Slower boats, quieter boats?

Could voluntary slowdown measures have a similar effect on noise exposure levels for whales in the St. Lawrence? According to Clément Chion, professor at the Université du Québec en Outaouais (UQO), their impact remains to be determined. Together with his research team, he is developing a simulation model to project the impact of navigation measurement measures on whale populations.

Even if he confirms that lower speeds can indeed have a positive effect on noise pollution reduction efforts, he considers that it is essential to include all elements of navigation in the equation in order to obtain a comprehensive portrait of the impacts. For example, a vessel moving at a lower speed will generally produce a lower instantaneous sound level, but as it stretches out its travel time, whales may be exposed to the noise it emits over longer periods. We must therefore distinguish between instantaneous exposure and cumulative exposure and avoid jumping to conclusions.

Furthermore, although it is critical to study the impacts on the resident beluga population, which are more at risk, Mr. Chion believes that it is important not to neglect certain other species, in particular mysticetes or baleen whales, which are affected differently by boat noise.

Researchers warn that shipping and boating traffic may increase in coming years, and stricter speed limits alone may not be enough to counter the effects of maritime activities. It is therefore necessary to conduct further research and combine these measures with other strategies such as “no-go” areas or alternative routes, while maintaining an open dialogue with the maritime industries, many of whose services remain essential.

Clément Chion believes that a relationship based on mutual cooperation will be more effective in protecting marine mammals, in addition to underscoring the good collaboration of the St. Lawrence maritime industries, which has already enabled a number of advances.