Abstract Coastal eutrophication is a common problem worldwide, with main drivers including land-based freshwater and nutrient discharges, as well as hydroclimatic and open sea conditions. This study investigates the combined effects of different hydroclimatic and eutrophication management scenarios on coastal water quality and ecological status. As a case study we consider and simulate these scenarios for the Himmerfjarden Bay, situated in the semi-enclosed Baltic Sea. Effects on different eutrophication-relevant variables are assessed for several potential land, coast and/or sea-based management scenarios under different hydroclimatic conditions spanning the range of recent past observations. Our results show that the land and sea-based management scenarios have different effects on each of the studied eutrophication-relevant coastal variable. In general, management strategies need to target both nitrogen and phosphorus reduction for robust coastal effects. We find hydroclimate as a key non-human eutrophication driver, which can substantially counteract management effects. For hydroclimatic conditions close to the recently experienced average, various management measures can improve water quality and ecosystem status in the studied local Baltic coast. Under projected climate change, however, such improvement will require combined land- and sea-based measures.

中文翻译：

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模拟养分管理和水气候对沿海水质和生态状况的影响——波罗的海 Himmerfjärden 湾案例

摘要 沿海富营养化是世界范围内的普遍问题，其主要驱动因素包括陆上淡水和营养物质的排放，以及水文气候和公海条件。本研究调查了不同水文气候和富营养化管理方案对沿海水质和生态状况的综合影响。作为案例研究，我们考虑并模拟位于半封闭波罗的海的 Himmerfjarden 湾的这些场景。在跨越最近过去观察范围的不同水文气候条件下，评估了几种潜在的陆地、海岸和/或海基管理情景对不同富营养化相关变量的影响。我们的结果表明，陆基和海基管理方案对每个研究的富营养化相关沿海变量都有不同的影响。一般而言，管理策略需要以减少氮和磷为目标，以实现强大的沿海效应。我们发现水文气候是一个关键的非人类富营养化驱动因素，它可以大大抵消管理效果。对于接近近期平均水平的水文气候条件，各种管理措施可以改善所研究的当地波罗的海沿岸的水质和生态系统状况。然而，根据预计的气候变化，这种改善将需要陆基和海基措施相结合。各种管理措施可以改善所研究的当地波罗的海沿岸的水质和生态系统状况。然而，根据预计的气候变化，这种改善将需要陆基和海基措施相结合。各种管理措施可以改善所研究的当地波罗的海沿岸的水质和生态系统状况。然而，根据预计的气候变化，这种改善将需要陆基和海基措施相结合。