ABSTRACT

Despite the diversity and oftentimes large biomass of jellyfish in marine systems, their ecological role remains poorly understood. We here provide the first systematic review of studies on jellyfish trophic ecology in the Baltic Sea (a regional marine system under strong multiple global and regional anthropogenic pressures). In total, we identified 57 peer-reviewed publications, with notable taxonomic bias towards two species (Aurelia aurita; non-indigenous Mnemiopsis leidyi) and spatial bias towards five areas (Bornholm Basin, Kiel Bight, Kertinge Nor, Lim- and Gullmarsfjord). The studies provide evidence for diverse trophic roles of jellyfish as predators and as competitors of other jellyfish, zooplankton and fish species. In combination, the studies also highlight potentially large impacts via top-down (grazing) and bottom-up (nutrient excretion) effects, but also, strong spatio-temporal variability in the magnitude of these effects, depending on the occurrence of jellyfish blooms. Studies on the role of jellyfish as prey for fish, seabirds or marine mammals, and for benthic systems via food-falls, were limited or lacking for the Baltic Sea, despite increasing focus on these topics globally. Improved understanding of the temporal (seasonal, inter-annual, long-term) and spatial variability of blooms and corresponding trophic effects, would provide more systematic understanding of the ecological role of jellyfish in the spatio-temporally variable Baltic Sea. A broader spatial coverage, inclusion of more jellyfish taxa and under-studied early life history stages, as well as the implementation and continuation of long-term data series would represent important steps towards this goal.

摘要

尽管海洋系统中的水母具有多样性并且通常生物量很大，但它们的生态作用仍然知之甚少。我们在这里提供了对波罗的海（一个在强大的全球和区域人为压力下的区域海洋系统）中水母营养生态学研究的第一次系统回顾。我们总共确定了 57 篇同行评审的出版物，对两个物种（Aurelia aurita；非本土Mnemiopsis leidyi）有明显的分类学偏见) 和对五个区域（博恩霍尔姆盆地、基尔湾、Kertinge Nor、Lim- 和 Gullmarsfjord）的空间偏差。这些研究为水母作为捕食者和其他水母、浮游动物和鱼类的竞争者的多种营养作用提供了证据。综合而言，这些研究还强调了通过自上而下（放牧）和自下而上（养分排泄）效应产生的潜在巨大影响，以及这些影响程度的强烈时空变异性，这取决于水母大量繁殖的发生。尽管全球对这些主题的关注越来越多，但关于水母作为鱼类、海鸟或海洋哺乳动物的猎物以及通过食物下降为底栖系统的作用的研究对于波罗的海来说是有限的或缺乏的。提高对时间（季节性、年际、长期）和水华的空间变异性和相应的营养效应，将为水母在时空变化的波罗的海中的生态作用提供更系统的理解。更广泛的空间覆盖、包含更多的水母分类群和研究不足的早期生活史阶段，以及长期数据系列的实施和延续，将代表实现这一目标的重要步骤。