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 The aim of this study was to compare the accumulation of heavy metals copper, zinc and cadmium and to investigate the changes of metallothionein as a biomarker of contamination in the gill tissue of the ghost crab Ocypode saratan in the two time periods before Monsoon (May) and after Monsoon (November) in mongrove forests. Chabahar and Gwater Bay was done in 2019. The results of the study showed that in both pre-Monsoon and post-Monsoon seasons the pattern of metal accumulation in the gill tissue of the ghost crab is zinc, copper, cadmium.The mean concentrations of copper, zinc and cadmium were obtained in the pre-monsoon and post-monsoon seasons at Chabahar station, 173.6 ± 3.83, 186.43 ± 3.1, 0.095 ± 0.008, respectively and 156.7±4.15 ،175.13 ± 2.8, 0.026 ±0.003 and in Gwater station the average concentrations of copper, zinc, cadmium in the two pre-Monsoon and post-Monsoon seasons were respectively 237.03 ± 6.4, 231.8 ± 1.8, 0.048 ± 0.003 and 205.9 ± 6.34, 253.2 ±  2.13, 0.037 ± 0.015 μg/g dry weight. The mean levels of metallothionein in pre-monsoon and post-monsoon season in Chabahar station were 2.02 ± 0.01 and 0.1 ± 0.06, respectively, and in goiter station were 2 ± 0.02 and 0.12 ± 0.02, respectively. Comparison of metallothionein levels between Chabahar and Gwater stations was not significant (P<0.05). But in both stations separately between the two pre-Monsoon and post-Monsoon seasons, there was a significant difference (P<0.05). Correlation between metallothionein and metals showed that there was no correlation between metallothionein and the studied metals. Therefore, according to the observations, changes in the concentration of metallothionein in this species are not affected by heavy metals and can be due to changes in the environmental conditions of the seasons.

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Fish is one of the most important sources of protein for human nutrition and health. Therefore, the monitoring of heavy metals accumulation in commercial fish is always important. In the present study, the accumulation of heavy metals (copper and lead) in muscle tissue and their potential hazards for consumers in three species of high-consumption fish in the south of the country(BandarAbas), namely black-spot snapper (Lutjanus ehrenbergi), javelin grunter (Pomdasys Kaakan) and Indian halibut (Psettodes erumei) was examined. The average concentrations (µg/g dry weight) of copper snapper, grunter and halibut were 0.078±0.017, 0.136±0.025, and 0.127±0.013, respectively, while the accumulation of lead in them was 0.079±0.018, 0.090±023, and 0.107±0.031, respectively. The highest daily intake (µg/ kg body weight/ day) of copper was equal to 0.023 and due to consumption of grunter, while the highest daily intake of lead was obtained due to consumption of halibut and equal to 0.018. The daily and weekly intake of both metals and all three fish species was less than the EPA reference dose and tolerable intake (TDI) values provided by the FAO / WHO Joint Commission. The risk level of target hazard quotient (THQ) calculated for both metals was significantly lower than 1. The results showed that the urban communities of Hormozgan province with the calculated consumption are not exposed to any risk due to the accumulation of heavy metals studied in this study.
 

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The accumulation of nanoparticles in the environment and aquatic ecosystems due to their wide application in industries, agriculture, medicine and pharmaceuticals has caused an increasing concern about the environment and increasing exposure to nanoparticles in ecosystems and humans. Iron oxide nanoparticles easily enter the bloodstream, accumulate in different tissues and cause damage to these tissues. Therefore, in this research, changes in the intestinal tissue of gray mullet fish (M. cephalus) and tissue accumulation in oral exposure to iron oxide nanoparticles were investigated.
110 pieces of young gray mullet after 2 weeks of adaptation were treated in four-time groups of 1, 7, 14 and 28 days, and one group was considered as a control. The mullet fish received iron oxide nanoparticles twice a day at the rate of 15 mg/kg attached to the food. The results showed that although the amount of tissue iron increased significantly only in the 28-day group, the consumption of iron oxide nanoparticles in almost all groups increases the tissue accumulation of iron in the intestine. The intestinal histological study showed changes such as the increase in the number and size of goblet cells, destruction of microvilli structure, bleeding and degrees of necrosis, and the intensity and extent of the changes in the intestinal tissue increased with increasing exposure time.
These observations showed that the consumption of iron oxide nanoparticles has a negative effect on intestinal function and causes iron accumulation and the occurrence of time-dependent injuries.

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This research was conducted with the aim of determining the biodiversity of Pertaran communities in three areas with mangrove cover and in 9 stations including one station in Gowatr Bay and 4 stations in each of Gowatr bay and Bahu Kalat on the eastern coast of Chabahar port. From each station, from the winter of 2019 to the fall of 2014, three sediment samples were collected seasonally for the separation and identification of sediments and one sample for the analysis of grain size and total organic matter of the sediments by Grab van Veen with a cross-sectional area of 0.028 square meters. In total, 12 genera belonging to 10 families were identified. Among the groups of the detected families of spionidae, the highest percentage of the average frequency with 13.70% was related to the Spionidae family. The survey of the density of the birds in total is 17800 ± 180 in the mentioned seasons, the average density of the birds in winter is 8720 ± 42 and the average density of the birds in the autumn is 9080 ± 181.63 in the mentioned seasons, the lowest average in winter is related to the Nereidae family: 0.5 600±67 and the most number was for Spionidae family: 1280±31.47 individuals in one square meter. The lowest average in autumn was related to the Nereidae family: 560 ± 32.65 and the highest to the Spionidae family: 1160 ± 62.94 individuals per square meter.

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