Finally, because of the sheer size of the fish, halibuts have few predators that can actually catch and kill them. Which, in turn, allows them to live longer and ultimately grow larger.
The fish are slow growing, it should be noted, so many halibuts that are caught are much, much smaller. Most halibut that humans catch rarely are longer than about 8 feet, with many averaging closer to 4 or 5 feet in length. Male halibuts also rarely reach even 100 pounds, while the females are the fish that hit up to five times that size (meaning most record-setters are females).
As slow-growing fish, they may well be caught easily by fishers and predators. Once they reach a certain size, however, capture is far less likely.