Bait Holding Tank - Dead Bait - What Happened?

[tiltntrim]

I took Primetime's instructions ( smlfishingforums.proboards.com/thread/3942/homemade-bait-cage ) and made a bait holding tank to keep under my dock. I only made mine 3 feet high instead of 6, but it sure looks great (3 ft wide by 3 ft high). Yesterday I caught some 6 to 10 inch gizzards, put them in the on-board tank and transported them to the dock tank. No problems that I'm aware of other than the on-board tank had a lot of foam which I have not had when using alewives. This is my first experience with gizzards. I lowered the dock tank down to about 15 to 18 feet. It is 21 feet deep under the dock with 60 feet deep water close by. This afternoon I went to see how they were doing and about 75% or 80% of them were dead. I had about 3 dozen in the tank. Any suggestions or ideas on what might have happened would certainly be appreciated!

[shadpuller]

The foam on top of your transport tank was most likely caused by ammonia. This can be avoided by a couple of easy steps. I use a purge/sorting tub when first caught. I allow them about 10 to 15 minutes to purge waste and settle down. This tub has about half a dose of Shad Keeper dissolved in it. My aerated tank has a full dose added to it with full aeration. After waiting 15 minutes, I transfer the Shad to my aerated tank with a wet dip net. The foam on top that you referred to has a smothering effect on the Shad. Maybe it stunned them and low oxygen caused their death.

[steviejayvaughan]

They were probably in bad shape before you loaded them in the holding tank. What size/brand on board tank do you have and how long before you transferred them? If strictly making a bait run I would dump directly to my on board tank to minimize handling. Dumping to a separate sorting tub is still better than dumping them on the floor. The dock cage does seem a little small for 3 dozen but I don't keep a dock tank just a 350 gallon home tank I'll let others comment on that. Then again could have been a big enough temp difference at that depth that stressed them.

[BentRod]

I wouldn't lower it that deep - keep it in the top 10ft of water until the water gets over 70-75. Gizzards aren't fans of that deep cold water. Highly doubt it had anything to do with ammonia if you only had them in the boat tank for a short period. I'm convinced some docks don't have the right water quality to hold bait well - my cage was never great at holding bait and my tank has water quality issues too I believe from time to time. Others have no problem at all.

[hotdog]

Then again could have been a big enough temp difference at that depth that stressed them.

I wouldn't lower it that deep - keep it in the top 10ft of water until the water gets over 70-75. Gizzards aren't fans of that deep cold water.

I think steviejay and Bent rod have it figured out. I've been seeing reports of surface temp in the 55 to low 60 degree range on the lake and the gizzard are probably heading for this warmer water. If you net them shallow and box them in a cage at 15 - 18 ft they won't be able to get to that warmer water. Try keeping your cage shallower.
Good luck.

[Yam]

I would go with temperature shock and lack of dissolved oxygen. This time of year, the temperature at the surface is drastically higher than the temperature at 30 feet. The less dense and warmer water at the top along with increased sunlight brings all the O2 creating flora to the upper layers. Photosynthesis creates oxygen in the water along with rain, wind and other surface agitation components. And although colder water is able to hold more dissolved oxygen, the lower and cooler layers of water have less O2 available.

In the Springtime, the upper layers of water are the fertile ones. As summer approaches the heat of the upper layers correlate to pushing the fertile areas deeper, often times near the thermocline if one exists.

In short, dump them puppies straight into your boat tank and keep your cage close to the surface. I would be interested in seeing if this works out.

Finally, foam is only bad if you close your tank. I welcome foam as I find it to be a great filter as long as you keep your lid open and you don't spray it with foam off which subsequently releases all of the junk that the foam has trapped back into your water. Use your net to remove foam unless you are just trying to quickly see your bait.

[Yam]

To clarify on foam. I don't actually welcome it. No foam means your water is good and your bait is not releasing protein into the water. However, foam is inevitable with freshly caught bait and rather than look at it as a problem, I look at it as a solution.

I feel the same about a fever. I never could understand why people want to get rid of a slight fever when in fact it is helping you to kill off the real problem.

[tiltntrim]

Wow! What a wealth of knowledge in the responses! Many thanks to all you guys! I'll make some changes and let you know how it works out.