Terms of Reference

Evaluation of the Scientific Evidence to Inform the Probability of Effectiveness of Mitigation Measures in Reducing Shipping-Related Noise Levels Received by Southern Resident Killer Whales

National Peer Review - National Capital Region

May 30 to June 1, 2017
Victoria, British Columbia

Chairperson: Gilles Olivier


Ambient underwater noise levels have increased significantly over the past half century, largely as a result of increasing human activities in the marine environment.  Marine shipping and navigation activities of all types have been identified as important contributors.  However, the extent of this contribution, and its associated impacts on marine species, is not well understood, and is complex to assess.  There have been growing demands for government action to address this issue domestically and internationally in order to protect the marine ecosystem, and more specifically, species at risk.  In Canada, concerns are growing over the effects of underwater noise on marine mammals particularly in the south coast of British Columbia, the St. Lawrence Estuary, and the Bay of Fundy.

Most recently, in its review of the Trans Mountain Expansion (TMX) Project, the National Energy Board (NEB) found that the increase in marine vessels associated with the Project would further contribute to cumulative effects that are already jeopardizing the recovery of the Southern Resident Killer Whale (SRKW).  Consequently, the Board concluded that the operation of Project-related marine vessels is likely to result in significant adverse effects to the SRKW population.  The NEB encouraged regulatory authorities who have jurisdiction, notably Transport Canada (TC) and Fisheries and Oceans Canada (DFO), to explore initiatives that would reduce the potential effects of marine vessels on the SRKW population.  In approving TMX, the Government of Canada committed to more than mitigate the impact of additional TMX traffic on the SRKW before any shipping associated with the Project begins in December 2019.

Fisheries Protection Program (FPP) has asked DFO Science to provide science advice on the effectiveness of various mitigation measures (or a combination of these) for reducing shipping-related noise received by SRKW. The proposed mitigation measures were developed by FPP and TC, and include:

  • Reducing the speed of vessels (or a specific vessel class) in areas of likely noise-whale interactions, i.e. areas where shipping and SRKW presence overlap (e.g., Haro Strait, Swiftsure Bank, etc.),
  • Relocation of shipping traffic lanes, (e.g., move traffic away from Swiftsure Bank, away from western San Juan Island, etc.),
  • Changes in timing of ship traffic, both on the short scale (hours of day) and the long scale (time of year),
  • Changes in shipping practices (station keeping vs. anchoring, number of tugs, use of on-board machinery, etc.),
  • Changes in ship design (e.g., electric engines, efficient propellers, hulls, etc.),
  • Modifications or retrofits to existing vessels (e.g., adding fins or plates in front of propellers to streamline flow, propeller shrouds),
  • Redirecting a portion of vessel traffic (e.g. vessel classes, project-related vessels, etc.) through alternate routes (e.g., Rosario Strait),
  • Changes in maintenance of ships (hull cleaning, propeller cleaning/inspection, etc.),
  • Real-time notification of whale presence in hot spot areas (traffic light system) leading to management action,
  • Slow down or minor route change avoidance when whales are detected within the vicinity of or encountered by individual vessels (e.g., using passive acoustic monitoring, a whale tracking network or marine mammal observers to determine whale presence),
  • Convoy approach (staged vessel movements) for specific vessels or vessel classes, whereby vessels transit under strict and condensed timing windows,
  • Creation of ‘quiet’/’no-go’ areas, or periods of quiescence in certain areas or segments.

Based on existing data and information, provide science advice on the effectiveness of mitigation measures (or a combination of these) in reducing shipping-related noise levels received by SRKW.  This advice may draw from evidence involving other species and locations, and other noise sources, and therefore may have applicability elsewhere.


The objectives of this national peer review will be to:

    1. Provide science advice on the probability of effectiveness of the listed mitigation measures (or a combination of these) in reducing shipping-related noise levels received by SRKW.
    2. Identify the circumstances (ship type, season, location, habitat use, etc.) that would increase the probability of effectiveness of the listed mitigation measure in reducing noise levels received by SRKW.
  2. Review experimental approaches to investigate the acute and long-term impacts of shipping-related noise on SRKW individuals and the population.
  3. Identify any uncertainties, limitations and/or knowledge gaps of the listed mitigation measures in reducing shipping-related noise or in reducing sound levels received by SRKW and consequently their impact on SRKW, and actions to address these.

Expected Publications

  • CSAS Science Advisory Report
  • CSAS Proceedings
  • CSAS Research Document


  • Fisheries and Oceans Canada (DFO) (e.g., Ecosystems and Oceans Science, Fisheries Protection Program)
  • Transport Canada
  • Academia or Academics
  • Other invited experts


Participation to CSAS peer review meetings is by invitation only.

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