A body that looks like it exists to protect a wild species may really exist to keep its export markets supplied. Judged by that real purpose, a population that crashes in size and number under its care is not a failure of the body. It is the body doing what it was built to do.
Managers who measure a species only as biomass, meaning how many tons exist, turn living creatures into a quantity to divide up. That framing makes ongoing extraction look normal and sensible. It hides losses the numbers do not capture, such as the disappearance of the giant fish.
The usual story says shared resources get overused because no one owns them, so the fix is more regulation. The deeper problem is that the animals are treated as goods for sale, and regulation built on that view keeps the extraction going. Real change has to alter how people value marine life, not just reform the rule-makers.