The impact of anthropogenic noise on wetland habitats

Abstract

Impacts of anthropogenic noise is an important but poorly studied aspect of wetland ecology. Many aquatic animals use sound to attract mates, coordinate movements, defend territory, and detect predators. However, anthropogenic noise (e.g., from boat or automobile motors) are increasingly important in wetlands. Therefore, it is important to understand how anthropogenic noise pollution affects these habitats. I sampled wetland soundscapes in urbanized and rural areas in northeastern Ohio, and used Raven software to analyze the data. Above the water line, average sound power was 38.9db–73.9db, which was similar to below the water line (48.6db–78.5db). Frequencies in the band 0–5 kHz had the highest overall power both above and below the water. One of the most urbanized sites had above/below readings as high as 83.9/79.3 dB. In comparison, one of the most rural sites had readings as low as 47.6/66.8 dB. At both urbanized and rural sites, the 0–5 kHz band had the highest overall power. I further tested if wetland invertebrates could be impacted by anthropogenic sounds. I found that Procambarus acutus crayfish produced audible clicks (frequency range 6 kHz–45 kHz, average power 69–73.5 dB). Ongoing laboratory research is testing if motorboat noise affects P. acutus behavior and sound production.