Research: Compliance of small vessels to minimum distance regulations for humpback and killer whales in the Salish Sea

Encounters between vessels and whales can result in ship strikes, exposure to pollutants, acoustic impacts, and physical/behavioural disturbances. Prevention via education and enforcement is key.

With myriad stressors in the Salish Sea, the last thing killer whales and humpbacks need is to be approached too closely by whale watching and recreational boats. 

The rise of vessel traffic, the growth of the whale watching industry, increased interactions between whales and small vessels, and the precarious existence of Southern Residents in particular, has given rise to some regulations from the federal government that attempt to mitigate the harm these interactions pose.

However, there has been limited research on compliance.

A new open access research paper, led by Molly Fraser from the University of Victoria, demonstrates that compliance is variable and generally poor, especially among recreational vessels. Commercial whale watching vessels, however, were also non-compliant, though at a lower rate. See the Abstract below for more details.

Notably, over two seasons and more than 400 hours of observations, federal enforcement vessels were only observed on three occasions.

More education and enforcement, and a clearer, more coherent, cross-jurisdictional policy approach is required to mitigate the harm imposed on whales by small vessels in the Salish Sea.


Fraser, Molly D., Lauren H. McWhinnie, Rosaline R. Canessa and Chris T. Darimont. 2020. Compliance of small vessels to minimum distance regulations for humpback and killer whales in the Salish Sea. Marine Policy: 104171, ISSN 0308-597X


To support optimal monitoring and enforcement investment, management aimed at minimizing disturbance to wildlife requires an understanding of how regulatory compliance might vary spatially as well as across species and human-user groups. In the Salish Sea, humpback whales (Megaptera novaeangliae) and two ecotypes (southern resident and Bigg’s) of killer whales (Orcinus orca) now interact with a large and growing number of small commercial and recreational vessels that partake in whale watching. Those vessels often approach close to cetaceans and thus pose risk via collision, marine noise and pollution, exposure to which may result in disturbance, injury and death. The primary management tool for mitigating impacts is minimum distance regulations. Compliance, however, is poorly understood. We examined commercial and recreational small vessel compliance with viewing distances across two seasons (June–September 2018 and 2019) in over ≈404 h of on-water observation. Overall vessel compliance was nearly 80%, but several distinct patterns emerged. Recreational boats were significantly more likely to violate distance regulations and boaters were more likely to be non-compliant around killer whales. Compliance did not vary with day of week or time of day. Spatially, non-compliance was concentrated in waters closer to coastal communities. Collectively, these patterns suggest that optimal enforcement could be targeted to identify areas of high non-compliance, especially for killer whales, with effort spread across days and times. Finally, we discuss how investments in education could target recreational boaters at a time when multiple and interacting stressors are accumulating in the Salish Sea.

Select figures

Author affiliations

  1. Coastal and Oceans Resource Analysis Laboratory, Department of Geography, University of Victoria
  2. Institute of Life and Earth Sciences, Heriot-Watt University
  3. Applied Conservation Science Lab. Department of Geography, University of Victoria
  4. Raincoast Conservation Foundation

Disclosure: This study received funding support from the Wild for Whales Foundation and Eagle Wing Tours, a commercial whale-watching company.

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