Sound:Wave – Passive Acoustic Monitoring of Recreational Boating in a Multi-Use Waterway

Recreational boating is increasingly recognized as a source of disturbance to freshwater ecosystems. Noise pollution and surface waves (wakes) are primary boat-induced stressors that can have immediate and cumulative impacts on waterways, biodiversity, and nearby users and residents. Navigation speed influences both underwater noise and wake height, highlighting the value of incorporating boat speed in monitoring programs. We present a practical, cost-effective, and fully autonomous method for estimating boat speed and traffic using open-source passive acoustic monitoring (PAM) devices in the Rideau River, eastern Ontario. Method validation was completed during experimental trials in September–October 2024 in the Eccolands Reach (Ottawa). A variety of recreational vessels were operated at known speeds (5-70 km/h), and passes were recorded at 48 kHz by two HydroMoths deployed parallel to the channel. Speed was automatically calculated from recorder spacing and the time interval between peak sound amplitudes (n = 67; RMSE = 10.2 km/h; MAE = 7.1 km/h). In August 2025, we surveyed the aquatic soundscapes at two sites in the Long Reach (Kars). Each HydroMoth recorded 20 minutes of 32-kHz audio per hour for one week (112 total hours). A machine-learning model was used to quantify boat traffic and estimates were compared with wake counts from do-it-yourself pressure gauges. This scalable approach demonstrates how PAM can simultaneously support boating management and ecological monitoring in recreational waterways.

Presentation Preference: Lightning Talk with Poster (5 Minutes)

Primary Presenter: Steven Robinson, Carleton University (steverobinson@cmail.carleton.ca)

Authors:

Steven Robinson, Carleton University  (steverobinson@cmail.carleton.ca)

Jesse Vermaire, Carleton University  (jessevermaire@cunet.carleton.ca)

Colin Rennie, University of Ottawa  (colin.rennie@uottawa.ca)

Neda Azari Dodaran, University of Ottawa  (neda.azari@uottawa.ca)

Steven Cooke, Carleton University  (stevencooke@cunet.carleton.ca)