Dark Sky – Young Curator Blog

The International Dark Sky Association works to protect the night skies for present and future generations. The excessive use of artificial light (known as light pollution) can and has had serious environmental consequences for humans, wildlife, and our climate. Planet PK have been working closely with Penwith Landscape Partnership, Cornwall AONB and Cornwall Council in full support of the West Penwith application aiming to become an International Dark Sky Park.

Increased light pollution from urbanisation across the UK and the world has led to the loss of ability to view the night sky in many locations. What once would have been a largely universal experience; to be able to look up and see the stars and even the milky way at night, is now only accessible in certain areas. Porthcurno itself is a wonderful place to view the night sky, and my passion for the conservation of our wildlife and dark skies, as well as photography, spurred me to try out some astrophotography in Porthcurno Valley for the first time.

Astrophotography

Astrophotography has always been something I’ve been interested in, but avoided, as I thought it required a lot of specialist equipment. However, as it turns out, it is very easy to get started with basic kit. Using my DSLR camera, a tripod and an 18mm lens I was able to capture the stars in some detail at an exposure of around 15 seconds. To create landscapes, I found it easiest to shoot the stars in a different exposure to the foreground. This meant that I could get the correct lighting levels for both, and create a composite image in photoshop, where both elements were in focus and bright enough.

In my first shoot, when I had not learned this technique, I found it quite hard to balance out small amounts of artificial light in the foreground (even in an area that’s quite dark!) and also getting a nice exposure on the sky, but the results were still interesting as you often get to see more stars in the image than you can all at once with the naked eye.

The effects of light pollution on humans

Dark sky designation can have great benefits for humans and animals alike, benefiting physiologically in many ways. For people, the increased implementation of artificial light throws off our circadian rhythm, which is the internal clock that humans have evolved to experience daytime as the light portion of the day, and night-time as the dark. It is obvious how artificial light can throw the rhythm off, which unfortunately has adverse effects on hormones, sleep patterns, eating patterns and body temperature. Irregular circadian rhythm has been linked to many chronic illnesses such as diabetes, sleep disorders, depression, and seasonal affective disorder

The effect of light pollution on animals

Artificial light can have adverse effects on many animals, just as with humans, it can affect their behavioural patterns. Nocturnal hunters such as bats and owls rely completely on low light and darkness to effectively hunt, as this is how they have evolved to best survive. The increase in light from urbanisation means that in many areas they can no longer thrive as they otherwise were able. The effects of light pollution on animal population and survival are easy to see yourself.

A well-documented example of this is the way that moths are attracted to streetlights. It has the effect of increased mortality rates and predation as they are more focussed on the light than on camouflaging from predators. Other animals that are affected by artificial light are frogs. Studies have found that when exposed to bright lights, frogs tend to lessen their mating calls meaning that they can no longer breed as successfully.

To conclude, the introduction of dark sky designation would have amazing affects on the preservation and protection of local species, ecosystems, and human behaviour, as well as overall health. It is not to say that artificial light is inherently bad, as it has many advantages. But its overuse and increased light pollution often goes too far, to the point where it has more draw backs than benefits to health and wellbeing. The added benefit of dark skies is of course the somewhat rare opportunity that it yields for night sky viewing and photographing. I personally have found this to be really enriching and rewarding experiences in Porthcurno.

Maeve Cushla, Young Curator, PK Porthcurno

https://www.ontarioparks.com/parksblog/health-benefits-dark-skies/
https://www.darksky.org/3-benefits-of-a-dark-sky-designation/
https://www.lonelyplanet.com/articles/travel-trends-for-2019-dark-skies
https://www.newscientist.com/article/dn21844-urban-street-lights-are-changing-animal-ecology/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2627884/