Abstract With successful mitigation of eutrophication and the reductions in nutrient concentrations and productivity of coastal waters, the targets set in nature protection legislation in the EU and the United States may no longer be achievable in regions where key ecological functions are coupled to benthic productivity. Yet, due to both the patchiness of invertebrate distribution and the fragmented and non-integrated nature of monitoring data direct coupling between nutrients, productivity and predators has proven difficult to achieve. As a result, assessments of the status of food webs based solely on monitoring data remains an almost impossible task. The aim of this modelling study was to test the application of fine-scale ecosystem models for assessing cost-benefits or food-web consequences of management decisions in relation to water quality of coastal waters. We applied a fine-scale ecosystem model calibrated against measurements in a coastal area in the Baltic Sea to quantify responses in higher trophic levels to changes in eutrophication over a 18-year period, 1990-2007. The resulting spatio-temporal trends reveal a number of characteristic responses and spatial dimensions in coastal food webs. The coupled hydrodynamic, bio-geochemical and waterbird energetics modules indicated nutrient-related changes and fine-scale covariance patterns across all trophic levels. A 50 % decline in bivalve biomass was predicted in a zone characterised by the overall highest biomass of bivalves and highest densities of bivalve-feeding waterbirds. The nutrient-driven local decline in productivity affected the entire food web with a predicted annual mortality of 72,000 Long-tailed Ducks Clangula hyemalis. This model-based study suggests a strong nutrient control of the available food supply to bivalve-feeding birds in coastal areas. Our results also show that high-resolution ecosystem models are required to resolve the heterogeneous distribution of effects.

中文翻译：

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波罗的海沿岸地区对富营养化控制的食物网反应

摘要 随着富营养化的成功缓解以及沿海水域养分浓度和生产力的降低，欧盟和美国自然保护立法中设定的目标可能无法在关键生态功能与底栖生产力相结合的地区实现。然而，由于无脊椎动物分布的不均匀性以及监测数据的分散和非整合性，营养物质、生产力和捕食者之间的直接耦合已被证明难以实现。因此，仅根据监测数据评估食物网状态仍然是一项几乎不可能完成的任务。本建模研究的目的是测试精细生态系统模型在评估与沿海水域水质相关的管理决策的成本效益或食物网后果方面的应用。我们应用了一个精细尺度的生态系统模型，该模型根据波罗的海沿海地区的测量结果进行了校准，以量化较高营养水平对 1990-2007 年 18 年间富营养化变化的响应。由此产生的时空趋势揭示了沿海食物网中的许多特征响应和空间维度。耦合的流体动力学、生物地球化学和水鸟能量学模块显示了所有营养级别的营养相关变化和精细尺度协方差模式。在以双壳类生物量总体最高和以双壳类动物为食的水鸟密度最高的区域中，预计双壳类生物量将下降 50%。营养驱动的局部生产力下降影响了整个食物网，预计每年有 72,000 只长尾鸭 Clangula hyemalis 死亡。这项基于模型的研究表明，对沿海地区以双壳类动物为食的鸟类的可用食物供应进行了强有力的营养控制。我们的结果还表明，需要高分辨率的生态系统模型来解决影响的异质分布。这项基于模型的研究表明，对沿海地区以双壳类动物为食的鸟类的可用食物供应进行了强有力的营养控制。我们的结果还表明，需要高分辨率的生态系统模型来解决影响的异质分布。这项基于模型的研究表明，对沿海地区以双壳类为食的鸟类的可用食物供应进行了强有力的营养控制。我们的结果还表明，需要高分辨率的生态系统模型来解决影响的异质分布。