I have used my boga on a number of species (bonito, yellowfin, bluefish, bass, permit, and bonefish) and have yet to see one get injured from the smooth jaws of the boga. Other brands out there have sharper surfaces on the tool and might break the skin of the fish, inviting infection.
This topic has been debated to death on many chat boards with some folks taking the PETA like stance that it is cruel and unusual to use a boga on a fish. I understand that it is a risk that you might injure a fish if you hold it by the mouth.
I take the stance that the boga is a much better way to grab a fish than with a gaff :twisted: Remember, even using a net can scrape the protective slime off a fish and risk injuring it. Hard to say about post release mortality, but I have never had a fish die from the boga, that I could tell. Once the fish has been released and swam away, I dont know the long term effect of suspending it by the mouth.
Catch and release has also been criticized for much the same reasons, but I am of the school that it is laudable for trying to ethically release the fish, regardless of what happens after the fish is released.
Certain fish like blues and bass, I never pull them entirely out of the water unless it is a trophy specimen, to minimize the amount of strain put on their mouth. I merely use the boga to control the fish while I remove the hook, holding it against the outside gunwale.
Another way to minimize the potential damage to the fish is to support the belly with your other hand while the boga is engaged to the mouth. Take a pic and send it back to the ocean. Ram breathers like tuna and bonito should be spiked into the water to jump start the flow of water across their gills.
Sorry for the ramble, but you should be fine using a boga.
T-Bro