Effects of Boating Disturbance on Seabird Abundance and Flushing Behavior in the San Juan Islands

Abstract

Boating traffic can disturb and negatively affect normal behaviors of marine birds, including foraging. Surveys of seabirds were performed on two vessel routes with different types of boat traffic in the San Juan Islands, Washington. Comparisons of data showed that birds were more abundant on the route taken by the Centennial vessel in the San Juan Channel than on the route taken by the Klahowya vessel in the Washington State Ferries’ San Juan Interisland route. Seabird species were non-uniformly distributed both between the two vessel routes and within each vessel route. My study was unable to find a correlation between seabird abundance and tidal state, contrary to established literature. Data on flushing behavior suggest that response to disturbance is variable between species, locations, and vessels causing the disturbance.