I honestly think that it is too easy for that title and they should make it harder :P If you want everything for free, there won't be fun in that - you just won't get one achiev, no big deal.
I feel like it drops every 50 fish, so you need around 700 fish to catch one particular saltwater fish (for collection between 2000 and 4000) - That's not that big number and I'm making gold from fishing in meantime. It is waaay faster than many wvw, pvp and fractal titles.