ارتباط ميزان صيد پره هاي ساحلي با فراواني بي مهره گان كفزي درياي خزر در حوزه استان گيلان

The relation between fish catch values and macrobenthic biomass in Caspian Sea of Guilan province

Caspian sea macrobenthos was surveyed during 4 periods from Autumn 1994 until Summer 1995. The study area was south west of Caspian sea in Guilan province at four depths 10 , 20 , 50 , 100 meter and 9 transect. The macrobenthos organisms were sorted and identified then was drawn the biomass distribution map. The fishing area were divided in seven regions for 1991-92 and 1994-95 years .The results showed that invertebrate biomass was varied from 1.57 to 65.78 with mean ± Se 13.97±1.6 g/m2. In this study the 100 meter depth had the lowest abundant and biomass while the 10 meter depth had the highest abundant and 20 , 50 meter had the highest biomass. There was seen the most and less biomass in Winter and Spring respectively. The observation number and biomass were high for Corophidae and Tubificidae that biomass was higher than 1 g/m2 . Although the frequency of Cardidae and Scorbiculidae were low they had the most biomass in this study. In generally the biomass were the most at out flowing of Anzali wetland and Sefidrud river and a small surface from the Astara-Ilashtpar regions and was not seen a distinct difference with study of Mirzajani in year of 1991-92. The results showed that there was not any significant difference in fish catch values to base on capture per unit effort (CPUE) for seven regions. The fish catch values was varied from 88 to 459 kg/cpue for 1991-92 and was 31 to 418 kglcpue for 1994-95. In general perspective the comparison of macro invertebrate biomass distribution maps with fish catch data showed a positive relation in many regions however it was not in other regions. The survey of fish catch data in 2000-01 showed the correction of this results where the Anzali region had the most fish catch values with a significant difference with Astara- Hashtpar and east of Guilan province regions.