Coastal kelp forest ecosystems create dynamic and productive habitats, supporting a wide range of epiphytic flora, invertebrates, fish and seabirds. Worldwide, kelp is harvested commercially, affecting kelp-associated animal communities. There is, however, limited knowledge of how fish and seabird respond to kelp harvest, highlighting the need to evaluate the ecological impact of harvest on all ecosystem levels. Using 6 years of GPS-tracking data, we examined the effects of kelp harvest on foraging behaviour of breeding European shags (Phalacrocorax aristotelis) from a colony in central Norway. We determined the spatial overlap between kelp harvest and foraging areas of shags and assessed the immediate, short- and long-term impacts of harvest on shag foraging behaviour. Our results demonstrated large spatial and temporal overlap in areas used by foraging shags and kelp harvest. We could not detect any clear alterations in the diving activity of shags due to kelp harvest. However, the broad temporal and spatial scale of our study constrained the detection of fine scale changes in shag behaviour in response to kelp harvest. Our study, nonetheless, identifies several issues that should be addressed before concluding on the effects of kelp harvest on seabird populations. This includes the need for experimental studies using directed and controlled harvest to investigate the effects of kelp harvest through the different trophic levels, including top predators. This is essential for ecosystem-based management of coastal resources, considering the many species composed in the coastal ecosystem.

中文翻译：

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共享邻里：评估海带收获对欧洲粗毛鱼觅食行为的影响

沿海海藻森林生态系统创造了充满活力和生产力的栖息地，支持各种附生植物、无脊椎动物、鱼类和海鸟。在世界范围内，海带被商业化收获，影响了与海带相关的动物群落。然而，关于鱼类和海鸟如何对海带收获做出反应的知识有限，这突出表明需要评估收获对所有生态系统水平的生态影响。使用 6 年的 GPS 跟踪数据，我们研究了海带收获对挪威中部一个殖民地繁殖欧洲粗毛（Phalacrocorax aristotelis）觅食行为的影响。我们确定了海带收获和粗毛草觅食区之间的空间重叠，并评估了收获对粗毛草觅食行为的直接、短期和长期影响。我们的结果表明，在觅食粗毛和海带收获所使用的区域中存在很大的空间和时间重叠。由于海带收获，我们无法检测到粗毛的潜水活动有任何明显的变化。然而，我们研究的广泛时间和空间尺度限制了对海带收获响应中粗毛行为的精细尺度变化的检测。尽管如此，我们的研究确定了在得出海带收获对海鸟种群的影响之前应该解决的几个问题。这包括需要使用定向和控制收获进行实验研究，以调查海带收获对不同营养水平（包括顶级捕食者）的影响。考虑到沿海生态系统中的许多物种，这对于基于生态系统的沿海资源管理至关重要。