MulkearLIFE hosted an extremely successful full day workshop on ‘The Control, Management and Monitoring of Invasive Weeds in the Mulkear Catchment’ on Friday, 11th March 2011, in Murroe, Co. Limerick.The workshop explored the problems posed by invasive weeds (Giant Hogweed, Japanese Knotweed, Himalayan Knotweeds and Himalayan Balsam) in the Mulkear catchment and how they are a major threat to native Irish Biodiversity through their impact on the provision of ecosystems services and biodiversity.The workshop explored the extent of the problem and the approach of MulkearLIFE / Inland Fisheries Ireland and its project partners in Limerick County Council and the Office of Public Works to address the problem. While the workshop was primarily aimed at the parties involved in the delivery of MulkearLIFE’s project actions specifically targeting Giant Hogweed and other Knotweeds, the workshop attracted interest far and wide. Workshop delegates included staff members from the Office of Public Works, Limerick County Council and Kerry County Council, NPWS staff from Tipperary, Limerick and Clare and Inland Fisheries Ireland Staff from Limerick, Kerry, Clare and Dublin. In addition, the workshop was attended by researchers and others.
Detailed workshop presentations were given by Dr. Joe Caffery (Inland Fisheries Ireland) on the history of addressing invasive species and on best practice, by Ms. Elaine Keegan, the National Parks & Wildlife Service on the Mulkear as a Special Area of Conservation,, by Mr. John Geraghty (Geraghty Consulting) on invasives and herbicide use and by Ruairí Ó Conchúir and Mr. Glen Wightman of MulkearLIFE / IFI on a range of areas including invasive species identification. The afternoon session focused on monitoring and networking on invasives and on approaches to support the regeneration of the riparian zone of rivers and their native riparian vegetation.
The workshop also included a field tripan, designed to be interactive training session, to Clonsingle Bridge, located on the banks of the Annagh/Clare River on the Tipperary Limerick border. The Annagh/Clare River drains 65.8km² which is approximately 10% of the Mulkear catchment. The river has excellent quality gravel beds which are utilised by salmonids for spawning. Consequently, the river has a healthy population of Atlantic salmon. Sea lamprey spawning has been reported near Clonsingle Bridge over several years. Otter are also found at the site and mink are know to be widespread problem for waterfowl.
The importance of the site from a workshop perspective was the heavy infestation with Himalayan Knotweed. The site also has significant infestations of both Giant Hogweed and Japanese Knotweed. It was noted that site access has been a considerable concern and that the OPW began treatment of the site in September 2010 by reopening the maintenance road along the river. This allowed an OPW tracked vehicle, equipped a 300 litre sprayer, to initiate spraying of knotweed species using Roundup Pro Biactive. The OPW sprayer is outfitted with two long lance nozzles which allow the operators to apply herbicide to the top of the plants. Workshop participants also reviewed the monitoring work which is being undertaken by MulkearLIFE at this site which has shown exceptional rates of kill-off of knotweeds. Areas of new re-growth were evident during the field trip and it was noted that based on the kill-off results in 2010, the 2011 programme of treatment will begin earlier in the year so that any re-growth of the knotweed can receive additional herbicide applications.
Workshop participants also discussed the site as an area of high nature value and the importance of addressing the invasives from an ecological and biodiversity perspective. While dipper were seen on site it was noted that otter and kingfisher are also common and electrofishing surveys have shown good populations of brown trout, Atlantic salmon and juvenile lamprey. The river possesses good spawning gravels.