A new study shows that light pollution is changing the night schedules of both flying and swimming creatures, leading to big implications for their offsprings. The results underscore the wide-ranging impacts of our bright and shiny modern world and drive home how pressing an environmental issue light pollution has become.
The Behavioral Impacts
New research conducted in China demonstrates that exposing female zebrafish to just a few days of artificial light at night can elicit significant changes in their behavior. They were slower to swim, shoaled more and stayed closer to the walls of their tank — behaviours that are consistent with anxiety.
Perhaps most remarkably, the effects were most evident in fish exposed to blue-spectrum light, which is the type of light that many modern sources — including electronic displays and street lamps — give off. This is consistent with what researchers have determined about blue light’s effect on human sleep cycles and circadian rhythms, but it does indicate that the behavioral effects of different wavelengths of light might not be so clear-cut on aquatic species.
Inter-generational impact
This is intriguing not just because it shows that light pollution can impact other species from the very first generation on but also because of the possible flow-on effects. When the female fish were then mated and had offspring that had never been exposed to artificial light at night, their offspring also showed reduced daytime activity; thus, these effects are lasting.
The findings suggest that light pollution may extend farther and have longer-lasting effects on aquatic ecosystems than has been previously assumed. If fish behavior and growth are disrupted, it could lead to a domino effect throughout the entire food web, shaking the foundation and balance of these systems.
Conclusion
The findings directly highlight the pressing issue of light pollution and its impact on wildlife. Reducing the number of blue-spectrum light sources in proximity to animal habitats is a key step towards ameliorating some of the harmful consequences artificial light at night has on a variety of wildlife, especially fish. The development of our built environments will continue to grow, it is important now more than ever that we retain this natural darkness for ourselves and the creatures who rely on it.
