Research on methodology to develop bottom seine nets for exclusion of bycatch

开发底部围网以排除兼捕的方法研究

• 批准号: 09660208
• 负责人: MATSUOKA Tatsuro
• 金额: $ 0.96万
• 依托单位: Kagoshima University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C).
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09660208/
• 关键词: Prawn; bottom seine; selectivity; bycatch; behaviour; simulation; coastal environment

Danish seine gear was studied on a combination of a tank experiment and operational survey with a gear newly designed for exclusion of bycatch as;(1) Observation of behavior of prawns to pass through meshes in a small-tank clarified that probability for prawns to be excluded is ruled by probability to pass through one mesh at once encountering and the probabilistic number of encountering for one prawn. The logistic selectivity of seine nets is induced by repetition of encountering to meshes by organisms. Simulation based on this model well represented the selectivity curve of Danish seine nets obtained from previous trials.(2) An experimental Danish seine net for exclusion of bycatch finfishes was designed on the basis of the above simulation and its selectivity was examined. Effects of enlargement and opening of meshes was as expected. A mesh size and fish size management diagram to design bycatch-exclusive fishing gears was proposed.(3) Behavior of finfish to Danish seine was observed underwater by diving. Few finfish were observed in front of the main net and they were conjectured to be excluded more anterierly. Selectivity of Danish seine was hypothesised to be affected by towing ropes, therefore, their motion while being towed was experimented in air. Difference in motion of ropes of a variation in structure under a variation of set condition on ground appeared around anterior positions of the ropes. This indicates that studies on selectivity of seine nets must take stimulation by ropes to organisms into account.(4) While the above experimental studies, record of discards of bycatch in small coastal Danish seine previously surveyed was analysed and it was clarified that evaluation and estimation of discards based on a newly-introduced concept, i.e. discard per unit effort (DPUE) is most accurate and reliable.

对丹麦塞纳河渔具进行了水箱试验和作业调查相结合的研究，采用了一种新设计的用于排除副渔获物的渔具；(1)对小池中对虾通过网眼行为的观察表明，对虾被排除在外的概率由一次相遇通过一个网眼的概率和一只对虾的概率相遇次数决定。围网的逻辑选择性是由生物与网的重复相遇引起的。基于该模型的仿真较好地反映了前人试验所得的丹麦围网的选择性曲线。(2)在此基础上设计了排除副渔获物的丹麦围网实验网，并对其选择性进行了检验。扩大和打开网格的效果与预期一致。提出了一种用于设计专用副渔具的网目尺寸和鱼体尺寸管理图。(3)水下潜水观察了鳍鱼对丹麦塞纳河的行为。在主网前观察到的鱼很少，推测它们更早被排除在外。假设丹麦塞纳河的选择性受到拖曳绳索的影响，因此，在空气中实验了它们被拖曳时的运动。在不同的地面设置条件下，不同结构的绳索的运动差异出现在绳索前部周围。这表明对围网选择性的研究必须考虑到绳索对生物体的刺激。(4)在上述实验研究的基础上，对以往调查的丹麦沿海小塞纳河副渔获物丢弃量记录进行了分析，明确了基于单位努力丢弃量（DPUE）这一新引入的概念对丢弃量的评价和估计是最准确和可靠的。

项目成果

Tatsuro Matsuoka: "Sampling and estimation of discards in multi-species fisheries"FAO, United Nations. 11 (1999)

Tatsuro Matsuoka：“多物种渔业中丢弃物的采样和估计”联合国粮农组织。

Tatsuro Matsuoka et al.: "Assessment by underwater infrared video of the selectivity of an experimental Danish seine for deep-water prawn" CSIRO Publishing,Australia, 551-557 (1997)

Tatsuro Matsuoka 等人：“通过水下红外视频评估丹麦实验围网对深水虾的选择性”CSIRO Publishing，澳大利亚，551-557 (1997)

松岡達郎: "混獲・投棄問題の研究手法と資源保全への応用"月間 海洋. 30・4. 193-197 (1998)

松冈达郎：“兼捕和丢弃问题的研究方法及其在资源保护中的应用”海洋月刊 193-197（1998）。

Tatsuro Matsuoka: "Methodology to study bycatch and discards and its application to conservation of resources"Ocean. Vol.30-4. 193-197 (1998)

Tatsuro Matsuoka：“研究兼捕和丢弃物的方法及其在资源保护中的应用”海洋。

Tatsuro Matsuoka: "Sampling and estimation of discards in multi-species fisheries International Conference on Integrated Fisheries Monitoring"Food and Agriculture Organizations, United Nations. (1999)

Tatsuro Matsuoka：“多物种渔业中丢弃物的采样和估计国际综合渔业监测会议”联合国粮食及农业组织。