The European sea bass (Dicentrarchus labrax) is a slow growing and late maturing high value fish that is exploited by both commercial and recreational fisheries. In recent years, scientific assessments have shown a rapid decline in spawning stock biomass around the UK attributed to poor recruitment (driven by environmental factors) and high fishing mortality. This resulted in significant reductions in the harvest of sea bass following technical measures implemented by the European Commission to conserve stocks. Individual-based models (IBMs) are simulations of individual ‘agents’ of organisms that interact with each other and their environment locally and have been shown to be effective management tools in many systems. Here, an IBM that simulates the population dynamics and spatial distribution of sea bass was developed to assess how technical management measures applied to subsets of the population impact the overall stock. Conventional stock assessment techniques were used to model the processes affecting population dynamics, while the spatial distribution was simulated using a combination of temperature preferences and information from tagging studies. The IBM was parameterised using existing knowledge from the literature and can mimic key assessment outputs used to inform management and advice on fishing opportunities. Utility of the IBM is demonstrated by simulating the population consequences of several key management scenarios based on those implemented by the European Commission, including short-term bans on pelagic trawling in spawning areas, commercial and recreational catch limits and increasing the minimum conservation reference size. The IBM has potential to complement the annual stock assessment in managing European sea bass because it models individual movement, environmental drivers and emergent spatial distribution, thereby providing enhanced predictions of management strategy outcomes that could inform spatial advice on fishing opportunities and policy.

中文翻译：

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一种空间明确的基于个体的模型，用于支持欧洲鲈鱼 Dicentrarchus labrax 的商业和休闲渔业管理

欧洲鲈鱼 (Dicentrarchus labrax) 是一种生长缓慢、晚熟的高价值鱼类，被商业和休闲渔业利用。近年来，科学评估表明，由于补充不足（受环境因素驱动）和高捕捞死亡率，英国各地的产卵种群生物量迅速下降。在欧盟委员会采取技术措施保护种群之后，这导致鲈鱼的收获量显着减少。基于个体的模型 (IBM) 是对有机体的个体“代理”的模拟，这些个体与彼此及其本地环境相互作用，并且已被证明是许多系统中的有效管理工具。这里，开发了一个模拟鲈鱼种群动态和空间分布的 IBM，以评估应用于种群子集的技术管理措施如何影响整体种群。传统的种群评估技术被用来模拟影响种群动态的过程，而空间分布是使用温度偏好和标签研究信息的组合来模拟的。IBM 使用文献中的现有知识进行参数化，可以模拟用于通知管理和捕鱼机会建议的关键评估输出。IBM 的效用通过模拟几个基于欧盟委员会实施的关键管理方案的种群后果来证明，包括在产卵区短期禁止远洋拖网捕捞，商业和休闲捕捞限制并增加最低保护参考规模。IBM 有潜力补充管理欧洲鲈鱼的年度种群评估，因为它对个体运动、环境驱动因素和紧急空间分布进行建模，从而提供对管理战略结果的增强预测，可为捕捞机会和政策提供空间建议。