Assessing recreational boat usage and compliance with marine park regulations in Anse de Saint-Étienne (Saguenay Fjord, Québec): Implications for beluga conservation

The Saguenay Fjord, a crucial habitat for the St. Lawrence beluga whale population, is a popular area for recreational boating. However, recreational boat activities are poorly documented, as these boats are not required to have on-board systems providing information on their movements. The aim of this study is to describe how a portion of the Saguenay Fjord is used by recreational boats and beluga whales, as well as their potential interactions, and to assess whether the Marine Park regulations regarding vessel transit speed and approach distance are respected. Daylight observations and theodolite surveys were conducted during the summers of 2021 and 2022 in an 8 km² area between two key beluga sites: the mouth of the Saguenay Fjord and Ste. Marguerite Bay. These observations allowed us to gather information on the area's use by recreational boats, beluga whales, and their interactions. Recreational boats were present for more than half of the observation time on average. Across all observation days, co-occurrences (distance < 400 m) between recreational boats and beluga whales were recorded on 45.45 % of days. Some recreational boats violated regulations concerning speed limits and the minimum mandatory distance from beluga whales. Recreational boating, whether with its engine on or off, can disrupt essential behaviors in marine mammals through both emitted noise and the mere physical presence of vessels. Adjusting monitoring and enforcement strategies could help address these challenges and enhance protection for the endangered beluga population. • Anse de Saint-Étienne is a key transit zone for belugas heading to Ste. Marguerite Bay. • Anse de Saint-Étienne heavily used by recreational boats, with over 50 % observation time. • Recreational boats sometimes violate speed and distance regulations near belugas. • Monitoring recreational boats with a theodolite to track potential regulation violations.