March 27, 2024 | Circular No. 11650

Dear Member,

The following whale-related speed restriction measures will apply on the East Coast as of April 17, 2024. This and information on slowdowns nation-wide are available and regularly updated on our website under Member Resources/ Environment/ Speed Restrictions for Whales and Shore Erosion.

Please note that there will be a voluntary slowdown in Cabot Strait again this spring and fall. Maintaining high participation in this slowdown remains important and protects vulnerable, critically endangered North Atlantic right whales as they migrate into and out of Canadian waters via Cabot Strait. We will distribute communication materials about this voluntary measure in the coming weeks.

Area/ Concern 2024 Mitigation Measures Maps and Links to Official Documents
East Coast

Gulf of St. Lawrence

North Atlantic Right Whales (NARWs)

Ship Strikes

Main mandatory measures, April 17 to November 15, 2024:

  • Static speed restriction zones (areas in light pink): Vessels to operate at 10 knots or less, except in the five dynamic sectors below.
    Dynamic shipping corridors (zones A, B, C, D, E – areas in green):  Vessels may travel at safe operational speeds when no NARWs are observed in these zones.
  • Vessel Restricted Area” in the Shediac Valley (approximately blue rectangular box. Coordinates, which have been the same since 2021, are below): Vessels are prohibited from transiting through the area bounded by:
    48˚31.8’ N 063˚39.6’ W
    48˚24.72’ N 063˚17.88’ W
    47˚18.84’ N 064˚10.8’ W
    47˚27.18’ N 064˚30.72’ W
  • Seasonal Management Areas (SMA-1 & SMA-2) Between April 17 and June 25, 2024: vessels to operate or 10 knots or less.

Voluntary Measure: April 17th to June 25th AND September 25 to November 15, 2024: Voluntary 10-knot slowdown in part of the Cabot Strait (shaded grey area) to protect NARWs in this migration corridor.

* NARW sightings can be viewed through an interactive Whale Map

1. Summary of 2024 NARW Measures (TC document)

2. Dynamic Shipping Zones: Navigation Warnings (NAVWARN) are broadcast directly to vessels.


East Coast

Roseway Basin


Ship strikes

June 1 to December 31, 2024

  • Formally adopted by IMO as a recommended “Area to be Avoided”
  • In place since 2007

Coordinates and Map

2007 IMO Circular Letter – see pages 8 and 9

East Coast

St. Lawrence River

Large Baleen Whales & Belugas

Ship strikes & ship noise

May 1 to October 31, 2024

  • Voluntary measure in piloted waters: 10-knot slowdown area in a portion of the St. Lawrence Estuary (between Les Escoumins and Saguenay River)
  • Measure in place since 2013.

Coordinates and Map available in NOTMAR 2024, see Sec. A2 Notice 5, or p.26 (html) (pdf)

NARW Information broadcasted to vessels and agents:

  • CCG MCTS will advise vessels when a speed restriction is activated in one of more of the dynamic shipping corridors via NAVWARN. You can register to receive NAVWARN alerts on NARW here. (Select “series Q”, Category: waterways information, subcategory: North Atlantic Right Whale).

Please contact the undersigned with any questions.


Miako Ushio
Director, Environmental Affairs