Vessel Slowdown Trial in Haro Strait




The vessel slowdown trial in Haro Strait ran between August 7 and October 6, 2017 and has now concluded.

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Studying the relationship of speed and underwater noise to reduce impacts on whales

The population of endangered southern resident killer whales is just 78 individuals (April 2017) and the species has shown little sign of recovery since the 1980s. Acoustic disturbance from vessel noise is identified by the federal government as a key threat to the recovery of the southern resident killer whale (SRKW). Research indicates that underwater vessel noise can interfere with their ability to hunt, navigate and communicate with each other. SRKW critical habitat directly overlaps with international shipping routes, ferry routes and other marine traffic routes in the Salish Sea.

The purpose of the trial was to better understand and measure the level of noise reduction which is achieved through reduced vessel speed. During the trial period, the ECHO Program team used AIS to monitor and measure commercial vessel participation rates, and hydrophones to assess the impact of reducing vessel speed on underwater noise. Potential financial and operational impacts to the shipping industry will be evaluated.

A full analysis of the effectiveness of slowing vessels down to reduce acoustic disturbance will be conducted by the ECHO Program team, with study results available in 2018. In consultation with our vessel operators committee regarding industry impacts, this analysis will be used to inform decision making and determine next steps.

Trial location

Trial area and transition zones.

Haro Strait is an important summer feeding area for southern resident killer whales and has been identified as a key hot spot for vessel noise disturbance.

The trial slowdown area was located between Discovery Island at the southern end, and Henry Island at the northern end. The distance of the trial area was16.6 nautical miles inbound, 14.9 nautical miles outbound.

Transition speed zones have been marked to the north and south of the trial zone.

Trial participants

The voluntary trial was planned and coordinated by the ECHO Program with the assistance of a vessel operators committee representing BC Coast Pilots, BC Ferries, the Chamber of Shipping of British Columbia, Cruise Line International Association North West and Canada, Hapag-Lloyd (Canada) Inc., Holland America Group, the Shipping Federation of Canada, the Pacific Pilotage Authority, Vancouver Fraser Port Authority, Washington State Ferries and Transport Canada.

Thank you to the following organizations for taking part in the vessel slowdown trial this summer:
AAL Shipping
ACGI Shipping Inc.
BC Coast Pilots
BC Ferries
Buchanan Cruises, LLC
Carnival Cruise Line
Celebrity Cruise Lines
Chamber of Shipping
Colley West Shipping Ltd.
Cruise Lines International Association North West and Canada
Crystal Cruises
CSL International
Disney Cruise Line
Evergreen Line
Fairmont Shipping (Canada) Ltd.
Fisheries and Oceans Canada
G2 Ocean
Georgia Strait Alliance
Hamburg Sud
Holland America Line
Hudson Shipping Lines
Inchcape Shipping Services
International Ship-Owners Alliance of Canada
K Line
Mason Agency Ltd.
Mitsui O.S.K. Lines
Montship Inc.
MSC Mediterranean Shipping Company
Navitrans Shipping Agencies West Inc.
Neptune Bulk Terminal
Norton Lilly Vancouver
Norwegian Cruise Line
NYK Line
Oceaenia Cruises
Oxbow Sulphur Canada
Pacific Basin Shipping
Pacific NorthWest Ship & Cargo Services Inc.
Pacific Pilotage Authority
Princess Cruise Line
Ravensdown Shipping Services Ltd.
Robert Reford
Royal Canadian Navy
Royal Caribbean International Cruise Line
SAAM SMIT Vancouver Inc.
Saga Welco AS
Seabourn Cruise Line
Seaspan ULC
Shipping Federation of Canada
Swire Shipping
Trans-Oceanic Shipping Co. Ltd
Transport Canada
Valles Steamship (Canada) Ltd.
Vancouver Fraser Port Authority
Washington State Ferries
Westward Shipping Ltd.
Westwood Shipping Lines
Wheelhouse Shipping Agency
Wilhelmsen Ships Service


We would like to thank the following organizations for foregoing their stipends to support continued ECHO Program research.

Evergreen Shipping Agency (America) Corporation
Holland America Line
Pacific Basin Shipping
Princess Cruise Line
Ravensdown Shipping Services Pty Ltd
Saga Welco AS
Seabourn Sojourn
Washington State Ferries

Results to date

At the conclusion of the nine week trial, the overall reported vessel participation rate was 61%. We are pleased with this result and want to express our sincerest gratitude to all those who supported and participated in the planning and execution of the trial.

The ECHO Program team and our consultants at JASCO Applied Sciences and SMRU Consulting have been working hard to interpret the underwater noise data collected from the trial. Although all collected data has not yet been analyzed, the initial results are encouraging. A summary report provides more technical information on the results processed to date, however, the preliminary information indicates:

  • The underwater noise generated by vessels (vessel source levels) are reduced at slower speeds. The reduction in noise is greatest for those ships that normally travel faster, and therefore have the largest change in speed. For example, if a containership that would normally travel at 18 knots slows to 11 knots, a greater reduction in vessel source level is measured than for a bulker that would normally travel at 13 knots reducing speed to 11 knots.
  • Total ambient noise is all the noise existing in the ocean at a given time and includes noise from large vessels, small vessels, wind, waves, marine mammals etc. Before and during  the trial, measurements of total ambient noise were taken at a location away from the shipping lane (the Lime Kiln hydrophone, located on the west side of San Juan Island) in an important killer whale feeding area. When comparing total monthly ambient noise measured before the trial, against noise measured during the trial (with 61% of commercial vessels slowing down), a reduction in total noise at the Lime Kiln hydrophone was observed.
  • Slowing vessels down means that they are generating less noise but are in a given area for a longer period of time. This in turn means that the quieter times experienced between vessel passes under normal vessel speed conditions are reduced in duration and are less quiet during slowdown conditions.

The results above are based on a preliminary assessment of the trial information collected and analyzed thus far. There is much more work to be done to better understand the results of the trial and the relationship between vessel speed and underwater noise, and how changes in underwater noise may impact the southern resident killer whale. We will continue to focus our efforts on the review, processing and analysis of data obtained through the trial, and look forward to sharing the final results with you in early 2018.


Vessel slowdown trial – backgrounder [PDF]
Vessel slowdown trial – operational communications, procedures and tracking plan [PDF]
Vessel slowdown trial – infographic [PDF]
Vessel slowdown trial – presentation: April 27, 2017 [PDF]
Vessel slowdown trial – map with coordinates [PDF]
Vessel slowdown trial – pilot decision matrix [PDF]
Vessel slowdown trial – agent decision matrix [PDF]
Vessel slowdown trial – agent portal instructions (provided by Pacific Pilotage Authority)  [PDF]
Vessel slowdown trial – stipend application [link]
Vessel slowdown trial – summary report – initial results [PDF]
ECHO Program


Pre-trial update August 2
Pre-trial update August 9
Newsletter Week 1
Newsletter Week 2
Newsletter Week 3
Newsletter Week 4
Newsletter Week 5
Newsletter Week 6
Newsletter Week 7  
Newsletter Week 8
Newsletter Week 9
Newsletter wrap-up

Please check back to this page for up-to-date information about the trial including resources, announcements and changes. Or subscribe to receive regular updates.