Baltic Sea Centre, Stockholm University, 106 91, Stockholm, Sweden.
AquaBiota Water Research, Löjtnantsgatan 25, 115 50, Stockholm, Sweden.
Ambio. 2019 Jun;48(6):539-551. doi: 10.1007/s13280-018-1088-x. Epub 2018 Aug 30.
Recreational boating increases globally and associated moorings are often placed in vegetated habitats important for fish recruitment. Meanwhile, assessments of the effects of boating on vegetation, and potential effects on associated fish assemblages are rare. Here, we analysed (i) the effect of small-boat marinas on vegetation structure, and (ii) juvenile fish abundance in relation to vegetation cover in shallow wave-sheltered coastal inlets. We found marinas to have lower vegetation cover and height, and a different species composition, compared to control inlets. This effect became stronger with increasing berth density. Moreover, there was a clear positive relationship between vegetation cover and fish abundance. We conclude that recreational boating and related moorings are associated with reduced cover of aquatic vegetation constituting important habitats for juvenile fish. We therefore recommend that coastal constructions and associated boating should be allocated to more disturbance tolerant environments (e.g. naturally wave-exposed shores), thereby minimizing negative environmental impacts.
休闲划船活动在全球范围内不断增加，相关的系泊设施通常设置在对鱼类繁殖很重要的植被栖息地中。与此同时，评估划船对植被的影响以及对相关鱼类群落的潜在影响的研究却很少。在这里，我们分析了（i）小船码头对浅海湾避风海岸植被结构的影响，以及（ii）与植被覆盖相关的幼鱼丰度。与对照入口相比，我们发现码头的植被覆盖度和高度较低，物种组成也不同。这种影响随着泊位密度的增加而增强。此外，植被覆盖度和鱼类丰度之间存在明显的正相关关系。我们的结论是，休闲划船和相关的系泊设施与水生植被覆盖度的降低有关，而水生植被是幼鱼的重要栖息地。因此，我们建议沿海建设和相关的划船活动应分配到更能耐受干扰的环境（例如自然暴露于风浪的海岸），从而最大限度地减少负面环境影响。
