Just to be clear, the imminent threat determination is made under the Species at Risk Act. That determination was made by the Minister of Fisheries and Oceans and the Minister of Environment and Climate Change in May. That was based on scientific assessment of the rapid decline that we've seen in the last few years and the absence of a successful birth in that population since 2015.
A couple of things to remember about the population of the whales when you're looking at the time frame you just referred to is that it starts after the removal of...the live capture of whales to put them in aquaria, which happened in the much earlier.... With the southern resident population in particular, numerous individuals were removed over a period of decades to display in aquaria. The time range that I believe you're referring to starts after the end of that period. You're starting with a diminished population.
Also, it's important to remember that when you talk about extirpation, that's when the species is gone. With a long-lived population like the southern resident killer whales, a species can be effectively extinct, unfortunately, before there are actually no whales.
That's what we saw with the killer whale populations in Alaska that are now gone. They were deemed effectively extinct, unfortunately, while there were still actually whales alive.