| 摘要: |
| 为了研究桁杆虾拖网40 mm方目分离网片对渔获物的分隔效果和选择性, 作者采用“套网法”于2015年8月在南海北部近海渔场进行了试验。计算分离网片对主要渔获物的尾数分隔率和质量分隔率, 使用Logistic曲线作为选择性模型, 运用极大似然估算法估算选择性参数。结果表明: 虾拖网的目标种类为刀额新对虾(Metapenaeus ensis)和周氏新对虾(Metapenaeus joyneri), 优势副渔获为丽叶鲹(Caranx (Atule)kalla); 刀额新对虾和周氏新对虾的尾数分隔率和质量分隔率均大于90%; 尾数分隔率和质量分隔率均大于80%的种类有: 杂食豆齿鳗(Pisoodonophis boro)、黄斑蓝子鱼(Siganus oramin)、高体若鲹(Carangoides equula)和卵鳎(Solea ovata Richardson); 丽叶鲹和脊突猛虾姑(Harpiosquilla raphidea)的尾数分隔率和质量分隔率均大于60%; 周氏新对虾、脊突猛虾姑、丽叶鲹和黄斑蓝子鱼对分离网片的接触率分别为0.51、0.69、0.41 和0.39, 其50%选择体长(L50)分别为57.96±2.07、69.62±2.13、68.19±0.49和73.12 mm±1.26 mm。研究结果可为提高南海桁杆虾拖网的选择性积累数据, 为缓解其对渔业资源补充群体的不良影响提供参考。 |
| 关键词: 虾拖网 分离网片 分隔率 选择性 |
| DOI：10.11759/hykx20170524004 |
| 分类号: |
| 基金项目:公益性行业(农业)科研专项(201203018); 农业部财政项目(20161102、20171102) |
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| Preliminary study of selectivity of separator panel with 40 mm square mesh of shrimp beam trawl in the South China Sea |
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YANG Bing-zhong,YANG Lin,TAN Yong-guang,Yan Lei,ZHANG Peng,LI Jie
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| Abstract: |
| We conducted fishing experiments using the covered codend method in August 2015 to assess the separating effect and the selectivity of separator panel with 40-mm square mesh for the major species in the northern South China Sea. The separating rates, both in number and in weight, of the major species were calculated. The logistic model was chosen to express the size selection, and the maximum likelihood method was used to estimate the parameters. The results indicated that the target species of the shrimp beam trawl were Metapenaeus ensis and M. joyneri, and the major by-catch species was Caranx (Atule) kalla. The separating rates of both M. ensis and M. joyneri were larger than 90%. The separating rates, both in number and in weight, were larger than 80% for four by-catch species, Pisoodonophis boro, Siganus oramin, Carangoides equula, and Solea ovata Richardson. For Caranx (Atule) kalla and Harpiosquilla raphidea, the separating rates were larger than 60%. The contact probabilities were 0.51, 0.69, 0.41, and 0.39, and the 50% selection lengths (L50) were 57.96±2.07, 69.62±2.13, 68.19±0.49, and 73.12 mm±1.26 mm for M. joyneri, H. raphidea, Caranx (Atule)kalla, and S. oramin, respectively. Our results may be useful for improving the size selectivity and addressing the negative impact of the shrimp beam trawl of the northern South China Sea on the recruitment of fishery resources. |
| Key words: shrimp beam trawl separator panel separating rate selectivity |
