| 摘要: |
| 为了分析黄海区虾拖网网囊网目对副渔获物的选择性, 运用套网法对30, 33, 40 mm 3 种网目尺寸的网囊进行了选择性试验。用统计学方法求得几种优势副渔物的逃逸率, 并用极大似然法对渔获数据进行处理求得相关的选择性参数。结果表明, 大部分副渔获物的逃逸率随着网囊网目尺寸的增大而增大, 在网目尺寸为30, 33, 40 mm 时矛尾鰕虎鱼(Chaeturichthys stigmatias)的逃逸率分别为48.3%,59.7%和2.6%; 细巧仿对虾(Parapenaeopsis tenella)的逃逸率分别为67.0%, 68.2%, 68.7%。矛尾鰕虎鱼的选择性参数也随着网目尺寸的增大而增大, 在网目尺寸为30, 33, 40 mm 时, 矛尾鰕虎鱼的50%选择体长L50分别为81.858, 86.715 和88.028 mm, 选择范围SR 分别为41.097, 45.007 和50.423 mm。研究表明, 单靠放大网囊网目尺寸来释放虾拖网中副渔获物, 效果不甚理想。 |
| 关键词: 虾拖网 副渔获物 选择性 |
| DOI： |
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| 基金项目:国家科技支撑计划项目(2006BAD09A05) |
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| The selectivity of different mesh sized-codends of shrimp trawl to by-catch species |
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TANG Yan-li,YANG Bing-zhong,ZHAO Tong-yang,SUN Guo-wei,HUANG Liu-yi,LIANG Zhen-lin
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| Abstract: |
| In order to reveal the selectivity to by-catch species by shrimp trawls ,which is operated in the Yellow Sea, experiments of codends with mesh sizes, 30, 33, or 40 mm were conducted using the cover-net method. The escape rates of main by-catch species were measured, and the selectivity parameters of Chaeturichthys stigmatias were estimated by using the maximum likelihood method. The results indicated that the escape rates of main by-catch species increased as the mesh sizes were increased. For mesh sizes of 30, 33, and 40 mm the escape rates of C. stigmatias were 48.3%, 59.7%, and 62.6%, respectively; the escape rates of Parapenaeopsis tenella are 67.0%, 68.2% and 68.7%, respectively. The selectivity parameters of C. stigmatias also increased as mesh sizes were increased. For the mesh sizes of 30, 33, 40 mm, the L50 of C. stigmatias were 81.858, 86.715, and 88.028 mm, respectively; while the SR were 41.097, 45.007, and 50.423 mm, respectively. Based on the results, we concluded that the effect of releasing by-catch species were not very good only by enlarging mesh sizes. |
| Key words: shrimp trawl by-catch selectivity |
