Fish Holding Tanks that Help Fish Survive

Most of the larger bass organizations and some smaller clubs use fish holding tanks in conjunction with weigh-in ceremonies at tournament events.

Though better to immediately return caught fish to a lake or river to insure survival, there are times, such as in competitive situations, when this practice simply isn't tenable.

But how about those periods between the time we transport our fish from the live well...to the scales at a weigh station...and release them back into the host lake or river?

Bass are usually transported from a boat to the scales in a large, plastic freezer or garbage bag that has been partially filled with water. However, what happens after the catch has been weighed in and recorded?

Most anglers who participate in club tournaments without fish holding tank capabilities simply return a catch to their boat's live well for later release, or release them directly into a bay or inlet nearest the weigh station which, in many instances--particularly during warm-weather months--place added stress upon the piscatorial prisoners because of water temperature variations or polluted surroundings.

Acquisition of a fish holding tank is relatively simple.

For example, commercially available fish transport tanks make good holding tanks, as do homemade or custom constructed tanks fabricated from wood, aluminum, or fiberglass.

When contemplating the design or selection of a holding tank, the Bass Research Foundation recommends that anglers consider the following factors.

1. The tank should have smooth interior walls with no obstructions to trap or injure the fish;

2. The tank should be able to hold at least one gallon of water per pound of fish (one cubic foot equals 7.5 gallons);

3. The tank should have easily operated hatches to prevent fish from jumping out of the tank and allow quick opening and closing for the introduction and removal of fish;

4. The tank should have a removable top with several small, hinged hatches;

5. The tank should not be more than four feet high and water depth should be less than 3-1/2 feet;

6. The tank should have a six-inch diameter or larger drain so all water and fish can be released directly into a 10- to 12-inch diameter PVC pipe of sufficient length to extend from the holding tank into deep water, a procedure that eliminates handling the fish with nets and additional stress from activity;

7. If the tank is mounted on a trailer or truck, keep in mind that one cubic foot of water weighs 62 pounds.

It goes without saying that adequate aeration of holding tank water is essential.

Aeration is most efficiently and economically accomplished by compressed oxygen-diffuser systems which are available in commercial models or made of porous plastic or PVC pipe.

A few things to keep in mind for those planning on purchasing or building a fish holding tank:

• All fish should be held in a large volume of clean, well aerated, and cool water;

• Use water from the lake or river where the fish were caught;

• Too much air is better than too little;

• An 80-pound oxygen cylinder should be sufficient to hold fish for several hours during and after weigh-in;

• The tank water temperature should be kept the same as the lake water if the lake water temperature is 75 degrees or less;

• When the lake water temperature is 80-90 degrees F, it is desirable to keep the tank water temperature five degrees cooler than the lake water;

• If the lake water temperature is higher than 90 degrees, the tank water temperature should be 86 degrees;

• At least 30 pounds of block ice per 100 gallons of water in the holding tank should be available to maintain constant, desirable water temperatures;

• Don't use commercially available additives, chemicals, or anesthetics in holding tank water;

• Do use 4-1/2 pounds of salt (sea salt is preferred, though rock salt or uniodized table salt works well) per 100 gallons of water to reduce stress and stimulate mucus secretion;

• Anti-foaming agents suitable for fishery use are available and may be used when aeration or agitation causes too much foaming water;

• Fish held in a tank will excrete carbon dioxide and ammonia. Release the fish as soon as possible to prevent these waste products from increasing to stressful concentrations.

Copyright (c) 1996 Herb Allen. All rights reserved.

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