by Andres Clavier, Freshwater Stewardship Education Intern

Light pollution is excessive or misdirected artificial light and it is stealing our starry nights, posing substantial threats to wildlife and our own well-being. This has spurred a global push for ‘Dark-Sky Reserves’ — sanctuaries free from light pollution. Why are these areas crucial for both nature and people?

Dark-Sky Reserves have many wildlife benefits. They act as sanctuaries for bird migration as many bird species, especially those that migrate at night, use the moon and stars for navigation. Excessive light pollution can disorient them, often leading to collisions with buildings or exhaustion from veering off course.

Dark-Sky Reserves are also beneficial for aquatic life. Artificial lights can interfere with the behaviours of aquatic organisms. Artificial light also disrupts the natural cycles of Zooplankton, which is crucial for aquatic food chains, reducing their consumption of algae under excessive light and often leading to algal blooms. Cyanobacteria, also known as blue-green algae, play a crucial role in aquatic ecosystems, contributing to primary production and nitrogen fixation. These photosynthetic organisms have evolved with specific light cues that regulate their diurnal rhythms (Woelfle et al., 2012).

However, light pollution, especially from artificial blue and white light, can disrupt these natural rhythms. When exposed to unnatural light at night, the circadian clock of cyanobacteria can become desynchronized, leading to altered gene expression patterns, photosynthesis, and nitrogen fixation (Diamond et al., 2015). This affects the cyanobacteria’s immediate metabolic processes and can have cascading effects on aquatic food webs and biogeochemical cycles, compromising ecosystem health and stability (Becher et al., 2013).

Artificial lights also affect nocturnal species. Bats, moths, owls, and many others rely on the dark to hunt, mate, and conduct their nocturnal lives. The interference of artificial light disrupts their activities, putting entire ecosystems out of balance. It is important to only use artificial lights when necessary and to make them dark sky friendly.

Apart from Dark-Sky Reserves, there are many other classifications and designations of dark sky sites. These can include Dark-Sky Preserves, Nocturnal Preserves, and Urban Star Parks, all which provide different levels of protection and benefit. The DarkSky International has five different classifications: Dark Sky Sanctuary, Dark Sky Reserve, Dark Sky Park, Dark Sky Community, and Urban Night Sky Place. One of these options may be a good fit for your community!

The push for Dark-Sky Reserves is not just about nostalgia for a starry night; it is a necessary response to a rapidly growing environmental and public health challenge. It also allows for the continued study of darkness – scotobiology. Many communities around the world are taking action. As we understand the profound impacts of light pollution, the case for these reserves becomes undeniable.

Support the Stars and Our Health

Watersheds Canada’s education toolkit will help you protect our night skies, ensure safer habitats for wildlife, reduce energy consumption, and improve human health by reducing disrupted sleep patterns caused by excessive artificial lighting. Protecting our freshwater areas and the wildlife that live there is important, and it is our collective responsibility to harmonize our actions accordingly. You can do your part by sharing the resources and information from Watersheds Canada’s light pollution awareness campaign! 

References
Becher, P. G., Beuchat, J., Chervet, N., & Chia, W. (2013). Environmental factors affecting large-scale synchronization of Prochlorococcus growth in the Red Sea. The ISME journal, 7(9), 1835-1845.
Diamond, S., Jun, D., Rubin, B. E., & Golden, S. S. (2015). The circadian oscillator in Synechococcus elongatus controls metabolite partitioning during diurnal growth. Proceedings of the National Academy of Sciences, 112(15), E1916-E1925.
Longcore, T., & Rich, C. (2004). Ecological light pollution. Frontiers in Ecology and the Environment, 2(4), 191-198.
Woelfle, M. A., Ouyang, Y., Phanvijhitsiri, K., & Johnson, C. H. (2012). The adaptive value of circadian clocks: An experimental assessment in cyanobacteria. Current Biology, 22(16), 1481-1486.

This education toolkit is generously funded by:

Education toolkit reviewed by: