ارزیابی ترکیب دورریز صید ترال ماهی در آبهای ساحلی استان خوزستان (مطالعه موردی: صیدگاه بوسیف)

ﻣﻄﺎﻟﻌﻪ ﺣﺎﺿﺮ ﺑﺎ ﻫﺪف ﺗﺨﻤﯿﻦ ﻣﯿﺰان و ﺗﺮﮐﯿﺐ ﮔﻮﻧﻪﻫﺎی دوررﯾﺰ ﺻﯿﺪ در ﺗﻮر ﺗﺮال ﮐﻒ و ﭘﺎراﻣﺘﺮﻫﺎی زﯾﺴﺘﯽ ﺑﺮﺧﯽ ﮔﻮﻧﻪﻫﺎ در ﻣﻨﻄﻘﻪ ﺑﻮﺳﯿﻒ در آبﻫﺎی ﺳﺎﺣﻠﯽ اﺳﺘﺎن ﺧﻮزﺳﺘﺎن ﺻﻮرت ﭘﺬﯾﺮﻓﺖ. دادهﻫﺎ ﺑﺮ اﺳﺎس ﻧﻤﻮﻧﻪﻫﺎی ﺣﺎﺻﻞ از ﺻﯿﺪ ﺗﺠﺎری و ﺑﻪوﺳﯿﻠﻪ ﻟﻨﺞ ﻫﺎی ﺻﯿﺎدی ﺗﺮال ﮐﻒ در ﺳﻪ ﻓﺼﻞ ﭘﺎﯾﯿﺰ و زﻣﺴﺘﺎن ﺳﺎل 96 و ﺗﺎﺑﺴﺘﺎن ﺳﺎل 97 ﺟﻤﻊآوری ﺷﺪﻧﺪ. ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ از اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﻧﺸﺎن داد ﻧﻤﻮﻧﻪﻫﺎی دوررﯾﺰ ﺷﺪه ﺷﺎﻣﻞ33 ﮔﻮﻧﻪ از 28 ﺧﺎﻧﻮاده ﺑﻮدﻧﺪ. ﺑﺮ اﺳﺎس ﻧﺘﺎﯾﺞ ﺣﺎﺻﻞ ﮔﻮﻧﻪﻫﺎی ﺳﻨﮕﺴﺮ ﭼﻬﺎرﺧﻂ و ﭘﻨﺠﺰاری ﺑﺎﻟﻪ ﻧﺎرﻧﺠﯽ ﺑﯿﺸﺘﺮﯾﻦ ﻓﺮاواﻧﯽ را داﺷﺘﻨﺪ. ﻫﻤﭽﻨﯿﻦ ﻧﺘﺎﯾﺞ ﺑﺪﺳﺖ آﻣﺪه ﻧﺸﺎن داد ﻣﯿﺎﻧﮕﯿﻦ ﻃﻮﻟﯽ اﻏﻠﺐ ﮔﻮﻧﻪﻫﺎ دوررﯾﺰ ﺷﺪه در اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﮐﻤﺘﺮ از 30 ﺳﺎﻧﺘﯿﻤﺘﺮ ﺑﻮد. ﻫﻤﭽﻨﯿﻦ ﻣﯿﺰان دوررﯾﺰ ﺑﻪ ازای واﺣﺪ ﺗﻼش ﺻﯿﺎدی در ﻓﺼﻞ ﻫﺎی ﭘﺎﯾﯿﺰ، زﻣﺴﺘﺎن و ﺗﺎﺑﺴﺘﺎن ﺑﻪ ﺗﺮﺗﯿﺐ 27/16±50/64 ،57/9±33/87 و 32/33±7/50 ﮐﯿﻠﻮﮔﺮم در ﺳﺎﻋﺖ ﺑﻮد. ﻫﻤﭽﻨﯿﻦ ﻣﯿﺰان ﺻﯿﺪ دوررﯾﺰ ﺑﻪ ازای واﺣﺪ ﺳﻄﺢ در ﭘﺎﯾﯿﺰ، زﻣﺴﺘﺎن و ﺗﺎﺑﺴﺘﺎن ﺑﻪ ﺗﺮﺗﯿﺐ 0/73±0/39 ،2/77±0/064 و 1/73±0/44 ﮐﯿﻠﻮﮔﺮم ﺑﺮ ﻣﺎﯾﻞ ﻣﺮﺑﻊ ﻣﺤﺎﺳﺒﻪ ﺷﺪ. ﻣﯿﺰان اﯾﻦ ﺷﺎﺧﺺ ﻫﺎ در ﻓﺼﻞ زﻣﺴﺘﺎن ﺑﻪ ﻃﻮر ﻣﻌﻨﯽ داری ﻧﺴﺒﺖ ﺑﻪ ﻓﺼﻮل ﭘﺎﯾﯿﺰ و ﺗﺎﺑﺴﺘﺎن ﮐﻤﺘﺮ ﺑﻮد )0/05

discards characteristics of bottom trawl fishery in khuzestan coastal waters (case study: bosif fishing grounds)

the aim of this study was to estimate the amount and species composition of discards in bottom trawl fisheries in the bosif fishing ground in the coastal waters of khuzestan. furthermore, the biological parameters of discarded species were assessed. specimens were collected from commercial catch data of trawl vessels in three seasons, autumn and winter 2017 and summer 2018. the results showed that discarded samples included 33 species from 28 families. orangefin pony fish and striped piggy species were the most frequent species in this study. the results also showed that the mean length of most of the discards species was below 30 centimeters. the amount of discards per unit of catching effort was 57.33±9.87, 27.50±16.64 and 32.33±7.50 in the autumn, winter and summer seasons, respectively. the catch per surface area in autumn, winter and summer were 2.77 ± 0.064, 0. 73 ±0.39 and 1.73 ± 0.44 kg/nm2, respectively. the results showed that cpue and cpua in winter were significantly higher than those in autumn and summer (p<0.05). in general, the results of this study represent high fishing pressure on ecologically important species in bosif fishing ground especially in their critical life cycle which may affect local ecosystem structure and function in future.