Aquatic Invasive Species in Ireland

Thanks to David Lee for the following report on the Aquatic Invasive Species Public Stakeholder Conferences in Galway and Tullamore April 2010 and background information. David is a longterm supporter of Cork Environmental Forum, a director of Sustainable Water Network (SWAN), an avid bee-keeper and angler.

Aquatic Invasive Species in Ireland

A Report on Aquatic Invasive Species Public Stakeholder Conferences in Galway and Tullamore April 2010.

The Central Fisheries Board has secured €1.5 million in funding from the European Community (EC) under the Life+ programme to control and eradicate invasive species in Lough Corrib, The Grand Canal and the Barrow Navigation Line. Minister Conor Lenihan formally launched the Life+ project ‘Control of Aquatic Invasive Species in Ireland’ (CAISIE) at the European Commission Office in Dublin on 23rd February 2010.



Aquatic invasive species are a major threat to biodiversity in Irish freshwaters and their adverse effect will continue to increase unless effective eradication and control methods are developed. CAISIE will focus on researching and implementing control and eradication methods, plus a marketing campaign to increase awareness and stakeholder engagement. The future cost of controlling Lagarosiphon major (African Curly Leaved Waterweed) in Lough Corrib by cutting and removing the deadly weed in a labour intensive process is estimated at €300k to €400k a year.

At the moment the funding is limited via the Western Regional Fisheries Board and the National Parks and Wildlife Service and a little in the past from Galway County Council and the OPW. But I think this funding will not continue long-term and is not sustainable so CAISIE have come up with a long term solution which is to cover the bottom of the lake with a material similar to old potato sacks (jute sheeting). This light excluding material saturates and sinks quickly on contact with water, and so is relatively easy to deploy compared to traditional benthic barrier methods. This will cover the bottom of the lake, thereby preventing the invasive weed from growing but allowing native plants to grow through the jute and provide food and cover for the fish stock in the lake as normal. Minister Conor Lenihan affirmed that this is a matter of considerable importance to the Inland Fisheries and this project, funded by the EU, brings together a number of State bodies to work together in the control of aquatic invasive species in Ireland.

The following is a list of invasive species which CAISIE – a group of 4 people headed by Senior Scientist Dr Joe Caffrey – will be occupied with, working on the sites where greatest risk is currently posed. Joe asked the audiences in Galway and Tullamore to inform him of any new outbreaks of any of the invasive species appearing in other rivers and lakes in Ireland and for people that were not at the meeting to also help be getting the booklet “Field Guide to Invasive Species in Ireland” which gives names and colour photographs that will help people to identify these dreaded plants.

For more information visit www.invasivesspeciesireland.com or contact by email joe.caffrey@cfb.ie

Key species in Lough Corrib:

• Lagarosiphon major (African Curly Leaved Pondweed)
• Dreissena polumorpha (Zebra Mussel)

Lagarosiphon major was first discovered on Lough Corrib in 2005 where it covered 9 bays. By 2006 it had spread to 24 bays, in 2007 64 bays were affected and in 2008 113 bays were covered. It now covers from the northern end of the lake at Cong down through all the bays to the middle lake and unless some remedial action is taken in the near future it will spread down lower Lough Corrib close to Galway City where it is likely to cause severe flooding as the water flow is restricted. It will also cause problems for boats navigating through the dense vegetation.

The plant originated in southern Africa where it is regarded as a nuisance. The weed grows during the winter months and has a long stem that is brittle and easily broken which aids dispersal. Only female plants are present in Lough Corrib and all reproduction is by fragmentation (asexual). Lagarosiphon major poses a serious threat to tourism, angling, boating and other recreational pursuits - it can also kill fish through oxygen depletion especially during very warm weather and low water during summer months.

Unfortunately Lagarosiphon major – along with other invasive plants species – is sold in garden centres and shops throughout Ireland as an oxygenating plant. This is one of the main sources of spread of the weed - other sources include anglers that snag pieces of stem when moving boats or trailers. (Anglers should make sure that their boats are properly washed down and all weed removed. Nets, waders and engines should all be properly cleaned.)

Presently there is no legislation in Ireland to prohibit the sale of the following invasive species in shops, which do untold damage to our natural resources.

These are:

• Azilla filiculoides (Water Fern)
• Crassuls helmsii (New Zealand Pigmyweed)
• Elodea nuttallii (Nuttall’s Waterweed)
  
• Hottonia palustris (Water Violet)
• Hydrocotyle ranunculoides (Floating pennyworth)
  
• Lanarosiphon major (African Curly Leaved Waterweed)
  
• Lemna minuta (Least duckweed)
• Lysichiton americanus (American Skunk Cabbage)
• Myrmphyllum aquaticum (Parrot’s feather)
  
• Nymphoides peltata (Fringed Water Lily)
  

Suggested Alternatives for your garden or Aquarium:

• Butomus umbellatus (Flowering Rush)
• Caltha palustris (Marsh Marigold)
• Iris pseudacorus (Yellow Flag Iris)
• Menyanthes trifoliata (Bogbean)
• Lychnis flos-cuculi (Ragged Robin)
• Mentha aquatica (Watermint)
• Potentilla palustris (Marsh Cinquefoil)
• Hippuris vulgaris (Mare’s Tail)
• Nuphar lutea (Yellow Water Lily)
• Potamogeton crispus (Curled Pondweed)
• Potamogeton perfoliatus (Perfolitate Pondweed)
• Potamogeton pusillus (Lesser Pondweed)

Floating Plants:

• Nymphaea alba (White Water Lily)
• Potamogeton natans (Broad Leaved Pondweed).

The following is a list of invasive species which CAISIE will work on and the sites where these pose the greatest risk at present.

Key species at Lough Corrib:

• Lagarosiphon major Curly Leaved Pondweed
• Dreissena polymorpha Zebra Mussels

Key species on the Grand Canal, Barrow Line and Navigation:

• Lagarosiphon major (Curly Leaved Pondweed)
• Leuciscus leuciscus (Dace)
• Hemimysis anomala ( Bloody Red Shrimp)
• Crangoyx pseudogracilis (Northern River Crangonyctid.)
• Elodea nuttallii (Nuttall’s Pondweed)
• Crassula hellmsii (New Zealand Pugmyweed)
• Azolla filiculoides (Red Water Fern)
• Dreissena polmorpha (Zebra Mussel
• Fallopia japonica (Japanese Knotweed)
• Heracleum mantegazzianum (Giant Hogweed)
• Impatiens glandulifera (Himalayan Balsam)
• Gunnera tinctoria (Chilean Rhubarb)
• Corbicula fluminea (Asian Clam)

The CAISIE meeting in Tullamore was chaired by Dr Stephanie Evers who outlined the efforts made by the EU commission through CAISIE in combating invasive species in Lough Corrib and the Grand Canal and Barrow Navigation area.

The EU commission has provided €1.5 million in funding through the Life+ project to combat the losses of biodiversity in the above areas in a project that will run until 2013.
The project objectives are to control and remove invasive species.

The meeting informed those attending that the EU recognised invasive species introduction as one of the main causes of biodiversity loss - second only to direct habitat destruction. It was estimated that the loss monetarily to the global economy caused by the impacts of all invasive species is $1.4 trillion or 5% of the global economy. The cost to the EU was estimated at €12 billion per annum.

Dr Evers informed the meeting that there are 14 invasive species present in the above areas, the Asian Clam being the most recent arrival.

Resources:
http://www.invasivespeciesireland.com/
http://www.cfb.ie/fisheries_research/invasives/index.htm
http://caisie.ie/