In Search of Dark Sky -
The
Effect of Light Pollution on Nature and Wildlife
I am drawn to the night!
Yes, it can be tiring, it can be scary to be out alone in darkness
and
my vigilance is heightened as I listen to the sounds of the night.
But the silence also lets me reflect on many issues as I wait for my
camera
to capture the night landscape under a brilliant sky and moon.
There is beauty in the night.
Unfortunately, as city dwellers and suburbanites we mostly
don’t see the millions of stars overhead since light pollution blocks out what
the Universe has to offer.
Tracking light pollution over the last ~60 years, the below
image shows how much light has been added to the landscape by cities and even
rural areas. And check out the
projections for 2025 – dark sky will almost vanish in most of the US sky.
When we zoom into the Silicon Valley and the greater Bay Area, it’s hard to find areas of ‘dark sky’ where we may observe the movement of the stars and gaze at the milky way.
The next image shows how much we are missing in light
polluted areas (left side) and how many stars and planet are visible without
light pollution (right side).
Light Pollution and
its Effect on Nature and Wildlife
But light pollution does not only hinder us to see the
stars, it also has a profound effect on nature and wildlife.
We all have seen how moth and insects are
drawn to light even to their death by an open flame.
It confuses baby turtles that are programmed
to run towards the light, but that light often comes from hotels and parking
lots, rather than reach the ocean to start their long life. Below is a graph that depicts the confused
wondering of loggerhead hatchlings. They
may never reach the water or their prolonged path may result in more hatchlings
loosing their lives to predators prior to reaching the ocean.
Tracks of disoriented loggerhead (Caretta caretta)
hatchlings, Melbourne Beach ,
Florida
Photograph by Blair E. Witherington.
Photograph by Blair E. Witherington.
It has been found that frogs that mate at night will seize
to mate in areas of light pollution.
It is known that big cities with their bright high-rises and
reflecting glass will draw migrating birds from their ancient migration routes
and they perish.
Here is a quote from Bart Kempenaers of the Max Planck
Institute for Ornithology in Germany :
"In
comparison to chemical and noise pollution, light pollution is more subtle, and
its effects have perhaps not received the attention they deserve," said
Bart Kempenaers. "Our findings show clearly that light pollution
influences the timing of breeding behavior, with unknown consequences for bird
populations." It is these unknown consequences over the long term that
needs to be understood.
[Source: Current Biology, 16 September 2010, Volume 20, Issue 19, pages 1735-1739.
10.1016/j.cub.2010.08.028.]
And unfortunately the list goes on and on with lots of
information available with a quick search on the web.
But what can be done? We all have responsibilities to take care of the planet Earth and we all can become more cognizant of how our actions influence our environment. Just as example: Turning off outside lights when we go to bed at night, installing lights that are directed downwards and that are on automatic shut-off when not necessary, supporting city street lights that are minimizing light pollution; these are all small but important contributions to the bigger issue.
I would like to conclude with a very informative video: ‘Our Vanishing
Night’ by AstroGirlWest
“Light pollution: its real, destructive consequences are
seldom recognized, but it is a problem with easy solutions that make economic
sense. All living creatures rely on the Earth's regular rhythm of day and night
to regulate internal cycles. Many use the protection of darkness to safely
forage and mate. We exist in a balance with our environment, a delicate balance
that we are shifting. In the process we are also losing our connection to the
night sky and the universe beyond.”
Til next time,
Meggi
