Mehrnaz Shirmohammadi; Babak Doustshenas; Simin Dehghan Mediseh; Ahmad Savari; Nasrin Sakhaei
Volume 12, Issue 1 , April 2013, , Pages 59-66
Abstract
The study took place to survey the changes in diversity and distribution of Polychaetes in fishing area of Bahrakan, due to the trawling. Sampling was taken before (15 May) of trawling and two weeks (5 Sep) and three months (14 Nov) after trawling in 2010, in three period in Bahrakan coast. Therefore, ...
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The study took place to survey the changes in diversity and distribution of Polychaetes in fishing area of Bahrakan, due to the trawling. Sampling was taken before (15 May) of trawling and two weeks (5 Sep) and three months (14 Nov) after trawling in 2010, in three period in Bahrakan coast. Therefore, eighteen stations placed with the depth of 6 meters and 10 meters.The amount abundance Polychaetes had decreased significantlyin both depths two weeks after trawling (P<0.05). Also in 6m depth, no significant difference was observed between abundance Polychaetes in two weeks and three months after the trawling (p>0.05). Only in 10m depth, abundance Polychaetes after three months comparing to two weeks after trawling had increased significantly (p<0.05). Changing biomass Polychaetes was similar to Changing abundance. After the trawling, small size individuals became dominant.Abundance Species ofCossura longicirrattahad increased in both depths in two weeks after the trawling. Also in both depths, Shannon Diversity and Margalef Species Richness indices showedprocess decreasing and Simpson dominant Index showedprocess increasing. In both depths, Pielou Evenness Index two after trawling had increased. While, after three months comparing to two weeks after trawling had decreased and most effects of trawling were on 6m depth.
Soroor Peyghan; Ahmad Savari; Nasrin Sakhaee; Babak Doustshenas; Simin Dehghan Madiseh
Volume 11, Issue 4 , March 2013, , Pages 74-82
Abstract
The present investigation is based on separation and identification of Planktonic Poecilostomatoida in Bahrakan waters during July, August, October of 2010 and December, February, April of 2011. In this study The order of Poecilostomatida was represented by 3 species, Corycaeus andrewsi and Sapphirina ...
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The present investigation is based on separation and identification of Planktonic Poecilostomatoida in Bahrakan waters during July, August, October of 2010 and December, February, April of 2011. In this study The order of Poecilostomatida was represented by 3 species, Corycaeus andrewsi and Sapphirina nigromaculata andSaphirella- like copepodid. Abundance of each species was measured in sampling months. The highest density of Poecilostomatoid copepods were recorded in August and October 2010. C. andrewsiwith relative frequency of 73% was dominant species during the studying period among Poecilostomatoida and maximum abundance of it were observed in October 2010. Saphirella- like copepodid was observed in all sampling months. Maximum abundance of this species was in August and October 2010 and this report is the first report of this species in the Persian Gulf. There was Positive significant correlation coefficient between density of C. andrewsi and water salinity (P<0.05) but there was no significant correlation between the rest species and water parameters.