The present study was conducted with the aim of identification of macrobenthos in the Yekshabe estuary in Persian Gulf. Sampling of macrobenthos was performed from spring 2015 for one year. It was carried out seasonally by the Van Veen Grab (0. 04 m ) at four stations, with three replications. The identified macrobenthos belonged to 51 families, 70 genera, 80 species, 4 classes (including Polychaeta, Malacostraca, Bivalvia, Gastropoda) and 5 Phyla. The average total density of macrobenthos was 760± 614 per square meter. The most frequently observed classes of macrobenthos belonged to Polychaeta (67. 8%), Malacostraca (18. 5%), Bivalvia (11. 6%) and Gastropoda (1. 2%), respectively. According to the results of the Kruskal– Wallis test, there was no significant difference between the macrobenthos classes among the different sampling stations. The highest values of the Shannon-Wiener index of diversity (3. 07) and the Margalef's richness index (4. 66) were observed in spring, whereas the highest value of the Pielou's evenness index (0. 95) was observed in autumn. The values of all indices at station 4 were the highest as compared to those of the others. The results of ANOVA test showed that the mean values of the indices were significantly different (p<0. 05) in different seasons, whereas the mean values were not significantly different at stations.

Artemia is one of the most important test organisms available for ecotoxicity tests. In this study the toxicity of five widely used herbicide formulations including: Paraquat, 2, 4-dichlorophenoxy acetic acid (2, 4-D), Trifluralin, Glyphosite and-Atrazine were compared using the ecotoxicity bioindicator, Artemia franciscana. Acute toxicity (48 h LC50) of five herbicides were determined via OECD standard methods. Artemia were hatched using standard methods and 12 h old nauplii were used for toxicity evaluation of herbicides. Nauplii were exposed to serial concentrations (more than 6 in triplicates) of each herbicid. Mortalities at 12, 24, 36 and 48 hours after exposure were recorded and the LC50 were calculated using the Probit software. The results showed that the mortality rate increased by increasing the exposure time in all herbicide toxicity assays. Besides 48 hours LC50 value of Paraquat, 2, 4-D, Trifluralin, Glyphosite and Atarzine were calculated at 15. 67, 12. 93, 11. 87, 164. 31 and 61. 34 mg L-1 in A. franciscana respectively. Glyphosate showed significantly less lethality and toxicity while Trifluralin and 2, 4-D showed the highest toxicity in A. franciscana among the examined herbicides. Then for sustainable agricultural activity, especially in areas that runoff water flows into aquatic ecosystems, it is highly recommended to use environmentally friendly herbicides like – Glyphosate as an alternative to the highly toxic herbicides like Trifluralin, Paraquat and 2, 4-D.

Background: Sulfur dioxide as one of the important gas pollutants has an irreparable impact on plants, animals and objects; therefore this monitoring and control is important. Biological indicators as air pollutants indicators, are appropriate conductive in order to air pollution control in urban and industrial environments. Lichens are one of the bioindicators that are used in this case.Material and methods: Therefore, survey of efficiency and effectiveness biomonitoring of SO2 with use of lichen, Lecanora mularis, was considered. In this research, Lecanora was placed into the special bags and exposed with 40, 100 and 200 ppb SO2 for three hours. Then chlorophyll determination (chl a, chl b and chl a+b) and ratio of OD 435/415 was measured by extracting of 20 mg net weight of lichen in 10 ml DMSO.Results: Thus, the average of chlorophyll determination (chl a, chl b) in control and exposed samples to SO2 was 94.1% and 77.3%, respectively; and there was a direct relationship between determination and pollutant's concentration, in all cases.Conclusion: So, in order to high sensivity of lichens to uptake the SO2, monitoring and indicating the existence and absence of sulfur dioxide in air is possible, thus this monitoring is one of the most effective and applicable approach.

In this study phytoplankton were used as a water quality index in agricultural sewage for feasibility study of aquaculture in Ahwaz and Khorramshahr region. Monthly sampling was done in 6 stations during one year period (2008-2009).34 phytoplankton genuses were identified. The most frequent classes were Bacillariophyceae (diatoms), Cyanophyceae, Chlorophyceae, Dinophyceae. The water flow of drainage channel had inverse relationship with phytoplankton density. Diatoms were present in all stations. Palmer index suggested that station 2, 5, 6, 3, 4 had the highest rate of pollution respectively and station 1 was relatively polluted. The stations of 1, 2, 5, 3, 6, 4 had the highest value of useful phytoplankton index for fish growth.

Ulmus glabra is one of the most important species of the industrial forests of northern forests of Iran. It is distributed from Gorgan (at the northeast) to Arasbaran (at the northwest). Due to development of Dutch elm disease in their habitats, countless numbers of this species have died and its presence in the forest ecosystems is in danger of being eliminated. There have been so many studies and efforts to save this valuable species all over the world. One of the efforts has been focusing on the evaluating both sound and diseased individuals in order to study natural balance ecosystem on sound physiological trees. nowadays one of the methods that are used to assess the ecosystem is to study the soil microorganism enzyme. Based on decreasing living conditions from top to bottom of the soil and also increasing living limits biological potential (constraints) towards the deep soil, the frequency of micro and macro organisms will decrease. Therefore the soil enzyme activities that are themselves related to these activities have a descending gradient from top to lower levels of soil. If the natural process for any reason will be abrupt may lead to an unbalanced ecosystem, which at the end will result to migrate to the living organisms to the lower levels. This will cause the change of the gradient shape and will follow a fluctuation. In this research, following the theorem and emphasis on phosphomonoesterase enzyme study, the soil of four forest habitats were studied which were located at Gorgan, Noshahr, Asalem and Arasbaran. Sampling was done on during Spring of 2004. The soil samples were analyzed and phosphomonoesterase activities were measured. The goal was to study the effects of natural balance on both sound and diseased elm individuals in normal and abnonnal ecosystems. The results were analyzed by GLM (General Linear Model) method and were compared by Tukey test. The results show that all of the sound elms are on the balance ecosystems (except one) and the diseased ones are on balanced. In addition the comparison of enzyme activity in each horizon in both groups shows that decrease of organisms activities in unbalanced elm ecosystem is quiet significant. In fact it can be stated that to save this valuable species it is not enough to only follow and find the resistant phenotypes and genotypes elms to Dutch elm disease. In other words, the interactions of different biological factors and balanced ecosystems have the main effects on saving sound elms, which may result to control the disease. This means that we have to induct a sound and powerful management for these forests.