Underwater Noise Emissions

The Marine Environment is in danger due to the increasing Underwater Noise Emissions (UNE) from ships in Indian waters, according to a News Research titled "Measuring Underwater Noise Levels Radiated by Ships in Indian Waters."

By deploying a hydrophone autonomous system around 30 nautical miles off the Goa coastline, the ambient noise levels were measured.

Key Findings of the Study:

• The sound pressure levels of the Underwater Noise Emissions (UNE) in the Indian waters range from 102-115 decibels (dB relative to 1 Pa).
• According to a scientific consensus, the reference pressure for underwater sound is 1 Pa.
• The level on the East Coast is a little higher than on the West.
• There is a noticeable increase of roughly 20 dB relative to 1 Pa.
• Constant shipping activity has been found to be a significant factor in the rise in ocean noise levels worldwide.
• Animals like bottlenose dolphins, manatees, pilot whales, seals, and sperm whales are at risk from Underwater Noise Emissions (UNE).
• In the low-frequency region of less than 500 Hz, the underwater self-noise and machinery vibration levels of ships overlap the communication frequencies of marine species.
• This process, known as masking, could modify how marine species migrate to shallower areas and make it more difficult for them to return to deeper waters.
• Yet, over time, the sound that ships emit harms them and causes internal injuries, hearing loss, altered behavioral reactions, masking, and stress.

Facts:

• In just 11.5 years, the global emissions of underwater noise from shipping have doubled.
• Ships' emissions of underwater noise rise sharply in Arctic regions.
• There is a lot of variation in regional patterns for shipping noise emission.
• The COVID-19 pandemic reduced worldwide maritime noise emissions to levels from 2017.
• The main source of shipping noise emissions is containerships.

What is Ocean Noise?

• The sounds produced by a human activity known as "ocean noise" stress marine ecology. It affects marine mammals' behavior, physiology, and reproductive cycle and has a direct impact on their mortality rates. This phenomenon is also referred to as anthropogenic noise pollution.
• Global warming, plastic pollution, acidification, and overfishing are just a few of the urgent issues affecting marine habitats. Ocean noise pollution is another.
• Since sound waves travel farther and quicker in water than they would on land while moving through the air, the issue is substantial. However, even low-frequency noise, which is barely audible to humans, can do great harm to marine life.

Sources of Noise Pollution in Seas and Oceans:

• There are a variety of sources of ocean noise pollution, such as ship noise, low-frequency sonar "sounds," which are frequently employed to locate submarines, seismic air cannon noise from oil and gas development, commercial shipping traffic, and coastal jet ski activity.
• In regions where ships' noise pollution is a problem, the number of cetaceans (whales and dolphins) has decreased.

Impact of Ocean Noise on Marine Ecosystems and Biodiversity:

• Hours after being exposed to loud underwater noise, marine animals can die. One of the numerous negative effects of ocean noise pollution is the displacement or relocation of marine species to newer locations.
• The strange sounds startle the majority of animals. Hemorrhages, altered diving patterns, migration to newer locations, internal organ damage, and a general panic reaction to unfamiliar sounds can all contribute to death.
• The frequent communication between marine species is further hampered by underwater noise pollution. As a result, animals that are sensitive to noise pollution are unable to communicate with one another, hunt for food, or even cry out for aid.

Initiative to Safeguard Marine Ecosystems:

• Global: The GPA is the Global Program of Action for the Protection of the Maritime Environment from Land-based Activities.
• The GPA is the only international body that specifically addresses the interconnectedness of terrestrial, freshwater, coastal, and marine ecosystems.
• 1973's MARPOL Convention: It addresses intentional or unintentional marine environment degradation by ships.
• It lists numerous types of marine pollution brought on by oil, toxic liquids, dangerous packed goods, ship sewage, and waste, etc.

The 1972 London Convention:

• Its goal is to encourage the effective control of all marine pollution sources and to take all reasonable precautions to avoid polluting the sea by dumping rubbish and other materials.

Way Forward

• The ocean is known as the "quiet planet" for a reason. This realm has its own exquisite, tranquil, and harmonic sounds. To comprehend the consequences of noise pollution on marine life and identify practical mitigation strategies, studies are being done. Up until that point, our best chance of preserving the integrity of this "quiet world" is safety through prevention.