How to survey oceans in silence and keep marine life thriving

FESCH.TV INFORMIERT:

Ever wonder how marine animals survive in the murky waters where light can’t travel far? They don’t navigate the world through sight, but sound. To survive, they must use their acute hearing abilities. Yet human-induced noises from seismic surveying of the ocean floor for natural gas, petroleum, and other mineral resources have industrialised their environment, creating a harmful cacophony. Blaring ships and blasts from explorations are not only alien to wildlife and cause distress, but also destroy the natural acoustic ecosystem that has kept them thriving for millions of years.

Marine mammals have an efficient communication system. Whales perform songs to reach out to each other and keep connected to their pods, while dolphins tailor their squeaks so that it’s unique to an individual. Dolphins have signature whistles similar to human names, allowing them to coordinate their activities and ensure their young remain in proximity for the first three years of their lives. However, noise explosions disrupt the behaviours that are essential to their survival. Air guns used for oil and gas explorations release air bubbles at a high speed and pressure, creating broadband pulses that can travel over 4 000 kilometres underwater. This is repeated every 10 seconds for weeks or months at a time, with devastating effects. Marine mammals can experience tissue damage in their ears, and the noise can hamper their ability to hunt as they rely on echolocation.

To minimise our acoustic footprint on the waterways, vessels can travel at a slower pace for a quieter experience, and air guns which blast its frequencies at once can be swapped for marine vibrators that only release what’s required in a given location. This marine seismic source lengthens its emissions, allowing sound waves to travel at a reduced pressure and with refined frequencies. Whales, dolphins, and numerous marine animals depend on an environment free from noise, with the only underwater chimes coming from the life who inhabit it.