Lough Major Monster Mystery

There have been sightings of a creature In Lough Major in Ireland. The first recorded report was  in about 1912 when three boys said they watched a strange  water creature playing in the lake. They threw stones at the creature and then ran when it moved towards them. It was described as having a hairy, horned head. Probably a hoax you might think  but  then I came across this article from 1963. 

The Evening Herald 1^st August 1963

Monster seen in Irish Lake

A Monster , 8 to 10 feet long, with two protruding tusks and hairy head scared the wits out of three youths who were returning from a fishing tri p in Lough Major ,Co Monaghan. The youths , G.Reilly(18),Talbot Duffy(17) and Paul Pentland(12) said they saw the “monster” splashing up and down the in the lake like sea lion. Although frightened they watched in amazement for a few minutes, but decided to make for home quickly, when one of them threw a stone in it’s direction and it made towards them at great speed. Badly frightened the boys ran across a filed, but were overtaken by the terrier dog ,which had at first stayed behind to bark at the “thing” but which shot past them with it’s tail between it’s leg, gaining an easy first in the race for home.Questioned later, it was suggested the monster might have been a large otter but Talbot Duffy denied this flatly stating he had shot plenty of otters. Returning the next day , the boys found that the dozen or so large bream left on the bank the night before had disappeared, only a few bones remaining. And later another local man, Patrick Brady, confirmed the boys’ description ,having also seen the animal surface; and it is now considered to be responsible for the disappearance of pike from the lines set by anglers, because on one occasion only the heads are found ;attached to the baited hooks.

 The creature sounds like a walrus or a seal of some kind but the lough is 36 miles from the sea and as far as I can see on the map does not drain into any large river that would facilitate the creature entering the lough that way. So where did it come from?