Syllabus: 

GS3: Conservation, Environmental Pollution and Degradation, Environmental Impact Assessment.

Context: 

A recent survey by the Annual Waterbird Census (AWC) revealed a steep decline in bird populations, from 8,776 individual waterbirds in 2020 to 3,380 in 2024 in Okhla Bird Sanctuary.

More on the News

• The drop in bird populations at Okhla Bird Sanctuary has disrupted key ecological processes, threatening biodiversity.

• This sharp decline in bird species and ecological highlights the growing threat to urban wetlands across India.

• It reflects the broader issue of humanity’s unsustainable interaction with nature amid rapid urbanisation. 

Okhla Bird Sanctuary (OBS) 

• In 1990, the OBS was declared a protected area under the Wildlife Protection Act, spans 3.5 square km and is one of India’s Important Bird Areas (IBAs).

• It is situated on the Yamuna River, and it played a critical role as a breeding ground, foraging site, and stopover point for migratory birds. 

Causes of the Degradation of Okhla Bird Sanctuary (OBS)

• Encroachment around OBS: Encroachments around Okhla Bird Sanctuary, both illegal by nearby settlements and legal by the Forest Department, are harming its ecosystem. 

• Structures like kiosks, roads, and large buildings on the eastern side have disturbed the sanctuary. 
• In 2015, the Ministry of Environment declared an eco-sensitive zone (ESZ) around the sanctuary to limit construction. 
• But instead of the standard 1-kilometer buffer, the boundary here was reduced to just a few meters, paving the way for urban sprawl.

• Pollution: Untreated sewage and industrial waste have made the river at Okhla Barrage highly toxic, with BOD levels hitting 58 mg/l in 2020—almost 20 times the safe limit of 3 mg/l.

• The sanctuary is surrounded by highways and bridges, contributing to incessant noise pollution. 

• Mismanagement: Mismanagement by authorities, leading to neglect of the sanctuary's ecological needs. 

• Climate Change Impact: Broader climate change impacts, such as altered precipitation patterns and increased drought frequency, can also affect water levels in the wetland. 

• Species Unrest: Birds, especially frugivores, are vital for seed dispersal and regenerating native vegetation. 

• Their absence severely reduces native plant regeneration, weakening the overall ecosystem with invasive species such as Typha and water hyacinth putting the sanctuary’s future in crisis.

Way Forward

• Successful river restoration efforts worldwide offer key lessons for reviving the Yamuna. Models like the Thames and Rhine highlight the need for stricter pollution control.

• Implement comprehensive strategies for treating urban sewage and industrial effluents before discharge into water bodies.

• Restore wetland health by ensuring consistent water flow from the Okhla Barrage, removing the invasive species, and planting native fruit-bearing trees to support bird populations. 

• Create and apply science-based wetland management plans that include regular monitoring, invasive species control, habitat restoration, and water management.