Part of it is indeed ensuring an appropriate and complete understanding of the measures Canada has put in place.
In specific terms, though, the U.S. MMPA legislation also requires that the level of mortality—and they attribute partial mortality to an entangled whale, even if it is subsequently successfully disentangled—needs to be below what the U.S. terms the “potential biological removal”, which is a scientific calculation based on the population. It's not a metric we use domestically for management purposes, but it is one that we have calculated because it is central to the Marine Mammal Protection Act.
In the case of this species, because the species goes from the U.S. to Canada, it's a single number that is revised each year, but it is below one. What that means—