Acoustic monitoring equipment set up in the forest to capture both natural and anthropogenic sounds.
All physical sound resources (for example, sounds made by wildlife, waterfalls, wind, rain, and cultural or historical sounds), regardless of their audibility, are referred to as the acoustic environment of a park. The quality of the acoustic environment in Sitka NHP affects the visitor experience, cultural landscapes and structures, and wildlife. Currently, there are some concerns about sounds that may negatively impact visitors and park wildlife. Significant power boat traffic in the adjacent navigational channel could be causing effects, but lack of study of these sound levels seriously hampers evaluation of these effects.
To model the acoustic environment, the National Park Service has developed a national geospatial noise pollution model. This model predicts the increase in median sound level that can be attributed to human activities on an average summer day. The model uses measured sound levels from hundreds of national park sites and about one hundred explanatory variables such as location, climate, land cover, hydrology, wind speed, and proximity to noise sources such as roads, railroads, and airports.
Recently, the park has begun conducting its own acoustic monitoring that includes an underwater hydrophone to capture sounds in the bay and intertidal zone, on land to capture natural and anthropogenic sounds, and acoustic surveys specifically to identify bat activity.
