Summary Protected areas usually have conservation regulations designed to minimize physical disturbances, yet wildlife within them remains vulnerable to external factors such as noise pollution. We assessed transportation noise in over 2400 protected areas across Norway – Europe’s second least populated country – by overlaying protected area maps with publicly available noise zone data modelled down to 50 dB for Lden (day–evening–night) and Lnight. Road traffic was the dominant noise source. As wildlife can be affected at levels below 50 dB and by short bursts of high noise, we also examined road noise modelled down to 40 dB in two national parks and 15 smaller protected areas, and we conducted field measurements at a Ramsar site to capture peak noise events. Road noise at Lden ≥50 dB impacted 176 (7.1%) areas, increasing to 229 (9.2%) areas when multiple sources were considered; 126 (5.1%) areas were exposed to Lnight road noise. Smaller protected areas were more exposed. Including noise down to 40 dB raised the average affected area from 39.6%/18.6% to 56.6%/45.0% for Lden/Lnight. Field data revealed frequent peak noise events exceeding 80 dB, even at night. We recommend ecologically sensitive noise mapping using lower thresholds and consideration of frequencies inaudible to humans to better inform conservation planning.
Eldegard et al. (Mon,) studied this question.