Menu

Ireland's sailing, boating & maritime magazine

Displaying items by tag: mollusc

#INLAND WATERWAYS - Trial dredging operations to curtail the spread of Asian clams at designated sites in the lower River Barrow are set to conclude today.

Inland Fisheries Ireland (IFI) employed the use of a a traditional cockle harvesting boat to physically remove the clams from the river bed, in an effort to explore methods of controlling or eradicating what it describes as an "ecosystem-changing invader" in other infested waters.

IFI scientists supervised the trials, using teams of divers to quantify the result of the dredging efforts.

The Asian clam (Corbicula fluminea) is "a most unwelcome addition to the fauna of the lower River Barrow". The bivalve mollusc is regarded as "one of the most notorious aquatic invasive species in the world".

First recorded in the river downstream of St Mullin’s in April 2010, subsequent IFI studies have revealed that the Asian clam is firmly established in the lower Barrow and in the River Nore downstream of Inistioge. Populations have also been recorded in the River Shannon and in Lough Derg.

In one section of the River Barrow the clam has achieved a "staggering" density of almost 10,000 per square metre.

Dr Joe Caffrey, senior scientist with IFI, said of the trial dregding: “It is imperative that every effort is made to control the expansion and spread of this highly adept invasive species.

"The results from these trials will inform future national management plans for this most unwelcome non-native species and will, at the very least, dramatically reduce the numbers of individuals in the test sites.

He added: "In tandem with these trials, research effort is being focused at producing other control methods that can be targeted as this species.”

Published in Inland Waterways

The Half Ton Class was created by the Offshore Racing Council for boats within the racing band not exceeding 22'-0". The ORC decided that the rule should "....permit the development of seaworthy offshore racing yachts...The Council will endeavour to protect the majority of the existing IOR fleet from rapid obsolescence caused by ....developments which produce increased performance without corresponding changes in ratings..."

When first introduced the IOR rule was perfectly adequate for rating boats in existence at that time. However yacht designers naturally examined the rule to seize upon any advantage they could find, the most noticeable of which has been a reduction in displacement and a return to fractional rigs.

After 1993, when the IOR Mk.III rule reached it termination due to lack of people building new boats, the rule was replaced by the CHS (Channel) Handicap system which in turn developed into the IRC system now used.

The IRC handicap system operates by a secret formula which tries to develop boats which are 'Cruising type' of relatively heavy boats with good internal accommodation. It tends to penalise boats with excessive stability or excessive sail area.

Competitions

The most significant events for the Half Ton Class has been the annual Half Ton Cup which was sailed under the IOR rules until 1993. More recently this has been replaced with the Half Ton Classics Cup. The venue of the event moved from continent to continent with over-representation on French or British ports. In later years the event is held biennially. Initially, it was proposed to hold events in Ireland, Britain and France by rotation. However, it was the Belgians who took the ball and ran with it. The Class is now managed from Belgium. 

At A Glance – Half Ton Classics Cup Winners

  • 2017 – Kinsale – Swuzzlebubble – Phil Plumtree – Farr 1977
  • 2016 – Falmouth – Swuzzlebubble – Greg Peck – Farr 1977
  • 2015 – Nieuwport – Checkmate XV – David Cullen – Humphreys 1985
  • 2014 – St Quay Portrieux – Swuzzlebubble – Peter Morton – Farr 1977
  • 2013 – Boulogne – Checkmate XV – Nigel Biggs – Humphreys 1985
  • 2011 – Cowes – Chimp – Michael Kershaw – Berret 1978
  • 2009 – Nieuwpoort – Général Tapioca – Philippe Pilate – Berret 1978
  • 2007 – Dun Laoghaire – Henri-Lloyd Harmony – Nigel Biggs – Humphreys 1980~
  • 2005 – Dinard – Gingko – Patrick Lobrichon – Mauric 1968
  • 2003 – Nieuwpoort – Général Tapioca – Philippe Pilate – Berret 1978

Featured Sailing School

INSS sidebutton

Featured Clubs

dbsc mainbutton
Howth Yacht Club
Kinsale Yacht Club
National Yacht Club
Royal Cork Yacht Club
Royal Irish Yacht club
Royal Saint George Yacht Club

Featured Brokers

leinster sidebutton

Featured Webcams

Featured Associations

ISA sidebutton
ICRA
isora sidebutton

Featured Marinas

dlmarina sidebutton

Featured Sailmakers

northsails sidebutton
uksails sidebutton
quantum sidebutton
watson sidebutton

Featured Chandleries

CHMarine Afloat logo
https://afloat.ie/resources/marine-industry-news/viking-marine

Featured Blogs

W M Nixon - Sailing on Saturday
podcast sidebutton
BSB sidebutton
wavelengths sidebutton
 

Please show your support for Afloat by donating