So, I have been farming for this turtle mount for exactly 9 days straight. I fish for about 7 hours a day. I started fishing in Howling Fjord. I figured I would try to catch 2 birds in one lake. I ended up catching the Dark Herring 3 times in one sitting 3 days ago. I got bored with Fangtooth Herring and moved to the Frozen Sea. Many more pools concentrated together. I have not stopped fishing. I am up to 6100 casts and I even opened up a ticket thinking that I was doing something wrong. I stopped doing my daily quest, stopped talking to people, pretty much cut myself off from enjoying anything about the game and even real life. I would see a turtle on TV or a picture on the internet that was unrelated and that would induce a marathon of fishing.
I have finally decided to stop trying for this mount. It's cute and all but I am really obsessing too much with this whole thing. I have read every forum post about it and GMs tell me that it could take 1 cast or 10000 casts. For the sake of my sanity (and my wife's), I am stopping. I know some people have had really good luck catching this thing and some people are still trying but I just cannot do it anymore.
I made sure I was always casting into a school of fish. I went all over Northrend to catch from every school I can find. My fishing skill was at 563 at all times. Good luck everyone! I hope you all catch this mount on your first cast!
Now I just need to win one of the derbies for "Salty" - fml <.<