An Assessment of Noise Pollution Propagated by WSDOT Ferries in the Puget Sound

Abstract

Increasing ferry traffic in the Puget Sound and Salish Sea raises concern for marine mammals due to noise pollution. This is not a topic of major environmental concern in the design process for future ferry generations. The factors of vessel type that influence noise levels are not known, and thus not used as a means of minimizing noise pollution. For the sake of sustaining future marine mammal populations in an environment of growing vessel traffic, this project tested the levels of noise pollution from two class of ferries in the Puget Sound. Multiple linear regressions with interactions and ANOVAs determined the relationships between continuous and categorical variables. Results determined one or more categorical variables influence SPL and kinetic variables that influence SPL are acceleration and range. These data are useful in quantifying the current acoustic overlap for different marine mammal groups and in minimizing the noise levels of new ferries.