Noise

You can find out more detail in our article Types of Noise, but for now, let's look at a summary.

Since the Industrial Revolution, the seas have become loud. Ships, sonar devices, oil drilling, and seismic tests have caused a large amount of noise pollution. This disrupts echolocation, impacting the behaviour of marine mammals.

Sonar is a significant problem. Naval sonar devices are like the human version of echolocation; sending pulses of sound into the ocean to bounce off an object and return an echo, indicating its position. Sonar pulses can be as loud as 235 decibels! They can travel for hundreds of miles, interfering with echolocation. Sonar has significantly influenced the behaviour of endangered blue whales, leading to altered feeding patterns and mass strandings.

Seismic surveys have similar effects to sonar. Ships use air guns to shoot pulses of sound down to the ocean floor to search for oil or gas deposits. The sound blasts cause damage to the ears of marine animals and can cause serious injuries.

Reducing the Effects of Noise Pollution on Aquatic Life

Scientists have called for the reduction of noise pollution in the oceans. Strategies include:

• Collecting data to create sound maps, used to visualise areas of noise pollution and its influence on marine mammals

• Establishing international noise pollution standards

• Redesigning propellers

• Installing quieting technologies, such as sound-absorbing tiles, vibration isolators, and air compressors

• Place restrictions on sensitive areas

• Further research to gain a deeper understanding of the effects of noise pollution on marine life

I hope that this article has explained noise pollution to you. Remember that noise pollution is defined as harmful or annoying levels of noise. Excessive noise may seem irritating but harmless; unfortunately that's not true. Exposure to noise pollution can affect health and behaviour, especially for marine mammals.

^{1. Center for Hearing and Communication, Common Noise Levels - How Loud is Too Loud?, 2022}

^{2. Dale Purves, Neuroscience, 2001}

^{3. Dave Cutten, The top 10 animals with the best hearing, Hidden Hearing, 2021}

^{4. Iberdrola, Noise pollution: how to reduce the impact of an invisible threat?, Sustainability, 2022}

^{5. J. Tate Mason, Anthropogenic noise impairs owl hunting behavior, Biological Conservation, 2016}

^{6. National Geographic Society, Noise Pollution, 2022}