somayeh sargolzaei; azita farashi; Omid Safari; hamidreza ahmadnia motlagh
Abstract
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 ...
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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.
Ali Heydari; Omid Safari; Hamidreza Ahmadnia motlagh
Abstract
The study was aimed to evaluate simultaneously the qualitative indices derived from the measurement of physicochemical parameters of water, as well as biological and demographic indices of the Bazangan wetland. Regarding to the high organic contamination from sediment amount and the stressful conditions ...
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The study was aimed to evaluate simultaneously the qualitative indices derived from the measurement of physicochemical parameters of water, as well as biological and demographic indices of the Bazangan wetland. Regarding to the high organic contamination from sediment amount and the stressful conditions of environment in this area, the highest relative frequency of macrobenthos was belonged to Chironomidae and Ephydridae families (resistant families to pollution) and the sensitive families to contamination (EPTs) were absent. The results of studying grading analysis and the total organic matter content in the sediments of samples stations during warm and cold seasons showed the texture of loam-silty, clay-sandy-loam and loam-clay. The maximum amount of organic matter (18.54%) in winter and the lowest amount of organic matter (4.65%) in spring was recorded in the stations. Finally, regarding the high correlation between biological and demographic indices and qualitative index with other indices, the parameters are more suitable indices to evaluate the ecosystem health of Bazangan wetland.
Ameneh Sazgar; Omid Safari; Shahnaz Danesh; Faezeh Yazdani moghaddam
Abstract
Khajoo fish is one of native fishes existing in the northeast of country. Regarding the ability of this species to live in the different habitats, 124 fishes from Tajan and Kavir basins were caught in seven different locations in the northeast of Iran. The left side of the samples was shot and 17 landmarks ...
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Khajoo fish is one of native fishes existing in the northeast of country. Regarding the ability of this species to live in the different habitats, 124 fishes from Tajan and Kavir basins were caught in seven different locations in the northeast of Iran. The left side of the samples was shot and 17 landmarks (sign mark) were digitized to extract body shape data. There was a significant difference between the bodies shapes of all five populations studied. Most of these differences were related to changes in the muzzle region, head depth, chest and thoracic position, indicating the flexibility of these parts in response to the environmental conditions of the habitat of the populations under study. Having a mouth with abdominal position, head shape, spindly body shape were common features among members of this species, which could indicate the generality of the shape of the body of this species, which for species that are found in variable environments such as rivers life, can be an advantage.
