Will Cullin come good?

Lough Cullin has been fishing very poorly for many years now which is a great pity as it has a character all of its own and used to be a favourite venue for me. Will it’s fortunes change for the better this season?

The whole area around Pontoon has fallen on hard times with both of the local hotels now shut down and the fishing on Loughs Conn and Cullin hitting an all time low. The may be a flicker of hope for lough Cullin though in the shape of an ugly concrete and steel construction a few miles away.

I quote directly from ‘A Review of Changes in the Fish Stocks of Loughs’ Conn and Cullin over time (1978 – 2001)’

Cultural eutrophication problems have been evident in Lough Cullin in recent years (McCarthy et al, 2001). While the enrichment of Lough Cullin may have contributed to the demise of the trout population there is another very obvious reason for the collapse of this stock. A baseline fishery survey of the Moy Catchment (O’Grady, 1994) illustrated that three particular sub-catchments were likely to be of significance as spawning and nursery areas for the Lough Cullin trout population – the Castlebar, Manulla and Clydagh River systems. Further investigation of fish stock in these sub-catchments indicated that, of the three systems involved, the Castlebar River was, by far, potentially, the most important spawning and nursery area for the L. Cullin trout population. Recognising this fact the Nw.R.F.B. expended significant monies in enhancing the capacity of the Castlebar River to optimise trout production. This programme failed because of declining water quality problems in the river to-date (2001) (Appendix II). Currently (2001) the river supports a very poor trout stock – several substantial fish kills have also been noted in this river in recent years (Nw.R.F.B., pers comm). A failure of trout to recruit, in significant numbers, from the Castlebar River to Lough Cullin is undoubtedly a major factor in the demise of the lake trout population – a small number of trout were tagged in the Castlebar River in 2000 while carrying out fish population estimates. It is noteworthy of the total catch of 15 trout in the 2001 L. Cullin survey three fish were individuals which had been tagged in the Castlebar River the previous year.

This is interesting because a fine new sewage treatment plant was built for the town of Castlebar a couple of years ago, right on the bank of the Castlebar river. From the above you can gather that this unimposing stream was in fact the main spawning river for the trout in lough Cullin. Water quality in the river has improved markedly and it now holds a fine head of resident brown trout as far up as the outskirts of the town itself. Could it be that the trout in lough Cullin are also benefiting from this long awaited piece of infrastructure?

The other big problem for Cullin is the immense shoals of roach which now pollute the lough, competing with the native trout for food. The direct descendants of live bait which Pike anglers released into the system 20 years ago, the roach outnumber the trout by a huge amount. Good news for the Pike who swallow up the Roach but make little or no impression on their numbers. Bad news for the trout though.

It is hard to tell if the trout will make a comeback or not. I fear there are just too many factors against them but nature usually finds a way of reaching a balance so there is hope yet.

Update, June 2022 – Since i wrote this original post there has been a noticeable improvement in the trout fishing on Cullin. Fish to five pounds have been caught over the last couple of seasons and catches of up to twenty fish in a boat have been recorded. There are fewer and fewer salmon with each passing season but that is the same all over these days. It certainly appears that the greatly improved waste water treatment in Castlebar has indeed helped Cullin.