A REGULAR reader writes to ask which are Ireland’s native freshwater fishes and which have been introduced to our waters.
There is no simple answer to this question. Some species, such as salmon, trout and eels, have clearly been here since the end of the last Ice Age. Archaelogy reveals they formed a substantial portion of the diet of early Stone Age man and there are many references to them in the oldest histories of the Irish people and its folklore. It is likely that the Lough Neagh pollan, a freshwater herring, also falls into this category. Pollan were also found in Lough Erne but have died out or been fished out.
Experts at Inland Fisheries Ireland, which conducts research into the matter, also classify the stickleback as a native fish.
An absence of diversity among Ireland’s freshwater fishes was noted by Geraldus Cambrensis, the Norman chronicler, in the 12th century and the first reference to ‘greedy pikes’ can be found in the work of the Elizabethan poet Edmund Spenser in 1595. It is likely they were introduced by Norman settlers who valued them as a delicacy for the table.
Carp and tench were first brought here by the first Earl of Cork in the 17th century and carp were introduced to Northern Ireland by the Northern Ireland Carp Angling Society in 2000. It has several fisheries in county Down.
Perch, bream, gudgeon, minnow, loach and rudd are not mentioned until the 18th century and may have been introduce by man or travelled across from Britain and Europe as spawn on the feet of migratory birds.
Roach and dace can be traced back to two cans of live bait which made their way into the Munster Blackwater in 1889.
Rainbow trout are very late arrivals and were introduced into Irish waters in the 1970s by Northern Ireland’s Department of Agriculture and some private fishery owners. The first rainbow trout fishery in Ireland is still operating at Kilgad in County Antrim and there are at least 60 more now scattered around the six counties. A few can now also be found in the Republic.
While most fishy foreign interlopers have become welcome settlers, providing sport for visiting and native anglers alike, other creatures are not so welcome. The Zebra Mussel and Asia Clam are causing concern to scientists despite measures to contain or eradicate them from our waterways.
The European Killer Shrimp, a ferocious cousin of our native Irish freshwater shrimp, has been found in England and Wales and plans are in place to prevent it reaching this island where it could do much harm to many fish stocks.