Baltic Sea Centre, Stockholm University, Stockholm, Sweden.
German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Germany.
PLoS One. 2019 Jan 28;14(1):e0211320. doi: 10.1371/journal.pone.0211320. eCollection 2019.
Different ecosystem models often provide contrasting predictions (model uncertainty), which is perceived to be a major challenge impeding their use to support ecosystem-based fisheries management (EBFM). The focus of this manuscript is to examine the extent of model disagreements which could impact management advice for EBFM in the central Baltic Sea. We compare how much three models (EwE, Gadget and a multispecies stock production model) differ in 1) their estimates of fishing mortality rates (Fs) satisfying alternative hypothetical management scenario objectives and 2) the outcomes of those scenarios in terms of performance indicators (spawning stock biomasses, catches, profits). Uncertainty in future environmental conditions affecting fish was taken into account by considering two seal population growth scenarios and two nutrient load scenarios. Differences in the development of the stocks, yields and profits exist among the models but the general patterns are also sufficiently similar to appear promising in the context of strategic fishery advice. Thus, we suggest that disagreements among the ecosystem models will not impede their use for providing strategic advice on how to reach management objectives that go beyond the traditional maximum yield targets and for informing on the potential consequences of pursuing such objectives. This is especially true for scenarios aiming at exploiting forage fish sprat and herring, for which the agreement was the largest among our models. However, the quantitative response to altering fishing pressure differed among models. This was due to the diverse environmental covariates and the different number of trophic relationships and their functional forms considered in the models. This suggests that ecosystem models can be used to provide quantitative advice only after more targeted research is conducted to gain a deeper understanding into the relationship between trophic links and fish population dynamics in the Baltic Sea.
不同的生态系统模型通常提供相互矛盾的预测（模型不确定性），这被认为是阻碍其用于支持基于生态系统的渔业管理（EBFM）的主要挑战。本文的重点是检验模型分歧的程度，这些分歧可能会影响到波罗的海中部 EBFM 的管理建议。我们比较了三个模型（EwE、Gadget 和多物种种群生产模型）在以下方面的差异：1）满足替代假设管理情景目标的捕捞死亡率（Fs）估计值；2）这些情景在性能指标（产卵种群生物量、捕捞量、利润）方面的结果。通过考虑两种海豹种群增长情景和两种营养负荷情景，考虑了未来影响鱼类的环境条件的不确定性。尽管模型之间存在着种群、产量和利润的发展差异，但总体模式也足够相似，在战略渔业建议方面具有很大的前景。因此，我们认为生态系统模型之间的分歧不会阻碍它们用于提供关于如何实现超越传统最大产量目标的管理目标的战略建议，也不会阻碍它们用于通知追求这些目标的潜在后果。对于旨在开发饲料鱼鲱鱼和鲱鱼的情景尤其如此，在我们的模型中，这些情景的一致性最大。然而，改变捕捞压力的定量反应在模型之间存在差异。这是由于不同的环境协变量以及模型中考虑的营养关系的数量和功能形式不同。这表明，只有在进行更有针对性的研究，以更深入地了解波罗的海营养联系与鱼类种群动态之间的关系后，才能使用生态系统模型来提供定量建议。
