Worrying decline in numbers of famous South Offaly fish

THERE has been a noticeable decrease in Croneen numbers in the River Camcor over the last couple of years.

This famous fish is much beloved locally and is a source of pride. However, naturalists have noted that, while no scientific study has been carried out to examine the issue, it would seem that the numbers of the fish have been declining for some time.

Speaking during his recent summer school, botanist John Feehan said he too has noticed the decline, but he is not certain what is the cause.

Croneen trout are a unique form of migratory lake brown trout which travel from Lough Derg to the Little Brosna to spawn every year. They behave like sea trout, spending the first one to two years in the river before migrating to Lough Derg to feed. Here they feed and grow quickly and mature. They return to the river in May - June and can often be seen in shoals in some of the deeper pools near Birr.

After spawning in November most Croneen return to Lough Derg to feed again. Some fish may spawn over a number of years. The average age of Croneen is between three and four years old. Although they are known to spawn in some of Lough Derg's other river systems, the Camcor River is best known and probably their last major stronghold. Therefore they are important as part of the heritage of not only Birr but also Offaly. The Croneen, like salmon and trout, are sensitive to environmental degradation. Lough Derg and its tributaries have been subject to environmental pressures from enrichment, peat siltation, fish species introductions and land drainage. Experts say that because of all these pressures it is remarkable that the Croneen have survived at all today.

Recent studies in Queen's University Belfast have shown that the Croneen are genetically unique and should be preserved for heritage and scientific purposes. Some people believe that the Croneen should be considered a separate species to brown trout.