All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad  is His slave and messenger.
  is His slave and messenger. 
It is permissible to fish or hunt an animal by using a trick as Allaah permitted us to hunt but He did not make it a condition that we hunt with dead bait and He did not forbid us from hunting with live bait or from using a trick. So one should not make things difficult while Allaah has made them easy. Ibn 'Abbaas  narrated: “Allaah has sent His Prophet
  narrated: “Allaah has sent His Prophet  and sent down His Book, and what Allaah has made lawful is lawful and what He has made forbidden is forbidden, and concerning that which He says nothing about, it is pardoned." [Abu Daawood]
  and sent down His Book, and what Allaah has made lawful is lawful and what He has made forbidden is forbidden, and concerning that which He says nothing about, it is pardoned." [Abu Daawood] 
As regards the story about Imaam Al-Bukhari, if it is authentic, it is not acceptable to cite it as evidence for the prohibition of hunting (or fishing) by using a trick. First of all, the way Imaam Al-Bukhari  acted does not stand as evidence in the sight of Sharee‘ah. Moreover, the donkey is not a game [animal hunted for food]. Furthermore, he decided not to learn Hadeeth from that man out of excessive prudence and cautiousness concerning the Ahaadeeth of the Prophet
  acted does not stand as evidence in the sight of Sharee‘ah. Moreover, the donkey is not a game [animal hunted for food]. Furthermore, he decided not to learn Hadeeth from that man out of excessive prudence and cautiousness concerning the Ahaadeeth of the Prophet  .
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Allaah Knows best.