The Year of the Quiet Ocean

The ongoing pandemic has been and continues to be an international crisis. While we all hope and pray for the malady and death toll to end soon, it cannot be denied that the current situation has opened doors to many opportunities for research and development.

Global lockdowns slowed the international shipping transport immensely and to an extent that was otherwise unimaginable. Oceanographers have taken this opportunity to study the ‘quiet’ that has come as one of the very few welcome outcomes of the pandemic times.

 

Relevance of the Experiment

Before the industrial revolution, ocean soundscape was prevailed by geophony (sounds from geological sources) and biophony (sounds from biological sources) with very little anthrophony (sounds from human sources). After the industrial revolution, biophony kept reducing due to depletion of marine life because of hunting and overfishing; and degradation of marine ecosystems, and anthrophony gradually increased.

Besides general pollution, rising sea levels, acidification of oceans and other environmental issues related to marine environment- industrial growth in the last century has also contributed to increased sea transport leading to noise pollution in our seas and oceans. Human-made noise has literally drowned the natural marine soundscape. Various industries such as shipping, construction, naval activity resource exploration and infrastructure development, as well as underwater surveys and drilling for oil and gas, have ill-affected the healthy ocean soundscape.

 

Importance of natural oceanic soundscape

When we are under water we can notice that one may not be able see across a long distance, but we can hear sounds from kilometers away. This is because sound travels faster and farther in water than in air. Marine organisms have adapted over the years to rely on this quality, transmission and reception of oceanic sounds as parts of their living mechanisms.

Many sea organisms have developed methods of effective communication based on oceanic sound behavior. Sound transmission also helps all types of sea life- it guides predator in finding prey or helps prey in escaping from predators. It is also believed that fish larvae decide settlement on coral reefs based on sounds from the reefs.

 

Some impacts of increased anthrophony

Over the years, adaptive behaviors of marine life have been threatened by an increasing human-produced cacophony in the oceans, thus causing a major impact on marine life. Anthropogenic noise is a stress on the marine environment.

Naval sonar has been linked to mass stranding of some species of deep-sea whales. Furthermore, noise impairs sensory function related to hearing and leads to behavioral changes in marine animals. It is not proven but may be possible that under water noise pollution increases marine life mortality and also hampers settlement of their larvae.

 

The Experiment

Researchers have planned to record, analyze and assess the ocean soundscape before, during and after lockdown. This colossal listening experiment to listen to the heartbeat of the ocean has been termed the ‘year of the quiet ocean’.

Two hundred ocean hydrophones (underwater microphones) are already in place under our oceans. These will be used effectively to record and measure the changes in noise levels as also study how these changes affect marine life.

 

Aims of the experiment

Besides measuring the changes this experiment would also shed light on the effects of decades of human made ocean noise on marine life in the Anthropocene era with increasing impact of human activity on the planet's climate and ecosystems. The experiment could spearhead a movement to achieve the right equilibrium between human activity and natural oceanic processes. Combined with other methods such as animal tagging, researchers hope this will reveal the extent to which noise in "the Anthropocene seas" affects life in the deep seas.

Prof. Jennifer Miksis-Olds, an ocean acoustics expert from the University of New Hampshire has a goal to use this experiment to “build a global ocean soundscape map, where you could see the sounds of shipping routes, see migration patterns of whales - from their song - and even learn about climate change from the sounds of icebergs calving."

 

As I wish success to the experiment, I want to highlight that while we are suffering the pandemic lockdowns, nature has flourished. Oceans too have had their voice heard as natural ocean sounds got to dominate the human made sounds. It is heartening to note that unlike other stressors of the environment, such as carbon dioxide emissions or pollutants dumped into the marine ecosystems, anthropogenic noise is mostly from specific point-sources. Accordingly, its effects last till the presence of the source. Thus it is more feasible to reduce marine noise to revive natural ocean soundscapes in order to maintain a healthy marine environment. As a marine Science student, I advocate for a healthy ocean soundscape to allow marine animals to re-establish their use of ocean sound as their unique sensory guide and adaptive trait.

 

Sources and References

https://www.bbc.co.uk/news/amp/science-environment-56676820

https://science.sciencemag.org/content/371/6529/eaba4658