Haha, pearls/jokers were a big part for the last day. I used the robot to help save actions to build up money in the first couple of days.
I'm not sure whether I got lucky at the end, or whether clicking on all of my fishing rods in quick succession caused all of the fish to receive the big fish bonus, but I was able to get a score of 1376, which was quite a bit higher than I was getting when I was clicking on them one by one!