It was during the Savage Wolverine serie and more precisely during issues 12-13.
Basically when Logan was in Madripoor as Patch in the past he made a point to stop a lot of criminal activites he despised more than anything such as child prostitution, gun running, slavery, drugs and made sure that no one would try anything like that or he would kill them. Unfortunately when Viper and then Daken seized control of Madripoor they made sure that those activites ran rampant again on an unbelievable scale.
Add this to the list of thing Daken did and why his characterization in All New Wolverine and Laura's interactions with him (especially after what happened to her in NYX) never made any sense.
Anyways in order to put an end to those crimes and especially child prostitution and to make up for the loss of money generated by those activites, Tyger Tyger decided to allow ivory trade which was in high demand:
It was something always allowed in Madripoor in the past until Logan as "Patch" put an end to it and made sure to hunt and kill whoever tried to do that kind of business in Madripoor (in the Punisher war journal serie for example). Tyger didn't know the scale of this thing, but for her the end justified the means. Let's just say that Logan was really pissed at her for that and showed her what happened to the animals that were killed in a really gruesome way, he then destroyed everything and put an end to this trade.
It was a really sad story but I thought Jimenez did a really good job with Logan's characterization (even if some of his actions were really extreme) and the ending was really gut wrenching.
Also there is a nice flashback when you see Logan "fighting" Kraven for the first time: