The WAKO 2025 show was a fantastic event, and I wanted to share my experience flying with fish and going through airport security.

The TSA allows passengers to carry live fish in their carry-on bags.  These fish need to be inspected by a TSA agent at the security checkpoint. The agent asked me to place all the bags containing the fish into a separate tray and request a "hand check" by the TSA agent so the bags do not go through the x-ray machine.

https://www.tsa.gov/travel/security-screening/whatcanibring/items/live-fish

At WAKO I bought more fish than could easily fit into my carry-on suitcase.  Each of the bags was full of air and water was about the size of a sub sandwich and I had over 20 of them. 

The solution to this problem is to rebag everything into breather bags, which are far more compact.  Depending on the size of the fish, each breather bag ranged in size from a billiard ball to softball.  A few tips on breather bags:

- The fastest way to pack the breather bags is by pouring in the fish and water in and tightly knotting each one.  Other methods include rubber bands and heat seals, but I find these slower and more prone to leaks.

- Pack the bags tightly so the water keeps the bag rigid.  Fish are less likely to get trapped in folds and corners if the bag has some rigidity from the water.  Do not leave any air inside, air in the bag will cause the water to slosh around and likely deflate the bag over time.

- Label each bag with a sharpie.  There's a good chance they will get mixed together during inspection by TSA and you do not want to sort through unlabeled bags of female killifish

- Breather bags need to breathe.  They do not work well if you put them into another plastic bag or if they are all touching each other.  Socks or clothing will do, as will paper towels.  I do not recommend using paper bags that tear or disintegrate in water.  Breather bags "sweat" a little water.  Even if there are no leaks the inside of your suitcase will be slightly damp. For dirty laundry this is not an issue, but I used plastic bags to waterproof the old JAKA issues I had in the suitcase ($1 each at WAKO!).

My preferred way of packing breather bags is in coarse mesh filter media bags.  Each bag can hold 1-4 breathers and is closed by a zipper or drawstring.  These bags are see-through and the TSA agents might not need to unpack each fish during the inspection.  The filter media mesh bags went into a larger mesh bags used for grocery store produce.