Aquatic Sciences

, Volume 72, Issue 3, pp 371–378

Year-round variability of ambient noise in temperate freshwater habitats and its implications for fishes

Research Article

DOI: 10.1007/s00027-010-0136-9

Cite this article as:
Amoser, S. & Ladich, F. Aquat. Sci. (2010) 72: 371. doi:10.1007/s00027-010-0136-9

Abstract

Changes in habitat acoustics over the year can potentially affect fish hearing and orientation to sound, especially in temperate climates. This is the first study where year-round changes in ambient noise in aquatic habitats were assessed. Seven different European freshwater habitats were chosen for this study. Sound pressure level (SPL) and spectral composition of the ambient noise varied in both quiet stagnant habitats (lakes, backwaters) and in flowing habitats (streams, rivers). Linear equivalent SPL (LLeq, 60s) tended to be lower in stagnant habitats (means: 91.6–111.7 dB) than in flowing habitats (means: 111.2–133.4 dB). The changes in SPL were smallest in the river (means: 4.2–4.4 dB, maxima: 8.5–10.1 dB), whereas significantly higher values were measured in stagnant habitats and the stream (means: 9.9–14.9 dB, maxima: 25.1–30.9 dB). The spectral compositions of the ambient noise determined at different times of the year were highly correlated to each other at the river sites (mean cross-correlation coefficients: 0.85 and 0.94) and were weaker or not correlated at the other study sites (means: 0.24–0.76). The changes in ambient noise spectra were negatively correlated to changes in SPL, indicating that large changes in SPLs were accompanied by large changes in spectral composition and vice versa. Comparison of these eco-acoustical data with a preceding study (Amoser and Ladich in J Exp Biol 208:3533–3542, 2005) indicates that the auditory sensitivity in hearing specialists is affected by changes in ambient noise levels and spectra throughout a year and that this effect tends to be more pronounced in stagnant waters and the stream than at river sites. On the other hand, absolute noise levels result in a higher degree of masking in flowing waters.

Keywords

Ambient noiseSound pressure levels and spectraFreshwatersFishMasking

Copyright information

© Springer Basel AG 2010

Authors and Affiliations

  1. 1.Department of Behavioural BiologyUniversity of ViennaViennaAustria