Abstract: (2512 Views)
This research was carried out in wild common carp (Cyprinus carpio) culture pens in Gorgan bay in 2011. Macrobenthoses were sampled from four stations, seasonally. Results showed that the most frequency of macrobenthoses in spring, summer, autumn and winter belonged to Phyrgulidae with frequency of 2430, 30451, 390, and 40 N/m2, respectively. The least frequency belonged to the families Nereidae, Cardidae, and Amphartidae (288 N/m2) in spring, Nereidae, Cardidae Neritidae, and Chironomidae in summer (288 N/m2), Nereidae, Cardidae, and Neritidae (39 N/m2) in autumn and Balanus (1 N/m2) in winter. In addition, the biomass was reduced to 1g/m2 in winter. The results showed that decreasing the water temperature from summer to winter caused decreasing the biomass of macrobenthoses in Gorgan bay. The species diversity indices were calculated using Shannon and Simpson indices. Based on the results, in treatment 1 (2fish/ m2), the lowest and highest diversity index was observed in winter with 0.13 and autumn with 0.55, respectively, but in treatment 2, the lowest and highest diversity index was 0.18 in winter and 0.76 in spring, respectively. The highest Shannon index was 0.94 in control station in spring, indicating that the diversity at the control station with no cultured fish was the greatest.
Type of Study:
Research |
Subject:
Special Published: 2019/09/23