شناسه هاي افزوده :
سبزعليزاده، سارا ، همكارطرح , اسكندري، غلامرضا ، همكارطرح , خلفه نيل ساز، منصور ، همكارطرح , مرتضايي، رضا ، همكارطرح , جهاني، نجمه ، همكارطرح , كيان ارثي، فرحناز ، همكارطرح , اسماعيلي، فوزيه ، همكارطرح , زرشناس، غلامعباس ، همكارطرح , مياحي، يوسف ، همكارطرح , بني طرفي، جميل ، همكارطرح
چكيده انگليسي :
Abstract
Cage aquaculture has grown rapidly in the past 20 years and now, in response to the pressures of globalization and growing demand for aquaculture production in developed and developing countries, has been changed rapidly. The application of environmental impact assessments as an environmental management tool to achieve sustainable development is one of the acceptable methods so that they can diagnose potential environmental impacts as result of the project performance and also the logical choices for impacts mitigation must be selected. Regardless of the method of rearing , rearing fish in cages can allow or interrupt the cycle of disease pathogens and parasites , changing the aquatic fauna and flora and the behavior and distribution of local fishes. Along with the intensive culture in cages , feces and uneaten food into the environment can be stimulated the primary production and causes adverse effect on water quality. The consequences of fish farming in cages on the aquatic environment can not only cause conflicts with other users , but can also have a negative result on the cages. Therefore, understanding and the ability to determine the implications of aquaculture in cages and prepare guidelines for sustainblae exploitation of marine resources is important.
The main objectives of cage farming is economic development through increase fishery production to compensate for reduced and endangered stocks and increase per capita consumption of fish. The development of aquaculture , cultivation of different species with high economical yield potential and nutritional value and use of coastal waters will be other purposes of this project. The current project in the Bahrekan area ( Khuzestan coastal waters), proposed suitable area for cage farming due to site selection study, (30 º 07 َ 30 to 29 º 53 َ 30 N and 49 º 48 َ 40 to 49 º 60 َ 00E) was conducted to achieving the objectives of the project , the environmental impact assessment of the development cage farming . Determine environmental compatibility of the project , evaluating and selecting the best method of available practical methods to identify and assess the significant environmental impacts of the project , evaluating the costs and benefits of the project and methods to mitigate the effects by using a combination of environmental management and monitoring , are important goals of these studies. In this study, first, introducing technical choices and the rules and regulations related to the project plan have been discussed. Based on ongoing projects in the area , all biotic and abiotic informations were collected and analyzed to assess the effects of projects on physico – Chemical, biological and ecological environments . Also the economical , social and cultural data in the area were collected and the effects of the project have been discussed. The evaluation method, according to the environmental conditions of project and existing information and to achieve a quantitative assessment of the effects of the plan ,by using of Leopold matrix because of the ease of judgment and as a comprehensive method , was carried out.
Based on the matrix to identify and prediction of the impacts in exploitation phase of the project a total of 95 effects were identified , of which 45 negative effect and 50 positive effect were assessed. In general, the predicted effects , 16.12 % in physico-chemical , 51.63 % in he biological and ecological environment , and 32.25 % in the socio-economic environment has been evaluated .
In the operation phase , all 15 impacts on physico-chemical environment were negative and among 48 effects on ecology and biology environment , of which 19 positive and 29 negative effect were diagnosed. in economic and social environment also, from all of 32 predicted impacts , only two negative effects were identified and other effects were positive. According to the results, the weighted scores of the different environmental , physicochemical ( 24 ) , ecological-biology (+1 ) and economic - social ( 212+ ) were obtained. Regarding the activities of this project , major negative impacts on the physico-chemical environment caused by the accumulation of food waste and followed by the changing the sediment quality and ultimately changing the water quality. Ecology and biology environment were shown balance in positive and negative effects of activities. the main activities were classified in groupe weakness that with providing solutions to controlling , mitigation and conservation , will be compensated. While the socio-economic impact assessment is very positive Finally, the sum of the different environments scores were obtained (189+) that indicating positive assessment of the work plan , especially in economic and social aspects
In this study, the method (MGM) by Lohani and Thanh (1980), which is designed based on Leopold , was used. According to results of different environments respectively, effect of project on fauna ( 34.13 % ) , benthic organisms and benthoses ( 27.14 % ) , sediment quality ( 10 % ) and health and safety of workers ( 8 % ) were obtained which reflects activity impacts on the environment from moderate to weak , that can be compensated by reduction and mitigation solution methods .
The value of Severity point (sp) also categorized. . According to SP values , only the effect on benthic organisms, SP (27), in the lower-middle category and other effects in the low category , less than 22.5, was classified. Despite the positive economic and social impacts of cage farming project in the region Bahrekan, in coastal waters of Khuzestan ,as mentioned in the identification of effects , If, necessary regulations and standards in the designing and implementation of project are obeyed and strategies for the elimination and mitigation of adverse environmental impacts are used , environmental damage in different environments would not exist.Considering that many of these negative effects can be minimized or even eliminated by implementing of mitigation and controling plans , possibility of implementation of cage farming in the area with emphasis on indigenous species rearing , especially Sobaity , Cobia and grouper , is accepted.
