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نقش رهاسازی بچه ماهی سیم در احیاء ذخایر این ماهی | ||
| مجله علمی شیلات ایران | ||
| مقاله 2، دوره 9، شماره 4، بهمن و اسفند 1379، صفحه 27-38 اصل مقاله (370.28 K) | ||
| نوع مقاله: مقاله پژوهشی | ||
| شناسه دیجیتال (DOI): 10.22092/isfj.2001.115987 | ||
| نویسنده | ||
| محمد صیاد بورانی | ||
| چکیده | ||
| رهاسازی، ماهی سیم ، دریای خزر، ایران | ||
| کلیدواژهها | ||
| رهاسازی؛ ماهی سیم؛ دریای خزر؛ ایران | ||
| عنوان مقاله [English] | ||
| The Role of Restocking Bream for Improvement of the Natural Stock | ||
| نویسندگان [English] | ||
| M. Sayad borani | ||
| چکیده [English] | ||
| Abramis brama orientalis is a valuable fish species in the Caspian Sea. Its stock after has been faced with pronounced depletion since 1941. The release of million of its fry have not been successful to restore its stock. A slim Iluctuation were observed in its natural stocks during last seven years in the Iranian coastal areas. In comparison to 1992-1993, catch showed a 4.4 tons Increasment in 1998-99. No pronounced increase was observed considering release of 70.46 million fry during mentioned period. Young and immature fish provide mainpart of the catch while mature individuals provided a small part of it during 1978-1979. For most rate of catch comprised by young and immature fish and the number of brood-stock fish were very small amount in the catch as in the year of 1998-1999, 20.3% of catch formed by one year old fish and 37.3% by two years old. The average length,weight and age of bream in the years of 1998-99 calculated 22.5cm , 212.2gr and 2.4 years respectively. The depletion of the stock could be attributed to the following important cases, such as non-rational catch practicing, environmental, pollution, destruction of natural spawning grounds, the existence of predatory fish for example Pike and Sheatfish in fries unloading site, and lack of necessary arrangement relevant to artificial spawning. The rate of recruitment of Bream to fisheries calculated 4.6% in 1991 and 2.7% in 1992. | ||
| کلیدواژهها [English] | ||
| releasing, ABRAMIS BRAMA ORIENTALIS, Caspian Sea, Iran | ||
| مراجع | ||
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آمار تعداد مشاهده مقاله: 446 تعداد دریافت فایل اصل مقاله: 316 |
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