Venting

Venting is a technique used on some deepwater fish species to release gases trapped in the fish's body cavity, allowing it to swim more quickly back to safe habitat depth when released.

Click the 'Play' button to watch this 10-minute video about successfully venting reef fish.

PowerPoint

Watch Fish Venting: How to Use Venting to Improve Survival of Released Fish, a 12-minute PowerPoint-to-Flash tutorial covering the how and why of using venting and deep release rigs to mitigate the effects of barotrauma in reef fish.

Why vent?

Reef fish taken from depths of 50 feet or more may undergo expansion of the gases in the swim bladder as they are brought quickly to the surface on hook and line. Swimbladders can expand only so far before they burst. When the swimbladder bursts, the gases escape into the fish’s body cavity, where they can continue to expand.

The pressure exerted by the gases on the fish's internal organs is considerable, and can result in serious injury to the fish. Often the pressure is sufficient to push the stomach out of the mouth, and the intestines out of the anus.

Moreover, if the fish is released in this buoyant condition, the fish may float away and die from exposure to the elements, or become an easy target for predators.

Regulations

As of June 1, 2008, anyone fishing for any species of reef fish in Gulf of Mexico waters will be required to possess and use a venting tool.

What are venting tools?

• Venting tools are sharpened, hollow instruments that are used to deflate the swim bladder of a fish to release the fish with minimum damage.
• Proper use of a venting tool will help the fish survive by allowing it to safely return to the bottom.
• Examples of venting tools include a hypodermic syringe with the plunger removed or a 16-gauge needle fixed to a wooden dowel (larger gauges may be harmful to the fish). A knife or ice-pick is not allowed.
• Venting tools can be found in stores or online from a number of fishing gear retailers.

When to use venting tools

• When retrieving a fish, carefully assess its condition. Venting should only be done fish that need it. If the fish appears normal, not bloated, and appears able to swim down to habitat depth on its own, do not vent the fish.
• Signs of a fish that needs to be vented include bloated belly, bulging eyes, protrusion of stomach from its mouth, or protrusion of intestines from the anus.

How to vent a fish

• Deflation of a bloated fish is done by holding the fish gently but firmly on its side, and inserting the venting tool needle under a scale into the body cavity at a 45° angle in an area approximately 1 to 2 inches behind the base of the pectoral fin, just deep enough to release the trapped gas.
• If the stomach is protruding from the mouth, do not puncture it or try to put it back into the mouth. It will return to its normal location following the release of the vented fish.
• Gently release the fish head first into the water as soon as possible. If necessary, revive the fish by holding it in the water and moving it back and forth to pass water over the gills until the fish is able to swim.

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