مقایسه ترکیب و تنوع گونه‌ای آبزیان صید شده در گرگورهای بندر بوشهر در فصل زمستان

ﻣﻄﺎﻟﻌﻪ ﺣﺎﺿﺮ ﺑﺎ ﻫﺪف ﻣﻘﺎﯾﺴﻪ ﺗﺮﮐﯿﺐ و ﺗﻨﻮع ﮔﻮﻧﻪای آﺑﺰﯾﺎن ﺻﯿﺪ ﺷﺪه در ﮔﺮﮔﻮرﻫﺎ در اﻋﻤﺎق و زﻣﺎنﻫﺎی ﻏﻮﻃﻪوری ﻣﺘﻔﺎوت در ﻓﺼﻞ زﻣﺴﺘﺎن اﻧﺠﺎم ﺷﺪ. اﯾﻦ ﻣﻄﺎﻟﻌﻪ در ﺑﻨﺪر ﺑﻮﺷﻬﺮ و در اﺳﻔﻨﺪ ﻣﺎه 1395 ﺻﻮرت ﭘﺬﯾﺮﻓﺖ. ﮔﺮﮔﻮر ﻣﻮرد اﺳﺘﻔﺎده دارای اﻧﺪازه ﭼﺸﻤﻪ 3/5-4 ﺳﺎﻧﺘﯽﻣﺘﺮ، ﺳﻄﺢ ﻣﻘﻄﻊ 150 ﺳﺎﻧﺘﯽﻣﺘﺮ، ارﺗﻔﺎع 87-92 ﺳﺎﻧﺘﯽﻣﺘﺮ، اﻧﺪازه دﻫﺎﻧﻪ ﺧﺎرﺟﯽ 70-79 ﺳﺎﻧﺘﯽﻣﺘﺮ و اﻧﺪازه دﻫﺎﻧﻪ داﺧﻠﯽ 35-36 ﺳﺎﻧﺘﯽﻣﺘﺮ ﺑﻮد. ﻣﻘﺎﯾﺴﻪﻫﺎی ﺗﺮﮐﯿﺐ ﮔﻮﻧﻪای ﺑﺮاﺳﺎس وزن و ﺗﻌﺪاد و ﻣﻘﺎﯾﺴﻪﻫﺎی ﺗﻨﻮع ﮔﻮﻧﻪای ﻃﺒﻖ ﺷﺎﺧﺺ ﺷﺎﻧﻮن ﺑﺮرﺳﯽ ﺷﺪ. ﺗﺮﮐﯿﺐ ﮔﻮﻧﻪای آﺑﺰﯾﺎن ﺻﯿﺪ ﺷﺪه در ﮔﺮﮔﻮرﻫﺎ ﺷﺎﻣﻞ 12 ﮔﻮﻧﻪ از ﻣﺎﻫﯿﺎن اﺳﺘﺨﻮاﻧﯽ ﻣﺘﻌﻠﻖ ﺑﻪ 7 ﺧﺎﻧﻮاده، 1 ﮔﻮﻧﻪ از ﺳﺨﺖﭘﻮﺳﺘﺎن و 1 ﮔﻮﻧﻪ از ﻧﺮمﺗﻨﺎن (ﻣﺎﻫﯽ ﻣﺮﮐﺐ ﺑﺒﺮی) ﺑﻮد ﮐﻪ در اﻋﻤﺎق ﻫﻤﭽﻨﯿﻦ زﻣﺎنﻫﺎی ﻏﻮﻃﻪوری ﻣﺨﺘﻠﻒ ﺗﻔﺎوت ﻣﻌﻨﯽداری داﺷﺖ (0/05> p). ﺷﺎﺧﺺ ﺷﺎﻧﻮن ﮔﺮﮔﻮرﻫﺎ ﺑﺮای اﻋﻤﺎق 25-40 ﻣﺘﺮ و 10-25 ﻣﺘﺮ ﺑﻪﺗﺮﺗﯿﺐ 1.421 (±0.362 s.d.) و 1.229 (±0.345 s.d.)ﺑﻮد. اﯾﻦ ﺷﺎﺧﺺ ﺑﺮای زﻣﺎنﻫﺎی ﻏﻮﻃﻪوری 8-14 روز و 2-8 روز ﺑﻪﺗﺮﺗﯿﺐ 1.441 (±0.302 s.d.) و 1.228 (±0.393 s.d.) ﺑﻮد. ﺷﺎﺧﺺ ﺷﺎﻧﻮن ﺑﯿﺎﻧﮕﺮ ﺗﻨﻮع زﯾ ﺴﺘﯽ ﺑﯿ ﺸﺘﺮ ﮔﺮﮔﻮرﻫﺎ در اﻋﻤﺎق 25-40 ﻣﺘﺮ ﻧ ﺴﺒﺖ ﺑﻪ 10-25 ﻣﺘﺮ و ﻫﻤﭽﻨﯿﻦ زﻣﺎنﻫﺎی ﻏﻮﻃﻪوری 8-14 روز ﻧﺴﺒﺖ ﺑﻪ 2-8 روز ﺑﻮد (0/05˃ p). در ﻓﺼﻞ زﻣﺴﺘﺎن ﺑﺎ ورود ﻣﺎﻫﯽ ﻣﺮﮐﺐ ﺑﺒﺮی ﺑﻪ ﺻﯿﺪﮔﺎهﻫﺎی ﮔﺮﮔﻮر در ﺑﻨﺪر ﺑﻮﺷﻬﺮ، اﺛﺮﮔﺬاری ﺑﺎﻻی آن ﺑﺮ ﺗﺮﮐﯿﺐ ﮔﻮﻧﻪای ﮔﺮﮔﻮرﻫﺎ ﻗﺎﺑﻞ ﻣ ﺸﺎﻫﺪه ا ﺳﺖ؛ زﯾﺮا اﯾﻦ ﮔﻮﻧﻪ ﻣ ﺴﺌﻮل ﺑﯿ ﺸﺘﺮﯾﻦ ﻋﺪم ﺗ ﺸﺎﺑﻪ اﯾﺠﺎد ﺷﺪه در ﺗﺮﮐﯿﺐ ﮔﻮﻧﻪای اﻋﻤﺎق ﻫﻤﭽﻨﯿﻦ زﻣﺎنﻫﺎی ﻏﻮﻃﻪوری ﻣﺘﻔﺎوت ﺑﻮد. ﺿﻤﻨﺎً ﺑﺎ در ﻧﻈﺮ ﮔﺮﻓﺘﻦ اﺛﺮ ﻣﺘﻘﺎﺑﻞ ﻋﻤﻖ و زﻣﺎن ﻏﻮﻃﻪوری، ﺑﯿﺸﺘﺮﯾﻦ ﻣﻘﺎدﯾﺮ ﺷﺎﺧﺺ ﺷﺎﻧﻮن در ﮔﺮﮔﻮرﻫﺎی اﻋﻤﺎق 10-25 ﻣﺘﺮ ﻫﻤﺮاه ﺑﺎ 8 ﺗﺎ 14 روز ﻏﻮﻃﻪوری ﻣﺸﺎﻫﺪه ﺧﻮاﻫﺪ ﺷﺪ.

Comparison of the species composition and the diversity of retained aquatics in the Bushehr port's Gargoors in the winter season

The present study was carried out with a purpose to compare the species composition and diversity of the Gargoor's trapped aquatics in different depths and soak times in the winter season. This study was done in the port of Bushehr from February to March 2017. The using Gargoors had mesh size of 3.54 cm, cross section 150 cm, height 8792 cm, outer span size 7079 cm and internal span size 3536 cm. Comparisons of species composition and diversity were based on weight furthermore number and the Shannon index, respectively. The species composition of the Gargoor's trapped aquatics included 12 species of bony fishes belonging to 7 families, one species of crustaceans, and one species of mollusks (Pharaoh Cuttlefish); While there was a significant difference in different depths as well as soak times (p <0.05). Gargoor's Shannon index for depths of 2540 meters and 1025 meters was 1.421 (±0.362 S.D.) and 1.229 (±0.345 S.D.), respectively. This index for soak times of 814 days and 28 days was 1.441 (±0.302 S.D.) and 1.228 (±0.393 S.D.), respectively. The Shannon index represented the more biodiversity of Gargoors between depths of 2540 meters compared to 1025 meters, as well as the soak times of 814 days compared to 28 days (p ˃0.05). In winter, with the arrival of Pharaoh Cuttlefish in the Gargoor's fishing grounds in Bushehr port is evident, this has high effect on the species composition of Gargoors and it was responsible for the most dissimilarity in the species composition of different depths and soak times as well. Also, if the interaction between depth and soak time taking into account, the highest values of the Shannon index observed in the depths between 1025 meters, with 814 days of soak time.