New guidelines to ship out noise from the Indian Ocean region soon

Mumbai The Indian Ocean Region (IOR), which includes Arabian Sea, Bay of Bengal and the southern Indian Ocean, will soon have standards to ensure noise pollution

Mumbai The Indian Ocean Region (IOR), which includes Arabian Sea, Bay of Bengal and the southern Indian Ocean, will soon have standards to ensure noise pollution is curtailed at sea.

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After concerns raised by several research bodies in India and abroad regarding the impact of shipping noise on the health of marine mammals, the ministry of shipping said the International Maritime Organisation (IMO) — an international regulatory body— had decided to implement noise abatement measures.

“Marine traffic noise has risen. As shipping is on international waters, it does not come only under the jurisdiction of the Indian government,” said S Barik, chief surveyor and additional director general, ministry of shipping. “There are many other countries and stakeholders involved that met with IMO over the past year, and a decision has been taken to control noise pollution due to shipping traffic across IOR for protection of marine mammals. IMO will publish the standards soon.”

Noise from shipping traffic in the Arabian Sea is much louder than the Bay of Bengal, a latest study highlighting the harm noise pollution poses to marine mammals has found. Between 2014 and 2019, peak decibel (dB) levels in the Arabian Sea ranged between 190 dB and 210 dB while Bay of Bengal witnessed 170 to 190 dB with isolated areas witnessing peak levels at 200 dB. Noise levels more than 120 dB cause discomfort to marine mammals, more than 170 dB causes injury (internal injuries, bleeding and hemorrhages), and beyond 200 dB can lead to instant death, the study said.

The Maritime Research Centre (MRC), Pune, under the Foundation for Underwater Domain Awareness, a non-government organisation working on marine ecosystem concerns due to acoustic habitat degradation, recently published its study using spatial noise mapping in the Indian Ocean Region (IOR) and outlined its results in the form of heat maps showing shipping traffic and noise coming from them. Similar noise data using satellite maps has been published by international studies between Seattle, USA and Vancouver, Canada where noise levels touched peak levels of 210 dB due to shipping traffic.

The study corroborates the stranding of a 40-foot Blue Whale and a 50-foot Bryde’s whale along the Maharashtra coast in 2016 and 2017, and states that noise from ships led to disorientation in both marine mammals to move towards the coast, which ultimately led to their stranding events. According to the Maharashtra mangrove cell, there have been 143 reported marine mammal deaths along the Mumbai Metropolitan Region from 2015 to 2019 (October). In 2019, however, there have only been six reported cases. Arnab Das, author of the study, former commander in the Indian Navy and director of the Maritime Research Centre, said, “Intense noise such as air gun blasts that ricochet of the seafloor, the sound of a ship’s propeller, engine noise, horn blast from a bulk carrier ship etc., all drown out animal sounds or interfere with frequency (sonar waves) in their attempt to communicate with each other causing hearing loss or injury.”

While the IOR (Arabian Sea, Bay of Bengal and Indian Ocean) represents 20% of the world’s ocean area, the Indian National Shipowners’ Association estimates that navy ships, vessels deployed for security purposes, seaborne trade, including regular export-import goods, dry cargo, petroleum products, gas load, and crude oil, all accounted for 35,383 million tonnes (mt) in 2019. The figure stood at 5,000 mt in 1970, and steadily increased to 20,000mt in 2014 and 27,500 mt in 2017, according to United Nations Conference on Trade and Development. Das pointed out two major reasons for high noise in Arabian Sea. “The first is due to shipping being directly related to economic growth and secondly anti-Piracy measures resulting in higher deployment of naval vessels combined with bunching of shipping traffic witnessed over the past six years,” he said. “Policy measures are required for marine spatial planning to have equitable distribution of maritime growth across the region.”

Dr V Kripa, principal scientist and head, fishery environment management division, Central Marine Fisheries Research Institute said, “We need more research to ascertain the exact health impact of shipping noise on marine life. Studies are still in their preliminary stages.”