With the summer months coming, I figured we could all use a little reminder of fish care. I came across this article written by Todd Driscoll of TP&W and thought I'd share.



Livewell Fish Care Very Important During Summer Months
by: Todd Driscoll
TX Parks and Wildlife

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 fish care recommendations are based on water temperature, oxygen, ammonia levels, and proper handling of fish. A majority of stress in the livewell occurs as a result of low oxygen levels, but ammonia buildup from fish waste can also contribute to stress. 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 75 degrees and less than 10 pounds of bass are in the livewell, at a minimum anglers should run either the recirculating (aerating) pump or intake fill pump at timed intervals. These timers should be set to run as often as possible. Recirculating water is best, as the livewell water can be treated with uniodized salt (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 while in the livewell, diluting body fluids below levels necessary for survival. Maintaining the salinity of livewell water to that of fish body fluids minimizes effects of stress. Uniodized salt is cheap and can be purchased in bulk (30+ pound bags) at your local feed store under the name �Stock Salt.� Pre-measured amounts of salt can be carried in ziplock bags. Commercial water conditioners (i.e., catch and release formulas) cannot be recommended by state agencies, because the ingredients have not been tested by the U.S. Food and Drug Administration as safe for human consumption, or the conditioners have not been scientifically proven to reduce livewell stress. 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 to maintain the 0.5% solution. Pumping fresh water in on a timer with fill pumps prevents toxic ammonia buildup but prevents use of salt additives. When there are more than 10 pounds of bass in the livewell, anglers must run either recirculating or intake pumps continuously to ensure optimal livewell conditions. Adequate, fully charged boat batteries should have no problem providing continuous, all-day power to the pumps.

When water temperatures are above 75 degrees, anglers must run their recirculating pumps continuously, even if there is only one bass in the livewell. As discussed above, uniodized salt must be added 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. Again, at these temperatures, running pumps on a timer does not maintain adequate oxygen levels in livewells. At these warmer temperatures, cooling the livewell water with ice is very important and allows it to hold more oxygen and reduces oxygen consumption by bass. Enough ice needs to be added to reduce the livewell temperature 5-10 degrees below reservoir surface temperature. However, excessive cooling beyond 10 degrees can cause heat shock and death when bass are released back into the lake. 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. Thermometers used to measure vehicle air conditioning work well and can be purchased at auto stores. Most of the electronic GPS/sonar units can support additional temperature sensors that can be permanently mounted in livewells. Here, ability to plot both livewell temperatures and the lake surface temperature on the GPS/sonar screen allows for continuous monitoring and adjustment of livewell temperatures.

To maintain livewell-held bass in the best possible shape, pure oxygen-injection systems (oxygen bottle, regulator, and fine-pore air diffuser) can be installed for approximately $300. By far, lack of oxygen is the primary reason fish die in livewells. During the most extreme conditions (i.e., 15 + pounds of bass in a livewell over 85 degrees), these systems are the only way to maintain optimum oxygen levels. I have this system installed in my boat, and would be happy to display and discuss this equipment with anyone that is interested. A TPWD presentation on these oxygen systems can be found at the web link at the end of the article.

Fish hooked in the gills or stomach may die even with appropriate care due to excess bleeding. 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 4 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. Many tournaments now have multiple air stones in each holding tank for placement inside your weigh-in bag. Oxygenating your water in the weigh-in bag while in line is absolutely critical, as oxygen in the weigh-in bag can drop to zero in just 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.

If you have specific questions regarding proper livewell fish care, contact me by phone (409-698-9114) or email (todd.driscoll@tpwd.texas.gov).

Livewell oxygen-injection system explained:
http://www.slideshare.net/raminlandfish/livewell-oxygen-injection-8773301



Oxygen-injection system (oxygen bottle, regulator, hoses, and diffusers).

Great info.. Thanks for sharing.