Hansen Matthew J, Cocherell Dennis E, Cooke Steven J, Patrick Paul H, Sills Michael, Fangue Nann A
Department of Wildlife, Fish and Conservation Biology, University of California, Davis, One Shields Ave, Davis, CA, USA.
Fish Ecology and Conservation Physiology Laboratory, Department of Biology, Institute of Environmental Science, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario, Canada.
Conserv Physiol. 2018 Jun 25;6(1):coy032. doi: 10.1093/conphys/coy032. eCollection 2018.
Exploiting species-specific behavioural responses of fish to light is an increasingly promising technique to reduce the entrainment or impingement of fish that results from the diversion of water for human activities, such as hydropower or irrigation. Whilst there is some evidence that white light can be an effective deterrent for Chinook salmon smolts, the results have been mixed. There is a need to test the response of fish to different spectra and strobing frequencies to improve deterrent performance. We tested the movement and spatial response of groups of four fish to combinations of light-emitting diode (LED) spectra (red, green, blue and white light) during the day and night, and strobing frequencies (constant and 2Hz) during the day, using innovative LED technology intended as a behavioural guidance device for use in the field. Whilst strobing did not alter fish behaviour when compared to constant light, the red light had a repulsive effect during the day, with fish under this treatment spending significantly less time in the half of the arena closest to the behavioural guidance device compared to both the control and blue light. Importantly, this effect disappeared at night, where there were no differences in movement and space use found between spectra. There was some evidence of a potential attractive response of fish to the blue and green light during the day. Under these light treatments, fish spent the highest amount of time closest to the behavioural guidance device. Further tests manipulating the light intensity in the different spectra are needed to verify the mechanistic determinants of the observed behaviours. Results are discussed in reference to the known spectral sensitivities of the cone and rod photopigments in these fish, and further experiments are suggested to better relate the work to mitigating the effects on fish of infrastructure used for hydropower and irrigation.
利用鱼类对光的特定物种行为反应是一种越来越有前景的技术，可减少因人类活动（如水电或灌溉）引水导致的鱼类误捕或撞击。虽然有证据表明白光对奇努克鲑鱼幼鱼可能是一种有效的威慑，但结果并不一致。有必要测试鱼类对不同光谱和频闪频率的反应，以提高威慑性能。我们使用创新的发光二极管（LED）技术作为一种用于野外的行为引导装置，测试了四组鱼在白天和夜晚对LED光谱（红色、绿色、蓝色和白光）组合以及白天频闪频率（恒定和2Hz）的运动和空间反应。与恒定光照相比，频闪并没有改变鱼类行为，但红光在白天有排斥作用，与对照组和蓝光组相比，接受这种处理的鱼在竞技场中最靠近行为引导装置的一半区域停留的时间明显更少。重要的是，这种效应在夜间消失，不同光谱之间在运动和空间利用方面没有发现差异。有一些证据表明，鱼类在白天对蓝光和绿光可能有潜在的吸引反应。在这些光照处理下，鱼在最靠近行为引导装置的地方停留的时间最长。需要进一步测试不同光谱中的光强度，以验证观察到的行为的机制决定因素。根据这些鱼中视锥和视杆光色素已知的光谱敏感性对结果进行了讨论，并建议进行进一步实验，以便更好地将这项工作与减轻水电和灌溉基础设施对鱼类的影响联系起来。
