The migratory waterbirds are going back before wintering in the lap of Loktak Lake
The impact of LED lights on the lake

R.K. Birjit Singh *

"When we add light to the wetland, that has the potential to disrupt habitat, just like running a bulldozer over the landscape can."

Since time immemorial, every year, during early winter, birds travel from their breeding haunts in the northern region of Asia, Europe and America to the Southern, warmer lands. They make return journey again during spring and early summer. They are very punctual too, unless they are delayed by bad weather. We may calculate almost to a day when we may expect our winged friends to return at Loktak, carrying winter on their backs.

In the olden days as one might describe the arrival of the thousands of enormous number of wintering birds with the quick flap of wings, the startled flight of the coots, the noisy chirps of thousands of maneuvering Common teal in flight, the graceful flight of the Northern pintail and the majestic perch of the Darters and Terns.

The verdant leaves of mustard plants wave, quiver become shivering on the Sesamum aroma exudes with the hasty breeze put off by the majestic flight of Gadwall (Thoiding-nam) over the local courtyard gardens herald the onset of winter. It was obviously, a classic nostalgia recalled and retold by the old people living in and around the Lake while enjoying the sun with their food in the front courtyard of their homesteads during winter.

Hume (Stray Feathers, 1888) had recorded as many as 57 species of water fowl species in Loktak alone and he had never seen such enormous number of swarms of ducks and geese in any parts of India. Some of these wild ducks came to Loktak from Central Asia, Tibet, Siberia and Yunnan province- flying 3,2000-4,800 kilometers over the Himalayan ranges.

Today the picture is very different; the numbers of these birds have been reduced drastically due to the disturbance of its habitat after the commissioning of Ithai Barrage. The natural rhythm and cycles of water level have been totally shattered. Huge pressure of human presence, killing and poaching of waterbirds by using insecticides and pesticides become a part of our culture.

Hardly, we have now 20-21 species of water fowl in Loktak. The problem which has been further and seriously complicated by using of LED (Light Emitting Diode) lights for fishing in the lake has dwindled the population of waterbirds including those of migratory species from 47088 with 68 species in 2016 to hardly 5000 with 17 species in January,2017. It seems that now they have diverted their migratory routes into a marginal habitat where it may succumb to predation, starvation or death.

Since life begun on earth some 3.5 billion years back, all forms of life had relied on earth’s predictable rhythm of day and night and they anticipated daily events because of ubiquitous internal circadian clocks that enabled living creatures to coordinate their actions with the external environment. It’s encoded in the DNA of all plants and animals. Humans have radically disrupted this cycle by lighting up the night. Plants and animals depend on earth’s daily cycle of light and dark rhythm to govern the life-sustaining behaviors such as reproduction, nourishment, sleep and protection from predators.

Scientific evidence suggest that artificial light at night has negative and deadly effects on many creatures including amphibians, birds, mammals, insects, fishes and plants. Glare from artificial lights can also impact wetland habitats that are home to amphibians such as frogs, toads and fishes, whose nighttime croaking is part of the breeding ritual. Artificial lights disrupt this nocturnal activity, interfering with reproduction and reducing populations.

Migratory birds depend on cues from properly timed seasonal schedules. Artificial lights also can cause them to migrate too early or too late and miss ideal climate conditions for roosting, foraging and other behaviours. The nesting, and breeding period and foraging behaviours of resident the waterbirds of Loktak have been severely affected due to LED lighting.

In the early days, people living in and around Loktak Lake used searchlights and kerosene pressured lanterns (Half lamp) to attract, capture, and kill hundreds of resident and migratory birds as a part of their fishing activities. They would attract the birds by putting kerosene pressured lanterns inside a tin box by making whole with a glass to reflect the light towards the birds.

When the light bleached the visual pigments of the birds and they are in their range, fishermen used to throw their multiple spike fishing spears locally known as "Long". This technique was evolved or developed to catch fishes and at the same time it became to be a very effective tool for killing and poaching birds.

As the population of fishing phum dwellers expands geographically, artificial lighting with LED also expands starting from eastern side of the lake and it is has now been almost impossible to find areas that are free from the influence of LED lighting in Loktak Lake presently.

Obviously, it is true that LED lighting for fishing also evolves as a result of ever increasing demand of fishes as the population of phum dwelling fishermen increases dramatically. Indeed, it’s a good catch and a grand harvest for the fishermen with the LED lights attract a large number of fingerling fishes and minnows during the night leaving a dark sight in the ecosystem of the Lake.

Recently, the Centre for Conservation of Nature and Cultivation of Science (CCNCS) conducted surveys on the impact of LED lights on waterbirds at 11 waterbird congregation sites of the lake covering 1 sq.km in each spot led by the author of this article and found that there are about 17 floating huts in average at least in each of these study areas with a minimum number of 179 Chinese LED bulbs ranging from 4-9 Watts powered by 12 Volt DC sources hanging on the bamboo poles implanted for the large deep fishing nets.

Taking the lower estimates of 4 Watt each of the bulbs, a total of 787,600 lumens of lights are produced in this small 11 sq.km. area of the Lake. This will be equivalent to a huge lighting system with 7,876 of Watts. One can imagine that what could and would be the impact of light coupled with the reflections from the water of the lake. This is truly a serious matter and issue of "Photopollution".

We have all witnessed the mind boggling visuals of Loktak Lake in the multitude of a city during the night time. It is a matter of grave concern and will have serious impact on the ecology and biodiversity of the Lake in the days to come if remedial measures are not taken before it is too late.

At the end of the day, it will be the responsibilities of Tom, Dick and Harry to conserve this wetland of international importance.