A guide to Releasing Reef Fish with Ruptured Swim Bladders
Determining Which Fish to Vent
Fish with large swimbladders such as red grouper, gag grouper, and black sea bass can benefit greatly from venting. Your ability to judge which fish should be vented will improve with practice and experience. After reeling in a fish, simply observe its condition. If the fish is bloated and seems to be floating (basically, unable to control its buoyancy) or if the fish’s stomach is distended out of the mouth, the fish should be vented. Venting is not necessary if the fish appears normal, not bloated, and is able to swim down to habitat depth on its own.
It is best to vent the fish as quickly as possible with a minimum of handling. If the fish's stomach is everted out of the fish’s mouth, do not attempt to push it back into the fish’s body. Expelling the swimbladder gases will allow the stomach to return to its normal position within a few hours. Start by holding the fish gently but firmly on its side and insert the venting tool at a 45-degree angle approximately one to two inches back from the base of the pectoral fin. Only insert the tool deep enough to release the gases — do not skewer the fish. You should be able to hear the sound of escaping gas and you will notice the body of the fish deflate. If a fish is extremely bloated, use gentle pressure on the fish’s abdomen to aid deflation.
Keep a good grip on the venting tool during the entire process, so that an unexpected jerk from the fish does not dislodge the tool and cause injury to others.
The fish’s everted stomach (sticking out of its mouth) should not be punctured. This practice is not as effective in releasing gas from the body cavity and results in additional injury.
Return the fish to the water as soon as possible. If necessary, revive it by holding the fish with the head pointed downward and moving the fish back and forth to pass water over the gills until the fish is able to swim unassisted.