Lessons Learned In Setting underwater Radiater Noise Targets: A Bc Ferries Case Study

摘要

In a typical year, the waters surrounding British Columbia's Port of Vancouver host approximately 3,000 deep sea commercial vessels and 19 of the 35 ferries operated by BC Ferries, one of the largest ferry operators in the world. These waters are also home to a wide variety of aquatic wildlife, including the southern resident killer whales (SRKW), which have been listed as endangered in Canada since 2003. With vessel-generated acoustic disturbances identified by Fisheries and Oceans Canada as one of four key threats to the SRKW, the Vancouver Fraser Port Authority launched the Enhancing Cetacean Habitat and Observation (ECHO) Program in 2014 to better understand and manage the impacts of com- mercial vessel traffic on at-risk whales, with a particular focus on vessel-generated underwater noise. In moving towards this goal, in 2015, the ECHO Program began monitoring underwater noise through a cabled hydrophone system installed in the Strait of Georgia, near the international shipping lane. The hydrophone system continuously measured underwater noise, showing that peak noise levels strongly correlated with BC Ferries' ferry schedule between Tsawwassen and Nanaimo (Figure 1). This initial study compelled BC Ferries - one of the ECHO Program's founding advisory working group members - to undertake research to better understand the underwater noise contributions of its fleet.