Artificial skyglow impacts on the chronobiology of marine organisms

The ecological impact of artificial light at night has been a rapidly growing field of global change science in recent years. While understanding of direct lighting impacts (for example street lights) has improved dramatically, the effect of artificial skyglow (light that is scattered in the atmosphere and reflected back to the ground) on species behaviours and distributions is lacking. Skyglow extends the geographical influence of artificial lighting from metres to kilometres. It interferes with the detectability of natural light cycles associated with the passage of the moon, which enable many organisms to time important biological events, and orientate themselves in space using the celestial compass. 22% of the world's coastal regions are now exposed to artificial skyglow, the ecological consequences of which are largely unknown.