At the 2002 Devils Lake PWT tournament, I lost nine fish during the three-day event, and I received a 2.7-pound deduction for those dead fish. This cost me thousands of dollars, and nearly cost me a championship birth. I vowed to spend the winter researching how to keep fish alive so that this would never happen again.

Fish need oxygen as much as we do. Since fish actually extract their oxygen from the water, it's difficult for us to determine whether they have enough. One thing is for certain, without enough oxygen, fish die.

The oxygen that fish extract from the water is referred to as saturated oxygen. Oxygen, is a gas, and has a known saturation level in water. Saturation level is the amount of oxygen water will hold when it is exposed to air for a period of time. Unfortunately, the saturation level of oxygen declines with increasing temperature.

In water temperatures above 75 degrees, it is impossible to keep oxygen saturation levels much above five to six parts per million (ppm), and that's with no fish in the livewell. To put this number in terms of what fish need to survive; oxygen concentrations below five ppm are considered stressful, and oxygen concentrations below three ppm are considered lethal. This gives some perspective about how much oxygen fish need, but other factors also come into play.

When you run a 100-yard dash, you get winded, and it takes you a while to "catch your breath". Another way to state it is, you were in "oxygen debt" until you caught your breath. A similar thing happens to fish that fight hard, or are played too long. These "winded" fish must be provided with even more oxygen than normal.

Fish in warm water have a higher metabolic rate than fish in cold water. This is quite a dilemma since fish in warm water have a faster metabolism, need more oxygen, and yet warm water contains less oxygen.

Most anglers mistakenly believe that running their aerators on the automatic timer is sufficient. The problem with aeration is that air is only 21 percent oxygen, and most of the oxygen that is bubbled into the livewell never becomes saturated...it just bubbles back out into the air. The answer is injecting pure oxygen into livewells.

Pure Oxygen Systems
Aqua Innovations has developed an extremely efficient system, called a Pure Oxygen System. Pure Oxygen Systems separate the water molecules into their elementary parts: Hydrogen and Oxygen.

The lighter hydrogen molecule rapidly leaves the water and dissipates into the atmosphere. The heavier oxygen molecule remains suspended until it dissolves into the water. In fact, the O2 bubble is so tiny it cannot break the surface tension of the water.

These systems have no moving parts, and are placed directly in the livewell. They come in both portable and permanently mounted models. Many boat manufactures are beginning to offer these systems as an option in a new boat package. The Magnum unit costs around $100, and is designed for 40-gallon livewells.

I hope this helps you keep your walleye alive. If you ever see a Cabela's-Ranger with NPAA #720, stop by and say hi.

Click here for more information on aerators.

Rick Gardner was born and raised in Colorado where he still resides with his family. A mechanical engineer by trade, he's been an avid angler all his life. He started competitive tournament fishing at the regional level and jumped into the Professional Walleye Trail in 2002. Some of his fishing accomplishments include: Rookie of the Year PWT Western Division, Angler of the Year PWT Western Division, Top Ten PWT Championship Qualifier, Member of the PWT advisory council.

— Your complete source for more Cabela's News, and updated hunting and fishing articles.