shahr Jask, Ariyan International Wetland Lagoon, Khorgorsuzan Bandar Abbas, Bostono Industrial Zone, Coastal Park of Khumir, Shahrbonderlangeh, Bandarreqam, Bostaneh Harbor in summer 2017. T-Hg concentration was measured by Ftomic Atomic Aabsorption Spectrometry (FAAS, GTA120). From 16 stations in the higher and lower tidal zones, the stations of Khorgorsuzan Station and Azzin kinetic showed the lowest concentration of T-Hg. Based on accumulation index (Igeo), the geochemistry of the Igeo studied areas had a moderate to high contamination. Enrichment Factor (EF) showed a strong to extremely high enrichment. Regarding SQGS, all stations were higher than Effect Range Low (ERL) value. These findings raise awareness of the contamination status of surface sediments in coastal zone of Hormozgan Province, provide a valuable benchmark for future comparisons in the area, and are important for the design of appropriate policies and long-term management of those ecosystems by local managers and the national authorities.

The accumulation of the heavy metals Cd, Zn, Cu, and Pb were surveyed in the samples of mantle tissues, crusts and so the habitat sediments of C. fluminalis to reveal the probable biomonitoring rule of the bivalve in the ecosystem. The warm-cold seasonally samplings were carried out over the stations of Zayandeh-Roud River in Safi'eh, Isfahan province, during 2014. The warm and cold seasonal average results from the initially acidic digested prepared samples of the bivalves (mantle and crust) and the sediments were recorded by furnace atomic absorption spectrometry methods. The results illustrated that the average of Zn accumulation has the maximum value in the sediment samples of warm-season samples (28.8±3.80 µg.g dry w.-1) as well the cold-season (16.9±1.23 µg.g dry w.-1). Furthermore, the accumulation values of zinc in the warm-season and the cold-season samples had the maximum values in the tissue samples with values 206.2±33.77 and 89.1 ± 19.02 µg.g dry w.-1 and the crust samples with values 35.6 ± 3.06 and 33.1 ± 3.10 µg.g dry w.-1 , respectively. Except for heavy metal Cd, the similarity values of the metals Zn, Pb and Cd in both sediment samples and the crusts of C. fluminalis demonstrates the relative extents of the heavy metals in the habitat of the bivalves with no seasonal effect on the values fluctuation. The levels of measured samples of mantles revealed the tissues of living C. fluminalis rule as the bioaccumulation of the metals Zn, Pb, Cu and Cd in the river ecosystem.

In order to determine heavy metals contamination in sediment and razor clams from Bushehr intertidal, samples were collected from 5 stations, including Khor Lailatain, Imam Hassan Port, Khor Genaveh, Rig Port and Shif Island. The samples were dried, acid digested and analyzed for their metals content using atomic absorption spectrophotometer. According to the results, the concentrations of Cu, Ni, Pb and Cd in the sediment of the mentioned stations ranged 5.6- 14.75, 19.67-58.72, 7.96-13.92 and 0.68-0.96 μ/g respectively. The concentration of the same metals in soft tissues of razor clam was 5.36-27.84, 0.24-2.72, 5.64-10.04 and 0.32-1.8 μ/g while in the shells they ranged 10.75-21.25, 1.36-3.52, 4.28-8.08 and 0.68-0.96 μ/g respectively. Generally the concentration of the studied metals in both sediment and clams was lower than proposed FAO and USEPA standards

Surficial sediments from the South-Western coast of the Caspian Sea (Anzali Port) were studied to determine the concentration and probable source of normal alkanes. In this regard, nine surface samples were collected and analyzed by gas chromatography–mass spectrometry (GC–MS). Concentrations of these compounds ranged from 743 to 6146 μg g-1 dw (average 2700 ± 1612 μg g-1 dw). Normal alkenes with long chain length were dominant in all studied stations. Based on used indices in this study, it was concluded that n-alkanes in sediments mainly come from petrogenic source, that was included the old oil spills (significant amount of UCM in all chromatograms) and recent inputs (high values for the ratios of n- C17/Pr and n-C18/Phy at some sampling sites). However, a contribution of hydrocarbons from higher and aquatic plants in the study area was observed.

In order to investigate the polycyclic aromatic hydrocarbons (PAHs) concentration in the marine coastal area of Bushehr، seawater and sediment samples were collected from 5 stations along Bushehr shore line. The total PAHs (tPAHs) concentrations ranged from 4. 0 to 31. 0 μg L-1 and 845. 0 to 4790. 0 ng g-1 in seawater and sediment، respectively. Results showed that tPAHs concentrations in seawater and sediment were significantly different among the studied stations (P<0. 05). The maximum tPAHs concentration was measured in the seawater and sediment collected from Rafael while the minimum values were observed in the Abshirinkon station. The Concentration of anthracene، phenanthrene، fluoranthene and pyrene in seawater was appeared above the standard rate mentioned by Canadian environmental quality guidelines. Different patterns of tPAHs composition were observed in water and sediment among the studied stations. Based on the number of the rings in the molecules، 3 rings PAHs were dominant in the seawater، while in the sediment، 5 and 6 rings PAHs appeared in the higher concentrations. Comparison between tPAHs concentration in Bushehr coastal area with previously studied locations in the world showed that PAHs contamination in the Bushehr coastal area is considerable.

In order to investigate heavy metals contamination in Bushehr costs, 5 different stations including ports and estuaries were studied. 3 sediment samples were collected from each station during winter 2009 and summer 2010. The samples were oven dried and acid digested and their heavy metals content was analyzed using atomic absorption spectrophotometer. Results showed that the concentrations of Cu, Ni, Pb and Cd in the sediment were 14.54, 55.31, 15.13 and. 76 µg/g dry weight respectively. Except for cd, the concentration of metals within various stations was significantly different during winter (P<0.05). Seasonal changes influenced metals level in the sediment so that their concentration in winter was less than summer. Generally the concentrations of studied metals appeared within the range of other researches in the Persian gulf region and less than proposed standards for sediment quality. Among studied stations, Bandar Rig and Shif exhibited higher concentrations of metals.

Geochemical studies of sediments، water bodies like rivers، estuaries and the sea bed، can be an effective step to find the source and distribution model assessment of environmental pollutants in a region. Sediments are the final destination of heavy metals in aqueous environments، but under the special situation، they can act as a source of water pollution. The presence of heavy metals in aqueous environments causes many risks such as cancer، toxication and etc in organisms. To study of the heavy metals concentration in Gorgan Bay in 15 stations، a core and several surface samples were taken. Fine-grain sediments were used to determine heavy metals concentration (Al، Sr، Ni، As، V، Fe، Co، Mn) applying inductivity coupled plasma-mass spectrometry (ICP-MS). The ratio of metal concentration in surface sediments to the crust sediments of the study area (Enrichment factors) were calculated in all stations and the obtained results showed that this factor was at the range of 3-42 for different metals. Mapping of heavy metals distribution indicates that the input of heavy metals from the river mouth (Grganrud، Nekarud and Gharehsoo) probably is the most important reason for the high enrichment factors. Geochemical indexes (Igeo) for all heavy metals were also determined and only the Igeo for strontium were over the standard.

The sediment samples and Avicennia marina tissues including root, steam, leaf and flower were collected from Gulf of Gowater in summer 2010. After preparation of samples, the concentration of heavy metals was measured by using atomic absorption spectrophotometer. The accumulation pattern of heavy metals in the sediment was obtained Ni>Zn>Cu>Cd. This pattern for root, steam, Leaf and flower were determined Ni>Cu>Zn>Cd, Zn>Cu>Ni>Cd, Zn>Cu>Ni>Cd and Zn>Cu>Ni>Cd respectively. According to the BCF (Bioconcentration Factor) values, mangrove tissues can be used as a bioindicator for contamination of Cd. whereas root and steam can be used as bioindicators for contamination of copper in Gowater and root can be used for Ni monitoring in this area. Plant tissues are not useful tools as bioindicators to detect contamination of Zn in the area. High TF (Transition Factor) values for root indicate that the root has significant role for metal transferring from root to other the plant tissues. Different metal ratios between A. marina tissues and sediment can be related to the character of heavy metals to be essential or not for plant.