Heck, I'd use a grinding mask/goggles for a heron. They WHIP that beak.
If you net it, don't dink around. Pin it quick, snip and gone.
Actually, I'm not sure what I'd do. We've got a local heron, and I can tell when he's been around, lots fewer fish visible in the creek. If it was hurt, I'd probably put it out of its misery only.