Livewell-Held Bass Require Special Care During Summer Months
By Todd Driscoll, Texas Parks and Wildlife Department

The popularity of bass fishing has exploded during the last 20 years. During this time many changes have taken place, including increases in fishing technology and the advent of more restrictive harvest regulations. However, one of the most important changes includes increased angler acceptance of catch and release practices. There is no doubt that the popularity of catch and release has helped sustain and enhance bass fisheries throughout Texas. Currently, almost all bass tournaments require release of all live fish weighed in and penalize those with dead bass. In addition, conservation of the resource should be a major consideration of all tournament anglers. Therefore, tournament anglers should do everything possible to ensure survival of released fish. By following the guidelines below, anglers can minimize stress on bass while held in livewells. All recommendations are based on water temperature, oxygen, ammonia levels, and proper handling of fish. Stress in the livewell occurs as a result of low oxygen levels and ammonia buildup from fish waste. As water temperatures increase, water holds less oxygen, bass consume more oxygen, and ammonia becomes more toxic. This implies that as the water temperatures increase, fish in a livewell require more attention and care in order to reduce stress.

When water temperatures are below 70 degrees, at a minimum anglers should run either the recirculating (aerating) pump or intake pump at timed intervals. These timers should be set to run as often as possible. By recirculating water, uniodized salt can be added to livewell water (1/3 cup per 5 gallons of water) to match the body fluid salt concentration of bass (0.5%). Fish experiencing stress absorb excess water, diluting body fluids below levels necessary for survival. Maintaining the salinity of livewell water to that of fish body fluids minimizes effects of stress. Pre-measured amounts of salt can be carried in ziplock bags. Many commercial water conditioners (i.e., catch and release formulas) cannot be recommended by state agencies, not due to ineffectiveness, but because the ingredients have not been tested by the U.S. Food and Drug Administration as safe for human consumption. If water is recirculated, replace half of the livewell water every 3 hours to prevent toxic ammonia build up that results from fish waste. When water is replaced, additional salt needs to be added. Pumping fresh water in on a timer with intake pumps prevents toxic ammonia buildup but prevents use of salt additives. Ideally, anglers should run either recirculating or intake pumps continuously to ensure optimal livewell conditions, especially if there is more than 10 pounds of bass in the livewell. Adequate, fully charged boat batteries should have no problem providing continuous power to the pumps.

When water temperatures are above 70 degrees, at a minimum anglers need to pump fresh water into the livewell continuously. Periodically pumping in new water using a timer does not maintain adequate oxygen levels. However, in an ideal sense, anglers should run their recirculating pumps continuously and add proper amounts of ice and uniodized salt to keep fish in the best shape possible. For boats equipped only with timer operated pumps, the switches should be replaced to allow the pumps to operate in continuous mode. At these temperatures, running pumps on a timer does not maintain adequate oxygen levels in livewells. Cooling the livewell water with ice allows it to hold more oxygen and reduces oxygen consumption by bass. Enough ice needs to be added to reduce the water temperature 5-10 degrees. Excessive cooling beyond 10 degrees can cause heat shock when bass are released back into the lake. Typically, block ice is preferred (it lasts longer) and can be made by freezing water in half-gallon milk jugs or 12-ounce water bottles. Again, when using recirculating pumps half the livewell water needs to be exchanged every 3 hours to prevent ammonia buildup. When water is exchanged, additional ice and salt need to be added. As a rule, 8 pounds of ice will cool the typical livewell 5-10 degrees for 3 hours. A frozen, half-gallon milk jug will weigh 4 pounds. During a typical tournament day (8-9 hours), 8 pounds of ice added every 3 hours when water is exchanged should maintain a cooler livewell temperature.

Thermometers are a must to insure water is not cooled more than 10 degrees. Inexpensive, floating aquarium thermometers can be used but now many of the marine electronic units can support additional temperature sensors that can be permanently mounted in livewells.

Some fish will die even with appropriate care. Dead fish will cause poor water quality conditions in the livewell and should be removed immediately and placed on ice. However, as required by state game laws, dead fish must be retained as part of your daily limit. It is illegal to cull dead fish.

The weigh-in is an additional stress factor. Probably the most important thing anglers can do during this time is to not carry bass in dry bags from the boat to the holding tanks. As simple as this sounds, it is surprising how many anglers do not take the time to get enough water in the bags to prevent stress during the time the fish are put into the bag until they reach the life-support tanks or scales. Fill your weigh-in bag with at least 2 gallons of water from your livewell, especially if you have been using ice to cool the livewell water. Holding tanks at the weigh-in line should be aerated, cooled with ice, and treated with salt. Effort should be taken while in the line to exchange the original water in the bag with the aerated, treated water in the tanks and to keep your bag submerged in the holding tanks. This is critical as the oxygen in the weigh-in bag can drop to zero in a couple of minutes!

If fish are held for pictures, wet hands before touching fish. Grasp fish by lower jaw but never bend the head down or hold horizontally by jaw. Avoid touching the body of the fish as this removes the protective mucous covering. When holding bigger fish, the lower body should also be supported with a wet hand under the belly to prevent jaw damage. Do not keep fish out of water any longer than you can hold your breath. Air exposure is extremely stressful to fish.

These suggestions were summarized from the B.A.S.S. publication "Keeping Bass Alive: A guidebook for anglers and tournament organizers" and this book should be required reading for all tournament anglers. An online version is available at http://sports.espn.go.com/outdoors/ bassmaster/news/story?page=b_consbass alivelaunch but $3.00 hardcopies can be purchased by contacting B.A.S.S. at 1-877-BASS-USA. Call the TPWD Inland Fisheries Office at the Jasper State Fish Hatchery (409-384-9572) with questions regarding proper fish handling procedures. We are also available to present these guidelines at your next bass club meeting.