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| 长江口禁捕区外鳗苗定置网兼捕鱼类种类组成 |
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陈昱颖1, 王晓东1, 施金金2, 赵度宾1, 陆天宇1, 刘企昂1, 钟俊生1, 汤建华2
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1.上海海洋大学;2.江苏省海洋水产研究所
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| 摘要: |
| 为探明长江大保护后长江口鳗苗定置网兼捕鱼类种类组成,2023年2-4月在长江口禁捕区北界外海域(31°42"N,122°11"E–122°13"E),收集鳗苗定置网内渔获物118网次。共采集到兼捕鱼类5482尾,隶属25科,47属,64种。其中,海洋性鱼类26种,河口性鱼类31种,洄游性鱼类5种,淡水性鱼类2种。发育阶段包括从后弯曲期到成鱼期,其中幼鱼最多,占总兼捕鱼类尾数的52.39%,其次是稚鱼23.61%。相对重要性指数IRI分析结果表明,优势种为矛尾虾虎鱼(Chaeturichthys stigmatias)和拉氏狼牙虾虎鱼(Odontamblyopus lacepedii)。重要种为刀鲚(Coilia nasus)、大银鱼(Protosalanx hyalocranius)、安氏新银鱼(Neosalanx anderssoni)、莱氏舌鳎(Cynoglossus lighti)、鲻(Mugil cephalus）、赤鼻棱鳀(Thryssa kammalensis)、陈氏新银鱼(Neosalanx tangkahkeii)、凤鲚(Coilia mystus)、棘头梅童鱼(Collichthys lucidus)。以上11种占总兼捕鱼类尾数的84.77%,占总兼捕鱼类重量的87.51%。最优势种矛尾虾虎鱼,占总兼捕鱼类尾数的8.99%,总重为21949.62g,占总兼捕鱼类重量的53.51%。次优势种拉氏狼牙虾虎鱼,占总兼捕鱼类尾数的26.71%,总重为5055.85g,占总兼捕鱼类重量的12.33%。兼捕鱼类数量2月最高,4月最低,渔获物重量也呈相同趋势。渔获物中兼捕经济鱼类共47种,平均每网44.13尾,占总渔获量的94.98%。采集鳗苗1363尾,平均每采集一尾鳗苗,兼捕经济鱼类3.82尾。结果表明,鳗苗定置网对非目标兼捕鱼类以及一些经济性鱼类的早期资源损害存在严重损害。 |
| 关键词: 长江口,鳗苗网,兼捕鱼类,鳗苗,种类组成 |
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| The species composition of bycatch fish collected in eel nets outside the Yangtze Estuary fishing ban area |
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Shi Jinjin1, Zhao Dubin2, Lu Tianyu2, Liu Qiang2, Zhong Junsheng2, Tang Jianhua1
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1.Jiangsu Marine Fisheries Research Institute;2.Shanghai Ocean University
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| Abstract: |
| In order to explore the species composition of eel nets in the Yangtze River Estuary after the Yangtze River fishing ban, a total of 118 eel nets were collected in the waters outside the northern boundary of the Yangtze River Estuary Fishing Ban Area (31°42"N,122°11"E–122°13"E) from February to April 2023. A total of 5,482 bycatch fish were collected, belonging to 25 families, 47 genera, and 64 species. Among them, there were 26 species of marine fish, 31 species of estuarine fish, 5 species of migratory fish, and 2 species of freshwater fish. The developmental stages included from the post-flexion stage to the adult stage, of which juvenile fish accounted for 52.39% of the total number of bycatch fish, followed by juvenile fish 23.61%. According to the relative importance index (IRI) analysis results, the dominant species were Chaeturichthys stigmatias and Odontamblyopus lacepedii . The important species were Coilia nasus, Protosalanx hyalocranius , Neosalanx anderssoni, Cynoglossus lighti , Mugil cephalus , Thryssa kammalensis , Neosalanx tangkahkeii , Coilia mystus , and Collichthys lucidus . These 11 species accounted for 84.77% of the total number of bycatch fish, accounting for 87.51% of the total weight of bycatch fish. Chaeturichthys stigmatias, the most dominant species, accounting for 8.99% of the total number of bycatch fish, and was caught at 71 sites. The total weight was 21949.62g, accounting for 53.51% of the total weight of bycatch fish. The second dominant species Odontamblyopus lacepedii, accounted for 26.71% of the total number of bycatch fish. The total weight was 5055.85g, accounting for 12.33% of the total weight of bycatch fish.The number of bycatch fish was the highest in February, lowest in April. The weight of collected fish showed same tendency. There were 47 economic fish collected, 44.13 ind./net, accounting for 94.98% of collected fishes. In addition, 1,363 eel were collected. One eel with an average of 3.82 economic fish were collected. The results showed that the eel nets not only causes damage to target fish, but also caused serious damage to bycatch fish, as well as individuals in the early development stages of some economic fish. |
| Key words: Yangtze River Estuary, eel net, bycatch fish, eel, species composition |
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