What is underwater noise?

LIAE is launching informational campaign about underwater noise within the framework of “Red Noise BaltShip” project

What is underwater noise? Is underwater sound the same as underwater noise?

Within the framework of “Red Noise Baltship” project Latvian Institute of Aquatic Ecology is launching an informational campaign about underwater noise – its types, occurrence and effects. For two months – December 2023 and January 2024 – we will publish an entry each week both on LIAE website and social network channels. The first article follows below.

If we look at the terms sound and noise, they seem very similar – they are vibrations in air or water that we perceive by hearing. The larger the sound waves (their amplitude), the stronger the vibrations and the louder the sound itself. However, when talking about noise, it is often defined as unwanted sounds that do not perform any useful or biological function. Unfortunately, such definitions are very subjective and not mutually exclusive. For example, the sounds produced in seismic research are intentional sound signals, not noise, but underwater inhabitants will find such sounds undesirable and as noise.

In order not to get confused in the various definitions, let’s use the general term – underwater noise. It includes all sounds produced by intentional or unintentional human activity. In contrast, the broader term underwater sound refers to the soundscape as a whole, including, but not necessarily distinguishing, biological, geophysical and anthropogenic sounds.

Why is underwater noise harmful?

Anthropogenic (caused by human activities) underwater noise is a major problem that seriously affects marine animal species. Underwater noise is a significant pollutant of the marine environment, posing a significant, if not immediately apparent, risk to marine ecosystems. Anthropogenic underwater noise can negatively impact marine biodiversity.

Marine mammals (whales, dolphins, seals, sea lions), as well as fish, use sound for communication and as a navigation tool to move around in the surrounding environment. However, under the influence of underwater noise created as a result of human activities, these biological functions are disturbed. This negatively affects the ability of marine inhabitants to find food. Underwater noise increases the stress level of underwater animals, which affects the functioning of hormones, including reproductive functions.

Latest studies show that seismic surveys have a negative impact on zooplankton, which provide food for fish and other animals in the marine food chain. Thus, underwater noise can not only negatively affect certain species of marine mammals or fish, but also cause degradation of marine habitats.

Latvian Institute of Aquatic Ecology (LIAE) is a partner in “Red Noise BaltShip” project since September 2023. Within the framework of the project work has been initiated on determining the environmental impact of small recreational ships and boats in the Baltic Sea region in the context of underwater noise. The project plans an informational campaign about underwater noise, its causes, effects and possibilities for reducing it in the Baltic Sea. In December 2023 and January 2024 weekly articles will be published providing information on the subject on LIAE website and social network channels. Within the framework of the “Red Noise BaltShip” project it is planned to achieve improvements in communication and knowledge exchange between researchers and interested parties – yacht clubs, boat owners, NGOs and others. The project is financed by the Swedish Institute, the leading partner is Coalition Clean Baltic, the other partners are the German Federation for the Environment and Nature Conservation “BUND”, Foundation for the Development of Gdańsk University “FRUG”, The Fisheries Secretariat (FishSec) and LIAE.

All campaign materials (in Latvian) will be available from now on in the “Outreach” section of the LIAE website under “Popular science materials”.


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Runko Luttenberger, L., Sliskovic, M., Ančić, Ukić Boljat, H. 2022. Environmental Impact of Underwater Noise. 4, 45-54.

Slabbekoorn, H., Dooling, R. J., Popper, A. N., Fay, R. R. 2018. Effects of Anthropogenic Noise on Animals. Chapter 10. Effects of Noise on Marine Mammals. Springer Handbook of Auditory Research, 66, 277–309.

Thomsen, F., Mendes, S., Bertucci, F., Breitzke, M., Ciappi, E., Cresci, A. Debusschere, E., Ducatel, C., Folegot, F., Juretzek, C., Lam, F-P., O’Brien, J., dos Santos, M. E. 2021. Addressing underwater noise in Europe: Current state of knowledge and future priorities. Future Science Brief 7 of the European Marine Board, Ostend, Belgium.

Van Geel, N.C.F., Risch, D., Wittich, A. 2022. A brief overview of current approaches for underwater sound analysis and reporting. Marine Pollution Bulletin, 178, 113610.




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