My oama tubs were probably triple the recommended capacity because I had planned to provide bait for a few boat and kayak fishing trips.  The weather didn’t allow us to fish so the oama sat in crowded conditions for a month.  Despite water changes and attempts to improve water quality, oama in all the three tubs began to develop cloudy eyes and lose their coloring.  Once that happened they’d die 2 days later and sometimes poison the tub with the chemicals released at death.

As a last ditch effort I put the remaining 10 oama of one tub in an aerated bucket with new water, and planned to use them for bait the next day.  I also took a bucket of healthy oama. Half of the weak oama died on the drive to the beach, whereas the healthy oama in the other bucket were fine.

When weak oama were mixed with healthy fish, the healthy fish didn’t weaken right away so it doesn’t seem like they were dying from a contagious disease, they were just worn out from living in poor water conditions for too long.  Oama that freshly died in the tubs or were euthanized worked well enough trolled, so they weren’t wasted.

Summary for those trying to keep a lot of oama alive:

• If you’re gonna keep oama in over crowded conditions for an extended period of time, change the water as often as you can.  The poor water quality will eventually weaken them.
• If they are all in a weakened state, the toxin a dying fish emits will kill others. If the rest are relatively strong, one dying fish won’t kill them instantly but will worsen the water quality.
• If the fish have cloudy eyes and seem “off color”, they may not be too contagious to the others but will probably die in the next few days. It’s better to remove them before they die in the tub.
• Often fish start dying at the same time in more than one tub. I used to think I was cross-contaminating the tubs but now I think that the fish just have a certain amount of time they can handle poor water conditions before giving up.