There is indeed an error with the Northern Alliance Upgraded Worker Outfit. Just found it - thanks for the report! It will be fixed for the next version.
Huh! There seems to also be an error there. Testing it right now. Thanks, will also be fixed! 
Right now you don’t have any means to kill fish, well not any easy means anyway. If you remove them from the water they’ll die.
There are fishing traps coming soon, though - then you’ll have a way to kill fish!
Thanks for all the reports 