I think there is a mix up for pokemon that you encounter when you fish and when you surf. Every time I see a place where there is only one or two pokemons you encounter by fishing I end up encounter every pokemon I would encounter if I was surfing instead. Today while fishing I encountered a Zubat (I wasn't moving). Is it a bug, a code problem or that's what it was suppose to happen, because rare pokemon are becoming impossible to find if there is fishing involved.