fa ارزیابی ذخایر تاسماهی ایرانی (Acipenser persicus) در حوضه جنوبی دریای خزر طی سال های 88-1387 ارزيابي ذخاير و پويايي جمعيت ارزيابي ذخاير و پويايي جمعيت كاربردي Applicable <p style="margin-left: 42.6pt; text-align: justify;">Species composition, relative abundance, absolute abundance and biomass of sturgeon species were studied during the years 2008-2009. Eighty five stations were covered in the stratified random sampling design in depths less than 1Om using 9m bottom trawl (head line) and in depths more than 10m using 24.7m bottom trawl (head line). More than 70 specimens of <em>Acipenser persicus </em>were caught during the effort.</p> <p style="margin-left: 41.65pt; text-align: justify;">CPUE decreased from 0.4 to 0.24 specimens per trawl in &nbsp;2009. &nbsp;The &nbsp;mean &nbsp;total &nbsp;length &nbsp;of &nbsp;the <em>A.</em><em> persicus </em>was 47.3&plusmn;29.lcm and 61.9&plusmn;28.7cm &nbsp;in &nbsp;2008 &nbsp;to &nbsp;2009, &nbsp;respectively. &nbsp;The &nbsp;smallest &nbsp;size &nbsp;of &nbsp;<em>A.</em><em> persicus </em>was 9cm in 2008 and 24.5cm in 2009, while the maximum size was I 02.5cm in &nbsp;2008 &nbsp;and 126.5&plusmn;29cm in 2009. The mean total weight in &nbsp;2009 &nbsp;in &nbsp;comparison &nbsp;with &nbsp;2008 &nbsp;increased &nbsp;from &nbsp;989(3- 5000g) &nbsp;to&nbsp; &nbsp;1569(42-71OOg).</p> <p style="margin-left: 43.3pt; text-align: justify;">Absolute abundance of <em>A. persicus </em>decreased from 2006000 specimens in 2008 to 1192000 specimens in 2009. The estimated biomass was 2010 and 1878 tons in 2008 and 2009, respectively.</p> <p style="margin-left: 43.55pt; text-align: justify;">According to the results of study, the stock status of <em>A. persicus </em>is highly critical in the Caspian Sea and a timely decision has to be taken for conservation of the species.</p> Stock assessment, Acipenser persicus, Catch per unit of effort, Caspian Sea, Iran 1 8 http://isfj.ir/browse.php?a_code=A-10-1417-54&slc_lang=fa&sid=1 M Tavakoli محمود توکلی M_ tavakoli_e@yahoo.com 100319475328460016384 100319475328460016384 Yes F Parafkandeh Haghighi فرخ پرافکنده حقیقی 100319475328460016385 100319475328460016385 No M.R Behrooz Khoshgalb محمدرضا بهروز خوشقلب 100319475328460016386 100319475328460016386 No F Kaymaram فرهاد کیمرام 100319475328460016387 100319475328460016387 No S.A Taghavi سیدامین الله تقوی 100319475328460016388 100319475328460016388 No