Iranian Scientific Fisheries Journal

fa مقاله علمی – پژوهشی:‌ تأثیر برخی شاخص‌های تغییر اقلیم بر توسعه ظرفیت پرورش قزل‌آلای رنگین‌کمان حوضه رودخانه بشار (استان کهگیلویه و بویراحمد) Effect of some climate change parameters on the development of rainbow trout farming capacity in the Bashar River basin (Kohgiluyeh and Boyerahmad Province) ليمونولوژي ليمونولوژي پژوهشي Research استان کهگیلویه و بویراحمد در سال 1402 با تولید23000 تن ماهی قزل‌‌آلای رنگین کمان در کشور از جایگاه سوم برخوردار بوده است. عمده تولید آبزیان این استان در حوضه رودخانه بشار صورت می‌‌گیرد. در این تحقیق، ضمن بررسی میانگین آمار دما، بارندگی سالانه و دبی رودخانه بشار در این حوضه طی یک دوره دراز مدت، تغییرات مهم‌ترین پدیده‌های متأثر از اقلیم با نتایج مطالعات نرم افزاری ارائه شواهد تغییر اقلیم در حوضه آبریز مقایسه شد. همچنین تأثیر تغییرات مذکور بر پایداری و توسعه تولید قزل‌‌الای رنگین‌‌کمان مد نظر قرار گرفت. یافته‌ها حاکی از افزایش میانگین دمای سالانه و کاهش بارندگی سالانه (18 درصد) در بلند مدت در حوضه بود به‌طوری‌که در ده ساله ابتدای دوره مورد بررسی میانگین بارش 287 ± 892 میلی‌متر و در هشت سال انتهایی به 275 ± 728 میلی‌متر (شکل 5) بوده ولی فاقد تفاوت معنی‌داری با هم بودند (05/0<P). کاهش میانگین دبی رودخانه در ده سال اخیر نسبت به 40 سال قبل از آن به میزان 30 درصد بوده است (05/0>P). یافته‌های حاصل از مطالعات نرم افزاری نشان داد که طی قرن آینده، افزایش درجه حرارت و کاهش بارندگی وجود داشته و کاهش بارش در نیمه دوم قرن بیشتر از نیمه اول آن است. بروز سیلاب و گل آلودگی آب سبب خسارت به مزارع با منبع آبی رودخانه شده و طی 4 سال اخیر 3 بار منجر به تلفات بیش از هزار تن ماهی شده است. احداث زه‌‌کش در حاشیه رودخانه با رعایت نکات فنی و ایمنی تاسیسات در مقابل سیل جهت احداث مزارع پرورش ماهی قزل‌‌الای رنگین‌‌کمان ضروری است. همچنین با افزایش تولید در واحد سطح با استفاده از مکانیزاسیون برگشت آب و فیلتراسیون در مزارع موجود می‌توان به توسعه آبزی‌پروری در جریان اصلی رودخانه بشار در پایین‌دست در محدوده دوروهان (بالاتر از ایستگاه 4) تا انتهای حوزه آبریز در استان امیدوار بود. علاوه‌براین، پیشنهاد می‌‌شود که صدور مجوزهای جدید به‌تدریج طی 10-5 سال تنها با بررسی بازخورد بهره‌برداری از مجوزهای اولیه صادره، انجام شود. Introduction Kohgiluyeh and Boyerahmad province ranked third in the country in 2023 with a production of 23,000 tons of rainbow trout (Qurbanzadeh and Sedghpour, 2023). The majority of this production takes placed in the Beshar river basin as one of the main branches of the Karun river (Rastiannasab et al., 2023). Climate change has been recognized as a major environmental crisis and concerned by the World Meteorological Organization (Kalbali et al., 2021). Climate change leads to changes in the amounts and patterns of precipitation and temperature at the basin (Sarkar and Chicholikar, 2017). In Iran, precipitation is one of the basic variables for evaluating the potentially available water resources, but its temporal and spatial distribution is very heterogeneous, therefore the distribution of water resources in the country is not uniform (Hassan et al., 2014). For this reason, temporal variability of precipitation  has great importance in assessing the available water resources of watersheds and studying the relative availability of water resources at local and regional scales (Sha et al., 2019). Despite the few studies conducted to investigate  the most important phenomena affected by climate change and impressive on water resources in Kohgiluyeh and Boyerahmad province, many applicants insist on issuing permits to build new farms. In this study, it is attempted to examine data of the most important meteorological stations in the watershed and the flow statistics of the Beshar river over a long period to compare the obtained results with the findings of software studies conducted to providing evidence of climate change in the watershed, to explain the impact of the weather changes on aquaculture activities, the production of freshwater fish in this area and the sustainability of this industry in the future. Methodology Average temperature and rainfall data were collected based on the average air temperature and rainfall from the Yasouj Synoptic Meteorological Station in the center of the studied basin in different months of the year and annual average over a 35-year period ended 2023, the flow statistics of the Beshar river over a long period to compare the mentioned statistics with the average of  them in the last ten years were used, Data on air temperature, precipitation, and river flow in the last 10 years were calculated and reported as monthly averages and standard deviations over a long period. Data analysis was performed using independent samples t-test using SPSS version 24 statistical software package in case of homogeneity of variance, and non-parametric Mann-Whitney U test was used in case of non-normality of data. Results The findings indicated an increase in the average annual temperature and a decrease in annual rainfall (18%) in the long term in the basin (Fig. 1) so that the average rainfall in the first ten years of the period was (892±287 mm) and the last eight years (728±275 mm) which had no significant difference (P<0.05). The decrease of the average discharge of the river in the last ten years compared to the previous 40 years was 30% (P<0.05). Figure 1: The location of the Beshar river flow monitoring stations, the river's catchment area regarding to the Persian Gulf watershed The results of the data analysis indicated a significant decrease in precipitation in the winter season compared to previous years (P<0.05), so that most of the decrease in precipitation in the last ten years is observed in the winter season (Fig. 2). Figure 2: Ten- year average annual air temperature of Yasouj meteorological station in the basin of Beshar River The Qalat station (station1) is located at the beginning of the watershed, within the village of Qalat, in the upper part of the river. Based on the data analysis, the average river discharge at the Qalat station has decreased by nearly 25 percent in the last ten years compared to the long term period (P<0.05). Patavah station (station 4) is considered the last hydrometric station of the Bashar river basin and receives water from all branches and after a distance in the Darb Qalat area, the River basin is ended. The decrease in the average flow in the last ten years compared to the previous 40 years in Patavah station was 35 percent (P<0.05).The river discharge in summer was lower than the other seasons. Discussion and conclusion According to the results, the decrease in flow of Beshar river is due to the decrease in rainfall in recent years compared to the long-term period, by 25 to 35 percent in the upstream and downstream river areas, respectively. Therefore, it is expected that the decrease in winter precipitation in the form of snow and rain in recent years has caused the decrease in the flow of river lately. The findings of the software studies showed that during this century, it will be an increase in temperature and a decrease in precipitation, and the decrease in precipitation in the second half of the century is more than the first half (Panahi et al., 2022). In addition to reducing the flow, the occurrence of floods and water turbidity resulted of climate change (Chun et al., 2013) have directly caused damage to the farms using the river water (Rastiannasab, 1998) and  effective in 3 times loss of more than a thousand tons of fish in the last 4 years. It is necessary to build a drainage system on the river bank to supply water as technical and safety facilities against floods in onset of rainbow trout fish farms construction. Apart of increasing the production per unit area by using the mechanization, filtration and reuse of drained out water in the active farms, we can be hoped for the development of aquaculture in the main flow of the Bashar River in downstream, from the Durohan area (near station 4) to the end of the catchment area in the province via issue new licenses gradually over 5 to 10 years and review the feedback of the initial licenses issued. Conflict of Interest We wish to confirm that there are no known conflicts of interest associated with this study. Acknowledgements This article is a part of the final report of the research project approved by the Iranian Fisheries Science Research Institute (IFSRI) from the fund of Kohgiluyeh and Boyerahmad Agriculture- Jahad Organization. We wish to express our thanks to Dr. Motamedi as the its chairman. رودخانه بشار, تغییر اقلیم, توسعه آبزی‌پروری, پرورش ماهی, قزل‌الای رنگین‌کمان Beshar river, Climate change, Aquaculture development, Fish farming, Rainbow trout 1 13 http://isfj.ir/browse.php?a_code=A-10-825-7&slc_lang=fa&sid=1 Abulhassan Rastiannasab ابوالحسن راستیان نسب rastian1920@yahoo.com 100319475328460039485 100319475328460039485 Yes Iranian Fisheries Science Research Institute (IFSRI), Shahid Motahary Coldwater Fishes Genetic and breeding Research Center-Yasoj, Agricultural Research Education and Extension(AREEO), Yasoj, Iran مؤسسه تحقیقات علوم شیلاتی کشور، مرکز تحقیقات ژنتیک و اصلاح نژاد ماهیان سردابی شهید مطهری یاسوج، سازمان تحقیقات، آموزش و ترویج کشاورزی، یاسوج، ایران mahmood Bahmani محمود بهمنی mahmoudbahmani@gmail.com 100319475328460039486 100319475328460039486 No Iranian Fisheries Science Research Institute (IFSRI), Agricultural Research Education and Extension(AREEO), Tehran, Iran مؤسسه تحقیقات علوم شیلاتی کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی، تهران، ایران seyed abdolhamid hosseini سید عبدالحمید حسینی hoseiniabdolhamid@gmail.com 100319475328460039487 100319475328460039487 No Iranian Fisheries Science Research Institute (IFSRI), Shahid Motahary Coldwater Fishes Genetic and breeding Research Center-Yasoj, Agricultural Research Education and Extension(AREEO), Yasoj, Iran مؤسسه تحقیقات علوم شیلاتی کشور، مرکز تحقیقات ژنتیک و اصلاح نژاد ماهیان سردابی شهید مطهری یاسوج، سازمان تحقیقات، آموزش و ترویج کشاورزی، یاسوج، ایران mohammad meysam salahi ardakani محمدمیثم صلاحی اردکانی mmsalahi.a@gmail.com 100319475328460039488 100319475328460039488 No Iranian Fisheries Science Research Institute (IFSRI), Shahid Motahary Coldwater Fishes Genetic and breeding Research Center-Yasoj, Agricultural Research Education and Extension(AREEO), Yasoj, Iran مؤسسه تحقیقات علوم شیلاتی کشور، مرکز تحقیقات ژنتیک و اصلاح نژاد ماهیان سردابی شهید مطهری یاسوج، سازمان تحقیقات، آموزش و ترویج کشاورزی، یاسوج، ایران esmaeil kazemi اسماعیل کاظمی esmaeil.kazemi.1986@gmail.com 100319475328460039489 100319475328460039489 No Iranian Fisheries Science Research Institute (IFSRI), Shahid Motahary Coldwater Fishes Genetic and breeding Research Center-Yasoj, Agricultural Research Education and Extension(AREEO), Yasoj, Iran مؤسسه تحقیقات علوم شیلاتی کشور، مرکز تحقیقات ژنتیک و اصلاح نژاد ماهیان سردابی شهید مطهری یاسوج، سازمان تحقیقات، آموزش و ترویج کشاورزی، یاسوج، ایران