The consideration that would need to be undertaken there, in terms of the precautionary principle, is that it would go in both directions in terms of also needing to take into account the risks that a population reduction of harbour seals would potentially pose to other whale populations. That's not to say the ultimate decision couldn't be that there be a population control measure for harbour seals, but it would need to be taken in the broader context of the suite of measures that's being undertaken for chinook.
Evidence of meeting #117 for Fisheries and Oceans in the 42nd Parliament, 1st session. (The original version is on Parliament’s site, as are the minutes.) The winning word was whales.
A recording is available from Parliament.