Bottom Fishing

Sea Grant Extension
Telephone: 251/438-5690
March 9, 2005

By: Rick Wallace, Extension Marine Specialist
Auburn University Marine Extension and Research Center

Fishermen who are looking to go bottom fishing this winter might want to consider using circle hooks to catch fish and a venting tool to let them go.

The red snapper season will be closed until April 21, 2006. Red grouper cannot be harvested until Jan 1, and there are length limits on the remaining grouper species. Anyone out trying to catch a few keeper grouper will find they have to sort through hungry red snapper and undersized grouper to find a legal fish. Circle hooks are more likely to hook a fish in the jaw, increasing the probability of a successful conservation release. A venting tool can remove gas from fish pulled up from deep water and improve release survivability.

Circle hooks, which are getting more popular, generally result in fewer gut-hooked fish and often mange to hook a fish in the corner of the jaw where the hook is easily removed. In a recent study, only 1% of grouper caught with circle hooks were gut-hooked while 15% of those caught with traditional J hooks were hooked in the gut. The evidence for red snapper is not as compelling but several local charter captains swear by circle hooks. Most studies on circle hooks show that hooks with no offset are more effective in hooking the jaw than those with an offset.

Even with circle hooks, fish caught in eighty feet or more of water are probably going to have a gas problem which may prevent them from surviving after release. All grouper and snapper have a swim bladder which is a balloon-like organ that holds gas. Fish control the amount of gas in the swim bladder to maintain neutral buoyancy at the depth they are living in but cannot change the amount of gas quickly.

When a fish with a swim bladder is rapidly pulled to the surface, gas in the swim bladder quickly expands as the water pressure decreases. At or near the surface, the bladder may burst releasing gas into the body cavity. Gas in the body cavity makes a fish overly buoyant and unable to readily swim back to the bottom. Trapped at the surface and unable to maneuver, these fish are very vulnerable to predation and have low survival.

Fishermen can release the gas from the body cavity by using a venting tool. The simplest venting tool is a 16 gauge needle attached to a large syringe with the plunger removed. The plunger must be removed to let the gas out.
When a fish that is going to be released comes up from deep water, handle the fish gently with a wet towel. Place the fish on its side and insert the needle at a 45 degree angle into the body cavity just behind the pectoral fin. The pectoral fin is the fin behind the head and the side of the body. Insert the needle only deep enough to release the gas. You can hear the escaping gas and deflation of the fish is often noticeable. Quickly return the fish to the water. Do not attempt to use an ice pick or a knife to release the gas. They do not work and will add to the physiological stress and injury from hooking

One more thing - fishermen often think that the object sticking out the mouth of fish brought up from the depths is the swim bladder and puncture it. That object is the stomach and it should never be punctured. The stomach will return to normal, in time, after the gas is released.