Aquatic Quarantine  

The best place for the trout is in The Lazy Drain. Most of the area around the Lost Village of Bobick has trout in it, but you have to dive down to it. If you have a spell that will get you to breath underwater this is fine (once you surface the trout heals itself.)
If you don't (like me) go to -133 -5 -252. There is only a few trout there and they take a while to respawn, but the water is shallow and you can just pick them off.

Has anyone actually been able to complete this quest since the DoF expansion? Every time I try to kill them (as a caster), I get one spell in, they instantly heal up, and nothing else. Seems that due to the changes in combat re: fish out of water, this quest is now bugged.