Dear MARMAM-Users, We are pleased to announce that we have published a new paper on the effectiveness of slowdowns for reducing underwater radiated noise from shipping in Southern Resident Killer Whale critical habitat: MacGillivray, Alexander O., Zizheng Li, David E. Hannay, Krista B. Trounce, and Orla M. Robinson. 2019. 'Slowing deep-sea commercial vessels reduces underwater radiated noise', 146: 340-51. https://doi.org/10.1121/1.5116140 Abstract: During 2017, the Vancouver Fraser Port Authority's Enhancing Cetacean Habitat and Observation program carried out a two-month voluntary vessel slowdown trial to determine whether slowing to 11 knots was an effective method for reducing underwater radiated vessel noise. The trial was carried out in Haro Strait, British Columbia, in critical habitat of endangered southern resident killer whales. During the trial, vessel noise measurements were collected next to shipping lanes on two hydrophones inside the Haro Strait slowdown zone, while a third hydrophone in Strait of Georgia measured vessels noise outside the slowdown zone. Vessel movements were tracked using the automated identification system (AIS), and vessel pilots logged slowdown participation information for each transit. An automated data processing system analyzed acoustical and AIS data from the three hydrophone stations to calculate radiated noise levels and monopole source levels (SLs) of passing vessels. Comparing measurements of vessels participating in the trial with measurements from control periods before and after the trial showed that slowing down was an effective method for reducing mean broadband SLs for five categories of piloted commercial vessels: containerships (11.5 dB), cruise vessels (10.5 dB), vehicle carriers (9.3 dB), tankers (6.1 dB), and bulkers (5.9 dB). Alexander MacGillivray, M.Sc. Senior Scientist ________________________________ JASCO Applied Sciences (Canada) Ltd 2305–4464 Markham Street Victoria, BC V8Z 7X8 Canada Tel: +1-250-483-3300 x2011 Fax: +1-250-483-3301 Cel: +1-250-507-6490 www.jasco.com<http://www.jasco.com/> Subscribe to the JASCO Newsletter<http://eepurl.com/cY6b5v> An ISO 9001 certified company CONFIDENTIALITY NOTICE This e-mail and any files transmitted with it may contain proprietary information and, unless expressly stated otherwise, all content and attachments are confidential. This e‑mail is intended for the addressee(s) only and access by anyone else is unauthorized. If you have received this e-mail in error, please notify the sender and delete all copies from your system. Thank you.