The technology that seeks to put an end to underwater noise pollution

Over the last decades, underwater noise and its consequences have received less attention than other ocean pollutants. However, the situation has changed in the face of growing evidence: noise generated by human activities such as shipping has negative effects on marine fauna and flora and can cause significant imbalances in ecosystems:

• PFor many animals, being exposed to high or continuous levels of anthropogenic noise causes stress and even physical damage. Some cetaceans may suffer damage to their auditory system, impairing their ability to communicate, detect threats or follow their migratory routes.
• Other organisms that live anchored to the seabed, such as corals, algae or aquatic plants like Posidonia oceanica, also suffer important morphological and physiological consequences.

Many of these problems end up generating behavioral changes, disorientation, strandings and even death, thus causing an impact on the entire food chain and ecosystems as a whole.

This reality has led different organizations to act to curb underwater pollution. In fact, according to the European Maritime Transport Environmental Report 2025, prepared by the European Maritime Safety Agency (EMSA) and the European Environment Agency (EEA), some important steps have been taken in recent years to tackle this problem.

A significant advance is the creation of models capable of generating data with which to draw a complete picture of the state of the oceans, both at European and global level. These data make it possible to compare how shipping affects different regions and have made it possible to identify techniques and operational measures to reduce underwater noise.

Innovative, accessible and scalable technology

Among these solutions plays an important role a technology that, in some cases, is still to be developed. Making it a reality is one of the objectives of the consortium LOWering underwater NOISE Radiation from waterborne transport (LOWNOISER), in which the Universitat Politècnica de Catalunya - BarcelonaTech (UPC) participates, through the Bioacoustic Applications Laboratory (LAB).

6.3 million to develop innovative noise reduction technologies, which will be tested on board five large vessels over the next few years.

The main objective is to test different solutions:

• “One of them consists of an air lubrication system that creates a layer of bubbles under the sea to reduce the friction and noise that boats generate in contact with the water, as well as fuel consumption,” explains Marta Solé, senior researcher at the UPC's LAB and leader of a team that will be in charge of verifying that the measures are effective in mitigating the acoustic impact on marine invertebrates.
• “Another is based on bevel gears and engine mounts designed to minimize vibrations and structure-borne noise from engines and propellers, and a third modifies the monitoring systems we carry on board the ships to know and be able to adjust in real time the level of noise emissions,” Solé continues.
• “Finally, we have a new system to detect and record the acoustics of the seas, which is called DAS [distributed acoustic sensing]. These are fiber optic cables that go under the sea and allow us to record and check for changes in sounds in sea areas where there is human activity,” he adds.

Over the next few years, the LAB team and the other entities involved will test whether, with the use of these technologies, the impact on marine life is reduced. “We will work both in laboratory conditions and at sea, checking whether there are really fewer injuries to the animals thanks to these modifications,” explains Solé.