As Sr Lanka is set to launch it’s first ever large scale wind farm, there are significant issues at hand with regard to its impact on the bird population in the Mannar region, where the wind power generation project is located.
The project, set in motion by CEB after 4 years of studies of its effect on the surrounding environment, still leaves many questions with regard to the impact on the huge bird population in the area, numbering over 200000, which either visits or inhabits this ecologically vital region.
Although the exhaustive report on environment impact gives the project the green light with few adjustments, a closer look at the report itself shows significant causes for concern with regard to the safety of the avifauna in the island and nearby sanctuaries-home to more than 30% of the bird population in the entire country.
The project funded by Asian Development Bank has been aimed at adding around 103.5 MW into the national grid. With a cost per unit of electricity as low as Rs 9, the Wind Farm would stand to make a significant contribution to cash strapped CEB which normally spends well over 3 times as many for an average unit of production. The 39 turbines of the project would make some of the tallest collection of structures in Sri Lanka, standing well over 150 meters, above the flat terrain of Mannar Island.
The turbines, as high as 50 storey buildings, with over 120m diameters in their rotors are produced by the Danish firm Vestas Asia Pacific, the largest manufacturer of wind power technologies in the world .The entire project costing over $ 157 million has been deemed as the first of its kind in the island of Mannar and might not be the last, with CEB entertaining intentions to further extend its production of wind energy in the region in the future.
Mannar, the birds paradise
Mannar, with its windswept terrain is undoubtedly highly suitable as a location for wind energy. The high winds observed in the island between mid April and Mid September would account for most of the targeted energy production. The wind farm, located in the South Shore of the island spreads for about 12 kms along the coastline, about 150 meters inland.
Mannar is a unique location for the birds of Sri Lanka. Its three sanctuaries are permanent home to a huge population which explodes into a paradise for avifauna during the season of migration which begins in October every year until the end of April when the visitors start to head back home. The landscape, with mudflats, coastal mangroves, extensive waterholes, ancient tanks, salt marshes, lagoons and widespread sea grass beds, combined with sand dunes, scrub jungle and, largely uninhabited arid grounds in the island of Mannar and nearby islets make this region unique in its richness in diversity seen nowhere else in Srilanka and arguably the entire world.
Adams Bridge sanctuary at the northern end of island extending to the islands form a highly crucial habitat –particularly the third island known as the Bird Island having a resident population of different types of sea bird species of Terns such as Bridled Tern, Little Tern, Sounder’s Tern etc . For some of these species, the Bird Island is the only known breeding colony in Sri Lanka.
Vankalai Sanctuary at the southernmost end of Mannar Island, extending deep into mainland is a Ramsar wetland with a number of the rarest of species making their home, such as Spot-billed Duck, Gadwall and Comb Duck. Vankalai attracts huge flocks of Greater Flamingo, Eurasian Wigeon, Black-tailed Godwit etc. during the migration season with many species numbering well over 1% of the total population in the world. Vidathalthivu Nature Reserve situated to the north of Mannar too is home to thousands of birds in a year-round basis, with an Important Bird Area allocated within its boundary for a colony of Black-tailed Godwit, a common winter migrant from West Asia and Europe.
According to the data provided in the EIA, Sri Lanka is home to more than 240 different species of birds breeding in the island, out of which more than 33 are endemic to Sri Lanka. Of the total number of 495 species recorded, about 125 are regular visitors and about 20 species are both resident as well as migratory. Wetlands, mud flats and the mangroves of Mannar region attract more than 178 of these species, including 115 breeding residents and particularly much of the visitors. The number of migratory species in the region stands at 63. The three-year study conducted by CEB between 2014 and 2016 recorded 129 species, including 4 endemic, 1 nationally threatened and 4 near threatened species in the project area. This is an indication of the sensitivity of the area where the wind turbines are being built.
However, some studies place the numbers as high as 505.
Migration of birds into Sri Lanka happens through three regions according to ornithologists and the studies undertaken by CEB. One crucial region is Jaffna, where the majority of the birds from the Central Asian Flyway [Eastern Flyway] enters Srilanka .Another point of entry has been the area north of Colombo which appears to be used by birds from the Western Flyway, comprising those from West Asia, flying via Pakistan and South India .A significant number makes landfall at Mannar, and they may belong to birds coming from both the Flyways.
According to the three-year study, majority of the birds using the Mannar entry makes landfall to the north of Mannar, flying across a region about 10 kms to the north of the project area. However, its reported that the species with lesser flying skills prefer island hopping along the Adams Bridge, eventually entering the mainland through a Flyway just to the south of the site, in the vicinity of the South Shore .The close proximity of wind turbines to both these flyways should be a cause for concern as the distance is as little as few kms, with the distinct possibility of deviation of flight by a flock of birds bringing them in harm’s way.
The EIA and the Challenges
The Environment Impact Assessment Report appears to have done an extensive study about the challenges that may lie ahead. It has in fact identified several species that may face the risk of collision with the huge turbines. They include Spot-billed Pelican, Indian Cormorant and Gull-billed Tern with a higher degree of risk and species such as Little Egret, Red-wattled Lapwing, Brown-headed Gull, Caspian Tern, Gull and Lesser Crested Tern at a lesser degree. However, a different study by CEB has found Northern Shoveler, Painted Stork, Whiskered Tern etc as facing collision risk as well.
Interestingly though, the EIA places the risk assessment as low as under 2%. The avian collision risk assessment as well as collision modeling undertaken by CEB have been used as evidence of such a low probability of threat to bird life. Yet, the extensive data collected by both the studies may show a different picture, with a multitude of critically important species listed as IUCN Global Red list as well in Srilanka National Red list either flying or inhabiting regions close to the project area of the Wind Farm.
EIA has in fact led to scaling down of the original project, from 56 turbines to current 39, which has been decided after studies, consultations with local communities, Ceylon Bird Club, non-government organizations etc. The report has set a maximum noise output of 108.5db for each wind turbine. The most significant protection measure initiated by the EIA has been the bird detection radar system which is said to be capable of automatically shutting down the turbines in the event of such an emergency. As a Further measure, the contractor is expected to repair damage to surrounding ground once the project has been completed.
EIA has suggested an Environmental Monitoring Plan as well as a Management Plan to further research on to the challenges at hand and implement mitigation measures, while another study has been emphatic on the need to make the monitoring mechanism to function as an independent one.
Although the primary means of defense is the Radar system, the conservationists around the world have been less confident on the effectiveness of these systems .In particular, with the high prevalence of bird movements in a known flyway, the programming of the radar to respond to bird movements could be a huge challenge which may take economic factors more in to account than bird safety. With a huge population of avifauna in the vicinity, it would be inevitable to cause collisions in a more frequent basis unless further mitigation measures are undertaken.
Possible way out
It is extremely crucial that the Radar tracking system is in its optimum performance right throughout, without being falling victim to malfunction or neglect which is not untypical of safety measures undertaken at high cost in Sri Lanka.
Srilanka is a signatory to International Convention on the Conservation of Migratory Species 1990 as well as the Convention on Wetlands of International Importance [Ramsar Treaty], both of which make the nations duty bound to the protection of migratory birds .A destruction of a flock of birds falling to harm’s way is a high possibility unless the defenses against such an occurrence are at the optimum levels of efficiency.
Interestingly ,the migration of birds occur during the season when there’s substantially lesser winds in Mannar ,leaving the possibility of closure of operations of the wind farm in the critical months of migration both in October when most of the birds make the landfall, and during early April ,when Mannar becomes the main staging area for mass departure. The period of windy conditions, between April and September, therefore, may result in significantly lesser bird activity.
A study recently published in Norway has found that the painting of one blade in black results in a higher degree of collision prevention, as much as 70% in the reduction of bird deaths-definitely an idea well worth trying in the wind farm of ours, in the highly sensitive region of Mannar. The science behind the strategy appears simple as it increases the visibility of the rotor blades from a distance, thereby giving the birds a greater chance at taking evasive action. The dramatic reduction in the annual fatality rate in the ‘’painted turbines’’ has led many nations to consider the strategy as a possible solution against increasing bird deaths
As per the EIA, it has been suggested to use grey as the colour for the turbines, with the view to be less intrusive on the landscape .A change of plans should be in order on the colour .
It is a known fact that the birds falling victim to wind turbines have a higher conservation value. These birds generally larger in size, have much lower reproductive rates than the smaller species, thereby the fatalities might cause a far higher impact on their numbers .Collision of species such as raptors is a serious cause for concern in the USA which has to face up to 500000 deaths of birds in its wind farms each year despite multiple measures.
‘’The long-term impact will be related to the flight pattern of migratory birds
during their arrival, breeding and departure seasons’’
The above sentence, copied from the EIA, poses a series of questions for which the answers remain in the dark yet. The margin of error for both the birds and the operators of the turbines are very little, considering the proximities to each other. One wonders whether the period of studies, extensive though, has been sufficient to study the behavioral patterns of individual species.
Any reasonable degree of safety would require the shutting down of turbines both during the crucial weeks of arrival in much of October as well as departure in first weeks of April. But such a step would bring down the capacity of power generation since the EIA itself states the calculation of 100 mw has been done without considering the possible shutdowns.
As section 504 of the EIA states, ‘’Mitigation measures for a wind farm will never guarantee to bring collisions down to zero, but the magnitude of impact can be significantly reduced. A range of important species (including Spot-billed Pelican, Indian Cormorant and Gull-billed Tern) could also be at significant risk of collision with the proposed wind turbines. CEB has agreed that if EIA of the wind farm cannot demonstrate negligible collision risk then wind turbines will be curtailed during the breeding and/or migratory period as appropriate’’.
Some of the flocks of endangered birds comprise of a high percentage of the entire world population. Thus, the stakes remain high for Srilanka to ensure minimum collision.
Birds and bats contribute hugely to regenerate the rainforests and vegetation elsewhere .While Srilanka takes welcome steps at generation of renewable energy, it’s essential that the impact on the environment is closely monitored .With the increased likelihood of further extensions of the wind energy production in the island of Mannar, Sri Lanka needs to keep constant watch on the safety of its avifauna, considered to be among the richest in the whole of Asia. (KS)