To be honest its moville peir that puzzles me the most, because with the likes of Malin Head, Culdaff, Lenan etc these piers all have decent rock marks pretty close to them which hold big fish. But 'as far as im aware' the closest 'bigger' fish mark to Moville is Shroove, which would mean that the fish would have to make a conscious effort to get to Moville to mate/spawn whatever and would have to swim past two other peirs to get to the upper pier in Moville?
Bit random I know but it does seem strange