Seanad Éireann debate -
Wednesday, 3 Jun 1998

Vol. 155 No. 17

Adjournment Matters. - Zebra Mussel Problem.

Ms O'Meara

This is a particularly important matter and I thank the Minister for his interest in it. I am raising the issue of the rapid and intense growth of the zebra mussel pest, particularly in Lough Derg and the waterways of north Tipperary. I am seriously concerned by the effects it is having on fisheries and tourism and its potential implications for domestic water supplies. I call on the Minister to act now and to put a plan of action in place to stop the damage being caused by the growth of the pest in Lough Derg, the waterways of north Tipperary and the rest of the country. This afternoon I was informed by Dan Minchen of the Marine Institute, one of the country's experts on this issue, that the zebra mussel has turned up on Lough Key. This is further evidence of the rapid growth of this pest and its ability of travel.

The pest is only in Ireland for two years but its growth has been intense. It is already causing major concern to anglers, boat owners, fishermen and environmentalists in the area I represent and in the Lough Derg region in general. It poses a serious threat to the public water supply. Many thousands of these mussels have already been found this year at the Coolbaun water treatment works on the lake shore north of Dromineer. The Minister may recall that this treatment works was installed a number of years ago to deal with a serious domestic water situation which presented itself in Nenagh. There is evidence that pipes are not only obstructed by mussels but that water for human consumption can be tainted by them and the waste left in their wake.

We need to know more about the pest and act before it does more damage to our water supply and our tourism industry. I hope the Minister will outline his plans for action in this regard.

The ecosystem of Lough Derg has already been affected by the mussel and we can expect more changes of an intense nature. Ironically, the mussel thrives where there is eutrophication, which is a problem in Lough Derg. Because of the strong growth of the mussel it is already carpeting the floor of the lake making the water clearer and leading to greater weed and algae growth. The waste left by the mussel is affecting the food chain of the fish population and, possibly, will directly effect the fish population in the future.

Studies of the effect of the zebra mussel on the ecosystem of the great lakes of North America show how its arrival has altered the food chain of those lakes, depriving it of energy and nutrients which support small plants and animals which in turn serve as a food base for young fish. The entire fish stock of these lakes has been placed in jeopardy and there is a real possibility that the same could happen in Lough Derg and any lake or waterway invaded by the pest.

The zebra mussel can also block pipes, including outflow pipes, and cause severe damage to water systems. Boats moored on Lough Derg, if not carefully monitored, can suffer engine damage due to the encrustation of these mussels, something which I believe has already happened. A boat moving from Lough Derg can, unless carefully cleaned, bring the pest elsewhere. I know advice is being given to boat owners, etc., but more careful monitoring and action is required.

The fisheries research centre has told me that the level of zebra mussel growth in Lough Derg is intense. Only recently the mussel turned up in Lough Key, suggesting its ability to travel is quite considerable. A small amount of weed on the bottom of a boat can contain the larvae of many thousands of zebra mussels with serious implications for our fisheries nationwide. The implications of the unchecked growth of the mussel are very serious.

I do not underestimate the problem, and I know the Minister does not either. The implications are extremely serious for our fishing and tourism industries and for our domestic water supply. I hope the Minister will tell the House of his plans for dealing with the problem and of the provision of necessary funding to conduct ongoing detailed research into it. It is not sufficient to rely on what has happened in other countries. The water systems of the country are potentially unique and the manner in which the mussel is thriving and growing at such a rate is potentially a unique scientific and marine phenomenon. In this context the problem needs careful and extensive research, which must be carried out rapidly. The zebra mussel will not go away. I do not consider, and I am sure the Minister does not consider, it a welcome visitor to the shores of our lakes and waterways. I look forward to the Minister's response to this urgent matter.

Minister for the Marine and Natural Resources (Dr. Woods)

This is a very important matter and I am pleased to advise the Seanad that I established a scientific steering group last year to investigate and tackle all aspects of the zebra mussel phenomenon. I was concerned about it when I first learned of it and was anxious that something should be done as a matter of urgency. The group is led by the Marine Institute. Although the zebra mussel was first reported in Ireland in 1997 the Marine Institute informed me that the species was probably introduced during or before 1994. It is particularly prevalent in Lough Derg and around Limerick city, where it is suspected that it first became established. Scientists believe the mussel was introduced through either boats being brought into the catchment or in ballast water from shipping in Limerick Docks.

The steering committee has produced a number of informal reports which are helping in the action being taken throughout the country. It also published a report in February 1998 — I see the Senator has a copy of it. The authors of that report are Dan Minchen and Chris Moriarty, who chairs the scientific steering group, two of the leading experts in the field.

When the presence of the zebra mussel was definitely confirmed I asked the Marine Institute to establish a steering group to develop a co-ordinated strategy involving all relevant agencies and organisations. From the outset my policy approach to the problem has been that rigorous survey and analysis of constantly updated information on the distribution and impact of the species will enable us to predict the likely progress and effect of the mussel on our ecosystem. Real time data and analysis will inform management strategies in dealing with the phenomenon. This is the task which I set the zebra mussel steering group.

The steering group has already carried out extensive surveys on the distribution of the species. The group, together with experts from University College, Galway, has also been examining the impact to date of the zebra mussel on Irish ecosystems. All relevant agencies are also working with the zebra mussel steering group, including the central and regional fisheries boards, the Environmental Protection Agency, the Department of Arts, Heritage, Gaeltacht and the Islands, the National Parks and Wildlife Service and my Department.

The zebra mussel can foul a wide array of structures, including water supply pipes. The species has been found attached to lock gates, sluice gates, waterpipes and hulls of vessels. Obviously their presence is a serious concern to amenity and industry and for local authorities. The scientists have been able to map the distribution of the mussel in our waterways and monitoring measures are in place.

I can reassure the House in one sense, namely, that the zebra mussel has been present in the UK and Europe for over 170 years and I am advised that there are no records of serious damage in the UK or continental Europe caused by the species. Based on the European experience, therefore, it is possible that the zebra mussel will cause no fundamental problems in Irish ecosystems. No serious economic damage caused by the zebra mussel has been reported in this country to date nor has any ecological damage become apparent.

I am pleased to confirm that the findings of the steering group surveys have already formed the basis of management strategies to deal with the species. An action plan has been prepared and is being implemented. This initiative covers information dissemination, monitoring of locations of the zebra mussel and other non-native species, scientific assessment of long-term ecological impact and advice on appropriate control measures. Information leaflets have been prepared and circulated widely to a targeted readership, including boat owners and fishermen, with the specific focus of controlling the spread of the species. I appreciate the Senator's point in that regard.

I am glad to have this opportunity to outline and acknowledge the very valuable work being undertaken by the zebra mussel steering group. My intention is that the steering group will continue to coordinate and drive the analysis and data collection on the spread of the mussel, underpinned by ongoing research and survey work as well as management and control strategies.

I have tasked the steering group to intensify its work programme during 1998. This will entail expanded survey work on inland waters while ensuring the focus of research will be on assessment of the potential impact of the species on the Irish ecosystem. I assure the Senator that the steering group will continue its investigation and assessment of the impact of the species in Lough Derg as part of its intensified work programme. Other areas are being highlighted because of the analysis being carried out. It is important to begin the process of rooting it out. This is very difficult, as Senators will appreciate. However, there is an action plan and a steering group set up and we will continue to take action in that regard.