Well, it’s at about 3.5% salt, while saline solution for the body is at about 0.9%. Basically, it would burn everything it directly came into contact with. Depending on how much you shot up, maybe your kidneys would stop anything systemic from happening, but that’s getting into medical territory I’m cloudier on. They used to further punish people after a whipping by cleaning up with seawater. It sounds like that was actually the more painful part of the event, when it was done.

I read a paper recently that suggested that it’s because vertebrates originally evolved in brackish river estuaries. That makes me curious how salty bugs are. Snails, at least, can definitely adapt to living in very concentrated brine, given a bit of time to evolve for it.

IIRC you can safely drink water that’s a bit more salty than you, given that you’re in good health. Seawater is too much for humans, though; it famously will only make you more thirsty. Sea birds have a special gland in their face that amounts to an extra kidney specifically for removing salt. Whales just get enough water from the fish they eat. I’m not sure about fish themselves now.