Improving water clarity is a core objective for eutrophication management in the Baltic Sea, but may influence fisheries via effects on fish habitat suitability. We apply an ensemble of species distribution models coupled with habitat productivity functions and willingness-to-pay estimates to assess these effects for two coastal predatory fish species, European perch (Perca fluviatilis) and pikeperch (Sander lucioperca). The models predicted a 37% increase in perch and 59% decrease in pikeperch biomass if reaching the reference level for water clarity in the Baltic Sea Action Plan. Reaching the target level was predicted to increase perch biomass by 13%. However, the associated economic gain for the recreational fisheries sector was countervailed by an 18% pikeperch reduction. Still, a net benefit was predicted since there are six times more fishing days for perch than pikeperch. We exemplify how ecological modelling can be combined with economic analyses to map and evaluate management alternatives.

中文翻译：

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预测富营养化缓解措施对掠食性鱼类生物量的影响以及休闲渔业的价值。

提高水的透明度是波罗的海富营养化管理的核心目标，但可能通过对鱼类栖息地适宜性的影响来影响渔业。我们将物种分布模型与栖息地生产力函数和支付意愿估算结合起来，以评估两种沿海掠食性鱼类欧洲鲈（Perca fluviatilis）和长鳍鲈（Sander lucioperca）的影响。）。这些模型预测，如果波罗的海行动计划中的水澄清度达到参考水平，鲈鱼的鲈鱼生物量将增加37％，鲈鱼的生物量将减少59％。预计达到目标水平会使鲈鱼生物量增加13％。但是，休闲渔业部门的相关经济收益却被减少了18％的鲈鱼所抵消。仍然可以预测会有净收益，因为鲈鱼的捕捞天数比鲈鱼多六倍。我们举例说明了如何将生态模型与经济分析相结合，以绘制和评估管理方案。