Marine vessel traffic is a significant source of anthropogenic noise pollution, but little is known of how it affects pinnipeds. Seal Rocks, Victoria, is the largest Australian fur seal breeding colony and receives a high volume of vessel visitation, which peaks during the breeding season. Approach regulations for vessels at Seal Rocks are based on a long-held assumption that the colony is habituated to human visitation. However, there is no research to support this assumption and the population currently faces multiple threats that could reduce its resilience to human disturbance.
This study aims to determine the behavioural response of seals at Seal Rocks to three levels of airborne motor vessel noise using controlled noise exposure (playback) experiments, undertaken during peak (summer) and off-peak (autumn/winter) visitation. Results show behavioural modification, such as decreased resting and increased vigilance and other activity, during and after noise playback in both peak and off-peak periods, which has implications for management of vessel visitation at Seal Rocks. These results will be used in combination with other data to develop an acoustic impact model to better inform adaptive management strategies at Seal Rocks and other Australian fur seal colonies.