To us the, "common folk" this might sound strange but its completely normal. Here is a quote from WXII-TV in Utah about how they restock the lakes with fish, "WATCH: Lakes are being restocked by plane. The Utah division of wildlife resources says transporting the fish by ground takes a lot longer and is more stressful on the fish.".
Wait, LESS STRESSFUL? have you ever jumped out of a plane of saw someone do it for the first time? They look perfectly calm from jump to landing right?
The next video is something I found on Youtube about it happening elsewhere. Again, this is normal...hahaha