What is the device used to catch fish?

there's a lot-

the typical fishing rod is the most known way, but you can use dredges, harpoons, hook and lines, longlines, purse seining, traps and pots, and trawls. you can see these in depth at http://www.motherjones.com/news/featurex/2006/03/fishing_methods.html

hop i helped!