Context

The rising man-made (anthropogenic) underwater noise emissions (UNE) from ships in the Indian waters are posing a threat to the life of marine mammals like Bottlenose Dolphin, Manatees, Pilot Whale, Seal, and Sperm Whale

About

Why sound is ‘critical’ for marine life?

• The main form of energy for multiple behavioural activities of marine mammals, which include mating, communal interaction, feeding, cluster cohesion and foraging, is based on sound.
• Sound is critical for communication, navigation, locating prey, avoidingpredators and finding mates.

Who are the major contributor to noise pollution?

• Human activities – known as anthropogenically generated sounds – are having a significant acoustic impact.
• Noise pollution, especially from ships and other vessels, fishing boats, military activities, oil rigs and seismic surveys is threatening the biodiversity.
• Continuous shipping movement is identified to be a major contributor to the increase in the global ocean noise level.
• “The frequencies of ships’ underwater self-noise and machinery vibration levels are overlapping the marine species’ communication frequencies in the low-frequency range of less than 500 Hz. This is called
  • Masking could have led to a change in the migration route of the marine species to the shallow regions and also making it difficult for them to go back to the deeper water.
    

Impact of noise pollution on marine life

• Changes in behaviors of mammals underwater, masking, and stress. 
• Impacts on reproduction, breeding and population
• Loss of hearing ability
• Injury and mortality