September 13, 2023 | Circular No. 11577

Dear Member,

As a reminder, the fall portion of the Voluntary Slowdown for North Atlantic Right Whales in Cabot Strait will run September 27th – November 15, 2023. The purpose of this voluntary slowdown is to prevent deadly strikes by vessels as the slow-moving, endangered North Atlantic right whales transit through Cabot Strait on their way out of the Gulf of St Lawrence where they spent the summer.

Details and Communication Materials

Details including coordinates, and communication materials for vessels are available below. Information for this and other speed restrictions in Canadian waters can also be found on our website under Member Resources/ Environment/ Speed Restrictions.

2023 Spring Slowdown Results

The voluntary slowdown in Cabot Strait had high participation in spring 2023 – around 84%, meaning this voluntary slowdown has become standard for the bulk of the shipping industry. We thank members for your continuing support of these important measures to protect these whales.

Members may note that this is a much higher participation rate than reported in the past. In the process of reviewing the three- year ‘trial period’ of the voluntary measure last year, the Federation had several conversations with TC about the way they were measuring and reporting participation rates. This resulted in new reporting methods that are in line with reporting of other voluntary slowdowns for whales in the country. Importantly, most ships are in fact participating, and now the reports (below) reflect this.

New Research on NARW use of Cabot Strait

Newer research shows that North Atlantic right whales use Cabot Strait throughout the year – not only during the spring and fall, as was previously believed. Therefore, there is a push from some groups to expand the period when this slowdown is in place. The Federation is a strong supporter of risk-based and evidenced- based management, and will review the information as it becomes available. Please contact the undersigned with questions.


Miako Ushio
Manager, Environmental and Regulatory Affairs