Thank you for the clarification. Yes, indeed, part of the careful consideration that the minister and his officials would need to take into account is the specifics of the situation and the impacts on navigation, fishers, indigenous rights, and other activities in that area. The obligation to immediately establish an emergency zone would require the deployment of resources and enforcement, and it wouldn't give the minister the discretion to assess on a case-by-case basis what the resolution of the situation needed to be.
On February 26th, 2018. See this statement in context.