My experience is that the fishing stuff is definitely a lot of grinding. For the biggest shark (Bruce) it does take literally hundreds of tries. I don't want to guess at how many hours I spent doing that, but I have my personal PC on the same desk as my work PC, and during boring meetings I would idly grind looking for Bruce. I agree that the fishing grind aspect is way out of balance with the reward. That said, I am stubbornly motivated to complete these kinds of tasks even though the reward is not matched by the amount of effort. I only caught Bruce a week or two ago but was so relieved when I could check it as done. I also never kept up with the temple puzzles, but finished those just today, mainly because they affected the "extras" count. Now I'm all caught up.