Our ability to anticipate and estimate how pollution affects biota is of paramount importance in the field of ecotoxicology. Impact of chemical pollution by metals, drugs or pesticides was widely studied in different species using acute and chronic scenarios. While environmental factors such as temperature are also often considered, noise is largely ignored in these models despite the knowledge of its detrimental effects in vertebrates. Studies of noise impacts included behavior and fitness endpoints and showed no effect to death depending on intensity, frequency and the distance from the noise source (Peng et al., 2015). Nonetheless, the impact of noise in biota is not well-understood, which impairs its effective mitigation. 

Noise or acoustic pollution due to boat traffic produce low-frequency stationary noise. It is a pervasive and ubiquitous pollutant found in aquatic ecosystems. In this context, Prosnier et al. (2023) addresses how intermittent and random noise impacted Daphnia magna, a representative of zooplankton model, widely used in ecotoxicology. Endpoints of lifespan and clonal offspring production were measured in the presence or absence of motorboat noises, in animals reared from birth to death. Noise consisted in a playlist of 15 sounds of motorboat recorded in the Grangent lake (Loire, France). Their intensity ranged from 0 to -25 dB Re 1 μPa by 5 dB to create 75 sounds from 103 to 150 dB RMS Re 1 μPa – a range of levels occurring in lakes. Treatment had no effect on analyzed endpoints, contrary to a continuous broadband noise (100-20,000 Hz) that caused higher survival and fecundity, and reduced speed of motion compared to control (Prosnier et al., 2022). Data point that temporal (continuous, regular, random) and frequency of noise are instrumental for its effects. 

References

Peng, C., X. Zhao and G. Liu (2015). "Noise in the Sea and Its Impacts on Marine Organisms." Int J Environ Res Public Health 12(10): 12304-12323. https://doi.org/10.3390/ijerph121012304

Prosnier, L., E. Rojas and V. Médoc (2023). "No evidence for an effect of chronic boat noise on the fitness of reared water fleas." bioRxiv: 2022. ver. 4 peer-reviewed and recommended by Peer Community in Ecotoxicology and Environmental Chemistry. https://doi.org/10.1101/2022.11.20.517267

Prosnier, L., E. Rojas, O. Valéro and V. Médoc (2022). "Chronic noise unexpectedly increases fitness of a freshwater zooplankton." bioRxiv: 2022. https://doi.org/10.1101/2022.11.19.517212