Understanding and managing underwater noise: results from the Haro Strait vessel slowdown trial

• Main Author: Trounce, Krista
• Format: Text
• Language: English
• Published: Western CEDAR 2018
• Subjects: Vessel slowdown; Managing underwater noise; Haro Strait; Fresh Water Studies; Life Sciences; Marine Biology; Natural Resources and Conservation; Terrestrial and Aquatic Ecology; British Columbia; Canada; Haro; Lanes; Pacific; San Juan; Killer Whale; Killer whale
• Online Access: https://cedar.wwu.edu/ssec/2018ssec/allsessions/498; https://cedar.wwu.edu/cgi/viewcontent.cgi?article=2933&context=ssec

The Enhancing Cetacean Habitat and Observation (ECHO) Program is a Vancouver Fraser Port Authority-led initiative aimed at better understanding and managing the impact of shipping activities on at-risk whales throughout the southern coast of BC. Between August 7 and October 6, 2017, the ECHO Program managed a voluntary vessel slowdown trial in Haro Strait, located between Vancouver Island in British Columbia and San Juan Island in Washington State. Haro Strait is an important summer feeding area for southern resident killer whales, and a busy international shipping route. Through extensive consultation and collaboration with the Pacific Pilotage Authority, BC Coast Pilots, regional shipping associations and agents, as well as international vessel owners and operators, the overall reported participation rate for piloted commercial vessels at the conclusion of the trial was over 60%. Temporary, deep-water listening stations in the shipping lanes of Haro Strait, a shallow hydrophone off Lime Kiln State Park, and the long-term listening station in the Strait of Georgia were all used to collect data on underwater noise during the trial. Due to the excellent vessel participation rates, the ECHO program team and our consultants at JASCO Applied Sciences and SMRU Consulting were able to obtain a robust data set to evaluate: how reduced speed changes the underwater noise (source level) generated by specific vessels and by vessel classes; how reduced vessel speed changes the total ambient noise; and how these changes in noise may impact the killer whale. The trial results will help the ECHO Program and the Government of Canada make informed decisions on how to reduce the impact of vessel noise on endangered whales. These learnings will be of interest globally to those looking to manage vessel noise in sensitive whale habitats.