Indian Ocean Region is getting louder, threatening marine ecosystem

From increasing commercial ship traffic, sonar and seismic activities, offshore energy exploration expeditions could be disrupting migration, reproduction and even the chatter of the seas’ creatures in the IOR 

New Delhi:  Increased commercial shipping activity is an indicator of rise in international trade. Bustling propeller activities on India’s both the eastern and western seafronts, indicate that India is set to become a major maritime player in the coming years. However, this flourishing story on the surface of the water is coming at the cost for the flora-fauna below the surface. 

The increased ship movements that has led to choppy waters in the Indian Ocean Region (IOR) – both the Arabian Sea and the Bay of Bengal – have had a confounding impact on the marine ecosystem – changing migratory patterns of sea creatures, causing displacement of species from their original habitats, and even threatening species towards extinction.

Oceanic research has indicated that the noise level in the IOR has increased from 180 decibels to nearly 210 decibels (dB) – which is now believed to be one of the main causes of unexplained deaths of whales, dolphins, porpoises, turtles, and other marine species.

Over the past decade, Arnab Das, a former commander in the Indian Navy and currently the director of the maritime research center at the Indian Maritime Foundation, Pune, has studied the noise in the IOR. He articulates the need for an ‘Underwater Domain Awareness’ (UDA) to analyze and take action on the acoustic habitat degradation in the IOR. 

UDA Calls for Attention

Marine scientists who study noise in the ocean have tried to understand how loud, man-made sounds disturb or injure whales and other marine mammals, even driving some to getting beached on the shore and eventually die.

Thus, Das underlines the need to focus on the more pernicious influence of chronic, large-scale noise on marine life.

Whales, dolphins, and seals use sonar sounds to communicate, navigate, find food and detect predators. According to Das, the rising level of cumulative noise from energy exploration, offshore development, and commercial shipping is a constant disruption on their social networks. 

“There are documented reports and findings of whale shark species found near Gujarat changing their migratory pattern. Several freshwater dolphins who were once abundantly spotted breaking on the waves of the Ganga river are now a rare sight. Several shrimp and fish species in the Bay of Bengal are now hardly netted – indicating either they have been pushed out of their natural marine habitat or their numbers have fallen low,” Das remarked.

Fears expressed by Das were also echoed by Dr. Shankar Gajbhiye, senior scientists of the National Institute of Oceanography (NIO). He confirmed that the loss of acoustic habitats for marine species that rely on sound to live and prosper is increasing in the IOR.

Technological Intervention

While the stark realities are worrying, Das claimed that there are emerging technologies for quantifying and visualizing the effects of noise pollution that can help drive a paradigm shift in how we perceive, monitor, manage and mitigate human sounds in the ocean. 

“Ocean noise is a global problem other nations have already started their work in this regards. India should also step up, if we are to save the IOR,” said Das, while adding that primarily efforts must extend to fully comprehend the acoustic footprint of offshore and coastal activities in the IOR. 

The former Navy officer urged the central government to develop and maintain dedicated undersea acoustic monitoring networks as integral parts of ocean observing systems. He added that, with proactive collaborations among corporates, marine scientists, environmentalists, and governments, efforts are currently underway at the United Nation’s International Maritime Organization to develop quieting technologies for the most pervasive global noise source – large commercial ships. 

Marine scientists and experts are urging that more research be conducted, to learn much more about the effects of sound and ship traffic on marine creatures.

“The government should encourage and accelerate the development of noise-reduction technologies. The IOR is in desperate need of a more holistic and biologically relevant risk assessment system, centered on the concepts of ocean acoustic habitats and ecosystems,” said Das.