Impact of motorboats on fish embryos depends on engine type

Change in heart rate of Amblyglyphidodon curacao embryos from pre- treatment conditions (ambient) to treatment conditions (ambient, 2-stroke engine, or 4-stroke engine). Both 2-stroke and 4-stroke treatments involved a boat driving at 0–35 km/h at 10–200 m from embryos. 
The full methodology is available in the Open Access publication from the Related Publications link below.
Abstract [Related Publication]: Human generated noise is changing the natural underwater soundscapes worldwide. The most pervasive sources of underwater anthropogenic noise are motorboats, which have been found to negatively affect several aspects of fish biology. However, few studies have examined the effects of noise on early life stages, especially the embryonic stage, despite embryo health being critical to larval survival and recruitment. Here, we used a novel setup to monitor heart rates of embryos from the staghorn damselfish (Amblyglyphidodon curacao) in shallow reef conditions, allowing us to examine the effects of in situ boat noise in context with real-world exposure. We found that the heart rate of embryos increased in the presence of boat noise, which can be associated with the stress response. Additionally, we found 2-stroke outboard-powered boats had more than twice the effect on embryo heart rates than did 4-stroke powered boats, showing an increase in mean individual heart rate of 1.9% and 4.6%, respectively. To our knowledge this is the first evidence suggesting boat noise elicits a stress response in fish embryo and highlights the need to explore the ecological ramifications of boat noise stress during the embryo stage. Also, knowing the response of marine organisms caused by the sound emissions of particular engine types provides an important tool for reef managers to mitigate noise pollution.

本数据集记录了库拉索凹牙豆娘鱼（Amblyglyphidodon curacao）胚胎的心率变化，涵盖从前处理条件（环境背景噪音）至三种实验处理条件（环境背景噪音、二冲程发动机噪音、四冲程发动机噪音）的全部组别。二冲程与四冲程发动机处理组均模拟了距离实验胚胎10~200米处、以0~35 km/h行驶的机动船舶所产生的水下噪音环境。

完整实验方法详见下方「相关文献」链接指向的开放获取论文。

「相关文献摘要」：全球范围内，人类活动产生的噪音正在重塑自然水下声景的原有格局。机动船舶是水下人为噪音最普遍的来源，现有研究证实其会对鱼类生物学的多个关键维度产生负面影响。尽管胚胎健康状态直接决定幼体存活与种群补充效率，但目前针对噪音对鱼类早期生活史阶段（尤其是胚胎阶段）影响的研究仍较为稀缺。本研究搭建了一套新型实验装置，在浅礁生境中监测鹿角豆娘鱼（staghorn damselfish，Amblyglyphidodon curacao）胚胎的心率，从而可在真实野外暴露场景下探究原位船舶噪音的生态效应。研究结果显示，船舶噪音暴露会使胚胎心率显著升高，该现象与鱼类应激反应存在明确关联。此外，二冲程舷外机船舶对胚胎心率的影响强度约为四冲程舷外机船舶的两倍以上，两组个体平均心率分别升高1.9%与4.6%。据我们所知，本研究首次证实船舶噪音可诱发鱼类胚胎产生应激反应，凸显了探究胚胎阶段船舶噪音应激所带来的生态后果的迫切性。同时，明确特定发动机类型产生的水下噪音对海洋生物的影响效应，可为礁区管理者开展噪音污染防控工作提供重要的科学支撑。