Generally, the catch efficiency (CE) of a set net is difficult to evaluate because it is affected by fish behavior. Therefore, to evaluate CE, we proposed a fish school behavior simulation model based on the boid model and applied it to a full-scale set net. The moving path of the fish school around the set net was simulated and visualized via the proposed method. From the moving path, three behaviors were identified: all individuals entering, all individuals escaping, and the school dividing in the entrance. A Monte Carlo simulation was conducted to evaluate the relationship between set net entrance shape and CE. The entrance net angle (θ) was considered over a range of 55°–90°. The ratio of fish entering the set net was ~ 60% at θ = 60°–90°, and significantly lower at θ = 55°. After entering the playground, over 80% of individuals entered the bag net. When θ = 60°, the ratios of fish escaping from the set net and entering the bag net were at their lowest and highest, respectively. Therefore, maximum CE was achieved at θ = 60°. We conclude that the proposed simulation method will contribute to more efficient set net design.

中文翻译：

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使用鱼群行为模型模拟集网捕鱼的捕获过程

通常，固定网的捕捞效率 (CE) 难以评估，因为它受鱼类行为的影响。因此，为了评估 CE，我们提出了一种基于 boid 模型的鱼群行为模拟模型，并将其应用于全尺寸集网。通过所提出的方法模拟并可视化了鱼群围绕固定网的移动路径。从移动路径上，识别出三种行为：所有个体进入，所有个体逃离，以及在入口处划分学校。进行蒙特卡罗模拟以评估设定的净入口形状与 CE 之间的关系。入口净角 (θ) 被考虑在 55°–90° 的范围内。进入固定网的鱼的比例在 θ = 60°–90° 时约为 60%，在 θ = 55° 时显着降低。进入游乐场后，超过80%的人进入了袋网。当 θ = 60°时，鱼从套网和进入袋网的比例分别为最低和最高。因此，在 θ = 60° 时实现了最大 CE。我们得出结论，所提出的模拟方法将有助于更有效的集合网络设计。