Underwater noise pollution in underexplored Australian estuaries

Human-made noise, also known as anthropogenic noise, has been identified as one of the most harmful forms of global pollutants impacting both terrestrial and aquatic species. The amount of urbanisation along coastlines is significantly rising as the world’s population continues to grow. Even while precautions are taken to lessen stress on wildlife, the effects of anthropogenic noise are rarely taken into account and it can have catastrophic effects on marine life.

In Australia, urbanisation of New South Wales (NSW) estuaries has increased significantly in recent years. Until a recent study by University of Newcastle researchers, there was still insufficient baseline information on these soundscapes to assess the threat posed by noise pollution. The study led by Brittney Valenzisi, involved collecting thousands of hours of underwater sound recordings to understand what noise can be heard beneath the surface in four estuaries across NSW. From as deep as six metres, planes and even people talking could be heard in the recordings! This research offers the first evaluation of baseline noises on a seasonal and temporal scale. The primary contributing source of anthropogenic noise in the estuaries was recreational boating, with noise levels higher in the estuaries with higher levels of urbanisation. With levels high enough to obscure some marine animals’ ability to communicate and navigate. 

Estuaries are much smaller in size to the offshore environment, meaning sound can bounce, reflect and potentially amplify in this smaller environment compared to open ocean where most research on noise pollution has been focused on the impacts on marine mammals such as whales and dolphins.This research provides useful information for environmental managers of NSW estuaries and is of global relevance in an era of increasing anthropogenic noise in estuarine and coastal ecosystems.

Learn more:

Valenzisi, B., Parsons, M., Huggett, M., Raoult, V., & Gaston, T. (2024). Urbanisation and boating are the main contributors to underwater soundscapes in three temperate estuaries. Marine Pollution Bulletin, 206, 116792. https://doi.org/10.1016/j.marpolbul.2024.116792