Archaeologists have discovered a complex series of weirs and dams to trap rare fish on Connemara's Errislannan peninsula (Ireland), and speculate that they may date back to the Mesolithic period.
     Local resident John Folan is still constructing and using traps for the weir and dam system, modelled on pre-Christian design, archaeologist Michael Gibbons said. Mr Folan said he had been unaware of the historical importance of the equipment, the coastal system and the fish species, until contacted by Mr Gibbons. The National Museum of Ireland has now commissioned John to construct one of his traps for its folklife collection.
     Mr Gibbons was walking on the north side of Errislannan, outside Clifden, when he noticed the stone ponds, channels and dams which link Mannin Bay to several inner lagoons. He learned that the system had been designed to enclose and trap a type of fish that frequent the river Barrow called 'marin' or 'mearachán'. The fish is similar to a smelt, and may be related to shad.
     Dr Cillian Roden, a marine biologist, said the fish type was 'fascinating', but its identity was uncertain. "It could be that these smelt do live in lagoons, and it would make the lagoons very important in environmental terms," he said. "It is going back generations," Mr Folan said. "People depended on the fish and you'd get hundreds of them sometimes, but only during early spring."
     Mr Gibbons said the system, which dates back to Mesolithic times, had been adapted for contemporary use over the centuries. "This is a very important part of the maritime history and archaeology, and shows how rich our coastline is in historical terms," he said.

Edited from The Irish Times (23 September 2010)