Posted 8:45 am Thursday, October 23, 2008
The Art of Fizzing
There is no argument that the Budweiser ShareLunker program has paid off in more than one way.
It has promoted Texas as a big bass state; it provided bass for the state's hatchery system; and it taught lessons about handling big bass.
Along the way, however, there have been some pains. Some of those fish died from broken jaws, the result of "lipping" a bass that weighed 13 pounds or more. Some died from a fungus that developed on their skin. And others died because of an over-inflated air bladder.
Through the ShareLunker program, fishermen have learned they have to hold a big bass by its belly to keep from damaging a jaw. They have also learned to keep the fish out of the water a matter of seconds for pictures and just as importantly make sure their hands are wet when they pick it up.
Now, Texas Parks and Wildlife Department biologists are looking at what can be done about the air bladder, a condition with the technical name of hyperbuoyancy. Bass have an air bladder that is constantly inflating and deflating to allow the fish to float. In some instances when a fish is brought to the surface the bladder can expand, putting pressure on other internal organs.
Not a lot is known about hyperbuoyancy, including what causes it. The first guess is that it is the result of a bass being pulled from deep water. However, while it is more common with bass caught in depths of 20-feet-plus, it has also occurred in bass taken from as little as 10 feet of water. The proof there comes from Lake Fork, the premier lake of the ShareLunker program. Lake Fork doesn't have a lot of deep water, but some of the program entries from there have been affected by hyperbuoyancy.
David Campbell, ShareLunker program coordinator, believes stress may also be a consideration.
"I strongly believe that exhaustion happens when the fish are trying to adjust to an environment, whether that is caused by being pulled from deep water, the stress of being caught, lack of oxygenated water or being in a crowded livewell," he says. "When a fish has room to swim but starts swimming nose down, has to fight to stay down or swims right-side up but never stays more than a few inches below the surface, it has preliminary hyperbuoyancy symptoms and needs relief -- and the sooner the better for survival."
Campbell has seen his share of fish affected by hyperbuoyancy. Looking over the program records for the last 10 years, he said in some years it has occurred in about 10 percent of the fish donated to the program. Overall, however, he said about 20 percent of the fish he has accepted have had it.
When a fisherman catches a fish with hyperbuoyancy, the bass more often then not recovers if released immediately. The concern of biologists is those bass that are placed in a livewell for a tournament or possibly donated to the ShareLunker program.
"It's important to understand that if you catch a fish from 30, 40, 50 feet deep and immediately release it, it usually goes right back down with no problem," said Randy Myers, Inland Fisheries district biologist from San Antonio, who is overseeing the research project. "Even after it goes through the struggle of being caught, the fish may have enough energy to swim back down to a depth where neutral buoyancy is regained. But if that same fish is kept in a livewell for several hours with an over-inflated bladder, it becomes exhausted from struggling to stay upright and floats on the surface."
Because the ShareLunkers aren't able to return to deep water, Campbell adopted a treatment of deflating the bladder using a hypodermic needle. It is called fizzing because of the sound the released air makes.
"We had them and if we didn't do anything, they died. We started sticking them and getting survival, so we continued to do it," Campbell explained.
Campbell has the drill down. After picking up a fish he thinks isn't swimming right, he will drive about 30 minutes and then pull off the road to check it. If the fish is still struggling, Campbell will deflate the bladder. To prevent other problems, he holds the fish in the water while performing the procedure.
He said the problem isn't always an extended bladder, though. In some cases he has gotten fish with air in their body cavity and the prospects for their survival aren't as good.
Some biologists believe delayed treatment of hyperbuoyancy can lead to physiological problems for a fish.
All of these issues have the department looking at fizzing -- attempting to determine whether deflating the bladder through a fish's side or mouth is the best option, or whether a third technique called caging is a better idea.
"In spring and early summer of 2009 we plan to conduct studies to answer two questions," Myers says. "One, which technique-side fizzing, mouth fizzing or deep release- increases survival the most? And two, will fish survive better if they are treated immediately after being caught rather than after having floated in a livewell for several hours?"
The study will be conducted at Lake Amistad by electrofishing. They will be put in to cages and submerged to 30 feet or more and then winched back to the surface immediately.
"All those fish will have been exposed to the same conditions," Myers says. "Some we will put in livewells for four or five hours before treatment. Others will be treated immediately. We will use all three methods of treating hyperbuoyancy but will leave some fish untreated. We will also have a group of fish that do not have hyperbuoyancy, but we will fizz them to see how much sticking the fish with a needle affects survival. We'll hold the fish in large cages for several days to watch for delayed mortality, and dead fish will be autopsied by TPWD fish health staff to identify cause of death. Above- and below-water video will be used to document the study and fish behavior in response to treatment."
In the end, fizzing may not be a practical solution for everyday anglers. The results of the study may have the biggest impact with tournaments where officials can treat the fish and increase survival rates.
