The level of mercury, iron, copper, and zinc was measured in 18 Great cormorants (Phalacrocorax carbo) collected from Anzali and Gomishan wetlands in the south of the Caspian Sea. The mean level of metals in dried tissues of the muscle, liver, and kidney was 2.26, 5.71, 3.79-Hg; 943.54, 379.97, 348.05-Fe; 42.64, 14.78, 60.79-Cu, and 71.97, 134.63, 77.82-Zn, respectively (mg/kg). There was no significant different between genders in terms of accumulation of metals, except for copper in the kidney. The results of Pearson correlation showed a positive and strong relationship between the fat in the liver and mercury (r = 0.95, R = 0.90). Also, there was a significant difference between the values of all metals with the allowable limits presented in EPA, WHO, and CCME, where all of values were above standard levels. Thus, as the muscles of the bird are sometimes eaten by humans, this result is a serious warning. Nevertheless, the relatively high levels of heavy metals accumulated in different tissues of Great cormorant at that time are a result of their high weight and nourishment they have at the terminal days of their migration due to lack of natural physical activity. Regarding to the importance of heavy metals in birds, we suggest the same study to be conducted on the species in other seasons and wetlands.

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Modifications in the ecological structure of macroinvertebrate communities could reflect changes in environmental conditions. Therefore, the aim of the present study is to identify macroinvertebrate assemblage and evaluating the efficiency of single-criterion and multicriteria indices for determining the ecological health of water quality of the Bakhtegan watershed located in the Eghlid city of Iran. A Surber sampler was used to sample eight sites along the river route. Physicochemical parameters were measured in each site including BOD, COD, nitrate, nitrite, phosphate, ammonia and fecal coliform in the laboratory and temperature, pH, EC, DO and hardness at the site of sampling. A total of 8161 macroinvertebrates were identified in 14 orders and 24 families recognized in the studied region and its highest frequency belonged to Gammaridae family (66%). Spearman correlation coefficient (r = 0.81) indicated that the BMWP/ASPT bioindex has a higher performance than other indicators for Bakhtegan area. The results of this study have shown no significant difference between control and non-control sites (Sig. 0.05). It was found that Gammaridae was the dominant major taxon in all sampling sites. Since the river's water is used for farming and also drinking, it is necessary for local managers to be more sensitive to the conditions of the region and try to increase public awareness and other researches to improve the ecological health quality.

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