Sharks are very hardy animals. We use steel hooks, no stainless, leave
a steel hook in salt water and you will be surprised just how fast they
rust out. As far as barbaric, it is very common to hook a shark, tag
and release him, only to catch the same fish again only a short time
later, sometimes multiple times. I've seen them cut off and just swim
over to the next bait and take that one. And they don't seem to mind
hooks in their mouth while they rust out. As far as circle hooks, for
most fish I would agree, circle hooks are the way to go. But most
sharks are hooked in the mouth, it's because they tend to pick up a
bait in their mouth and swim off with it before swallowing it. Their
kind of like when you feed a group of dogs, or, for that matter, most
animals, they grab their food and get away from the group before eating
it, so no one else can grab it. Most fishermen will let a shark run for
a short distance before trying to set the hook, their's not much time
for the shark to actually swallow the bait to the point that it's in
its stomach. So, for the most part, the fish are hooked in the mouth,
no one wants to keep cutting off more expensive circle hooks, some may
be tempted to hang the shark until it's dead to get them back (on a
good day you can go through lots of hooks) and that defeats the whole
purpose.

On fish like Striped Bass, I can see them having a higher mortality
rate. With them use heavier line if your releasing the fish, to get
them in ASAP, they will not be as tired. Also, resist the urge to bring
the fish into the boat to take the hook out, do it with the fish still
in the water, the less you handle them and the sooner the fight is
over, the better the chances of surviving.