This study was conducted to examine the population ecology MACROBENTHOS Kelerud Rivers of Babol (Mazandaran province) during 2010-2011 seasons were sampled at six stations. Benthic invertebrates collected by the sampler little surber sampler were isolated in the laboratory using a loop. MACROBENTHOS simultaneous sampling, hydrologic variables were recorded at each station. Generally benthic river wide crotch strap end and creams containing 5 Class 8 orders and 12 families. In total, category 5 orders and six families with the most diverse groups of insects in the river macrobenthic accounted for, of which the Ephemeroptera (day of) the most diverse and Plecopte (Springs) had the lowest variability in macrobenthic Kelerud River. The greatest diversity and abundance of all identified families with an average of 103 samples and 89/20 % belonging to the genus Heptagenia diversity and abundance with an average minimum of 3 and 60 / 0 % belonging to the family Gammaridae.

Background and Objective: The present study investigates the water quality of Sufi Chay river in Maragheh, Iran using Benthos groups and their population structures in 2015. Material and Methodology: Overall, 9samplingsites were selected in the region and MACROBENTHOS were sampled in triplicate at each siteusing a 25×50 surber. The samples were stabilized by Formaldehyde 4% and their species, family and genus were identified. A total of20MACROBENTHOS species from 19 families, 10 orders and 2 classes were evaluated. Baetis sp. was the dominant species in winter and summer. Findings: The results indicate that the 7 and 9 sites with the aggregation of 47 and 128 MACROBENTHOS per m2 were dominant in winter and summer, respectively. Regarding Welch model, water quality of Sufichay river was moderate at most sites in both seasons. However, the water quality at the 7 site in winter and the 8 and 5 sites in summer was unsuitable. According to the BMWP Index, water quality of the river, except the 8 and 9 sites in winter, was suitable. Discussion and Conclusion: Regarding the results of this research it can be concluded that MACROBENTHOS community is an effective bioindicator to assess environmental conditions of the Sufi chay river. In addition, the results of this study display the relatively suitable water quality of Sufi Chay river.

Karaj River as one of the most important water sources of Tehran city, has special importance. This study consisted of diversity and distribution of Macro benthos on Karaj River that was conducted during years 2014-2015. It was started in fall 2014 and it was finished in summer 2015. In the mentioned area, the total of five study stations were selected based on environmental impact, MACROBENTHOS fauna samples were taken by Quadrat with dimensions of 50 × 50 cm such that were repeated 5 times at each station with seasonal frequency. Samples were fixed with 4% formalin, were separated in a lab, and then identified and counted. In surveys conducted, 23 genuses from 21 families and 5 orders of MACROBENTHOS were identified. The results show the station 4 in winter season had most abundance (1067) and the station 5 in spring season had the less abundance (254) of specimen. Insecta had the most abundance (88.8 % of total) and Malacostraca had the less abundance (0.1 % of total) between five classes were identified on Karaj River. The genera of the Simulim with the number of 879 per square meter the highest abundance and The genuses of the Asellus and Atherix With the number of 1 per square meter the lowest among the species had been identified. During this study the average of the Shannon-Wiener diversity index was calculated 1.73, Simpson dominance species was calculated 0.74 and Margalef richness species was calculated 3.31. According to the biological values of Hilsenhoff (HFBI), the water quality status of Karaj River at stations 2 and 3 were evaluated excellent, at stations 5 was evaluated very well and at stations 1 and 4 were evaluated well. Overall according to the results, it was determined that aquatic insects constitute the dominant population of the benthic fauna in Karaj River. In winter season the classes: Insecta, Turbellaria, Gastropoda, Malacostraca and Clitellata had the greatest density and diversity compared to other seasons.

This study was done in order to determine the pollution effects on growth of MACROBENTHOSes in Jadjrud River, between Saeedabad area and Ghareboron village. Three stations considered for invertebrates sampling. Assessment of some parameters such as air and water temperature, BOD5, dissolved oxygen, and pH were done monthly along with invertebrate sampling. Total existence, EPT existence, Shanon-Winner diversity index and HFB1 were used in assessment of MACROBENTHOSes. During experiment, air and water temperature were 1.3-32.5 and 3-25.1oC, respectively. BOD5 was 3.9-9.98 mg L-1, dissolved oxygen 4.85-9.52 mg L-1, and pH 8.8-9.6. In benthic fauna assessment, 7 orders and 5 genera were known, where some resistant groups against pollution such as Diptera, families of chironomidae and gastropods were dominant in estuary zone of the river. Maximum and minimum EPT dominance were 45% in spring (station 3), and 34% in summer (station 2), respectively. The results of this study showed that the pollution in station 1 was considerable, station 2 highly polluted, and station 3 relatively polluted. Based on Helsinhophe index, water quality in first station was low, while in station 2 was highly low an in station 3 was relatively low.

This study was carried out to investigate microbenthic diversity and seasonal variation in two sampling areas including estuary and river stations during 4 season in 2010. Sampling was done using Van Ven Grab in 3 replicates and the collected samples were fixed in 4% formaldehyde. The results showed that there are 12 benthic taxa families belonging to 9 orders in the river station, in which the most frequent family was Lumbriculidae (19. 39%), and Tubificidae has the lowest abundance (2. 07%). While the estuary station contained 12 families belonging to 10 orders. The following families had high abundance: Ampharetidae (21%), Lumbriculidae (11. 55%), Naididae (11. 32%) and Gammaridae (9. 98%). The highest and lowest abundance of MACROBENTHOSes in the river station were observed in fall and in winter respectively, while in the estuary station the maximum and minimum were observed in spring and in winter. The maximum Shannon-Wiener index in the river were observed in the spring (2. 36) and in the estuary was in the summer (2. 13). The highest value of Simpson index in the river area was in the summer (0. 19) and in the estuary area in the spring. Results of Richness index showed that the highest amount in the river was observed in the spring, while the highest amount in the estuary was obtained in the autumn. It can be concluded that river station had higher density and diversity than estuary, indicating better ecological conditions.

The purpose of this study is to determine the diversity and the accumulation of MACROBENTHOS of Bahoush River and assess the condition of water quality using Welch's index. Sampling was done in summer and winter seasons during 2012 year. Sediment sampling was done three times for each station. MACROBENTHOS samples were collected using van veen grab with 0. 025 cross-section, (they were fixed using 5% buffered formalin) so were counted and identified in the laboratory. Further, physicochemical parameters of water including temperature, pH, dissolved oxygen (DO), water salinity was measured at each station. The diversity index was examined using Shannon-Weiner formula. Dominant index was examined using Simpson formula. Species richness was examined using Margalof formula and water quality was assessed using Welch index. The identified samples were composed of 13 genus, 10 families and 3 classes. The most identified species in stations belongs to Caenidae, Lymnaeidae and Chironomidae families. The results of the study indicated that according to the identified samples and Welch index, water quality in Bahoush River was medium.

Kardeh River is one of the most important permanent rivers of Khorasan Razavi province Which supplies a large part of Mashhad's drinking and agricultural water. Multivariate analysis was used to find out the quality of Kardeh River in this study and to understand the impact of macroinvertebrates community structure drivers on ecosystem management. For this purpose, macroinvertebrates sampling was performed from four study stations during four seasons in 2018-2019, physical and chemical parameters also were measured. In this study, Of the Ephemeroptera, the total number of Caenidae and Baetidae families had the highest abundance (66 / 60 %). The results showed that the Index of Biotic Integrity varied from 3 to 1. 1 and based on this biodiversity indicator, Kardeh River water quality was classified into three relatively good, poor and very poor quality classes. The Stream Invertebrate Grade Number Average Level index was classified into two categories: moderate pollution and severe pollution. Canonical Corrspondence Analysis also showed that nitrate, biochemical oxygen demand and chemical oxygen demand had the most effect on the distribution of macroinvertebrates at the study stations. In general, the Kardeh River water quality was poorly evaluated and among the study stations the station conditions were relatively better than the other stations. Therefore, among the available indices, multimetric indices are more reliable. However, these index should be calibrated according to the conditions of Iranian rivers.

Estuaries are the main crossing areas between rivers and sea ecosystems. The Shirud River is located in the west of Mazandaran province. Sampling of sediments was done monthly for one year (Jul 2012- Jun 2013). Five stations were sampled, includes two stations in upper part, one station in delta of estuary and two stations in the sea. Environmental parameters such as salinity (ppt), pH, water temperature (Co) and depth (cm) were recorded in any station. 5182 number MACROBENTHOS were counted; there were recognized 36 genera, 25 families and 15 orders. The most abundant recorded for Obesogammarus sp. as 36%. In accordance with the results, salinity and depth of water affect the density of MACROBENTHOS (p<0.05), however pH did not effect on density and diversity, though (P>0.05). Also temperature changes cause modifications in density and diversity among different species of Macrobentozes during different months, so that the most and least density were recorded during July and January, respectively. The most and least diversity were shown during September and March (p<0.05). In average the most live mass was realized in August (1.61 gr/m2) and the least live mass was for March (0.03 gr/m2). The average ecological indices results are as follows: Shannon-Wiener 0.83; Simpsons Dominance 0.48 and Margalef Richness 2.42, there were a significant difference between indices during different months in a year (P<0.05).

Abundance, biomass and diversity of MACROBENTHOS were assessed in Baho-kalat estuary. This estuary is located on the south-east of Iran and Coasts of Oman sea Sampling were carried out by Ekman grab at 8 stations during 4 seasons starting from Autumn 1996 to Summer 1997. As a result of this study, 11 groups of macrofauna were recognized, counted and weighed. The majority of macrofauna belonged to Bivalvia (42%) and polychaeta (26%). Dominant family of bivalvia was veneridae and that of polychaeta was cossuridae. Biomass (wet weight) of macrofauna was ranged from 0.254 g/m2 (in spring) to 715.82 g/m2 (in autumn). Abundance of macrofauna showed significant difference in winter and autumn (post monsoon) with summer (monsoon) and spring (premonsoon). There was also significant difference between station 3 and other stations. Maximum rate of diversity was in winter seasons (station 3) and minimum rate was in winter and spring (station 1 which is located in entrance of estuary). It seems, the variations and fluctuations of macro benthos community in Baho-kalat estuary were mainly due to the effect of monsoon's streams and the impact of localized biotic and biotic factors.

Sampling from sediment and environmental factors for investigating the structure and population dynamic of MACROBENTHOS community in 5 stations in lagoon Lipar located 19 k. m. east of chabahar in sistan and balouchestan province from NOV in 2013 to APR in 2014. Mean density of MACROBENTHOS in station 3 with 1441 ind/m2 was maximum during 6 month sampling period and density for stations 5, 4, 2, 1, was 1043, 580, 141 and 108 ind/m2 respectively. MACROBENTHOS density was also maximum in May with 1078 ind/m2 and 717, 675, 541, 523, 441 ind/m2 was for Feb, Mar, Des, Jan and Apr respectively. Among MACROBENTHOS community only 3 groups, including chironomids with 8873, Foraminifrans and gastropods with 2162 and 10 ind/m2 were abundance respectively. Among environmental factors, salinity (mean: 137± 90 ppt) and temperature (mean: 25± 5O ° C) poss the highest variation. Results show that between MACROBENTHOSe and sand grain was a significant correlation (P<0. 05). According to results it seems that the lipaar ecosystem is in stress condition because of high temperature, low rainfall, high evaporation, high content of organic matter and fine grain structures in most stations and sensitive groups under stress condition omitted from the environment and tolerant groups to bad condition exist in ecosystem.