Displaying items by tag: genetic

19th February 2012

Results of Genetic Studies of Brown Trout Stocks in Suir and Boyne Catchments

#INLAND WATERWAYS - Inland Fisheries Ireland (IFI) has announced the results of studies on the genetic makeup of brown trout stocks in the Suir and Boyne river catchments.

These studies form part of a wider scheme looking at Ireland's larger riverine catchments - assisted by the Office of Public Works, geneticists from UCD and trout anglers across Ireland - and involve a chemical analysis of scale samples from fish known as 'micro-satellite DNA analysis'.

The results from the Suir and Boyne are described by IFI as "quite amazing" and "of significant value" to managing the fisheries in these areas.

In both catchments, the first step saw trout stock samples of young fish examined genetically, and they were shown to be discrete - in other words, fish from any given tributary were found to be genetically different to those from others.

The next step involved samples of adult fish from the main river, contributed by anglers, which were then related to the different tributary genetic types.

Summary results from the Suir and Boyne show that there are respectively seven and five distinct families of trout in the catchment area; that most fish born in tributaries migrate to the main stem till adulthood before returning to their tributaries to spawn; that numbers migrating from individual tributaries are variable, but fish don't cross into adjacent catchment areas; and that there movement of young trout along the river system is "extraordinary", with fish often migrating from near the source to the mouth.

More details on findings for the Suir catchment and Boyne catchment are available on the IFI website.

Published in Inland Waterways

Tagged under

About Conor O'Brien, Irish Circumnavigator

In 1923-25, Conor O'Brien became the first amateur skipper to circle the world south of the Great Capes. O'Brien's boat Saoirse was reputedly the first small boat (42-foot, 13 metres long) to sail around the world since Joshua Slocum completed his voyage in the 'Spray' during 1895 to 1898. It is a journey that O' Brien documented in his book Across Three Oceans. O'Brien's voyage began and ended at the Port of Foynes, County Limerick, Ireland, where he lived.

Saoirse, under O'Brien's command and with three crew, was the first yacht to circumnavigate the world by way of the three great capes: Cape Horn, Cape of Good Hope and Cape Leeuwin; and was the first boat flying the Irish tri-colour to enter many of the world's ports and harbours. He ran down his easting in the Roaring Forties and Furious Fifties between the years 1923 to 1925.

Up until O'Brien's circumnavigation, this route was the preserve of square-rigged grain ships taking part in the grain race from Australia to England via Cape Horn (also known as the clipper route).

At a Glance - Conor O'Brien's Circumnavigation

In June 1923, Limerick man Conor O’Brien set off on his yacht, the Saoirse — named after the then newly created Irish Free State — on the two-year voyage from Dun Laoghaire Harbour that was to make him the first Irish amateur to sail around the world.

June 1923 - Saoirse’s arrival in Madeira after her maiden passage out from Dublin Bay

2nd December 1924 - Saoirse crossed the longitude of Cape Horn

June 20th 1925 - O’Brien’s return to Dun Laoghaire Harbour