International light pollution guidelines for migratory species prepared

Subject: Environment

Section: Pollution

Context:

The International Light Pollution Guidelines for migratory species were developed in response to the growing concern of light pollution, first acknowledged during the CMS COP 13 meeting in Gandhinagar four years ago.

About International Light Pollution Guidelines for migratory species:

These guidelines, discussed at the CMS COP14 in Samarkand, Uzbekistan emphasize the conservation value of natural darkness, akin to clean water, air, and soil.
With artificial light emissions increasing by over 49% between 1992 and 2017, the guidelines aim to mitigate light pollution’s adverse effects on wildlife, which can lead to significant behavioural and physiological changes.
Adapted from Australia’s 2020 National Light Pollution Guidelines, the recommendations include reducing light pollution, conducting environmental impact assessments, and employing best practices in lighting design such as managing light time, colour, intensity, and minimizing light spill.
Specific measures like avoiding lighting within a 20-km radius of wildlife habitats and managing existing light pollution are also advised to protect migratory species and their ecosystems.

Artificial Light’s impact:

The COP document on light pollution highlights the adverse effects of artificial light on wildlife, particularly marine turtles, seabirds, migratory shorebirds, land birds, and bats.
It details how artificial lighting, even from distances as far as 15 km, can disorient birds, causing them to collide with structures, disrupt their foraging patterns, and hinder the fledging process in seabirds.
Artificial light also diverts migratory birds from their paths, affects the roosting behaviour of migratory shorebirds, and increases stress hormones in songbirds, potentially reducing their reproductive success.
Moreover, the guidelines outline the negative impacts of artificial lighting on other species, including mammals, reptiles, and fish, with specific examples like the delayed reproduction in Tammar wallabies and the failure of clownfish eggs to hatch under constant light.
Marine turtle hatchlings may struggle to reach the ocean due to beach lighting, and bats experience disruptions in their natural behaviours such as roosting and foraging due to artificial light.

Successful implementation:

The document also shares success stories of mitigating light pollution, such as the Gorgon Liquefied Natural Gas Plant in Western Australia, which implemented lighting management to reduce skyglow, aiding in marine turtle conservation.
Additionally, it mentions the positive outcome for migratory short-tailed shearwaters on Phillip Island in Victoria, Australia, underscoring the potential for effective light pollution management to support wildlife conservation.
Light pollution can be defined as the introduction by humans, directly or indirectly, of artificial light into the environment.
Avoidable light pollution refers to light flow emitted at night by artificial light sources which are inappropriate in intensity, direction and/or spectral range, unnecessary to carry out the function they are intended for, or when artificial lighting is used in particular sites, such as observatories, natural areas or sensitive landscapes.

Types of Light pollution:

Light trespass: When unwanted light enters one’s property, for instance, by shining over a neighbour’s fence.
Over-illumination: It is the excessive use of light.
Glare: Glare is often the result of excessive contrast between bright and dark areas in the field of view.
1. Blind glare: describes effects such as that caused by staring into the Sun. It is completely blinding and leaves temporary or permanent vision deficiencies.
2. Disability glare: describes effects such as being blinded by an oncoming cars lights, or light scattering in fog or in the eye reduces contrast, as well as reflections from print and other dark areas that render them bright, with significant reduction in sight capabilities.
3. Discomfort glare: does not typically cause a dangerous situation in itself, and is annoying and irritating at best. It can potentially cause fatigue if experienced over extended periods.
Clutter: Clutter refers to excessive groupings of lights. Groupings of lights may generate confusion, distract from obstacles (including those that they may be intended to illuminate), and potentially cause accidents. Clutter is particularly noticeable on roads where the street lights are badly designed, or where brightly lit advertising surrounds the roadways.
Skyglow: refers to the “glow” effect that can be seen over populated areas.

It is the combination of all light reflected from what it has illuminated escaping up into the sky and from all of the badly directed light in that area that also escapes into the sky, being scattered (redirected) by the atmosphere back toward the ground.

Impact of light pollution:

Wastes Energy and Money:
- Lighting that emits too much light or shines when and where it’s not needed is wasteful. Wasting energy has huge economic and environmental consequences.
Disrupting the ecosystem and wildlife:
- Plants and animals depend on Earth’s daily cycle of light and dark rhythm to govern life-sustaining behaviours such as reproduction, nourishment, sleep and protection from predators.
- Scientific evidence suggests that artificial light at night has negative and deadly effects on many creatures including amphibians, birds, mammals, insects and plants.
  - Ex: A study has now shown how nocturnal dung beetles are forced to search for cues in their immediate surroundings when they can no longer navigate using natural light from the night sky.
  - The effect of light in the form of fire or lamps attracting migratory and non-migratory birds at night, especially when foggy or cloudy, has been known since the 19th century and was and still is used as a form of hunting. The reasons for disorientation of birds through artificial night lighting are not well known. Experts suggest that the navigation of birds using the horizon as orientation for the direction is disrupted by lighting and sky glow.
Harming human health:
- Like most life on Earth, humans adhere to a Circadian Rhythm — our biological clock — a sleep-wake pattern governed by the day-night cycle. Artificial light at night can disrupt that cycle.