Evaluation of Agreement among Ecological Indices in Determining the Quality of Karaj River (Alborz Province)

Introduction: The study of the structure of aquatic communities in aquatic ecosystems has a special place in the ecological studies of aquatic organisms. Among the important and common macrobenthic indices, we can mention uni- variate and multi-variate ecological indices, which having different advantages and disadvantages, are still used in various studies in riverian waters. In recent years, studies using biodiversity index and bioindices, especially the Helsinhof index, were used to assessment of the water quality of the Karaj River. Assuming that there is agreement between the ecological indices of the region, the present study evaluated the degree of agreement between the quality statuses results obtained from different ecological indices in the Karaj River. Materials and Methods: In this study, we sampled macrobenthic fauna using a sorber sampler in nine stations during 2017-2018, seasonally. After separating and identifying macrobenthos, Shannon's index, EPT, ASPT, BMWP and HFBI were calculated. Then the ecological status of the stations was classified based on these indices. The percentage of stations whose ecological status was acceptable or unacceptable, as well as the compatibility level between these five indices in the study area, were calculated. To determine the similar tendency of the different indices in the classification of stations, the degree of correlation between them was determined using a non-parametric test. SPSS23 and Excel software were used for statistical analysis and Primer6 was used to determine biodiversity index. Shapiro-Wilk test was used to check the normal distribution of the data. In order to determine the significant difference between the desired data, one-way ANOVA and Kruskal-Wallis tests were used at the significance level of p<0.05. ArcGIS 10.3 and Terrset 17.3 software were used to prepare maps using the IDW method. Results: In terms of abundance, the Shironomide family was dominant. Baetis, Tubifex, Micrasema, Rhithrogena, Eporus, Hydropsyche, Leptophlebiidae, and Simulium made up 83% of the samples. The values ​​of H', EPT, ASPT, BMWP and HFBI were calculated (12.2±0.65), (5.6±2.8), (3.9±1), (48.8±23.34) and (4.6±1), respectively. The relative agreement in the results obtained from the five studied indices was seen in 67% of the stations with unacceptable quality in the case that 22% of the river stations showed complete agreement and 11% of the stations showed disagreement.  The statistical analysis shows that there is a significant agreement between the results of the ecological status obtained from EPT with ASPT, BMWP and Shannon, if they are different with HFBI index. Also, based on the results of the correlation between the classification of the ecological quality obtained from the bioindices (positive and strong correlation between the EPT and the Shannon and BMWP), it indicates the similar direction of these indices in the classification of the stations. Discussion: There are structural and population changes of macrobenthos in aquatic ecosystems due to natural factors and human activities. Due to the lack of complete agreement between the assessment results of the five indices in this study, in order to use biological indices in each region for environmental management, there is a need to simultaneously use indices. Also, it is important to check the agreement between different indices and choose the appropriate ecological index. As a result, using each of these indices alone and without considering the above considerations can lead to wrong results. Based on the results of the present study, the Helsinhof index (HFBI) can be introduced as a more suitable index than other studied indices to assess the ecological status of the Karaj River

Investigating the fishing activity in the coral habitat around Kharg and Khargo islands by using the SWARA method

Introduction: Considering the importance of corals in different dimensions of human life, their investigation and study will become more necessary. Kharg and Khargo islands are very important from the point of view of the environment, especially the unique coral covers. In the past few decades, many potential threats such as destructive human activities related to the oil industry and the resulting wastes in coastal environments, oil and hydrocarbon pollution, industrial and urban pollution, air pollution, discharge of municipal effluents and sewage, thermal stresses caused by changes Climatic and fluctuating middle and upper water levels, fishing with nets by fishermen and hunting fish by divers in coral areas, as well as carelessness of divers, have faced many challenges in coral habitats. One of the activities that is in relative conflict with the ecosystem of Khark Island and especially the location of the coral beaches, is the activities and movements related to fishing in Khark and Khargo Island. These activities date back several decades. Extreme poverty in many areas has caused a large number of people to go fishing. Therefore, the purpose of this study is to examine the various aspects of the fishing challenge that threatens the geographical territory of coral reefs. The aim of this study is to emphasize the investigation of human-environmental challenges. Materials and Methods: In this research, for evaluate and investigate the threats created in the geographical area the first step we investigated the challenges of fishing activity of Khark Island. Then these challenges were classified and finally analyzed and investigated the contribution of each of its aspects in the fishing communities near the coral habitat of Kharg and Khargo islands. In order to investigate fishing and fishing challenges, using the statistical method of Cronbach’s alpha analysis and Likert scale. For trust final results and analyzes must the confidence percentage was calculated and confirmed. The weights of each of the criteria were finalized by the SWARA fuzzy-numerical test. In this questionnaire, there are 21 questions and Cronbach’s alpha is at an acceptable and good level of 0.72. Results: In the questionnaire of this research, there are 21 questions and the Cronbach's alpha level is at an acceptable and good level of 0.72. It was found that trust in the content of the questionnaire confirms. The effectiveness and weight of each of the criteria showed that the highest percentage of fishing is done by motor boats in the winter season and early in the morning (93%). The results showed that more than 85% of fishermen have not received any necessary training for fishing in coral areas, and this challenge is considered serious and fundamental. The results showed that more than 85% of fishermen have not received any necessary training for fishing in coral areas, and this challenge is considered serious and fundamental. Discussion: The output indicates that the fishing tool is valued as a criterion with the first rank, in other words, it explains 31% of the weight of the items. On the other hand, fishing time has the lowest weight in the criteria definition with 23%. These statistical processes show that human-environmental factors should be prioritized in examining the challenges and threats of the coral reef in Khark Island. In other words, the control and management of man-made challenges and related factors can create safe coral environments